Eusarsiella absens (Kornicker 1981)

Eusarsiella absens (Kornicker, 1981)

Sarsiella absens Kornicker, 1981a:2, figs. 1, 2.

HOLOTYPE.—USNM 158116, adult female on slide and in alcohol.

TYPE-LOCALITY.—Castle Harbor, Bermuda.

MATERIAL.—None.

DISTRIBUTION.—Bermuda, in shallow water (Table 1).

DIAGNOSIS.—Carapace of female oval in lateral view with truncate posterior; posteroventral corner rounded; horizontal rib present below central adductor muscle attachments; a second rib extending onto posterodorsal bulge; surface with abundant well-developed fossae; few bristles present on lateral surface (Figure 25).

Size: Length 1.17–1.22 mm (3 specimens).

First Antenna: Second joint with 1 dorsal bristle; third joint without ventral bristle; fourth joint with 3 ventral bristles.

Second Antenna: Endopodite with single proximal anterior bristle and bare ventral margin.

Seventh Limb: Proximal group with 4 bristles, 2 on each side.

Eusarsiella absens (Kornicker, 1981)

Sarsiella absens Kornicker, 1981a:2, figs. 1, 2.—Maddocks and Kornicker, 1986:283, pl. 90.

Eusarsiella absens.—Kornicker, 1986a:46 [key], 54, fig. 25, tables 1, 4.

HOLOTYPE.—USNM 158116, adult female.

TYPE LOCALITY.—Castle Harbor, Bermuda.

MATERIAL.—Harrington Sound, collected 1980–1981: USNM 193401, 1 adult male; USNM 193402, 3 adult males; USNM 193403, 15 ovigerous females, 4 adult females without eggs, 5 juveniles.

DISTRIBUTION.—Bermuda: Castle Harbor (Kornicker, 1981a:2), Harrington Sound.

DESCRIPTION OF ADULT MALE (Figures 14–16).—Carapace elongate with distinct rostrum in lateral view and shallow incisur; caudal process forming right-angle (Figure 14).

Ornamentation (Figure 14, 15b): Carapace with 2 horizontal ribs: ventral rib broad over central adductor muscle attachment area, becoming narrow posteriorly, and terminating near caudal process (Figure 14); dorsal horizontal rib terminating at posterodorsal corner of valve and joining indistinct vertical rib just anterior to valve midlength; ventral end of vertical rib joining anterior end of ventral rib. Long bristles, some with broad basal part, abundant along anterior and ventral margins and along edge of caudal process (Figure 15b), but very sparse on lateral surface. No gelatinous coating on valves. Valves weakly calcified; USNM 193401 with oval plate-like concretions within shell.

Infold: Anterior infold with 1 minute bristle just ventral to valve midheight (Figure 15a); midwidth of infold of caudal process with 6 small bristles forming row (Figure 15b); 9 small bristles forming row along inner edge of infold anterior to caudal process and posterior valve edge; 2 setal bristles on infold dorsal to caudal process.

Selvage: Broad lamellar prolongation without marginal fringe present along anterior, ventral, and posterior margins of each valve.

Carapace Size: USNM 193401, disarticulated valves: left valve, length 1.04 mm, height 0.71 mm; right valve, length 1.02 mm, height 0.68 mm. USNM 193402, 3 specimens: length 1.09 mm, height 0.77 mm; length 1.06 mm, height 0.76 mm; length 0.96 mm, height 0.65 mm. (Slightly smaller than 3 females described in Kornicker (1981a:3), which range in length from 1.17 to 1.22 mm.)

First Antenna (Figure 15c): 1st joint bare. 2nd joint with dorsal bristle with long proximal marginal spines. 3rd joint fused to 4th joint, with long dorsal bristle and no ventral bristle. 4th joint with short dorsal bristle and 2 long, slender, ventral bristles. 5th joint wedged ventrally between 4th and 6th joints; stem of sensory bristle with 4 distal marginal filaments and bifurcate ti p. 6th joint long, with small medial bristle (length about equal to width of joint near dorsal margin. 7th joint: a-bristle bare, slightly shorter than length of 6th joint; b-bristle about twice length of a-bristle, with distal marginal filament and bifurcate tip; c-bristle long, with 5 marginal filaments and bifurcate tip. 8th joint: d- and e-bristles long, bare, with blunt tips; f-bristle long, with 4 distal marginal filaments and bifurcate tip; g-bristle long, with 5 short distal filaments and bifurcate tip.

