Comprehensive Description
provided by Smithsonian Contributions to Zoology
Cycloleberis squamiger (Scott, 1894)
Asterope squamiger Scott, 1894:140, pl. 14: fig. 58; pl. 15: figs. 24, 28, 29, 31.—G. W. Muller, 1912:52 [Cypridinarum genera dubia et species dubiae].
Cyclasterope lobiancoi.—Klie, 1943:50, figs. 1–4.
Cycloleberis squamiger.—Kornicker and Caraion, 1974:47, figs. 24–31.
LECTOTYPE.—A juvenile instar in the British Museum (Natural History) (registration number 1893.4.22.1) by subsequent designation (Kornicker and Caraion. 1974).
TYPE-LOCALITY.—São Tomé Island, Gulf of Guinea.
MATERIAL.—Ivory Coast specimens: 10 adult females: USNM 143975 (sta. 15), 143979 (sta. 15), 149271 (sta. 14), 149272 (sta. 12), 149274A (sta. 11), 1 specimen (sta. 11), 149275A (sta. 10), 149276 (sta. 13), 149277 (sta. 9), 149278A (sta. 8); 2 adult males, USNM 149280 (sta. 6), 149281 (sta. 5); juvenile males: USNM 143994, 143995 (sta. 15), 149273 (sta. 12), 1 specimen (sta. 10), 1 specimen (sta. 7), 1 specimen (sta. 8). The following specimens reported from Mauritania by Kornicker and Caraion (1974) were restudied: USNM 143798, an adult male; USNM 143993, an A-1 female.
Through the courtesy of Dr. Roger Lincoln, I received from the British Museum (Natural History) a specimen (in alcohol) which had been identified by Scott (1894) as Asterope squamiger. In addition to the name, the label contained the words “Buccaneer, W. coast of Africa.” The specimen is a complete, undissected juvenile 1.09 mm long and 0.92 mm high. It obviously is one of the two specimens reported by Scott (1894:140). Scott gave the length as 1.15 mm, so it is possible that the other specimen in the collection was slightly larger than the one at hand. The specimen dissected and illustrated by Scott (1894:140, pl. 14: figs. 56, 57; pl. 15: figs. 14, 22, 23, 26) could not be located. The specimen on hand was designated lectotype by Kornicker and Caraion (1974). I did not dissect the specimen, but managed to draw the distal parts of appendages protruding from the shell and parts of appendages visible through the shell (Figure 10). The presence of more than two bristles on the end joint of the maxilla (Scott, 1894, pl. 15: fig. 26; and Figure 10g, herein) indicates that this species belongs in the Cyclasteropinae. The lack of ridges on the carapace restricts the genera to which it could belong to Cycloleberis and Cyclasterope. The latter genus has not been reported from the Atlantic Ocean. Because a single species of Cycloleberis is abundant in shelf and bathyl waters off Spanish Sahara and Mauritania (Kornicker and Caraion, 1974) as well as off the Ivory Coast, I have assumed that it is conspecific with Scott’s species, called Cycloleberis squamiger (Scott) here and in the paper by Kornicker and Caraion (1974).
I had borrowed, for another study (Kornicker and Caraion, 1974), three specimens in the collection of the Hamburg Zoological Museum that had been collected off Mauritania and had been reported on by Klie (1943), who had identified them as Cyclasterope lobiancoi (Muller, 1894). This material consisted of the following four items:
1. One vial containing four disarticulated valves (2 lefts, 2 rights), one undissected specimen (length 3.58 mm, height 3.04 mm), a label with the number “10,” and a second label stating, “Cyclasterope lobiancoi (G. W. Müller) Mauritanien: Muschelgrunde vor Port Etienne, 20–30 m, August 1923, fide R. Ph. Dollfuss.”
2. A glass slide containing appendages labeled, in black ink, “ Cyclasterope lobiancoi (G. W. Müller) Mauritanien, Glycerine gelatine, Gliedmassen einer Körperhälfte, Port Etienne, August 1923, fide R. Ph. Dollfuss.” On the label in red ink are the numbers “1” and “10a.” This slide contains some appendages of a juvenile male.
3. A glass slide with appendages containing on the label, in black ink, the same information as that in black ink on the previous slide but also, in red ink, the numbers “2” and “10b.” The appendages on this and the previous slide are from the same specimen.
4. A glass slide with appendages containing on the label, in black ink, “ Cyclasterope lobiancoi (G. W. Müller) Mauritanien, Glycerin gelatine, Fr. a1, a1, a2, M,M, m,m, mp1, mp1, mp2, mp2, p, p, F, F, Port Etienne, August 1923, fide R. Ph. Dollfuss.” On the label in red ink is the number “10c.” The absence of the endopodite of the second antennae on the slide prevents determination of the sex of the specimen, but I have assumed it to be a juvenile male because of Klie’s description and because the appendages are about the same size as those on slides 10 and 10b, but the presence of nine secondary claws on the furca suggests that it could be an adult female.
DESCRIPTION OF ADULT FEMALE (Figures 2–5, 6a–i, 7–9, 11c–h).—Carapace (Figures 2–4, 5a): Without vertical rows of posterior hairs and without small indentation in posterodorsal margin as on male; otherwise similar to that of male holotype (see Kornicker and Caraion, 1974).
Size; USNM 143975, length 3.26 mm, height 2.58 mm; USNM 143979, length 3.21 mm, height 2.63 mm; USNM 149271, length 3.80 mm, height 3.01 mm; USNM 149272, length 3.30 mm, height 2.80 mm; USNM 149274A, length 3.91 mm, height 3.16 mm; USNM I49274B, length 3.73 mm, height 2.92 mm: USNM 149275A, length 3.85 mm, height 3.13 mm; USNM 149276, length 3.53 mm, height 2.88 mm; USNM 149277, length 4.32 mm, height 3.69 mm; USNM 149278A, length 3.93 mm, height 3.14 mm. Range of length: 3.21–4.32 mm.
Micromorphology of Carapace (based on scanning electron microphotographs; Figures 3, 4): In order to determine the effect of cleaning with a sonic vibrator on the outer surface of the shell, the left valve of USNM 149278A was photographed without treatment with the sonic vibrator (Figures 3e–i; 4a–c,g–k) and the right valve of USNM 149278A was photographed after treatment for about 10 seconds (Figures 3j–m; 4d–f,l). The treatment had little effect on the appearance of the microstructure of the valves (compare Figure 3f–i with Figure 3j–m). The microstructures of the female are similar to those described for the male of the species by Kornicker and Caraion (1974) except that the posterior end of the valve of the female does not have bristles forming a verticle row. A scalloped border around the anterior valve margin is shown in Figure 4a–d. Small bristles are present along the outer edge of the scalloped border near the inner margin of the lamellar prolongation of the selvage (Figure 4c,e,f). The outer surface of the lamellar prolongation of the selvage is pustulose (Figure 4c,e,f). A fringed lamellar prolongation is present along the anteroventral list (Figure 4g,h) similar to that on the male (see Kornicker and Caraion, 1974). The channel formed between the list and selvage may be used for circulating water into or out of the carapace when the valves are closed, possibly during feeding. The position of the epipodial appendage of the 5th limb and the 6th limb relative to the channel is shown in Figure 4l and also in Figure 2. The distribution of bristles and types of bristles on the infold of the female (Figure 4g–l) are similar to those of the male (see Kornicker and Caraion, 1974).
