Rutiderma vox Kornicker 1991

Rutiderma vox

Rutiderma sp. Kornicker, 1987b:217, 218, fig. 1b.

ETYMOLOGY.—From Latin vox (voice, sound, call).

HOLOTYPE.—USNM 158309, ovigerous female on slide and in alcohol.

TYPE LOCALITY.—Enewetak lagoon (from composite sample).

PARATYPES.—Enewetak lagoon: Composite sample: USNM 158316, 1 adult male on slide and in alcohol; USNM 158314, 1 adult female and 1 adult male in alcohol. Midwater trawl off Bokandretok Island: USNM 193636, 2 ovigerous females and 3 adult males in alcohol. Sta A, plankton trap 6, sand substrate: USNM 193650, 1 adult male in alcohol.

DISTRIBUTION.—Enewetak Atoll.

DESCRIPTION OF ADULT FEMALE (Figures 39, 40a–d, 41).—Carapace with broadly curving anterodorsal and ventral margins; posterodorsal margin straight forming obtuse angle with vertical posterior margin (Figure 39). Each valve with lateral alate process terminating anteriorly at vertical rib and reaching posterior edge of valve only at posterodorsal corner. Short rostrum forming right angle with anterior margin of valve ventral to rostrum in lateral view (Figures 39, 40a). Caudal process short, triangular; process of right valve of holotype more slender than that of left (Figures 39, 40b,c).

Ornamentation (Figures 39, 40d): Carapace with 3 horizontal ribs: dorsal rib paralleling anterodorsal margin and with 6 radial riblets extending to valve edge (most ventral of the radial riblets extending onto rostrum); middle rib just dorsal to central adductor muscle and terminating posteriorly on dorsal corner of alate process; and ventral rib just ventral to central adductor muscle attachments and terminating posteriorly on ventral corner of alate process. Middle and ventral ribs connected anteriorly by vertical rib extending past ventral rib and terminating ventrally at anteroventral corner of valve. 6 radial riblets along ventral margin of valve not reaching ventral horizontal rib. Straight posterior edge of alate process with several minute processes projecting posteriorly. Small posteriorly pointing process at midlength of straight posterodorsal valve margin; small process at midheight of straight vertical posterior edge of left valve. Valve surface with abundant oval fossae with minute papillae along edge and at bottom (Figure 40d). Anterodorsal and ventral margins of valves with minute scallops. Edge of valves with long and short bristles, some long bristles with broad base (not shown), additional bristles sparsely distributed on valve surface.

Infold: Rostral infold with 8 bristles parallel to anterodorsal margin and 2 small bristles at inner end of incisur (Figure 40a); anteroventral infold with 10 bristles forming row parallel to valve edge, and 6 striae proximal to bristles (only 5 of these shown in Figure 40a); ventral infold anterior to caudal process with 10 small bristles, mostly along narrow list but some proximal to list. Infold of caudal process forming “pocket” with anterior lip (edge of lip is continuation of list) with 3 or 4 bristles (1 or 2 at dorsal end, 1 at midheight, 1 ventral) and narrow transparent vellum (Figure 40b,c,h); posterior infold dorsal to caudal process with 2 small bristles (Figure 40b).

Selvage: Lamellar prolongation divided at inner end of incisur and at ventral edge of caudal process on each side of small bristle (Figure 40b,c,h). Prolongation along anterior, anterodorsal, anteroventral selvages, and anterior part of ventral selvage with hirsute fringe along outer edge; fringe not observed elsewhere.

Carapace Size: USNM 158309, length 0.91 mm, height 0.67 mm. USNM 158314, length 0.91 mm, height 0.68 mm. USNM 193636, 3 specimens: length 0.90 mm, height 0.63 mm; length 0.91 mm, height 0.64 mm; length 0.95 mm, height 0.64 mm.

