Rutiderma apex Kornicker & Harrison-Nelson 1997

Rutiderma apex

Rutiderma sp. Tuel et al., 1976:155.

ETYMOLOGY.—From the Latin apex (tip, top).

HOLOTYPE.—USNM 158263, undissected ovigerous female in alcohol.

TYPE LOCALITY.—Pillar Point Harbor, Half Moon Bay, California, Sta 9A (Dec).

PARATYPES.—Pillar Point Harbor: Sta 5A (Jun): USNM 194349, undissected adult male in alcohol. Sta 5C (Jun): USNM 194335, undissected adult male in alcohol. Sta 6A (Dec): USNM 194333, undissected specimen in alcohol (length 1.16 mm, height 0.80 mm); USNM 194334, adult male in alcohol with body removed and some appendages missing. Sta 6B (Jun): USNM 194332, 2 undissected adult females in alcohol. Sta 6C (Sep): USNM 194337, undissected ovigerous female in alcohol (length 1.18 mm, height 0.86 mm); USNM 194338, 3 undissected specimens (includes A–1 male) in alcohol. Sta 8B (Jun): USNM 194331, undissected adult female in alcohol; USNM 158264, adult male on slide and in alcohol; USNM 194336, 2 undissected ovigerous females in alcohol. Sta 9A (Dec): USNM 158262, ovigerous female on slide and in alcohol. Dark Gulch, Mendocino County, 29 Jan 1986: USNM 194339, ovigerous female with body removed from carapace, in alcohol; USNM 194340, 2 undissected juveniles in alcohol. Dark Gulch, Mendocino County, 12 May 1992: USNM 194341, 7 undissected specimens in alcohol (1 adult male, 1 ovigerous female, 3 adult females, 2 juveniles); USNM 194342, partly dissected adult male in alcohol. Tamales Bay: USNM 158269, 1 undissected ovigerous female in alcohol; USNM 194343, 78 undissected specimens in alcohol.

DISTRIBUTION.—California coast: Stations 5–9, Pillar Point Harbor, Half Moon Bay, depth range 1.8–5.2 m; Dark Gulch, Mendocino County, 39°14.5′N, 123°45.8′W, depth 9.1–11 m; Tomales Bay (detailed station data unavailable).

DESCRIPTION OF ADULT FEMALE (Figures 19–22).—Carapace oval in lateral view with convex ventral and dorsal margins, moderately well-developed incisur, small rostrum with slight overhang when viewed laterally, and small projecting caudal process with slightly rounded tip (Figures 19, 20) (projection of caudal process negligible in some specimens).

Ornamentation (Figures 19, 20): Each valve with 2 well-developed ribs (Figure 19): 1 above (rib 1) and 1 below (rib 2) central adductor muscle attachments; anterior ends of both ribs terminates at about valve length, upper rib slightly longer; posterior end of rib 1 terminates in small process just reaching (or just reaching past) posterior edge of valve, and a small projecting process present between posterior end of rib and valve edge; posterior end of rib 2 broadly rounded and joins a vertical rib that connects with posterior end of upper rib 1; vertical rib distinctly concave posteriorly and shape constant for species (Figure 20d,g,i–k). Many large irregular shallow fossae (much better developed in some specimens than in others) on surface between anterior ends of both ribs and the short vertical rib just posterior to incisur; valve surface ventral to rib 2 with large irregular shallow fossae (better developed in some specimens than in others); some specimens with few large irregular fossae between ribs 1 and 2. Dorsal end of the short vertical rib posterior to incisur bends anteriorly and intersects a 3rd rib lying just within anterodorsal and dorsal valve margins. Oblique posterodorsal margin of valve posterior to midlength fairly straight and with projecting triangular process near midlength (Figure 20a); this process appears as posterior end of 3rd rib on some specimens (Figures 19, 20b,c), but on most specimens 3rd rib appears to terminate anterior to triangular process (Figure 20a); this process better developed in some specimens than in others but observed on all specimens; process rarely with 2 or 3 adjacent nodes (Figure 20f). A 4th rib lies along ventral edge of valve (Figures 19, 20a); 6 or 7 short radial riblets (better developed in some specimens than in others) extend dorsally from 4th rib. Anterior end of 4th rib terminates anteriorly at anteroventral valve curvature (Figure 19); rib 4 near anterior end intersects the short vertical rib posterior to incisur (Figures 19, 20a). Posterior edge at midheight of each valve without small projecting process present on valves of Rutiderma judayi McKenzie, 1965 (Kornicker and Myers, 1981, fig. 17). Surface of valves including ribs and bottoms of large fossae with abundant minute round fossae. Undivided bristles very sparsely distributed on valve surface but more abundant (some with broad bases) along anterodorsal, anteroventral, and ventral margins. Anterodorsal and anteroventral margins, and anterior of ventral margin scalloped (Figure 19).

