Eusarsiella costata (Kornicker 1958)

Eusarsiella costata (Kornicker, 1958)

Sarsiella costata Kornicker 1958:251, figs. 47:4A,B, 80A–E, 81 A–E, 88B,C,G.

Eusarsiella costata.—Poulsen, 1965:83.

HOLOTYPE.—USNM 122912, dry specimen, length 1.02 mm, (Kornicker, 1958:252, number 156–2).

TYPE-LOCALITY.—Bimini Islands, Bahamas.

MATERIAL.—Holotype; in addition, see “Station Data with Specimens Examined.”

DISTRIBUTION.—Bahamas at depths of 1–5 m (Figure 1, Table 1).

SUPPLEMENTARY DESCRIPTION OF ADULT FEMALE (Figures 31, 32).—Carapace oval in lateral view except for truncate posterior (Figures 31, 32a); anterior and ventral margins extending past valve edge.

Ornamentation (Figures 31, 32a): Each valve with oval ridge, broad and rounded anteriorly but becoming narrow posterodorsally; posterior tip of ridge may extend slightly past valve edge; oblique rib branching dorsally from ventral part of oval ridge and terminating just ventral to central adductor muscle attachments. Posterior margin of each valve with 2 low processes extending slightly past valve edge. Valve surface with numerous large fossae with irregular margin (just a few shown in Figure 32a). Bristles present along anterior and ventral margins, and very sparsely distributed on lateral surface. Surface not coated by gelatinous substance.

Infold (Figure 32b): Anterior infold with minute bristle near middle of valve; infold of caudal process with 12 or 13 small bristles (a few of these branching distally); 2 setal bristles present on posterior infold just dorsal to middle of margin (Figure 32b); several minute bristles present along inner edge of infold in vicinity of caudal process.

Selvage: Broad lamellar prolongation with smooth outer edge present along free margin of each valve.

Size: USNM 158334, length 1.18 mm, height 1.01 mm; USNM 157880 (3 specimens), length 1.19 mm, height 0.99 mm, length 1.14 mm, height 0.95 mm, length 1.16 mm, height 0.96 mm; USNM 158332, length 1.18 mm, height 0.98 mm.

First Antenna (Figure 32c): First joint bare. Second joint with few dorsal spines, and 1 dorsal bristle having long hairs near middle. Third and fourth joints fused; third joint with 2 bristles (1 ventral, 1 dorsal); fourth joint with 4 bristles (1 dorsal, 3 ventral). Bristle of fifth joint with 1 minute proximal filament and 1 minute distal spine. Sixth joint fused with fifth with short medial bristle. Seventh joint: a-bristle about twice length of bristle of sixth joint; b-bristle longer than a-bristle, with minute distal filament or spine; c-bristle slightly longer than bristle of fifth joint, with 1 or 2 minute proximal filaments. Eighth joint: d- and e-bristles bare with blunt tips; d-bristle slightly longer than f-bristle, shorter than c-bristle; e-bristle more than one- half, but less than two-thirds, length of d-bristle; f-bristle stout, shorter than c-bristle, without marginal filaments; g-bristle slightly shorter than c-bristle, with 2 minute filaments near middle; bristle of fifth joint, b- and c-bristles of seventh joint, and f- and g-bristles of eighth joint with minute terminal spine.

Second Antenna (Figure 32d): Protopodite bare. Endopodite single jointed with 1 proximal anterior bristle, 1 minute terminal spine with tip drawn out (could be interpreted as unringed bristle) and spines of different widths forming several rows on medial surface (Figure 32d). Exopodite: first joint with minute, terminal, medial bristle; bristles of joints 2–8 with proximal ventral spines and distal natatory hairs; ninth joint with 2 bristles (ventral bristle with proximal spines and distal natatory hairs, dorsal bristle short, bare); basal spines absent; joints 3–7 with few minute spines along distal dorsal corner.

Mandible (Figure 32e): Coxale: endite consisting of stout spine with few faint marginal spines; ventral margin with stiff hairs. Basale: dorsal margin with spine-like midbristle, and 2 small terminal bristles; 5 small bristles present near ventral margin. First endopodial joint: medial surface with stout spines; ventral claw with few proximal ventral spines. Second endopodial joint with faint dorsal bristle and stout ventral claw. End joint with stout terminal claw and 2 minute bristles (1 ventral, 1 dorsal).

Maxilla (Figure 32f–h): Three endites with claws and bristles (Figure 32g). Coxale with short dorsal bristle; precoxale and coxale with fringe of long hairs near dorsal margin. Basale with 1 bristle near exopodite (Figure 32f). Exopodite with 3 bristles (middle bristle longer than others; (Figure 32h). Endopodite: first joint with pectinate alpha- and beta-bristles; second joint with 2 bare a-bristles, 1 c-bristle, and usual 5 pectinate end bristles.