First Antenna (Figure 41a,b): 1st joint bare. 2nd joint with proximal dorsal hairs, lateral spines forming row in distal dorsal corner, dorsal bristle with short marginal spines, and distal spinous lateral bristle. 3rd joint short, fused to 4th joint, with 2 spinous dorsal bristles, and 1 spinous ventral bristle. 4th joint with 3 spinous bristles (2 ventral, 1 dorsal). Sensory bristle of long 5th joint with 2 short proximal dorsal filaments, 2 minute distal dorsal hairs, and terminal spine (not shown). 6th joint short, fused to 5th joint, with short spinous medial bristle. 7th joint short, with spinous a-bristle longer than bristle of 6th joint, b-bristle shorter than a-bristle (proximal 1/3 unringed, broad; and distal 2/3 narrower, ringed), and long c-bristle slightly shorter than sensory bristle of 5th joint, with short proximal filament, 2 minute distal hairs, and terminal spine (Figure 41b). 8th joint: d- and e-bristles bare with short blunt papilla at tips; f-bristle stout, with short proximal filament and terminal spine; g-bristle long, with fairly long proximal filament Right limb of USNM 158309 aberrant in having bristles only partly extruded as if ecdysis incomplete.

Second Antenna (Figure 41c): Protopodite bare. Endopodite 1-jointed with 3 or 4 small bare bristles. Exopodite: 1st joint with short bent medial spine on distal corner close to ventral margin; bristle of joint 2 reaching past 9th joint, with minute rounded spines along ventral margin; bristles of joints 3–5 longer than bristle of 2nd joint but much shorter than bristle of 6th joint, with rounded ventral spines similar to those of bristle of 2nd joint; joints 6–8 with long bristles with natatory hairs, no spines; 9th joint with 6 bristles (3 long and 1 short, all with natatory hairs, and 2 minute, bare); joints 2–5 with minute indistinct spines forming rows.

Mandible (Figure 41d): Coxale endite well developed, bifurcate with long slender and short stout spines. Basale: dorsal margin with 3 slender bristles; proximal ventral corner with 4 bristles (2 stout pectinate, 2 slender); medial side near ventral margin with 3 bristles. Exopodite absent. 1st endopodial joint triangular, with 2 short ventral bristles and long medial spines. 2nd endopodial joint: dorsal margin with 3 short proximal bristles; ventral margin with 2 minute a-bristles; terminal margin with small b-bristle in form of small round process with terminal spine, c-bristle in form of stout claw (with serrate dorsal margin, small proximal dorsal tooth, and tip with serrate inner margin), and 2 slender lateral d-bristles; medial surface with long spines on proximal half. 3rd endopodial joint: 3 slender medial a-bristles, b-bristle slender claw-like, and c-bristle stout claw-like with truncate tip.

Maxilla (Figure 41e): Endite I with 2 pectinate claws and 2 ringed spinous bristles; endite II with 2 pectinate claws and 4 ringed bristles; endite III with 3 pectinate claws, 2 distal ringed bristles, and 1 proximal ringed bristle. Coxale with short bare dorsal bristle. Basale with 3 distal bristles (1 dorsal spinous, 1 medial at joint midwidth, spinous, 1 ventral). Exopodite with 1 short and 1 long bristle. 1st endopodial joint with 1 spinous alpha-bristle and 1 spinous beta-bristle. 2nd endopodial joint with spines forming rows, 2 stout pectinate claws (inner claw longer), 2 short spinous bristles dorsal to claws, 1 short spinous bristle with base just medial to base of stout inner claw, and 2 spinous a-bristles.

Fifth Limb (Figure 41f–h): Epipodite with 34 hirsute bristles. Endite I with 3 short spinous bristles; endite II with spines forming row and 4–6 bristles; endite III with 4 bristles. 1st exopodial joint with 4 teeth (Figure 41f,g): proximal tooth small, smooth; 2nd to 4th teeth larger and with marginal cusps; 1 spinous bristle proximal to smooth tooth, and 1 longer bristle on margin adjacent to middle tooth. 2nd exopodial joint comprising large flat sclerotized tooth having 3 lobes along inner edge (Figure 41h), each lobe with 2 marginal teeth; posterior side of joint with 1 long proximal bristle and 2 shorter bristles at midlength. Inner lobe of 3rd exopodial joint with 3 bristles (2 spinous and 1 with widely separated marginal spines), outer lobe with 2 spinous bristles. Fused 4th and 5th exopodial joints with total of 4 spinous bristles.