Infold: Rostral infold with 10 long bristles forming row parallel to anterior margin of rostrum (Figure 21a); 2 small bristles present at inner corner of incisur; anteroventral infold with row of 10 or 11 bristles (only 7 bristles and 2 sockets shown in Figure 21a). Anterior ridge of infold of caudal process more distinct at posterior end but visible to about valve length measured from dorsal end of valve, with 16 small bristles along edge (not all shown in Figure 21b); 1 small bristle in pocket posterior to posterior end of ridge, and row of 3 small bristles on infold dorsal to posterior end of ridge (Figure 21b).

Selvage: Wide lamellar prolongation present along anterior, posterior, and ventral margins; with hirsute fringe along anterior and ventral margins; prolongation divided at inner corner of incisur, and with indentation at bristle at tip of caudal process (detail in Figure 21b).

Central Adductor Muscle Attachments (Figure 20e): With 16 ovoid attachments.

Carapace Size (length, height in mm): Pillar Point Harbor: USNM 158262, 1.20, 0.87. USNM 158263, 1.25; 0.91. USNM 194331, 1.18, 0.90. USNM 194332, 2 specimens, 1.23, 0.89; 1.20, 0.89. USNM 194336, 1.25, 0.91. USNM 194337, 1.18, 0.86. Dark Gulch: USNM 194339, 1.15, 0.90. USNM 194341 (ovigerous female), 1.20, 0.94. Tamales Bay: USNM 158269, 1.21, 0.91.

First Antenna (Figure 21c): 1st joint with rows of minute medial spines. 2nd joint with 2 spinous bristles (1 lateral, 1 dorsal) and spines forming row along distal lateral margin and dorsal margin. 3rd and 4th joints fused; 3rd joint short with 3 spinous bristles (2 dorsal, 1 ventral); 4th joint long with 3 spinous bristles (1 dorsal, 2 ventral). 5th and 6th joints fused. Sensory bristle of long 5th joint with minute proximal filament. Medial bristle of minute 6th joint short spinous. 7th joint: a-bristle spinous, about same length as bristle of 6th joint; b-bristle almost twice length of a-bristle, bare; c-bristle about same length as sensory bristle of 5th joint, bare. 8th joint: d-and e-bristles about same length as c-bristle, bare with blunt tips; f-bristle about twice length of b-bristle, with short proximal filament; g-bristle about same length as c-bristle, with short proximal filament. Some bristles of 7th and 8th joints with spine at tip.

Second Antenna (Figure 21d): Protopodite bare: Endopodite single jointed with 4 short proximal anterior bristles. Exopodite: 1st joint with minute straight medial terminal bristle; bristle of 2nd joint reaching to about 9th joint, with row of minute blunt ventral spines and minute hook-like spine at tip; bristles of joints 3–5 longer but with similar ventral spines; bristles of joints 6–8 longer, with natatory hairs, but no spines; 9th joint with 6 bristles (3 long and 1 short with natatory hairs, 2 (dorsal) minute bare).