First Antenna (Figure 5b): 1st joint with spines along ventral margin and on distal medial surface; 2nd joint with spines along ventral margin, proximally on dorsal margin, and abundant on lateral and medial surfaces; 4–6 spinous bristles of unequal length along dorsal margin; 4–7 short, slender bristles on distal lateral surface; 3rd joint with 11–19 spinous bristles along dorsal margin and 1 short, bare bristle near middle of ventral margin; 4th joint with 1 long, spinous terminal dorsal bristle and 4 or 5 spinous terminal ventral bristles (3 or 4 short, 1 long); 5th joint with convex dorsal margin; sensory bristle with 2 short proximal filaments and 12–14 long distal filaments; medial bristle on 6th joint terminal with minute plate at base. Seventh joint: a-claw curving dorsally, with rounded tip; b-bristle about 2.5 times length of a-claw, with 12 marginal filaments; c-bristle about 1.75 times length of b-bristle, with 8 marginal filaments. Eighth joint: d- and e-bristles bare, longer than b-bristle; f-bristle reflexed, about same length as b-bristle, with about 6 marginal filaments; f-bristle about same length as c-bristle, with about 11 marginal filaments; g-bristles longer than f-bristle, with about 14 filaments.
Second Antenna (Figure 5c,d): Protopodite with short, slender medial bristle, numerous hairs along ventral margin and medially near dorsal margin. Endopodite 3-jointed: 1st joint with 1–4 proximal bristles on or near protopodite and with 5 or 6 distal ventral bristles; 2nd joint with 0–4 distal ventral bristles; 3rd joint with long terminal bristle; all endopodite bristles bare. Exopodite: 1st joint with short terminal medial spine and groups containing 2 or 3 teeth forming rows on lateral side near dorsal margin or along dorsal margin; joints 2–8 with short spines forming row along distal margin and slender basal spines; 9th joint with short, slender lateral spine and 5 bristles—3 long, 1 medium, 1 short (dorsal); bristles on joints 2–8 and 3 long bristles on joint 9 with ventral marginal spines along proximal part; all exopodite bristles with natatory hairs.
Mandible (Figure 5e–h): Coxale endite with medial bristle near base; ventral branch with 6 oblique rows of spines; distal row on USNM 142795B with 3 spines with bulbous tips (foreign growth?), no bulbous tips on USNM 143795A; tip of ventral branch with 3 teeth, dorsal of these longer than others and with minute terminal teeth; ventral margin of dorsal branch with 2 short, double teeth followed by 2 short, single teeth and 4 slender, recurved teeth; the 4 short teeth with spines or teeth along posterior margins, the 4 slender, recurved teeth with spines along anterior margins; long bristle with few hairs present at tip of dorsal branch; short spines present on narrow ridge along dorsal margin of tip of dorsal branch.
Basale endite with 7 short bristles with spine-formed tips and 22 longer pectinate bristles with minute triaenid tips, longest of the pectinate bristles terminal; dorsal margin of basale with 4 short, bare bristles and 2 terminal bristles with long marginal spines; ventral margin of basale with 12 short bristles with triaenid tips and about 15 pairs of marginal spines near tip, and following these 1 slightly longer bristle and 1 very long bristle, both with long marginal spines; medial surface with 5 minute bristles with spine-formed tips near ventral margin, and long hairs forming clusters on proximal dorsal half. Exopodite reaching distal end of 1st endopodite joint, hirsute; ventral margin with bare midbristle slightly longer than exopodite, and a 2nd bristle just distal to midbristle and about one-half its length. Endopodite: ventral margin of 1st joint with 6 medium-length, slender bristles with short marginal spines and 2 long, stout bristles with long marginal spines; ventral margin of 2nd joint with 3 slender subterminal bristles and 2 terminal bristles, all with short marginal spines; dorsal margin and medial surface of 2nd joint with abundant bristles; end joint with 3 long, bare, clawlike bristles, 1 long lateral bristle, and 2 short ventral bristles.
Maxilla (Figure 5i,j): Epipodite narrow, pointed, bare, about two-thirds length of basale. Protopodite of USNM 143975 with 1 short and 4 long bristles adjacent to scythe-shaped bristle, followed by group of 8 spinous bristles of various length and then 6 short, bare bristles with bases on medial side (for range of total number of protopodial bristles see Table 1); lateral side of basale with 1 short bristle; medial surface with 6–22 short, spine-tipped bristles forming row proximally near dorsal margin, 1 short, spine-tipped bristle ventral to above bristles, and 3–7 short bristles and 1 long (ventral to others) spine-tipped bristle forming row along terminal margin; distal dorsal margin with 1 long and 5–15 short, spine-tipped bristles; ventral margin with 16–18 short, bare bristles, 1 long spinous bristle (distal to others), and 1 long, bare terminal bristle, all bristles spine-tipped; dorsal margin of basale proximal to distal bristles and medial surface spinous; medial surface with long, stiff hairs proximally near middle. Exopodite minute, with 3 bristles of unequal length (Figure 5j). Endopodite: 1st joint with spine-tipped bare bristle near middle of dorsal margin, 1 long β-bristle with few marginal spines, and hairs on medial surface; 2nd joint with 6 bare bristles (2 long, 1 medium, 3 short), some spine-tipped, some with faint marginal spines.
Fifth Limb (Figure 5k): Epipodial appendage with 96 bristles, anterior and posterior bristles shorter than those in middle part. Comb (Figure 5k): dorsal margin hirsute, with 4—12 minute bristles; anterior margin hirsute; ventral and anterior margins with spinous bristles; lateral surface with 15 bristles: 2 slender, spinous bristles near anteroventral margin; 1 stout, spinous bristle near middle, 12 bristles with bases ventral and posterior to stout bristle (includes 1 long, spinous bristle, 5 minute, bare bristles near base of stout bristle, and 6 short, spinous bristles near ventral margin).
Sixth Limb (Figure 5l): Shape similar to that of male; anterodorsal corner with about 8 minute, broad medial spines; medial side of protopodite just within anterior margin with 1 small, bare bristle followed by 2 rows of spinous bristles extending to upper suture (inner row of 15 bristles short, stout; outer row of 29 bristles slightly longer and more slender); 3 somewhat longer bristles present just above upper suture; 11 spinous, slender bristles forming single row on medial surface near anterior margin between upper and lower sutures; 1 much longer, spinous medial bristle above lower suture; medial surface near anterior margin with about 27 slender, spinous bristles along anterior edge; ventral margin with about 72 short and long bristles in addition to about 20 minute bristles (the minute bristles, most short bristles, and some long bristles have bases on medial surface, remaining bristles have bases on ventral margin); extended posterior tip with 2–6 spinous bristles; 2–4 short, bare bristles in place of epipodial appendage; limb hirsute.
Seventh Limb (Figures 7, 8): Broad, distal one-third with 77 bristles, 37–10 on each side, each bristle with 3–7 bells; most rings with 2 bristles (1 on each side), some distal rings with 3 (1 or 2 on each side); terminus with opposing combs, each with about 25 teeth with pectinate margins.
Micromorphology of Seventh Limb (based on scanning electron microphotographs; Figure 7): Terminal end of each limb with 2 opposing combs; each comb with 3 types of teeth, called here A-, B- and C-teeth (Figure 8). Six A-teeth in middle of each comb curving inward; middle tooth longer than side teeth; each tooth with 2 well-developed secondary teeth near middle of each margin followed by 2 or 3 large, less well-developed teeth; tip either smooth or with minute nodular teeth and with pore (Figure 7h,k). Two or 3 B-teeth on each side of the A-teeth bearing about 6 well-developed secondary teeth proximally and about 12 smaller teeth distally along each margin; tip bearing numerous nodular teeth (Figure 7l); no pores observed at tips but presumed to be present. About 5 C-teeth at each end of the comb bearing proximally about 10 long secondary teeth, that together are frondlike, and distally about 12 short secondary teeth (Figure 7d,e).
