Scleroconcha ruffi Kornicker 1988

Scleroconcha ruffi

ETYMOLOGY.—The species is named for Dr. Eugene Ruff who collected the material reported upon herein.

HOLOTYPE.—USNM 157835, dissected specimen in alcohol.

TYPE-LOCALITY.—Sta PP-100, 71°23′12″N, 152°41′48″W, 101 m (SMG-1579-10: USCGC Glacier, cruise OCS-7, 12 Aug 1977).

PARATYPES.—USNM 157833, 1 ovigerous female (sta PP-55, SMG-1541-12); USNM 157838, 1 adult female (sta PP-100, SMG-1579-10); USNM 158459, 1 juvenile male (sta PP-100, SMG-1096-14); USNM 158471, 1 juvenile male (sta PP-100, SMG-1093-17); USNM 158518, 1 juvenile male (sta PP-70, SMG-1109-15); USNM 158546, 1 adult male (sta PP-100, SMG-1162-13); USNM 158555, 1 adult male (sta PP-100, SMG-1162-13); USNM 158572, 1 ovigerous female (sta PP-100, SMG-1096-14); additional specimens are listed in the appendix.

DISTRIBUTION.—Beaufort Sea, 35–189 m.

DESCRIPTION OF ADULT FEMALE (Figures 10–12).—Carapace oval in lateral view with prominent rostrum and small rounded caudal process (Figures 10, 11a–c).

Ornamentation (Figures 10, 11a–c): Lateral surface with prominent rib just within ventral margin terminating anteriorly in small anteroventral process, and terminating posteriorly on caudal process; a 2nd small process present on edge of anteroventral margin anterior to previously mentioned process; a 2nd rib just ventral to central adductor muscle attachments does not reach anterior margin of valve, and terminates posteriorly on distinct bulge of carapace; a 3rd rib dorsal to central muscle attachments terminates anteriorly as process extending past anterior edge of rostrum, and posteriorly joins an oblique rib terminating on caudal process (the oblique rib bears 2 weakly defined processes near its dorsal end) (Figure 10); a 4th rib lies just within the dorsal margin of valve; a 5th very faint rib located between the 3rd and 4th ribs terminates anteriorly on rostrum, and posteriorly does not reach valve midline. Surface of valve with abundant, weakly developed, round fossae; some specimens with reticulations encompassing several fossae in the posterodorsal part of the valve. Undivided bristles, some with broad bases, sparsely distributed over valve surface.

Infold (Figure 11a–c): Rostral infold with 6 or 7 bristles; 2 bristles present on valve edge medial to selvage at inner end of incisur; 1 small bristle present ventral to inner edge of incisur (Figure 11a); anteroventral infold with about 8 ridges and, also, 8 or 9 bristles forming row parallel to valve edge; infold along middle of ventral margin bare; posterior end of ventral infold and posterior infold in vicinity of caudal process with numerous slender bristles forming groups of up to 5 bristles (Figure 11b–c); infold of caudal process with narrow flap bearing 3 or 4 small bristles (Figure 11b,c): some bristles missing on illustrated specimen but represented by empty pores); edge of flap with faint, narrow, lamella prolongation; 1 small bristle present between shelf and valve edge (Figure 11b,c).

Selvage: Broad lamella prolongation with marginal fringe present along anterodorsal, anterior, and ventral margins of valve; lamella prolongation narrower and with minute fringe along posterior edge of valve and caudal process. Selvage divided at inner edge of incisur (Figure 10).

Size: USNM 157833, length 2.51 mm, height 1.81 mm; USNM 157835, length 2.58 mm, height 2.03 mm; USNM 157838, length 2.64 mm, height 1.78 mm; USNM 158425, length 2.54 mm, height 1.75 mm; USNM 158572, length 2.65 mm, height 1.81 mm.