Second Antenna (Figure 15d): Protopodite bare. Endopodite 2-jointed: 1st joint with medial spines forming rows, and 1 short, proximal, anterior bristle; 2nd joint short, with 2 terminal bristles. Exopodite: 1st joint with small, terminal, medial bristle forming right angle; bristles of joints 2–8 long, with ventral spines proximal to middle (spines on bristles of joints 2–4 stouter than on bristles of joints 5–8) and distal natatory hairs; small 9th joint with 2 bristles (dorsal bristle short; ventral bristle long with proximal ventral spines and distal natatory hairs).

Mandible (Figure 15e–g): Coxale: endite comprising a small spine (Figure 15f); lateral side near distal ventral corner with 4 minute spine-like processes (Figure 15e) (not previously reported on Sarsiellidae). Basale: dorsal margin with 3 distal bristles; ventral margin with 2 short bristles near midlength; medial surface with 4 bristles (3 forming group near proximal ventral corner; 1 closer to midlength; tips of bristles knife-like). Exopodite short, hirsute (Figure 15f). 1st endopodial joint: medial surface with long proximal hairs and shorter distal spines forming rows; ventral margin with 2 short bristles; dorsal margin with distal spines forming rows. 2nd endopodial joint: ventral margin with long terminal bristle; dorsal margin with small spines, and short bristle distal to midlengh; medial and lateral surfaces with spines forming rows. End joint with stout claw-like bristle (with proximal medial spines forming row), 1 short ventral bristle, and 2 minute medial bristles near base of claw-like bristle (Figure 15g).

Maxilla (Figure 16a): Extremely reduced. Coxale with short dorsal bristle. Exopodite with 2 ringed bristles. Endites with weakly developed bristles, some hirsute. Basale with short dorsal bristle and long ventral bristle. No suture observed separating 1st and 2nd endopodial joints. (Bristles of illustrated limb indistinct, endites and not all bristles shown.)

Fifth Limb (Figure 16b): Epipodite of illustrated limb with 27 bristles but several may be missing. Single endite with 1 short bristle. Exopodite reduced: 1st joint with 2 bristles. 2nd–5th joints not well defined, with total of 7 bristles.

Sixth Limb (Figure 16d): Single endite with 3 bristles (2 minute, 1 longer). End joint with 11–13 bristles forming 2 rows (medial row with 4 bristles with long proximal and short distal spines; lateral row with 7–9 plumose bristles) closely followed by 2 plumose bristles; limb hirsute.

Seventh Limb (Figure 16c): Minute, bare.

Furca (Figure 16e): Furca with 5 claws (claw 1 fused to lamella) followed by several minute spines.

Bellonci Organ (Figure 16f): Elongate, with weak suture near middle and rounded tip.

Eyes (Figure 16f,g): Medial eye with dark amber pigment. Lateral eye with dark amber pigment and 9–10 ommatidia.

Upper Lip (Figure 16f): In lateral view not projecting anteriorly, with crenulations anterior to mouth.

Genitalia (Figure 16h): Elongate copulatory organ on each side of body terminating in sclerotized hook; lobes proximal to hook with small bristles.

Anterior of Body (Figure 16f): Broadly rounded with projecting convex process at midlength.

Y-Sclerite: Similar to that of female.

Sarsiella absens

ETYMOLOGY.—The specific name is from the Latin absens (away from, absent) in reference to the lack of a ventral bristle on the 3rd joint of the female 1st antenna of this species.

HOLOTYPE.—USNM 158116, adult female on slide and in alcohol.

TYPE-LOCALITY.—Castle Harbor, Bermuda.

PARATYPES.—USNM 158114, 1 adult female and USNM 158291, 1 ovigerous female, both from same sample as holotype; USNM 158290, 1 juvenile from station 630827(1) Castle Harbor.

DESCRIPTION OF ADULT FEMALE (Figures 1, 2).—Carapace oval in lateral view with short rounded caudal process; posterodorsal part of each valve forming large bulge (Figure 1).

Ornamentation (Figures 1, 2a,k,l): Each valve with 2 more-or-less horizontal ribs: 1 extending onto posterodorsal bulge, other below bulge; anterior part of valves with weakly developed radiating ribs (Figure 1). Surface with numerous well-developed fossae (Figures 1, 2a); surface between fossae and also inside of fossae with minute papillae. Anterior and ventral margins, and margin of caudal process with long bristles (Figure 2k,l); bristles very sparsely distributed on lateral surface of valve (Figure 2a). No gelatinous coating on valves.

Infold (Figure 2k,l): 1 minute bristle present near inner edge of infold near middle of anterior edge of valve (Figure 2k); infold of caudal process with 8 or 9 small bristles (Figure 2l); additional smaller bristles present along inner edge of infold (Figure 2l); 2 setal bristles present on posterior infold dorsal to caudal process.