Furca (Figure 6a–c): Each lamella with 3 main claws followed by 8–10 (usually 9) secondary claws; primary claws with 2 rows of teeth (1 medial, 1 lateral); both rows formed of large teeth separated by 2 or 3 minute teeth; hairs along convex margins of main claws; concavity in lamella between bases of claws 1 and 2 with greatest depth 46 to 86 percent of greatest width;1 concavity on lamella between claws 2 and 3 with greatest depth 61 to 100 percent of greatest width; projections of lamella forming bases of claws 1–3 with medial hairs forming 2 rows; secondary claws with distal spines and midteeth along anterior and posterior margins; secondary claws 1 and 9 smaller than secondary claw 2; secondary claws decrease slightly in diameter posteriorly along lamella; secondary claws 2–4 slightly shorter than secondary claws 5–8; secondary claws 2–9 decrease slightly in diameter proximally along lamella; base of claw 4 offset very slightly inward from claw 5; short segment following lamellae with long hairs forming row; secondary claw 1 of USNM 143975 immediately adjacent to main claw 3 on left lamella but located almost the width of base of claw 3 posterior to claw 3 on right lamella.
Eyes and Rod-shaped Organ: Medial eye and rod-shaped organ similar to those on adult male (Figure 6d); lateral eye (Figures 6e, 9a,b) about one-half size of eye of male but with about same number of ommatidia (5 rows with about 12–14 ommatidia per row).
Upper Lip: Consisting of 2 anterior, ovate, hirsute lobes with saddle between them and 2 posterior lateral flaps (Figure 6d).
Posterior: Dorsum fringed with long hairs; small lobe, without hairs, present in place of dorsal process; few minute spines present on margin dorsal to small lobe.
Gill-like Processes: Broad, terminating in acute angle.
Y-Sclerite: Slightly arcuate with down-curving anterior tip (Figure 6g,h).
Genitalia and Brushlike Organ (Figure 6f): Genitalia ovoid; brushlike organ with 15 minute bristles adjacent to genitalia.
Eggs: USNM 143975A with 28 eggs in marsupium; USNM 143979, 22 eggs; USNM 149271, 38 eggs; 149275A, 26 eggs.
Ectozoa: Protistan attached to endopodite of left 2nd antenna (Figure 6i).
SUPPLEMENTARY DESCRIPTION OF ADULT MALE (Figure 6j).—Specimens from Ivory Coast smaller than specimen from Mauritanian coast described by Kornicker and Caraion (1974): USNM 149280, length 3.96 mm, height 2.87 mm; USNM 149281, length 3.60 mm, height 2.41 mm. Shape of comb of 5th limb similar to that described by Kornicker and Caraion. Distribution of bristles on the 2 Ivory Coast specimens and that on the specimen from Mauritania are compared in Table 1.
SUPPLEMENTARY DESCRIPTION OF JUVENILE MALES.—My measurements of 2 left valves of specimens from Mauritania reported on by Klie (1943): length 4.51 mm, height 3.46 mm; and length 3.96 mm, width 3.27 mm. Dimensions of Ivory Coast specimens: USNM 143995, length 2.96 mm, height 2.52 mm; USNM 149273, length 2.98 mm, height 2.41 mm; USNM 149287B, length 3.03 mm, height 2.38 mm; USNM 149273, length 2.67 mm, height 2.06 mm; USNM 149275B, length 3.44, height 2.79 mm. Appendages of Klie’s specimens and an A–1 male from Mauritania reported on by Kornicker and Caraion (1974) are compared in Table 1.
DESCRIPTION OF A-1 FEMALE (Figure 6k–m).—Morphological characteristics of an A-1 (USNM 143993) from Mauritania reported by Kornicker and Caraion (1974) are presented in Table 1.
DESCRIPTION OF JUVENILES.—See Figures 6n–r, 10, 11g,h.
COMPARISONS.—Cycloleberis lobiancoi (Muller, 1894) is very close to C. squamiger and perhaps they should be considered conspecific. I have kept them separate because of a small difference in the armature of the 6th limbs. The single female of C. lobiancoi described by Kornicker (1974) bears five epipodial bristles on one 6th limb and four on the other; whereas, of the 12 6th limbs on adult females of C. squamiger examined herein, one had four epipodial bristles and the remaining 11 had only two or three. Additional collections of C. lobiancoi are needed from the vicinity of the Gulf of Naples to assess the variability of that species.
Cycloleberis galathea Poulsen, 1965, is based on a juvenile (A–1 instar) female (holotype) and a juvenile male. In describing the female 6th limb Poulsen states: “Along the anterior side of the protopodite is a row of abt. 12–14 short plumose bristles, and at the distal end of this row one longer bristle with a few shorter marginal hairs.” Because the 6th limbs of C. squamiger contained many more bristles along the anterior margin of the protopodite, I borrowed the holotype of C.galathea from the Copenhagen Museum and upon examination found more anterior bristles on the protopodite of the 6th limb (Figure 12f) than given in Poulsen’s description. The anterior margins of the protopodites of C. galathea and C. squamiger bear about the same number of bristles (compare Figures 5l and 12f). The left 1st antenna illustrated by Poulsen (1965, fig. 87b) bears six dorsal bristles on the 1st joint, a number which rarely occurs on C. squamiger. The left 1st antenna in the vial, however, bears only five bristles (Figure 12a). The right 1st antenna was not present in the vial. The endopodites of the 2nd antennae in the vial also differed somewhat from the endopodite illustrated by Poulsen (1965, fig. 87c). The 1st joint of the endopodite of the left limb bears two proximal bristles close to the protopodite and six distal bristles (Figure 12c); no bristles were observed on the 2nd joint; the 3rd joint bears one long terminal bristle (Figure 12c). The endopodite of the right limb bears three proximal and six distal bristles on the 1st joint one distal bristle on the 2nd joint, and one long terminal bristle on the 3rd joint (Figure 12d) The proximal part of the 1st joint on the right limb also bears three or four strands of a foreign growth. Each strand is segmented and resembles a bristle except for being more slender and having parallel sides. Poulsen (1965, fig. 88b) illustrated the comb of the left 5th limb. The right 5th limb has the same number of dorsal bristles (Figure 12e).
The protopodite of the 2nd antenna of C. galathea has, in addition to the ventral hairs mentioned by Poulsen (1965:262), several medial hairs near the dorsal margin (Figure 12b). Hairs occur in that locale on both C. squamiger and C.lobiancoi. Several segmented strands of a foreign growth were observed along the dorsal margin of the protopodites of both limbs of the holotype of C. galathea (Figure 12g).
The juvenile male of C. galathea described by Poulsen (1965:267) is unusual in having 10 proximal bristles on the 1st joint of the endopodite of the 2nd antenna. Although I have not seen the specimen, I suggest that some of the “bristles” may actually be strands of foreign growth that strongly resemble bristles, like those on Poulsen–s female. The epipodite of both the left and right maxillae of the juvenile male has a distal bristle not found on the female or on any other species in the family. If this is not a strand of a foreign growth, it may be an aberration and not a character useful for taxonomic discrimination.
Cycloleberis galathea is very similar to C. squamiger and the two may be conspecific. Both species are recognized herein because the basale of the maxillae of both the juvenile male and female of C. galathea described by Poulsen (1965) bear only four distal bristles on the dorsal margin. Of the 23 specimens of C. squamiger studied herein, only one limb (on an adult male) contained four bristles there (Table 1); the remaining limbs had more (5–15, average 11). Additional collections of C. galathea are needed to determine its variability.
Moguilevsky and Ramirez (1970) considered their new species, Cycloleberis poulseni, to have concavities between the main furcal claws not deeper than a semicircle. However, applying the formula derived herein (see footnote, page 10) to their illustration of the left lamella (Moguilevsky and Ramírez, 1970, fig. 3), the maximum depth of the concavity between the 2nd and 3rd claws is 75 percent of the maximum width, which is much deeper than a semicircle. Their species differs from C. squamiger in having four short proximal filaments on the sensory bristle of the 1st antenna, more lateral bristles (10) on the 2nd joint of the 1st antenna, more recurved spines (4) following the main spine on the dorsal branch of the coxale endite of the mandible, and a larger carapace (length 5.30 mm). I was unable to obtain specimens of C. poulseni for comparative purposes.