First Antenna (Figure 12a): 1st joint with faint medial and lateral spines forming rows. 2nd joint spinous, with 3 bristles (1 ventral, 1 dorsal, 1 lateral). Short 3rd joint with few medial spines and 3 bristles (1 ventral, 2 dorsal). 4th joint spinous, with 6 bristles (4 ventral, 2 dorsal). Long 5th joint with few faint spines; sensory bristle with 7 short proximal filaments and 5 terminal filaments including tip of stem. 6th joint minute, fused with 5th joint; medial bristle with long proximal and short distal spines. 7th joint: a-bristle similar to bristle of 6th joint except with 2 wreaths of long proximal hairs; b-bristle about twice length of a-bristle, with 2 proximal and 4 terminal filaments; c-bristle about same length as sensory bristle of 5th joint, with 7 proximal and 5 terminal filaments. 8th joint: d-and e-bristles slightly longer than b-bristle, about same length as c-bristle, bare with blunt tips; f-bristle about same length as c-bristle, with 5 proximal and 5 terminal filaments; g-bristle same length as c-bristle, with 6 proximal and 5 terminal filaments.

Second Antenna: Protopodite bare. Endopodite 2-jointed (Figure 11d): 1st joint short, with 5 proximal bristles (1 longer than others) and 1 distal bristle; 2nd joint with 1 very long spinous proximal bristle, and 1 shorter terminal bristle. Exopodite: 1st joint with minute medial bristle on distal margin; bristles of joints 2–4 bare, fairly short but all reaching well past 9th joint; bristles of joints 5–8 broken; 9th joint with 7 bristles (3 long, stout, broken; 1 medium, broken, with few natatory hairs; 2 short with few long hairs; 1 very short, bare); joints 2–8 with slender spines forming row along distal margin, and with minute basal spine.

Mandible: Coxale with medial hairs and spines forming rows; minute bristle present near base of endite; endite bifurcate, hirsute proximally, pectinate distally. Basale: dorsal margin with 3 spinous bristles (1 distal to middle, 2 subterminal); medial surface hirsute, with 5 bristles (3 pectinate, unringed; 2 ringed with long proximal and short distal spines) in proximal ventral corner and 1 ringed spinous bristle closer to middle of joint; ventral margin with 8 spinous bristles (some with bases on medial surface near ventral margin). Exopodite hirsute, length about three-fourths length of dorsal margin of 1st endopodial joint, with 2 bristles bearing wreaths of long spines (distal outer bristle about three-fourths length of inner bristle). 1st endopodial joint with 4 ventral bristles bearing wreaths of long spines. 2nd endopodial joint: ventral margin with bristles forming 2 distal groups (3 bristles in each group); dorsal margin with 8 or 9 bristles near middle, some with bases on medial and lateral sides of joint; medial surface and proximal dorsal margin spinous. End joint with 3 bare claws (dorsal claw about two-thirds length of ventral claw; middle claw slightly shorter than ventral claw), and 4 ringed bristles.

Maxilla (Figure 11g): Precoxale and coxale with dorsal hairs; coxale with hirsute dorsal bristle. Endite I with 10 spinous and pectinate bristles; endites II and III narrow, with terminal bristles; endite III also with 1 proximal bristle. Basale with 3 bristles along distal margin (dorsal of these relatively small). Exopodite with 3 spinous bristles. 1st endopodial joint spinous, with 1 spinous alpha-bristle and 5 beta-bristles (bare or with few short spines). End joint: 3 bare a-bristles; 2 b-bristles (1 ringed and bearing small spines, 1 stout, unringed, claw-like, bare); 2 of the d-bristles stout, unringed, claw-like, bare; remaining c- and d-bristles slender, ringed, bristle-like.