Sixth Limb (Figure 41i): 1 short epipodial bristle. Endite I small with 3 bristles (2 short with long spines, 1 long with short spines); endite II small with 2 bristles (shortest with long marginal spines, other with short spines); endite III small, with 2 long bristles with few short marginal spines; endite IV small with 2 long bristles with indistinct short marginal spines. End joint with 7 bristles (3 long slender anterior bristles (with short marginal spines) on short quadrate lobe projection; following 2 bristles stout, hirsute proximally and with short spines distally; 2 posterior bristles stout, hirsute).

Seventh Limb (Figure 41j): Terminus with 6 bristles (3 dorsal, 3 ventral), distal bristle on each side with 2 bells, other bristles with 5, all with distal marginal spines (spines not shown); 4 bristles proximally (2 dorsal, 2 ventral), each with 3 bells and distal marginal spines. Tip with opposing indistinct combs (each tooth of comb with trifid tooth on each side, but number of teeth not resolved with certainty).

Furca (Figure 41k,n): Each lamella with 3 stout claws followed by 3 slender claws; claws 1–3 with distal ends slightly offset and without marginal teeth, and with tips rounded; tip of claws 4–6 pointed; anterior margins of claws 1–4 with few small hairs or spines; claw 1 with medial and lateral teeth along posterior margin, some lateral teeth longer than others; claw 2 with slender closely spaced teeth more numerous than on claw 1; claws 5 and 6 very slender and indistinct, trifurcate; claws 1–3 with long hairs forming row near base (not shown); anterior edge of each lamella with few short hairs; right lamella with long hairs near insertion of claw 1; long lateral hairs present on lamellae following claw 6; right lamella slightly anterior to left lamella.

Bellonci Organ (Figure 41l,m): Elongate with 2 sutures or creases delimiting short segment proximal to midlength, with minute spine on pointed tip.

Eyes: Medial eye unpigmented (light amber color), with short dorsal filaments; eye in lateral view with dorsal part projecting anteriorly (Figure 41l,m). Lateral eyes absent.

Upper Lip (Figure 41m): Simple, rounded.

Genitalia: Not observed.

Anterior of Body (Figure 41m): With rounded lobe at midheight.

Posterior of Body (Figure 41n): With hairs along posterior margin and low rounded lobe on posterodorsal corner.

Y-Sclerite (Figure 41n): Branching distally with dorsal branch more slender than ventral branch. Girdle with ventral end at Y-sclerite and dorsal end not reaching posterior margin of body.

Eggs: USNM 158309 with 1 well-developed egg (showing some partly developed appendages) in marsupium. USNM 193636, 2 specimens, each with 4 eggs in marsupium.

Gut Content: USNM 193636 (adult female) with large whole nematode coiled in gut with one end extending into esophagus.

DESCRIPTION OF ADULT MALE (Figures 40e–g, 42).—Carapace more elongate than that of female and with rostrum forming obtuse angle with anterior margin of valve ventral to rostrum (Figure 40e); each valve with alate process not extending anteriorly past midlength of valve. Caudal process triangular in lateral view.

Ornamentation: Valve surface with abundant oval fossae similar to those of adult female (Figure 40e); anterior edge of rostrum with minute scallops (Figure 40f). Edge of valves with long and short bristles, some long bristles with broad base; additional bristles sparsely distributed on valve surface.

Infold and Selvage (Figure 40f,g): In general, similar to those of adult female, except without striae on anteroventral infold proximal to bristles (Figure 40g).

Carapace Size: USNM 158316, length 1.00 mm, height 0.57 mm. USNM 158314, length 0.99 mm, height 0.57 mm. USNM 193636, 3 specimens, length 0.96 mm, height 0.60 mm; length 0.94 mm, height 0.55 mm; length 0.95 mm, height 0.58 mm.