Adult males have been described for only two species of Cycloleberis: C. bradyi Poulsen, 1965 (Poulsen, 1965:268), and C. squamiger (Scott) (Kornicker and Caraion, 1974). Both species have a large, hooklike process at the middle of the dorsal margin of the comb of the 5th limb. The process, absent on the A–I male, probably is used by the adult male for clasping the female during copulation. The dorsal margin of the comb of C. squamiger has a rounded protuberance anterior to the hooklike process, but this process is absent on C. bradyi.
The brief description of “Cypridina (?) bradyi” De Folin, 1871, given by De Folin (1871:245) leads me to believe that this species may belong in the genus Cycloleberis, and, if so, could be a senior synonym of Cycloleberis squamiger. At the present state of our knowledge concerning De Folin’s species, however, it seems best to leave the species where it was referred to by Muller (1912:50): “Cypridinidarum genera dubia et species dubiae.”
DISTRIBUTION.—Cycloleberis squamiger is now known from the lagoon at São Tomé Island, Gulf of Guinea, where it was collected in a night surface tow; from the continental shelf of Spanish Sahara at a depth of 53 m; from the continental slope of Mauritania at a depth of 1100 m; and from the continental shelf of the Ivory Coast at depths of 10 to 40 m.
This genus is represented in the collections by three varieties (A, B, and C) of Asteropteron setiferum Kornicker and Caraion, 1974. Members of this genus range from about 33°N to 37°S and from intertidal depths to 1100 m, but most occurrences are shallower than 100 m.
One of the criteria specified by Kornicker and Caraion (1974:75) for distinguishing A. setiferum from Asteropteron nodulosum Poulsen, 1965, was the presence of fewer coarse fossae on the carapace of the former. In the present work, specimens with many fossae are included in A. setiferum (varieties B and C have many fossae, whereas variety A has few). The absence of a U-shaped ridge in the posterodorsal part of the carapace of A. setiferum remains a criterion for distinguishing that species from A. nodulosum. Adults of only the female of A. setiferum and the male of A. nodulosum are known, making comparison difficult. In general, the carapaces of adult females of A. setiferum are smaller than carapaces on most nodose species of the genus and, also, mandibles have more bristles on the basale (Figure 14). Information is required about the adult stage of juveniles from South Africa identified by Hartmann (1974) as Asteropteron aff. nodulosum Poulsen (1965:235) and Asteropteron cf. nodulosum Poulsen (1965: 372) before they can be identified with certainty.
Asteropteron setiferum Kornicker and Caraion, 1974
Asteropteron setiferum Kornicker and Caraion, 1974:66, figs. 37–43.
HOLOTYPE.—Number 271, a female (length 2.70 mm) in the Museum of Natural History “Grigore Antipa,” Bucharest, Romania.
TYPE-LOCALITY.—Thalassa station X044, 20°09′06″N, 17°48′09″W, 1100 m, Mauritania.
MATERIAL.—Four adult females, USNM 128851, 143996, 149283, and 149319, from station 4; 1 adult female, USNM 149282, from station 2; 1 adult female, USNM 149284, from station 3; 1 adult female, USNM 149285, from station 1; 1 adult female from station 15; 1 adult female from station 17; 1 adult female and 1 specimen of undetermined sex from station 12; 2 adult females from station 16.
The collection from the Ivory Coast contained 13 specimens in the genus Asteropteron. The specimens are slightly smaller (length 2.22–2.62 mm) than the unique female of A. setiferum from the Mauritanian coast (length 2.70 mm). The specimens from the Ivory Coast vary considerably in carapace morphology and in the number of bristles on the dorsal margin of the mandibular basale; and, initially, I thought them to be three new species. However, because of having only a single specimen of one of the proposed new species and only two specimens of the second, and because of the variability of the third species, I found it expedient to refer all the specimens to A. setiferum, which if not conspecific with the Ivory Coast specimens is more closely related to them than are other species of the genus. But in order not to lose information, I have assigned the Ivory Coast specimens to three varieties: A, B, and C. The appendages of variety A are described and illustrated (Figures 13a,b; 15–20a–f). The distribution of bristles on all three varieties is given in Table 2. Carapaces of the three varieties are illustrated (Figures 13, 15–18, 21–25).
The carapace of variety A has fewer fossae than carapaces of varieties B and C. Also, the carapaces of varieties B and C bear a prominent node posterior to the middle; the node is absent or subdued on carapaces of variety A. The specimen of A. setiferum from Mauritania has a carapace similar to that of A. setiferum variety A except for being larger (2.34–2.59 mm for variety A; 2.70 mm for Mauritanian specimen).
Four of the five specimens of variety A examined bear a total of 14–19 bristles on the dorsal margin of the mandibular basale (Figure 14). The fifth specimen bears 30 or 31 bristles. The Mauritanian specimen bears 35 bristles. The two specimens of variety B in the collection bear 26–39 bristles on the dorsal margin of the mandibular basale. The single specimen of variety C in the collection bears 12 or 14 bristles.
Specimens of variety A were collected at five stations at depths of 35–50 m between Jacqueville and Vridi. Specimens of variety B were collected at two stations at depths of 40–80 m between Jacqueville and Grand Bassam, and farther from shore than the specimens of variety A. The unique specimen of variety C was collected at a station near Sassandra at a depth of 10 m.
DISTRIBUTION.—Asteropteron setiferum is now known from the continental shelf off Spanish Sahara at a depth of 53 m, from the continental slope off Mauritania at a depth of 1100 m, and from the continental shelf off the Ivory Coast at depths of 10–80 m.
A. setiferum variety A
MATERIAL.—One ovigerous female (USNM 128851) and 3 nonovigerous adult females (USNM 143996, 149283, 149319) from station 4; 1 ovigerous female from station 17; 2 ovigerous females from station 16; 2 ovigerous and 2 nonovigerous females from station 12; 1 ovigerous female from station 15.
DESCRIPTION OF FEMALE (based mainly on USNM 128851, 143996, 149283; Figures 13a,b, 15–20a–f).—Carapace: Similar to that of unique specimen described by Kornicker and Caraion (1974) from off Mauritania.
Infold: Rostral infold with cluster of about 12 long and short bristles near rostral tip, row of 49 long and short bristles (29 long, 20 short) forming row parallel to anterior margin; 42 short bristles between row of bristles and anterior margin of carapace; 1 short, stout bristle dorsal to inner end of incisur; about 28 minute bristles between row of bristles and inner margin of infold; about 8 very short bristles forming row on anterodorsal infold (this row is continuation of anterior row of long and short bristles); 3 minute bristles posterior to inner end of incisur; anteroventral infold with about 10 bristles forming row near middle and about 8 minute bristles or pores near outer edge; distinct list near inner margin of infold extending from below incisur to posterior end of ventral infold; ventral infold near list with 11 widely spaced, short bristles; total of 21 short bristles and 8 minute bristles or pores between list and outer edge of infold; posteroventral infold with about 15 short bristles forming row posterior to list; posterior infold with outer row of 11 short bristles and inner row of 15 short and about 19 minute bristles (bristles of inner row on broad list); 9 short bristles forming row ventral to inner row; outer margin of posterior infold (edge of valve) forming right angle near valve middle.
Central Adductor Muscle Scar: Consisting of about 21 individual ovoid scars (Figure 19a).
Size: USNM 128851, length 2.45 mm, height 1.84 mm; USNM 143996, length 2.34 mm, height 1.72 mm; USNM 149283, length 2.33 mm, height 1.73 mm; USNM 149319, length 2.42 mm, height 1.89 mm; specimen A from station 12, length 2.38 mm, height 1.80 mm; 2 specimens from station 16: specimen A, length 2.39 mm, height 1.87 mm, and specimen B, length 2.45 mm, height 1.86 mm; specimen B from station 12, length 2.62 mm, height 1.82 mm; specimen from station 15, length 2.53 mm, height 1.94 mm.