Fifth Limb (Figure 12f–h): Endite I with about 5 spinous bristles; endite II with about 7 spinous bristles; endite III with about 9 spinous bristles. 1st exopodial joint: anterior margin with 2 spinous bristles at middle, and 1 bristle with long marginal hairs on lobe near outer edge (Figure 12g); main tooth with 4 constituent teeth consisting of 3 pectinate teeth and 1 proximal, smooth, pointed tooth; 1 spinous bristle proximal to pointed tooth (Figure 12f); distal, constituent tooth with proximal tooth-like process (Figure 12h). 2nd exopodial joint: large tooth with 1 small pointed tooth along inner margin (Figure 12f); distal outer corner of large tooth with minute posterior bristle (Figure 12g;) long proximal posterior bristle bare; outer of group of 3 posterior bristles short; inner bristle about two-thirds length of middle bristle, all bare (Figure 12f). 3rd endopodial joint: inner lobe with 3 bristles; outer lobe with 2 bristles. 4th and 5th joints fused, hirsute with total of 6 spinous bristles. Epipodial appendage with 51 bristles.

Sixth Limb (Figure 12b): Endite I with 3 spinous bristles; endite II with 1 proximal and 3 terminal spinous bristles; endite III with 1 proximal and 6–8 terminal spinous bristles; endite IV with 1 proximal and 6 or 7 terminal bristles. End joint with total of 30 spinous and hirsute bristles. Three bristles with long proximal hairs and short distal spines present in place of epipodial appendage.

Seventh Limb (Figure 12c,d): Terminus consisting of comb with 4–7 small teeth (some with few faint marginal spines) opposite 1 smooth peg. Each limb with 12–15 bristles, 6 in terminal group (3 on each side) and 5–8 in proximal group. The distribution of proximal bristles on both 7th limbs of 4 specimens is as follows.

Limb A Limb B

USNM 157833 7(4+3) 8(5+3)

USNM 157835 7(4+3) 5(3+2)

USNM 157838 7(4+3) 7(4+3)

USNM 158425 6(3+3) 8(4+4)

USNM 158460 6(3+3) 6(3+3)

Furca (Figure 11e,f): Each lamella with 12–15 claws (usually 14 or 15); claw 3 more slender than claw 4; left and right lamellae may have slightly different numbers of claws; teeth present along dorsal margin of all claws (teeth not shown on illustrated lamella); claws 6 to 12 or 15 with distal teeth along anterior margin; right lamella with medial hairs forming clusters near anterior margin, and positioned slightly anterior to left lamella (Figure 11f); hairs present at bases of some claws and on margin of lamella following claws. The number of claws on the left and right lamella of 5 specimens are as follows.

Left lamella Right lamella

USNM 157833 14 12

USNM 157835 15 15

USNM 157838 15 15

USNM 158425 14 13

USNM 158460 14 14

Bellonci Organ (Figure 12e,i): Elongate with about 18 sutures; minute spines observed in vicinity of sutures on some specimens; part distal to sutures generally same width and terminating in broadly rounded tip with 1–3 spines, but narrowing slightly near rounded tip on some specimens.

The morphology of the tips of 4 specimens is as follows.

USNM 157833 Narrowing to broadly rounded tip with 2 spines

USNM 157835 Broadly rounded with spine at tip

USNM 157838 Broadly rounded with 3 spines at tip

USNM 158425 Broadly rounded with spine at tip

Eyes: Medial eye with brown pigment, bare (Figure 12e,i). Lateral eye minute, with 2 small ommatidia (Figure 12j); lateral eyes not observed on all specimens.

Upper Lip (Figure 12e): Normal for genus, with small anterior process.

Anterior of Body (Figure 12e): Single rounded process between upper lip and medial eye.

Posterior of Body: A few minute spines forming rows in vicinity of posterodorsal corner.

Y-Sclerite: Normal for genus.

Eggs: USNM 157833, 158460, each with 12 eggs; USNM 157835 with 15 eggs; USNM 157838, 158425, each with 6 eggs.

DESCRIPTION OF ADULT MALE (Figures 13–15).—Carapace more elongate than that of the female and with more open incisur (Figure 13).

Ornamentation (Figure 13): Lateral surface with weakly developed ribs in posterior half; surface with faint minute fossae.

Infold and Selvage: Similar to that of female.

Size: USNM 158546, length 2.53 mm, height 1.41 mm.