Mandible (Figure 21e): Coxale endite well developed, bifurcate, pectinate, with long hairs at base. Basale: dorsal margin with 3 bristles (1 at midlength, 2 just distal to midlength); medial surface near ventral margin with 4 proximal bristles (1 (proximal) long spinous, 2 short pectinate, 1 short bare), 1 near midlength minute, and 1 distal long. 1st endopodial joint with medial spines and 2 small ventral bristles. 2nd endopodial joint: medial surface spinous; dorsal margin with 3 short slender proximal bristles; ventral terminal margin with 2 short a-bristles, 1 small b-bristle with broad base, 1 stout claw-like c-bristle with proximal dorsal peg-like process, serrate dorsal margin, and curved tip, and 2 short lateral d-bristles. 3rd endopodial joint with 3 slender medial a-bristles, broad unringed b-bristle with perpendicular spines along edges, and stout claw-like terminal c-bristle with minute medial process near dorsal edge of curved tip.

Maxilla (Figure 22a,b): Endite I with 2 stout pectinate claws and 2 ringed spinous bristles (Figure 22a); endite II with 2 pectinate claws and 3 ringed bristles; endite III with 3 pectinate claws, 3 distal bristles, and 1 proximal ringed bristle. Precoxale and coxale with dorsal fringe of long hairs; coxale with ringed spinous dorsal bristle. Basale with 3 short distal ringed bristles (1 dorsal spinous, 1 medial with few spines, 1 ventral (ventral bristle shown in Figure 22b)). Exopodite with 2 bristles (1 short, 1 long) (Figure 22b). 1st endopodial joint with medial and dorsal spines, 1 spinous alpha-bristle and 1 spinous beta-bristle. 2nd endopodial joint with 2 terminal pectinate claws (inner of these stouter), and 5 short ringed spinous bristles (2 lateral a-bristles, 1 medial b-bristle proximal to inner terminal claw, 1 bristle on outer edge dorsal to outer terminal claw, and 1 slightly lateral bristle near base of inner terminal claw).

Fifth Limb: Epipodite with 37 bristles; proximal and distal bristles shorter than others. Endite I with 2 short ringed bristles; endite II with 6 bristles; endite III with 6 or 7 bristles (not all endite bristles shown in Figure 22c). Main tooth with 4 constituent teeth (Figure 22d): proximal tooth small smooth; 2nd to 4th teeth larger and with marginal teeth; 1 ringed bristle proximal to smooth tooth, and 1 ringed bristle on margin proximal to 4th tooth. 2nd exopodial joint consisting of large flat sclerotized tooth having 3 smooth lobes forming inner margin, 1 proximal ringed bristle on inner margin, and 2 smaller posterior ringed bristles near proximal lobe of inner margin of flat tooth (Figure 22e). Inner and outer lobes of 3rd endopodial joint each with 2 ringed bristles (Figure 22c). 4th and 5th exopodial joints fused, with total of 5 ringed bristles.

Sixth Limb (Figure 22f): With 2 epipodial bristles. Endite 1 with 3 bristles; endites II—IV each with 2 bristles. End joint with projecting anterior part broader than endite IV, with 3 terminal bristles; posterior part of distal margin of end joint with 4 bristles (posterior 3 plumose).

Seventh Limb (Figure 22g): With 4 proximal bristles, 2 on each side, each with 3 or 4 rings and marginal spines. Terminus with 6 bristles, 3 on each side, each with 2–5 bells and marginal spines; distal end of terminus with opposing combs, each with about 6 alate teeth.