Micromorphology of Carapace (based on scanning electron micrographs; Figures 15–18): Kornicker and Caraion (1974) described carapace morphology of the holotype of A. setiferum treated with a sonic vibrator prior to freeze-drying. To assess the effect of the sonic vibrator, the right valve of USNM 143996 was vibrated and the left valve was not. The left and right valves are compared in Figure 15 (right valve, a,c,e; left valve, b,d,f). Most large fossae are visible on the untreated valve but are partly filled with a debris like substance (compare c and d of Figure 15). The surface between large fossae, which has shallow fossae and a reticulate structure on the treated valve, is covered by an amorphous layer on the untreated valve (compare c and d, Figure 15, and e and f, Figure 15). Smooth clumps of material scattered on the surface of the unvibrated valve may be a foreign growth (Figure 15f).
The fossae and microstructure of the valve surfaces are similar to those on A. setiferum described previously (Kornicker and Caraion, 1974). To that description may be added that short bundles of polygonal tubes project inward along the dorsal margin of each valve (Figure 16a–c).
In order to determine the relationship between tubes within fossae (Figure 18a) and the haemocoele of the animal, the freeze-dried and goldplated right valve of USNM 143996 was cut in two with a razor blade and the cut edges examined with the scanning electron microscope. Surprisingly, the tubes are merely surface ornamentation with no connection with the haemocoele, and they are not evident in cross sections of the shell except in the thin surface layer (Figure 18b–f).
The distribution and types of bristles and pores on the infold of A. setiferum were described by Kornicker and Caraion (1974). Similar bristles and pores are on the specimens of A. setiferum variety A examined herein (Figure 16j–l).
Each central adductor muscle consists of several clusters of individual strands at its point of attachment with the shell (Figure 16f–i). The structure is quite unlike the undivided muscle of Cylindroleberis bacescui Kornicker and Caraion (1974, fig. 16c,e).
The lamellar prolongation along the ventral margin is faintly striate medially (Figure 17a) and bears minute denticulations along the margin (Figure 17b). The outer side bears ribs which decrease in height distally (Figure 17e,f). The laminated internal structure of the shell and infold along the ventral margin is shown in Figure 17c,d.
First Antenna (Figure 19b): 1st joint with long hairs on medial and lateral surfaces near ventral margin, short spines forming clusters on medial surface near distal dorsal corner, and longer spines forming clusters on medial surface near distal dorsal corner; 2nd joint with spines along ventral and proximal dorsal margins and with 5 spinous dorsal bristles—4 proximal, 1 distal (2nd proximal bristle missing on right limb of USNM 128851); 3rd joint with 1 short ventral bristle and 3 dorsal bristles (1 near middle, 2 terminal); 4th joint with 1 long, spinous terminal bristle on dorsal margin and 3 terminal bristles on ventral margin (1 long, spinous, 2 minute, bare); sensory bristle of 5th joint with 2 or 3 short proximal filaments and 4 long terminal filaments; lateral surface of 5th joint with hairs forming row along dorsal half of terminal margin; 6th joint with short medial bristle near middle of terminal margin. Seventh joint: a-claw slightly longer than joints 5 through 8, ringed in distal part; b-bristle witli 4 marginal filaments and bifurcate tip; c-bristle slightly longer than b-bristle, with 7 marginal filaments and bifurcate tip. Eighth joint: d- and e-bristles bare, about same length as c-bristle; f-bristle about same length as c-bristle, with 8 filaments including tip; g-bristle longer than others, with 9 filaments including tip.
Second Antenna (Figure 19c,d): Protopodite with medial bristle and numerous short spines forming rows on medial surface near dorsal margin; several short hairs present on posterior part of dorsal margin. Endopodite: 3rd joint fused with 2nd and no suture evident between them; 1st joint with 9–12 bristles; 2nd joint bare; 3rd joint with long, bare terminal bristle. Exopodite: 1st joint with short distomedial bristle; bristles on 2nd and 8th joints and 3 long bristles of 9th joint with slender spines proximally along ventral margin and with natatory hairs; 9th joint with 1 medium-length bristle and 1 short bristle with natatory hairs, in addition to 3 long bristles.
Mandible (Figure 19e–g): Coxale endite (Figure 19e): Ventral branch with 2 clusters of long hairs followed by 6 or 7 rows of stout spines; tip with 2 stout teeth (a 3rd tooth might have broken off the specimen examined); minute bristle on endite near base of ventral branch; ventral margin of dorsal branch with 4 knobs followed by short main spine with serrate posterior margin; about 15 spines forming row on lateral side of branch proximal to main spine; tip of dorsal branch with short spines forming cluster at base of terminal bristle; margin between main spine and terminal bristle serrate. Basale: endite with about 7 pectinate terminal bristles, 6 triaenid bristles, 3 dwarf bristles (distal of these longer than others), and glandular peg with about 14 pores; ventral margin of basale with 3 or 4 triaenid bristles having a pair of spines much longer than others, 2 or 3 short, spinous proximal bristles, 1 long, spinous bristle, and 3 or 4 short, spinous distal bristles; dorsal margin of basale and lateral surface near dorsal margin with total of 14–19 bristles—3–6 proximal, 9–13 distal (for total numbers of bristles on other specimens see Table 3 and Figure 14); medial surface near dorsal margin hirsute. Exopodite hirsute, slightly longer than dorsal margin of 1st endopodite joint, with 2 subterminal bristles, both with short marginal spines (proximal bristle longer than distal bristle). Endopodite: ventral margin of 1st joint with 2 long, stout proximal bristles with long marginal spines and 1 shorter bristle near middle with short marginal spines; medial surface of 2nd joint with spines forming rows in distal half; ventral margin with 3 spinous terminal bristles; dorsal margin with about 35 bristles (some of these of triaenid type); end joint with 2 short, spinous bristles on ventral corner, 1 long lateral bristle with short marginal spines, 1 straight, clawlike bristle witli marginal spines on dorsal edge of terminal margin, 1 long, slightly curved, bare, clawlike bristle on ventral end of terminal margin, 1 long (longer than other clawlike bristles), slightly recurved, clawlike bristle medial to others and near middle of terminal margin.
Maxilla (Figure 19h): Epipodite long, slender, tapering to point, few to many hairs observed; endite I with 5–7 bristles (4 or 5 long, 1 or 2 short); endite II with 1 long, stout, hirsute bristle, 0 or 1 long, slender bristle, and 8–11 short bristles. Basale: dorsal margin witli 9–12 (left limb of USNM 143996 with only 3) proximal bristles of varying length and with 5–9 short and 4 or 5 (left limb of USNM 143996 with only 2) long distal bristles; medial side hirsute, with 3 distal bristles; ventral margin with 8–13 short bristles and 1 long terminal bristle on lateral side at end of baleen comb. Exopodite consisting of 3 bristles (1 long, 2 short), but no definite lobe observed. Endopodite: medial side of 1st joint hirsute; dorsal margin with 2–4 short bristles; ventral margin with 1 long, spinous β-bristle; end joint with 5 spinous bristles.
Fifth Limb (Figure 19i): Epipodial appendage with 79 bristles. Comb: dorsal margin hirsute, with 6–12 short bristles (3–8 proximal, 3–6 distal). Lateral surface with stout, spinous exopodial bristle, a pair of short, slender bristles posterior to stout bristle, and 4 slender bristles near ventral margin posterior to stout bristle; 1 or 2 bristles on medial side with bases almost on ventral margin.