First Antenna (Figure 14a): 1st joint bare. 2nd joint with medial spines forming rows and 3 spinous bristles (1 ventral, 1 dorsal, 1 lateral). 3rd joint with medial spines and 3 spinous bristles (2 dorsal, 1 lateral near ventral margin). 4th joint with medial spines and 5 or 6 spinous bristles (3–4 ventral, 2 dorsal). 5th joint minute, wedged ventrally between 4th and 6th joints, with stout sensory bristle bearing abundant long thin filaments on broad proximal half; distal end of bristle with 3 short marginal filaments and bifurcate tip. 6th joint about same length as 4th joint, with lateral spines and spinous medial bristle (missing on illustrated specimen). 7th joint: a-bristle short, spinous (slightly shorter than bristle on 6th joint); b-bristle with 4 marginal filaments and bifurcate tip; c-bristle very long, with about 14 marginal filaments. 8th joint: d- and e-bristles about same length as b-bristle, bare with blunt tips; f-bristle similar to c-bristle; g-bristle with 6 short, proximal, and 2 distal marginal filaments, and bifurcate tip.

Second Antenna (Figure 14b): Protopodite bare. Endopodite 3-jointed: 1st joint with 5 proximal bristles and 1 distal bristle; 2nd joint with 1 long spinous proximal bristle, and 3 or 4 short, spinous bristles near middle (spines on midbristles not shown on illustrated endopodite, Figure 14b); 3rd joint reflexed toward 2nd joint, with 1 bare proximal bristle, 2 or 3 short, bare, subterminal bristles, 4 minute sclerotized teeth on concave side distal to middle, and about 5 ridges at tip. Exopodite: 1st joint with minute medial bristle on distal margin; 2nd about one-third length of 1st joint and about one-half length of 3rd joint; bristle of second joint bare, reaching to about 8th joint; bristles of joints 3–8 long, with natatory hairs; 9th joint obscure on specimen examined, but with at least 5 bristles (3 long with natatory hairs, 2 short); joints 2–8 with spines forming row along distal margin; joints 3–8 each with short basal spine (basal spine of 8th joint sightly longer than others, about one-third length of 9th joint).

Mandible (Figure 14c): Coxale endite consisting of 2 stout spines bearing minute marginal spines; a small bristle with drawn-out tip present dorsal to spines. Basale: dorsal margin with 3 spinous bristles (1 distal to middle, 2 subterminal); medial surface hirsute, with 5 spinous bristles in proximal ventral corner, and 1 spinous bristle closer to middle of joint; ventral margin with 7 or 8 spinous bristles (some with bases on medial surface near ventral margin). Exopodite hirsute, length about two-thirds of dorsal margin of 1st endopodial joint, with 2 bristles with long spines (distal outer bristle about three-fourths length of inner bristle). 1st endopodial joint with medial spines and 4 or 5 ventral bristles. 2nd endopodial joint: ventral margin with bristles forming 2 distal groups (3 bristles in each group); dorsal margin with 9 bristles near middle, some with bases on medial and lateral sides of joint; medial surface spinous. End joint with 3 stout claws (medial claw slightly smaller than lateral claw, dorsal claw about two-thirds length of medial claw) and 4 ringed bristles.

Maxilla (Figure 15a): Limb reduced. Precoxale and coxale with dorsal hairs; coxale with hirsute dorsal bristle. Endite I broad, with numerous ringed bristles; endites II and III narrow, with numerous ringed bristles. Basale with 3 bristles along distal margin. Exopodite with 3 spinous bristles. 1st endopodial joint spinous, with 1 spinous alpha-bristle and 4 beta-bristles. End joint with 11 bristles (3 of these stouter than others).

Fifth Limb (Figure 15b,c): Endite I with 6 short bristles; endite II with about 7 bristles; endite III with 9–11 bristles. 1st exopodial joint with about 5 slender bristles and 2 finger-like, hirsute, terminal bristles. 2nd exopodial joint with several ringed bristles and 1 finger-like hirsute bristle. 3rd exopodial joint with 3 bristles on inner lobe and 2 stout hirsute bristles on outer lobe. 4th and 5th joints fused, hirsute, with total of 6 spinous bristles.