Furca (Figure 22h): Each lamella with 4 primary claws followed by 2 secondary claws; claw 1 with lateral and medial rows of teeth along posterior edge, some teeth longer than others, and lateral teeth longer than medial teeth; claw 2 with lateral and medial rows of teeth smaller than those of claw 1; claws 3 and 4 with slender spines along posterior margin; secondary claws 5 and 6 with long slender spines along posterior edge (proximal spine stouter than others); claws 1 and 2 with long medial hairs near base; long hairs on lamellae between and following secondary claws; claw 1 with slender spines along anterior margin; claws 2 and 3 with few anterior spines; right lamella with spines along anterior margin (distal spines longer). Right lamella anterior to left by more than width of base of claw 1.

Bellonci Organ (Figure 22i): Elongate with broad, short, central part, and broadly rounded tip.

Eyes (Figure 22i): Lateral eye small with 4 amber-colored ommatidia. Medial eye bare with brown pigment (stippled).

Genitalia: Small amber-colored oval on each side of body anterior to Y-sclerite (Figure 22h). USNM 158262 with few spines in vicinity of genitalia (Figure 22h).

Upper Lip (Figure 22i): Simple lobe.

Posterior of Body (Figure 22h): With numerous spines.

Y-Sclerite: USNM 158262 with ventral branch weakly developed (Figure 22h).

Number of Eggs: USNM 158262 with 4 eggs in marsupium and several smaller unextruded eggs; length of 1 extruded egg 0.25 mm. USNM 158263, 194336, 194339, and 194340 each with 4 eggs in marsupium. USNM 194337 and 158269 with 3 eggs in marsupium. Ovigerous females were present in Pillar Point Harbor all 3 months that were sampled (Jun, Sep, Dec). An ovigerous female was also collected in May in Dark Gulch.

DESCRIPTION OF ADULT MALE (Figure 23–25a–f).—Carapace with posterior end of alar process similar to that of adult female (Figure 23); other ribs absent or subdued; surface with abundant minute round fossae similar to those of carapace of adult female (not shown).

Infold: Not examined.

Carapace Size (1ength, height in mm): Pillar Point Harbor: USNM 158264, 1.29, 0.79. USNM 194334, 1.28, 0.81. USNM 194349, 1.22, 0.75. Dark Gulch: USNM 194341, 1.30, 0.86. USNM 194342, 1.32, 0.85.

Central Adductor Muscle Attachments (Figure 24a,b): With 15–17 small ovoid attachments.

First Antenna (Figure 24c).—1st joint bare. 2nd joint with short spinous dorsal bristle distal to midlength, 1 distal lateral bristle, ventral spines, medial spines in ventral half, and distal lateral spines. 3rd joint well defined, shorter on medial side than on lateral side, with 3 bristles (1 ventral, 2 dorsal). 4th joint with 4 bristles (3 ventral, 1 dorsal). 5th joint small, wedged ventrally between 4th and 6th joints; sensory bristle with stout proximal part having obtuse distal end bearing numerous thin filaments, 1 small filament just distal to stout proximal part, 1 or more minute spines near midlength, and minute terminal spine. 6th joint with short spinous medial bristle near dorsal margin. 7th joint: a-bristle spinous, about same length as bristle of 6th joint; b-bristle about 3 times length of a-bristle, with 2 small proximal filaments and minute spine at tip; c-bristle extremely long, with 11 short filaments, each with 2 spines at tip. 8th joint: d- and e-bristles slightly longer than b-bristle, bare with blunt tips; f-bristle similar to c-bristle, g-bristle longer than b-bristle, with 1 or 2 short proximal filaments and minute spine at tip.