Sixth Limb (Figure 19j): Anterodorsal corner with short marginal spines; anterior margin with 1 or 2 sutures; margin above lower suture with medial bristles forming inner row and outer row; inner row with 9–13 short bristles with long hairs along proximal two-thirds; outer row with 19–23 longer plumose bristles (the one at suture longer than others); margin between sutures with only 1 or 2 short bristles in inner row and 4 longer bristles in outer row (the one closest to lower suture longer than others); margin below lowermost suture with row of 4–7 bristles; 10 spinous bristles on limb medial to lateral flap (these bristles could be considered to be on anterior part of ventral margin); ventral margin posterior to lateral flap with 10 spinous bristles; hirsute posterior margin tapering to rounded tip; lateral flap with 6–9 short, slender, spinous bristles; ventral bristles including those on flap total 23–30; posterior margin with 1 short, hirsute epipodial bristle; medial surface of end joint with about 28–42 minute bristles forming 2 irregular rows near ventral margin and near middle of limb.
Seventh Limb (Figure 19k–m): Each limb with 4 or 5 bristles; some distal segments near tip with 2 or 3 bristles on one side and with 1 or 2 on the other; each bristle with up to 7 bells. Terminus: each opposing comb with 17–19 teeth, 3 or 4 A-teeth, 14 or 15 B-teeth (see page 36 for description of teeth).
Furca (Figure 20b,c): Each lamella with 3 long, stout claws followed by 7–9 short secondary claws; main claws with medial and lateral teeth along concave margins; secondary claws with slender teeth along posterior margins and distal part of anterior margins; anterior margin of lamellae with slender spines; lamellae at base of main claws and between and following secondary claws with long hairs.
Rod-shaped Organ (Figure 20a): Broadening near middle and with rounded tip.
Eyes: Medial eye large, pigmented, bare (Figure 20a). Lateral eye (Figures 19n, 20a) slightly smaller than medial eye, pigmented, with about 14 ommatidia, most of these embedded in pigment and difficult to discern; each eye attached to head region by a narrow stalk.
Posterior: Hirsute; dorsal process finger-like with spinous lobe at tip (Figure 20d).
Upper Lip (Figure 20e): Consisting of 2 hirsute lobes on each side of low saddle; each lobe and saddle with 5 anterior spines; a hirsute flap posterodorsal to each lobe.
Brushlike Organ: Not observed.
Genitalia: Consisting of oval sclerotized ring.
Gill-like Structures: Well-developed.
Υ-Sclerite: Slightly sinusoidal (Figure 20f).
Eggs: USNM 128851, 12 eggs; USNM 149283, 11; specimen from station 17, 5; specimen B from station 16, 12; specimen from station 15, 13.
Ectozoa: The right valve of USNM 143996 had laterally a stemmed, vaselike protistan (Figure 16d). The base of its stalk appears cemented to the ostracode shell with a smooth substance that covers the microstructure of the shell (Figure 16e).
DISTRIBUTION.—Collected at 5 stations between Jacqueville and Vridi between depths of 35 and 50 m.
A. setiferum variety B
MATERIAL.—1 adult female, USNM 149282, from station 2; 1 adult female, USNM 149285, from station I.
DESCRIPTION OF FEMALE (Figures 13c,d; 21–26).—Carapace with more numerous fossae than that of A. setiferum variety A. Left valve of USNM 149285 strongly calcified with feathery calcite under the shell layer containing fossae; right valve of that specimen and both valves of USNM 149282 translucent, light brown, without crystalline calcite. Black lateral eye of specimen visible through anterior node of carapace (Figure 13c).
Size: USNM 149282, length 2.24 mm, height 1.73 mm; USNM 149285, length 2.22 mm, height 1.89 mm.
Micromorphology of Carapace (based on scanning electron photographs; Figures 21–25): The right valves of both specimens assigned to A. setiferum variety B were studied as well as two fragments of recrystallized calcite from the left valve of USNM 149285. The fragments, which were obtained from beneath the outer layer of shell, form anastomosing patterns (Figure 23a,b,e). The outer surface of the recrystallized calcite bears impressions presumably of overlying fossae (Figure 23c,d). The underside of the recrystallized calcite is smooth on the fragment on which it was examined (Figure 23d). The edge of the calcite perpendicular to the axis of the anastomosing pattern appears randomely pustulose (Figure 23f). The carapace of A. setiferum variety B contains many more punctae than that of A. setiferum variety A (compare Figures 21a–d and 24 with Figure 15a,b). The fossae on the carapace of USNM 149285 (Figure 22a–c) and some fossae on the carapace of USNM 149282 (Figure 25j) are of a type similar to those of variety A. However, many fossae of USNM 149282 have a polygonal network, which may represent the bases of broken processes (Figure 25b,c,h,i). Whereas the area of the carapace between fossae of variety A consists of a reticulate structure (Figure 15e), that area contains elongate processes on both USNM 149282 (Figure 25d–g) and USNM 149285 (Figure 22c,d). A pair of bristles and a broad lamellar prolongation of selvage are present along the ventral margin (Figure 21e). The distal margin of the selvage is denticulate (Figure 22f). Bristles and pores on the posterior infold are shown in Figure 25k,l.
Appendages: Similar to those of A. setiferum variety A, except dorsal margin of mandibular basale with more bristles than on basale of many specimens of variety A (Table 2; Figure 14). Brushlike organ consisting of small lobe with about 9 minute bristles dorsal to genitalia (Figure 20h). Second joint of left 2nd antenna with short bristle (Figure 20g); same joint of right 2nd antenna bare.
Micromorphology of Seventh Limb (based on scanning electron microphotographs; Figure 26): Terminal end of each limb with 2 opposing combs (Figure 26a–c); each comb with 2 types of teeth called here A- and B-teeth; 3 or 4 A-teeth (Figure 26d) in middle of each comb similar to those of 7th limb of Cycloleberis squamiger (Scott) (see Figure 7h); 7 or 8 B-teeth at each end of comb with well-developed secondary teeth of similar length along edge of outer segment of tooth (Figure 26c,e); inner segment with depression at tip containing pustulae and central pore (Figure 26e,f). No C-bristles similar to those of Cycloleberis squamiger present.
DISTRIBUTION.—Collected at a depth of 80 m off West Vridi and at a depth of 40 m off Grand Bassam.
A. setiferum variety C
MATERIAL.—One ovigerous female, USNM 149284, from station 3.
DESCRIPTION OF FEMALE (Figure 13e).—Carapace: With fossae more numerous than on carapace of A. setiferum variety A and with nodes more prominent than those on both A. setiferum variety A and variety B.
Appendages: Dorsal margin of mandibular basale with 12 or 14 bristles; limbs otherwise similar to those of A. setiferum variety A and variety B (see Table 2 and Figure 14).
DISTRIBUTION.—Collected near Sassandra at a depth of 10 m.
This family was not represented in the collection from the Ivory Coast. A supplementary description is given below of a species from São Tomé Island.
This genus is widespread between latitudes 63°N and 37°05′S and in depths ranging between intertidal and 205 m.
- bibliographic citation
- Kornicker, Louis S. 1975. "Ivory Coast Ostracoda (Suborder Myodocopina)." Smithsonian Contributions to Zoology. 1-46. https://doi.org/10.5479/si.00810282.197
Comprehensive Description
provided by Smithsonian Contributions to Zoology
Cycloleberis squamiger (Scott, 1894)
Asterope squamiger Scott, 1894:140, pl. 14: fig. 58, pl. 15: figs. 24,28,29,31.—Müller, 1912:52 [Cypridinarum genera dubia et species dubiae].
Cyclasterope lobiancoi.—Klie, 1943:50, figs. 1–4.
LECTOTYPE.—A juvenile instar in the British Museum (Natural History), designated herein (label in British Museum: “Asterope squamiger”).
TYPE-LOCALITY.—São Thomé Island, Portugal.