First Antenna (Figure 42a): 1st joint with medial spines. 2nd joint with medial spines forming rows, lateral spines forming row near distal margin, 1 spinous dorsal bristle, and 1 slender distal lateral bristle. 3rd joint short, trapezoidal, with well-developed medial suture and less-developed lateral suture separating it from 4th joint, and 3 spinous bristles (1 ventral, 2 dorsal). 4th joint with 3 or 4 bristles (2 or 3 ventral, 1 dorsal). 5th joint small, wedged medially between 4th and 6th joints near ventral margin; sensory bristle with stout proximal part bearing numerous slender filaments at its tip (not all filaments shown) and stem with 2 minute proximal hairs; tip of stem missing on USNM 158316. 6th joint slightly longer than 4th joint, with short spinous medial bristle near distal ventral corner. 7th joint: a-bristle spinous, about same length as bristle of 6th joint; b-bristle about twice length of a-bristle, with 2 marginal filaments; c-bristle long, stout, with about 10 marginal filaments. 8th joint: d- and e-bristles about ¼ longer than b-bristle, bare with blunt tips; f-bristle similar to c-bristle; g-bristle about same length as e-bristle, with short proximal filament.

Second Antenna: Protopodite with tuft of short lateral hairs at dorsal distal corner near insertion of exopodile (not shown). Endopodite 3-jointed (Figure 42b): 1st joint short, with 5 small anterior bristles; 2nd joint elongate, with 2 small bristles near midlength; 3rd joint elongate, reflexed on 2nd, with 1 short proximal bristle and 2 minute slender subterminal bristles. Exopodite: 1st joint elongate with minute medial spine near middle of distal margin; length and width of 2nd joint equal, with long spines forming row along distal margin near dorsal edge, and bare ventral bristle (bristle not reaching distal end of 3rd joint); 3rd joint 2½ times length of 2nd joint; 4th to 9th joints decreasing in size distally along exopodite, and with combined length about ¼ length of exopodite; bristles of joints 3–8 long with natatory hairs, no spines; 9th joint of left limb of USNM 159316 aberrant (right limb of specimen missing), fused to 8th, with 1 short bristle with few subterminal natatory hairs, 1 long bristle with natatory hairs, and 1 long bristle bifurcating at 1/3 length of bristle, each distal branch with natatory hairs.

Mandible (Figure 42c): Coxale endite represented by small spine near midlength of joint. Basale: dorsal margin with bristles forming 2 groups near midlength (1 bristle in proximal group, 2 in distal group); medial surface with spines forming oblique rows (spines not shown), 3 short bristles in proximal ventral comer, and 2 short bristles near midlength of ventral margin. Exopodile finger-like, hirsute, with minute indistinct blunt process near tip (process not shown). 1st endopodial joint: medial surface spinous (spines not shown); ventral margin with 2 bristles near midlength. 2nd endopodial joint: medial surface spinous; dorsal margin with bristles forming 2 proximal groups (1 bristle in proximal group, 2 in distal); ventral margin with 2 a-bristles, 1 b-bristle, 1 c-bristle, and 2 smaller d-bristles. 3rd endopodial joint with 3 a-bristles, 1 b-bristle, and 1 stout c-bristle with ventral spines.

Maxilla (Figure 42d): Limb minute, indistinct, details difficult to resolve. Endites with weekly developed bristles, some with long spines. Coxale with slender bare dorsal bristle. Basale with 1 slender dorsal bristle and 1 slender bristle at midwidth. Exopodite small with 1 slender short bristle and 1 long hirsute bristle. 1st endopodial joint hirsute, with 1 slender alpha-bristle and 1 hirsute beta-bristle. 2nd endopodial joint hirsute, with 2 stout bristles (ventral longer) and 5 slender bristles.

Fifth Limb (Figure 42e): Limb reduced. Epipodite fragmented, with 25 hirsute bristles on remaining part (not shown). Endites I and II each with 3 small bristles; endite III with 3 slender bristles, 1 long stout ringed bristle, and 2 weakly developed unringed finger-like bristles. 1st exopodial joint with 3 short weakly developed finger-like bristles and 1 ringed bristle. 2nd exopodial joint with 3 finger-like bristles and 1 ringed bristle. 3rd exopodial joint with 3 weekly developed bristles on inner lobe and 2 ringed bristles on outer lobe. 4th and 5th exopodial joints fused, with total of 4 ringed bristles.