Second Antenna: Protopodite bare. Endopodite 3-jointed (Figure 24d): 1st joint small with 5 short anterior bristles; 2nd joint elongate with 2 small bristles near midlength; 3rd joint elongate, reflexed on 2nd joint, with short proximal bristle (bristle missing but socket visible on USNM 158264, and dashed bristle shown in Figure 24d drawn from right limb of USNM 194341) and 2 small subterminal bristles. Exopodite (Figure 24e): 1st joint elongate with minute straight medial spine on distal margin; 2nd joint short with 2 rows of long lateral spines along distal edge; ventral bristle of 2nd joint reaching 6th joint, with few proximal ventral spines followed by smaller spines in 6 linear sections (sections not well defined in Figure 24e); 3rd joint about twice length of 2nd joint, with spines along distal edge, and long ventral bristle with natatory hairs but no spines (Figure 24e); bristles of joints 4–8 with natatory hairs, no spines; joint 9 with 1 short bare medial bristle near dorsal edge and 4 long terminal bristles with natatory hairs.

Mandible Figure 24f): Coxale endite represented by 2 minute distal medial spines near midwidth. Basale: dorsal margin with 3 bristles; medial surface with 6 bristles near ventral margin and rows of spines. Exopodite finger-like, hirsute. 1st endopodial joint: medial surface spinous; ventral margin with 2 bristles. 2nd endopodial joint: medial surface spinous; dorsal margin with 3 proximal bristles; distal ventral margin with 2 slender spinous a-bristles, 1 small bare b-bristle, 1 spinous c-bristle, and 2 small d-bristles. 3rd endopodial joint with 3 or 4 small a-bristles (some with spines), 1 spinous b-bristle, and a stout claw-like spinous c-bristle.

Maxilla (Figure 25a): Limb extremely small, details difficult to resolve. With 3 endites: I with 5 bristles; II with about 4 bristles; III with about 6 bristles. Precoxale and coxale with fringes of long hairs. Basale with 2 spinous distal bristles (1 ventral, 1 dorsal). Small exopodite with 2 bristles (1 long, 1 short, both with indistinct hairs). 1st endopodial joint with 1 alpha-bristle with few spines and 1 hirsute beta-bristle. 2nd endopodial joint with 1 long bristle with long proximal hairs and 6 shorter bristles.

Fifth Limb (Figure 25b): Epipodite with about 31 spinous bristles. With 3 endites: I with 3 or 4 ringed bristles; II with 5 ringed bristles; III with 6 or 7 ringed bristles. 1st exopodial joint with 2 ringed bristles and 3 weakly developed unringed bare finger-like bristles. 2nd exopodial joint with 3 ringed bristles (not shown) and 3 bare finger-like bristles. 3rd exopodial joint with 3 short bare ringed bristles on inner lobe, and 2 stout ringed hirsute bristles on outer lobe. Fused 4th + 5th joints with 4 bare ringed bristles.

Sixth Limb (Figure 25c): With 1 epipodial bristle. Endite I with 3 small bristles; endite II with 2 bristles (1 long, 1 short); endites III and IV each with 2 long bristles. End joint with projecting anterior part (broader than endite IV but with similar amount of projection) with 3 terminal bristles with short spines; posterior part of distal margin of end joint with 4 broad bristles with long hairs.

Seventh Limb (Figure 25d): With 3 proximal bristles, 1 on one side, 2 on other side, each with 3 bells and marginal spines. Terminus with 4 bristles, 2 on each side with 3–6 bells and marginal spines. Tip of terminus with opposing combs, each with 3 alate teeth. (Marginal spines of bristles not shown.)

Furca: Distribution of claws similar to those of adult female. Claws 1 and 2 more elongate than those of female.

Bellonci Organ (Figure 25e): Similar to that of adult female.

Eyes: Medial eye similar to that of adult female but with black pigment (stippled) (Figure 25e). Lateral eye large with 16 amber-colored ommatidia, with black pigment between ommatidia (stippled) (Figure 25e,f).

Genitalia: Indistinct lobes.

Upper Lip (Figure 25e): Simple lobe.

Anterior of Body (Figure 25e): With broad anterior process.

Posterior of Body: With few spines dorsal to dorsal end of girdle.

Y-Sclerite: Obscured on USNM 158264.

DESCRIPTION OF A–1 MALE (Figure 25g).—Carapace similar in shape to that of adult female.