MATERIAL.—USNM 143798, 1 adult male from Thalassa station X052; USNM 143992, 2 juveniles from Thalassa station X052; [USNM 143980], 1 juvenile from Thalassa station X033; [USNM 143976], 1 juvenile female, length 2.45 mm, height 2.05 mm, from Thalassa station X044;USNM 143993; 1 juvenile female from Thalassa station X044. USNM 143978, 1 juvenile male, length 3.77 mm, height 3.06 mm, from Cornide de Saavedra station A7b, sample 14; USNM 143990, 1 juvenile female, length 2.42 mm, height 2.05 mm, from Cornide de Saavedra station A3a, sample 11; USNM 143991, 1 juvenile from Cornide de Saavedra station A1a, sample 10. [USNM 143980] and [USNM 143976] deposited in the collection of the Museum of Natural History “Grigora Antipa,” Bucharest, Romania.
DISTRIBUTION.—Specimens assigned to Cycloleberis squamiger were collected from 5 localities off the coast of Mauritania and 1 off the coast of Spanish Sahara at depths of 20 to 1100 m (Figures 2, 3).
Kornicker examined specimens, identified by Klie (1943) as Cyclasterope lobiancoi (Müller, 1894), from the Hamburg Zoological Museum. These specimens consisted of a vial containing 4 disarticulated valves and a complete undissected juvenile, a label with the number “10” and a second label stating, “Cyclasterope lobiancoi (G. W. Müller) Mauritanien: Muschelgrunde vor Port Etienne, 20–30 m, August 1923, fide R. Ph. Dollfus.” Three glass slides containing appendages of 2 juvenile males were also received. Because of the similarity in appendages and carapaces, and the proximity of the collecting areas, we have assumed that Klie’s specimens and ours are conspecific. Klie’s specimens will be discussed further by Kornicker (in prep.).
Reasons for assigning the Mauritanian specimens to C. squamiger and a supplementary description of the lectotype will be given by Kornicker (in prep.).
DESCRIPTION OF ADULT MALE (Figures 24–31).— Carapace elongate, smooth, with widely spaced minute punctae (Figures 24, 28a); shallow incisur at valve middle; posterior evenly rounded with slight indentation in posterodorsal corner; long hairs forming row near posterior margin (Figure 24c,f,g).
Infold (Figures 25f,l, 26, 27a–i, 28d): Behind rostrum with about 275 simple bristles, mostly on anterior half of infold; about 30 simple bristles between list and incisur; anteroventral infold ventral to incisur with about 50 long and short simple bristles on outer half and about 12 long bristles near inner margin; ventral margin with about 100 short spinous bristles forming 1 or 2 rows along inner margin of infold (list) and about 100 long spinous bristles forming 1 or 2 rows near middle; posterior with broad list with 18 long bristles (many of the long bristles with shorter bristle near base); and about 150 short bristles (some appearing as minute spines); about 50 bristles present between broad list and posterior valve margin (bristles shorter near dorsal margin); bristles forming row present along anterior margin ventral to incisur, and along ventral and posterior margins.
Vestment: Long hairs forming cluster present in anterodorsal corner (Figures 25i, 28c).
Size: USNM 143798, length 4.55 mm, height 3.10 mm.
Micromorphology of carapace (based on scanning-electron photomicrographs): Lateral surface: Surface with abundant shallow fossae (Figure 24a–e, h–l); fossae with reticulate flat bottom (Figures 24k,l; 25b,e) except along anterior and anteroventral margin of valve where bottoms are slightly concave (Figure 24e); each fossae with short bristle emerging from closed pore; bristle usually posterior to center of fossae; each fossae along ventral part of carapace with oblique ridge at ventral margin (Figure 24i,j); some fossae along anterior part of carapace with ridges along anterior margins more-or-less parallel to anterior valve margin (Figure 24d,e); bristle in each fossae on anteroventral part of shell longer than those in fossae elsewhere (Figure 24e); surface between fossae faintly reticulate (Figure 24h,k,l); short bristles emerging from open pores widely scattered over surface (Figure 24h–l, 25a–c); reticulations on carapace tend to be radiate in vicinity of the short bristle (Figure 24l); open pores widely scattered on surface (Figure 24k,l, 25d); these pores tend to be between adjoining reticulations (Figure 24k,l); minute porous surface visible at magnifications above about × 1000 (Figures 24l, 25a,c,d); these pores tend to be aligned along margins of reticulations (Figures 24l, 25c), but some form rough circles (Figures 25a); slender and stout bristles form vertical row near posterior shell margin (Figure 24a,c,f,g); microconcretions form ovoid discs in valve (Figure 24a); these discs project outward from valve surface (Figure 24b,c); reticulations in shell are visible on concretions (Figure 24h). Medial surface: Ridges and faint indications of fossae visible on medial surface of carapace except over microconcretions (Figure 25f,g,l); the ridges appear to be more extensive than on lateral surface of carapace.
Vestment: Long hairs are present on the anterodorsal part of the vestment posterior to the rostrum (Figure 25i).
Posterior list: List bears posterior row of bristles emerging from closed pores and anterior row of short and long bristles emerging from open pores (Figures 25l, 26); bristles from closed pores consist of long stout bristles alternating with short tubelike bristles with alar projections or pore at base (Figures 26d–l, 27b,c); a short raised pore present between each pair of bristles emerging from closed pores and usually slightly anterior to them (Figures 26d–k, 27a,c).
Infold between posterior list and posterior margin of valve: Bristles form row just anterior to posterior margin of valve (26a,b, 27d); small mounds, some with pores, present between bristles and posterior valve margin (Figures 25l, 26b,c).
Ventral list: List with fringed lamellar prolongation extends anteriorly from point just posterior to valve middle to point about one-fourth length of valve from anterior end (Figures 25f, 27e–k).
Selvage: Lamellar prolongation with fringe present along lower margin of incisur (Figure 25j,k); lamellar prolongation with serrate margin present along anteroventral margin (Figure 25h) and ventral margin (Figure 27l).
First antenna (Figures 28e, 31a): 1st joint with spines along ventral margin and on distal medial surface; 2nd joint with spines along ventral margin, proximally on dorsal margin, and abundant on distal medial surface; 5 slender straight bristles present along dorsal margin (4 proximal of these with short faint marginal spines, distal bristle longer than others and with long proximal and short distal spines), 6 short spinous bristles present on distal lateral surface; 3rd joint with 16 spinous bristles along dorsal margin and 1 short bare bristle near middle of ventral margin; 4th joint with 1 long spinous terminal dorsal bristle and 5 spinous terminal ventral bristles, 1 short, 4 long; 5th joint slightly longer than 4th, sensory bristle with abundant thin filaments and at tip 7 stouter and shorter filaments; dorsal margin of 6th joint much shorter than dorsal margin, with short faint marginal spines. Seventh joint: dorsal margin of joint offset from dorsal margin of 6th joint; a-claw on short pedestal, with rounded tip curving dorsally, bare; b-bristle about two and one-half times length of a-claw, with 14 marginal filaments; c-bristle extremely long, tip broken off on both limbs of specimen, but with 41 filaments on remaining part. Eighth joint: d- and e-bristles bare, shorter than b-bristle; f-bristle similar to c-bristle; g-bristle slightly longer than b-bristle, with 19 marginal filaments.
Second antenna (Figures 28f, 31b–d): Protopodite with short slender medial bristle, but no spines or hairs. Endopodite 3-jointed: 1st joint with 1 proximal and 3 or 4 distal bristles, all bare; 2nd joint longer than 1st, with 7 or 8 short distal bristles; 3rd joint reflexed, with 1 long proximal bristle and pointed ridged tip. Exopodite: 1st joint with short terminal medial spine; joints 2–8 with short slender basal spines, short hairs or spines along distal medial margin, and long hairs on distal dorsal corner; 9th joint with 2 short slender lateral spines about one-third length of joint, and 5 bristles, 4 long, 1 short (short bristle medial and proximal); bristles of joints 2–9 with natatory hairs, but no marginal spines.