Sixth Limb (Figure 42f): 1 short epipodial bristle. Endite I with 3 short bristles; endite II with 1 short and 1 long bristle; endite III with 2 long bristles (distal twice length of other); endite IV with 2 long bristles. End joint with 6 bristles (2 long bristles on short quadrate lobe (anterior bristle with short spines, posterior bristle stouter, hirsute proximally and with short spines distally); following 2 bristles stout, hirsute proximally and with short spines distally; following 2 bristles stout hirsute).

Seventh Limb (Figure 42g): Terminus with 4 bristles (2 ventral, 2 dorsal), each with 4 bells and distal spines; 4 proximal bristles (2 dorsal, 2 ventral), each with 2 or 3 bells and distal spines. Tip with opposing combs, each with 3 minute teeth, middle tooth of each comb longer and bare, each lateral tooth of comb with few marginal spines.

Furca (Figure 42h): Lamellae and claws 1–3 more slender than those of female, claws 5 and 6 more distinct than those of female; all claws with slender teeth along posterior edges.

Bellonci Organ (Figure 42i): Similar to that of adult female.

Eyes: Lateral eye well developed with 15–18 divided amber-colored ommatidia; area between ommatidia also amber colored (Figure 42i). Medial eye about same size as lateral eye, without pigment, with short dorsal filaments (Figure 42i).

Upper Lip (Figure 42i): Similar to that of female.

Genitalia (Figure 42h): On each side of body elongate copulatory limb bearing minute processes and lobe with bristles.

Anterior of Body (Figure 42i): With broad anterior projection at midheight.

Posterior of Body (Figure 42h): With hairs along posterior margin and low rounded lobe on posterodorsal corner.

Y-Sclerite: Similar to that of female (Figure 42h). Girdle with ventral end at Y-sclerite and dorsal end reaching posterior margin of body (Figure 42h).

COMPARISONS.—R. vox differs from R. normani Poulsen, 1965, in not having a serrate list on the infold of the caudal process of the right valve, and from R. darbyi Kornicker, 1983c, in not having a serrate list on the infold of the caudal process of the left valve. The female R. vox differs from the female R. lomae (Juday, 1907) in having a longer caudal process, fewer bristles on the list of the caudal process, a shorter b-bristle on the 7th joint of the 1st antenna, an endopodite of the 2nd antenna without a minute bristle near middle of its margin, and a slightly stouter 4th claw on the furca. R. vox differs from R. judayi McKenzie, 1965, in not having a deep indentation at midheight of the posterior edge of the alate process on each valve. R. vox differs from R. gerdhartmanni Kornicker, 1975, R. chessi Kornicker and Myers, 1981, R. sterreri Kornicker, 1981a, R. arcuatile Kornicker, 1983c, R. cohenae Kornicker, 1983c, and R. kalkei Kornicker, 1983c, in having marginal teeth on the 3 lobes of the 2nd joint of the female 5th limb. The female R. vox differs from the female R. compressum Brady and Norman, 1896, R. rostratum Juday, 1907, R. leloeuffi Kornicker, 1975, and R. tridens Kornicker and Caraion, 1978, in not having a prolonged tip on the c-bristle of the 2nd endopodial joint of the female mandible. R. vox differs from R. hartmanni Poulsen, 1965, R. pax Kornicker, 1984, and R. licinum Kornicker, 1983c, in not having an upturned tip on the c-bristle (claw) of the 2nd endopodial joint of the female mandible. The list of the caudal process of the female R. vox is longer and more oblique man that of the female R. dinochelatum Kornicker, 1958.

SARSIELLIDAE Brady and Norman, 1896

COMPOSITION.—This family includes 2 subfamilies: Sarsiellinae Brady and Norman, 1896, and Dantyinae Kornicker and Cohen, 1978. Only Sarsiellinae are in the collection from Enewetak.

DISTRIBUTION.—The known latitudinal range of members of this family is 63°N and 73°29′S, and the known depth range is interudal to 4758 m (Kornicker and Caraion, 1980:2).

SARSIELLINAE Brady and Norman, 1896

COMPOSITION.—This subfamily comprises 13 genera including the new genus Metasarsiella proposed herein. Four genera are in the collection from Enewetak: Anscottiella, Eusarsiella, Ancohenia, and Metasarsiella.

DISTRIBUTION.—Same as for Sarsiellidae.