Carapace Size (mm): USNM 194338, length 1.15, height 0.76.

EPIZOA.—Stemmed protistans, which were abundant on the carapaces of Euphilomedes carcharodonta and E. morini, were absent on the carapaces of 30 specimens (males, females, and juveniles) examined.

COMPARISONS.—The surface ornamentation of R. apex resembles that of R. judayi McKenzie, 1965, except the female is without a small process near the middle of posterior margin that projects past posterior end of valve. The length of the female carapace of R. judayi is 0.95–1.05 mm, compared to 1.18–1.25 mm for R. apex. The rostral infold of the female R. judayi bears a row of 7 bristles compared to 10–12 on R. apex. The vertical rib at the posterior end of the alar process on the carapace of the female R. lomae (Juday, 1907) has a space near middle (Figure 26b), whereas it is continuous on R. apex (Figure 26a), and R. lomae is larger (Figure 26). Adults males of R. lomae and R. apex are difficult to separate, except the middle part of the vertical rib of the carapace of R. apex does appear to be better developed (see Kornicker and Myers, 1981:15, for R. lomae). The caudal process of the carapace of the female R. chessi Kornicker and Myers, 1981, projects farther than that of R. apex, the c-bristles of the 2nd and 3rd endopodial joints of the mandible are more elongate, and the Bellonci organ has a pointed rather than a rounded tip. The ridges of the carapace of the female R. rostratum Juday, 1907, are less well-defined than those of R. apex, and the c-bristle of the 2nd endopodial joint of the female mandible of R. rostratum has a long produced tip that is absent on R. apex. The ribs of the carapace of R. apex resemble those of R. hartmanni Poulsen, 1965, from the Gulf of Panama, but the carapace of R. apex is slightly larger and the caudal process has less posterior projection; the anterior ridge of the infold of the caudal process is more concave posteriorly on R. hartmanni, and the c-bristle of the 2nd endopodial joint of the female mandible of R. hartmanni bears a small terminal extension that is absent on R. apex. The lateral ribs of R. rotundum Poulsen, 1965, are evenly rounded posteriorly, not indented like the vertical rib of R. apex, and each lamella of the furca of R. rotundum bears 3 primary claws compared to 4 on R. apex.

CYLINDROLEBERIDIDAE Müller, 1906

The family contains three subfamilies: Cylindroleberidinae Müller, 1906, Cyclasteropinae Poulsen, 1965, and Asteropteroninae Kornicker, 1981. All subfamilies have been reported from the Californian coast (Kornicker, 1981), but only the first and last were collected in Pillar Point Harbor. The last subfamily is represented by Asteropella slatteryi Kornicker, 1981. Specimens of this species collected in Pillar Point Harbor were part of the type series in the original description (Kornicker, 1981:260), and no supplementary description is present herein.

CORRECTION.—Kornicker (1981:97) stated that specimens of Leuroleberis sharpei Kornicker, 1981, USNM 13107, from San Diego Bay, California, which were reported by Sharpe (1908:425), could not be located. In the present study a slide (in poor condition) with that number and containing appendages of that species, as well as a vial with that number containing two specimens (bodies removed from shell) of that species in alcohol, were found in the collection of the National Museum of Natural History; both are incorrectly labeled “Cylindroleberis oblonga Grube, San Diego Bay, Calif. From H. Hemphill (4).”

CYLINDROLEBERIDINAE Müller, 1906

This subfamily has 16 genera of which three have been reported off the Californian coast: Bathyleberis Kornicker, 1975a, Parasterope Poulsen, 1965, and Postasterope Kornicker, 1986.

Postasterope Kornicker, 1986

This genus contains four species of which only P. barnesi (Baker, 1978) has been reported from the Californian coast.

DISTRIBUTION.—This genus has been reported from Florida, Bahamas, West Indies, and California at depths of 1–401.4 m (Kornicker, 1986:96).