Sixth Limb (Figure 15d): Endite I with 3 spinous bristles; endite II with 1 proximal and 3 terminal spinous bristles; endite III with 1 proximal and 7 terminal spinous bristles; endite IV with 1 proximal and 6 terminal spinous bristles. End joint with total of 25 spinous and hirsute bristles. 3 spinous bristles in place of epipodial appendage.

Seventh Limb (Figure 14d): Terminus consisting of comb with 3 short teeth with faint marginal spines opposite 1 smooth peg. Each limb with 10 bristles, 4 in terminal group (2 on each side) and 6 in proximal group (2 to 4 on each side).

Furca: Each lamella with 13 claws; claw 3 more slender than claw 4; distribution of claws similar to those of female; medial hairs present at bases of claws; few hairs on lamella following claws; claw 1 of right lamella anterior to claw 1 of left lamella.

Bellonci Organ (Figure 14e): Elongate with about 14 sutures in middle part; tip pointed and with minute terminal spines.

Eyes (Figure 14e): Medial eye with brown pigment, bare. Lateral eye well developed, about twice size of medial eye, with black pigment obscuring number of ommatidia (about 19).

Upper Lip (Figure 14e): Normal for genus, with small anterior processes.

Posterior of Body: With long hairs forming row extending from posterior end of Y-sclerite to midheight of posterior end of body; minute spines in vicinity of posterodorsal corner.

Copulatory Organ: Consisting of 3 lobes on each side of body, with few bristles.

Y-Sclerite: Typical for genus.

COMPARISONS.—The new species, S. ruffi, differs from S. trituberculatus (Lucas, 1931) in having no more than 15 claws on the furca, and in the distal bristle of the 1st endopodial joint of the 2nd antenna of the female being about the same length as the shorter proximal bristles. Only 2 previously described species have the tip of the Bellonci organ of the female rounded: S. rectangularis Chavtur, 1983, and S. pavluchkovi Chavtur, 1983. The carapace of ruffi differs from that of rectangularis in having fewer bristles on the rostral infold (6 or 7 compared to 16–18) and in not having the lower horizontal lateral midrib bending ventrally to meet the ventral rib. The carapace of ruffi differs from that of pavluchkovi in not having a process at the anterior end of the lower horizontal midrib.

CYLINDROLEBERIDIDAE Müller, 1906

The family Cylindroleberididae comprises 3 subfamilies: Cylindroleberidinae Müller, 1906; Cyclasteropinae Poulsen, 1965; and Asteropteroninae Kornicker, 1981. Only the first subfamily was present in the Beaufort Sea.

CYLINDROLEBERIDINAE Müller, 1906

This subfamily is represented in the Beaufort Sea by 2 genera, Empoulsenia Kornicker, 1975, and Bathyleberis Kornicker, 1975.

Empoulsenia Kornicker, 1975

TYPE-SPECIES.—Asterope quinquesetae Skogsberg, 1920.

COMPOSITION.—Only 1 species, E. polythrix Chavtur, 1983, has been described previously from northern seas, whereas 4 species, E. quinquesetae (Skogsberg, 1920), E. pentathrix (Kornicker, 1971), E. antarctica Kornicker, 1975, and E. weddellensis Kornicker, 1975, have been described from southern oceans.

DISTRIBUTION.—Empoulsenia polythrix, according to Chavtur (1983:81), is widespread in the Northwest Pacific at depths of 85–2579 m; in the Sea of Japan (only in the subarctic), and Okhotsk and Bering seas at 300 m, but in adjacent Pacific (Kuril Islands, Kamchatka) at depths of 510–2570 m. The new species, E. monothrix, was collected only at 1 locality in the Beaufort Sea at a depth of 101 m. The 4 species reported in the southern oceans were collected south of 49°50′S at depths of 40–1212 m, but seldom at less than 200 m (Kornicker, 1975:501). The known localities of members of the genus suggest a bipolar distribution.