Mandible (Figures 29a,b, 31e,f): Coxale endite with medial bristle near base; ventral branch with 6 or 7 oblique rows of spines; distal 2 or 3 rows with stouter spines than others, and with some spines blunt or bulbous (the blunt and bulbous spines are probably the result of growths of foreign material); tip of ventral branch with 3 teeth, dorsal of these longer than other 2 and with minute terminal teeth; ventral margin of dorsal branch with 5 short stout teeth followed by 4 slender recurved teeth; posterior bristle with faint short hairs present at tip of dorsal branch; short spines present on dorsal margin of tip of dorsal branch appear to be continuation of hairs on bristle; faint line parallel to dorsal margin near tip gives false impression that base of posterior bristle is proximal to tip (Figure 29b).
Distal end of basale endite with 5 pectinate bristles of varying length; 7 shorter bristles pectinate near tip form row medial to the 5 end bristles; row continues with 10 short bristles along dorsal margin of endite (tips of bristles with 6–12 pairs of marginal spines decreasing in length distally along bristles; end of each bristle with minute triaenid tip); dorsal margin of endite with 10 short slender bare bristles with spine-shaped tips, 6 forming distal row, 4 forming proximal row; ventral margin of basale with 10 short bristles, proximal 6–8 of these with triaenid tips, remaining with very slender spines in distal part; distal ventral margin with 2 long, or 2 long and 1 short, distal bristles with long marginal spines; medial surface near ventral margin with 5 minute bare bristles with spine-formed tip; dorsal margin of basale with 5 short slender bare subterminal bristles and 2 long spinous terminal bristles; medial surfaces of coxale and basale with long hairs; hairs restricted to dorsal halves of joints.
Exopodite reaching just beyond distal end of 1st endopodite joint, hirsute with long proximal and short distal hairs; ventral margin with bare midbristle about two-thirds length of exopodite; slightly shorter bare bristles present just distal to midbristle. Endopodite: ventral margin of 1st joint with 1 minute bare bristle, 5 long slender bristles with short marginal spines, and 2 long stout bristles with long marginal spines; ventral margin of 2nd joint with 4 long slender bristles with short marginal spines (bases of bristles form oblique row on medial surface), and 2 long stout terminal bristles with short marginal spines; dorsal margin and medial surface of 2nd endopodite joint with abundant bristles; end joint with 3 long bare claws, 1 long lateral bristle with short marginal spines along ventral margin, and 2 short ventral bristles, both with short marginal spines.
Maxilla (Figures 29c–e, 31g): Epipodite narrow, pointed, bare, about two-thirds length of basale. Bristles on protopodite indistinct on both limbs of specimen, but appearing to have scythe-shaped bristle of baleen comb and 1 slender bristle followed by group of 3 long and 3 short bristles followed by group of 6 long bristles adjacent to 4 or 5 short bristles (Figure 29e). Basale: lateral surface with 1 short proximal bristle; medial surface with 20 short proximal spine-tipped bristles near dorsal margin, and 4 short spine-tipped distal bristles forming row along terminal margin; distal margin with 1 long, 11 or 12 short bristles, all spine-tipped (3 short bristles anterior and 8 or 9 short bristles posterior to the long bristle (Figure 29c,d); ventral margin with 17 or 18 short spine-tipped bristles (distal 3 bristles longer than others; middle of these with marginal spines) and 1 long spinous terminal bristle; dorsal margin proximal to distal bristles and medial surface spinous; medial surface with long hairs proximally and near ventral margin. Exopodite small with 3 bristles of unequal length, shortest of these bare, others with marginal spines. Endopodite 1st joint with 1 spine-tipped bristle near middle, 1 long spinous -bristle, and hairs on medial surface; 2nd joint with 6 unequal terminal bristles, some with a few marginal spines and spine at tip.
Fifth limb (Figures 30a, 31h): Epipodial appendage with 110 bristles, anterior and posterior bristles shorter than those in middle part. Comb: dorsal margin with 2 sclerotized processes, a curved process near middle, and a rounded process distal to middle; 7 minute bristles present along posterior margin and near tip of curved process; anterior margin hirsute; ventral and anteroventral margins with spinous bristles; lateral surface with 15 bristles: 2 slender spinous bristles near anteroventral margin, 1 stout spinous bristle ventral to middle, 12 bristles with bases ventral and posterior to stout bristles (includes 1 long spinous bristle and 4 minute bare bristles forming 2 pairs near base of stout bristle, and 7 short bristles closer to ventral margin).
Sixth limb (Figures 30b,c, 31i): Maximum width about three and one-third times narrow proximal part; anterodorsal corner with about 18 minute broad medial spines; medial side of anterior margin of protopodite with 4 minute bristles followed by 14 short spinous bristles forming row extending to upper suture; 2 slender bristles present near anterior margin dorsal to upper suture; 8 slender bristles either bare or with spines present on medial side between upper and lower sutures; anterior margin of protopodite with 34 slender hirsute bristles forming row; anterior margin between sutures with 12 slender spinous bristles; anterior margin from lower suture to anterior tip of limb with about 25 slender hirsute bristles; lateral flap with about 4 slender spinous bristles along anterior edge; ventral margin with about 80 short and long bristles in addition to about 35 minute bristles (minute and short bristles as well as some long bristles have bases medial to ventral margin, all remaining long bristles have bases on ventral margin); extended posterior tip of limb with 3–5 spinous bristles; 3 short bare bristles present in place of epipodial appendage.
Seventh limb (Figure 31j): Broad, distal one-third with 67 or 68 bristles, 32–35 on each side, each bristle with 3–9 bells; most rings with 2 bristles, 1 on each side, rarely with 1 or 3; terminus with opposing combs, each with about 32 teeth, all with pectinate margins.
Furca (Figure 30d–f,i): Each lamella with 3 main claws followed by 9 secondary claws; primary claws with 2 rows of teeth, one along concave margin, other on medial surface slightly in from concave margin; teeth subequal in length but all fairly large (no minute teeth present); hairs present along convex margins of primary claws; concavity in lamella between bases of main claws 1 and 2 with greatest depth 47–52 percent of greatest width; concavity on lamella between bases of main claws 2 and 3 with greatest depth 72–79 percent of greatest width; projections of lamella forming bases of main claws 1 to 3 with medial hairs forming 2 rows; secondary claws with spines and teeth along anterior and posterior margins (teeth near middle, spines distal); secondary claws 1 and 9 smaller than secondary claw 2; secondary claws 2–5 slightly shorter than secondary claws 6–8; secondary claws 2–9 decrease slightly in diameter proximally along lamella; secondary claw 1 only very slightly offset proximally from secondary claw 2; short segment following lamellae with long hairs forming row; secondary claw 1 immediately adjacent to main claw 3 on left lamella, about width of base of claw 3 distant from claw 3 on right lamella.
Eyes: Lateral eye (Figure 30h) well developed with about 74 ommatidia (5 rows, each with 12–14 ommatidia); medial eye (Figure 30g) bare, about one-half size of lateral eye, pigmented distally.
Rod-shaped organ (Figure 30g): With broad base and weakly 2 or 3 jointed, tip rounded.
Posterior (Figure 30i): 1st and 2nd segments above furcal lamellae hirsute; dorsum with very faint minute spines; dorsal process absent.
Gill-like structures (Figure 30j): Distal ends acuminate.
Y-sclerite: Consisting of simple concave sclerite (Figure 30i,k,l)
Asteropteron Skogsberg, 1920
The collection contained two new species of this genus: A. upsilon and A. setiferum. A juvenile of another species was also present and is designated Asteropteron species indeterminate.
DISTRIBUTION.—Species of the genus Asteropteron are worldwide between latitudes of about 33°N and 37 °S. Previously known depth range of the genus was 4 to 100 m (Kornicker, in press). The depth range is increased with the present collection to 1100 m.
- bibliographic citation
- Kornicker, Louis S. and Caraion, F. E. 1974. "West African Myodocopid Ostracoda (Cylindroleberididae)." Smithsonian Contributions to Zoology. 1-78. https://doi.org/10.5479/si.00810282.179