Selvage: Wide lamellar prolongation without marginal fringe present along anterior, ventral, and posterior margins of each valve.

Size: USNM 158116, length 1.17 mm, height 0.97 mm; USNM 158114, length 1.17 mm, height 1.02 mm; USNM 158291, length 1.22 mm, height 1.01 mm.

First Antenna (Figure 2b): 1st joint bare. 2nd joint with single dorsal bristle bearing few spines. 3rd and 4th joints fused; 3rd joint short, with short spinous dorsal bristle and no ventral bristle; 4th joint long, with single dorsal bristle with few spines, and 3 ventral bristles of different lengths. Sensory bristle of long 5th joint with minute proximal filament and spine at tip. Minute 6th joint with small medial bristle. 7th joint: a-bristle about twice length of bristle of 6th joint, with faint marginal spines; b-bristle about one-third longer than a-bristle, bare; c-bristle slightly longer than sensory bristle of 5th joint, with minute proximal filament and spine at tip. 8th joint: d-and e-bristles bare with blunt tips; d-bristle stouter and about one-third longer than e-bristle, only slightly shorter than c-bristle; f-bristle only slightly shorter than d-bristle, with 1 minute proximal filament and spine at tip; g-bristle slightly longer than f-bristle, with 2 minute proximal filaments and spine at tip.

Second Antenna (Figure 2c): Protopodite bare. Endopodite 1-jointed with 1 short spinous anterior bristle and small process near middle of ventral edge. Exopodite: long 1st joint with small medial terminal bristle with blunt tip; bristle of 1st joint long, with about 20 stout proximal ventral spines followed by natatory hairs; bristles of joints 3–8 with stout ventral spines and distal natatory hairs; 9th joint with 2 bristles (1 long with faint proximal ventral spines and distal natatory hairs, 1 short with faint slender marginal spines), joint small (width about half that of width of 8th joint).

Mandible (Figure 2d): Coxale endite consisting of stout spine; ventral margin of coxale spinous with distal spines stouter than hairlike proximal spines. Basale: dorsal margin with 1 spinelike bristle distal to middle and 2 subterminal bristles; medial side with 3 short proximal bristles near ventral margin; ventral margin with 1 spinelike bristle distal to middle; lateral side with 2 distal bristles near ventral margin. 1st endopodial joint with medial spines, 1 minute spinelike medial bristle near base of stout terminal claw; terminal claw with few minute proximal teeth on each margin. 2nd endopodial joint with 2 minute spinelike dorsal bristles and stout ventral claw. 3rd endopodial joint with stout terminal claw and 3 minute spinelike bristles at base, 2 ventral, 1 dorsal; tips of stout terminal claws of endopodial joints tapering to point.

Maxilla (Figure 2e): Typical for genus. Exopodite with 3 bristles (longer of these spinous and slightly more than twice length of 2 other bare bristles).

Fifth Limb (Figure 2f): Single endite with 1 small bristle. Exopodite: 1st joint with 2 spinous bristles; remaining joints fused; 2nd joint with 3 spinous bristles; joints 3–5 with total of 4 bristles.

Sixth Limb (Figure 2g): Single endite with 2 or 3 bristles. End joint with 12 spinous bristles followed by space and then 2 broad hirsute bristles.

Seventh Limb (Figure 2h): Proximal group with 4 bristles, 2 on each side; terminal group with 6 bristles, 3 on each side; each bristle with up to 8 bells. Terminus with opposing combs, each with 6–9 recurved teeth.

Furca (Figure 2i): Each lamella with 5 slender, pointed claws; claw 1 fused to lamella, remaining claws separated from lamella by suture; claws 1–4 with large and small teeth along posterior margin; several minute spines following claw 5.

Bellonci Organ (Figure 2j): Elongate with suture near middle and weakly segmented proximally, tip rounded.

Eyes (Figure 2j): Lateral eye with 5 ommatidia, pigmented light amber. Medial eye about same size as lateral eye, bare, pigmented light amber.

Upper Lip: Helmet shaped, typical for genus.

Genitalia (Figure 2m): Oval sclerotized ring on each side of body.

Y-Sclerite (Figure 2m): Typical for genus.

COMPARISONS.—The new species Sarsiella absens differs from previously described species of Sarsiella that have a short rounded caudal process in not having a ventral bristle on the 3rd joint of the female 1st antenna. The endopodite of the 2nd antenna of the female differs from many species of the genus in having only 1 proximal anterior bristle and in not having a ventral spine or bristle.

RUTIDERMATIDAE Brady and Norman, 1896

Rutiderma Brady and Norman, 1896