Fifth Limb (Figure 32i): Epipodial appendage with 33 bristles. Single endite with 1 short bristle. Exopodite: first joint with 2 spinous bristles; second joint with 3 spinous bristles; third to fifth joints fused (third joint with 3 short bristles on inner lobe and 1 bristle on outer edge of fused joints; fourth and fifth joints with total of 2 spinous bristles).

Sixth Limb (Figure 32j): Single endite with 3 bristles. End joint with 11 or 12 bristles with short marginal spines followed by space and then 2 stout hirsute bristles.

Seventh Limb (Figure 32k): Six bristles in terminal group (3 on each side); 4 bristles in proximal group (2 on each side); each bristle with up to 6 bells (diameter of terminal bell very small). Terminus consisting of opposing combs, each with 3 recurved teeth (only 2 teeth shown in each comb of illustrated limb).

Furca (Figure 32l): Each lamella with 5 slender pointed claws; claw 1 fused to lamella, re- maining claws separated from lamella by suture; right lamella slightly anterior to left lamella, and with minute pointed process following posterior claw; left lamella with 4 pointed processes following posterior claw; posterior margins of claws with teeth forming row; long teeth interspersed with shorter teeth on claws 1–3.

Bellonci Organ (Figure 32m): Elongate, broadening distally, with rounded tip.

Eyes (Figure 32m): Medial eye bare, with light brown pigment. Lateral eye slightly smaller than medial eye, with light brown pigment and 5 ommatidia.

Upper Lip: Typical for genus.

Posterior of Body (Figure 32l): Bare.

Genitalia (Figure 32l): Oval sclerotized ring on each side of body anterior to furca.

Y-Sclerite (Figure 32l): Dorsal branch of USNM 158334 tending to have faint dorsal branch at tip.

Eggs: USNM 158334 with 4 eggs in marsupium and additional smaller unextruded eggs. USNM 157880 includes 2 ovigerous females, 1 with 4 eggs, other with 5. USNM 158332 with 5 eggs in marsupium.

SUPPLEMENTARY DESCRIPTION OF ADULT MALE (Figures 33, 34).—Carapace in lateral view differs from that of female in having slightly projecting rostrum forming below it a shallow incisur; caudal process more strongly developed than that of female (Figure 33).

Ornamentation (Figure 33): Similar to that of female.

Infold and Selvage: Not examined in detail.

Size: USNM 158333, length 0.91 mm, height 0.68 mm.

First Antenna (Figure 34a): First and second joints without spines; dorsal bristles of first and second joints broken off on right limb of USNM 158333 (left limb missing), third joint with small ventral bristle; third and fourth joints fused; fourth joint with 1 dorsal bristle (ventral bristles not observed), fifth joint wedged ventrally between fourth and sixth joints, with bulbous proximal part bearing abundant thin filaments, and with single stout bristle having at least 1 short filament (distal part of bristle broken off on limb examined). Sixth joint long, with single, bare, medial bristle. Seventh joint: a-bristle longer than bristle of sixth joint, with few faint spines; b-bristle about twice length of a-bristle, with 1 distal filament; c-bristle stout (distal part broken off on limb examined). Eighth joint: d- and e- bristles about twice length of b-bristle, bare, with fairly blunt tips; f-bristle only slightly shorter than d- and e-bristles, with 3 marginal filaments, and 2 minute spines at tip; g-bristle stout (distal part broken off on limb examined).

Second Antenna (Figure 34b): Protopodite bare. Endopodite 3-jointed: first joint short, with 1 small, proximal, anterior bristle, and numerous spines forming rows; second joint elongate with 3 short ventral spines bearing faint hairs; third joint recurved, with 2 small bristles near tip. Exopodite: elongate first joint with minute, terminal, medial bristle; second joint about twice length of third joint; remaining joints slightly smaller than preceding joint; bristle of second joint long, with about 7 stout, proximal, ventral spines, and distal, faint, natatory hairs; bristles of joints 3–8 with proximal ventral spines and natatory hairs; small ninth joint with 2 bristles (ventral bristle long, with proximal ventral spines and distal natatory hairs, dorsal bristle short, bare).

Mandible (Figure 34c,d): Coxale endite consisting of short bristle-like, medial spine. Basale: dorsal margin with small bristle distal to middle, and 2 terminal bristles (1 long, 1 short); ventral margin with 1 small midbristle; medial side with 4 small bristles (3 proximal forming group, 1 distal). First endopodial joint: ventral margin with 1 ventral bristle bearing few hairs; medial surface with long proximal hairs near dorsal margin and short spines near ventral margin; lateral surface with spines in distal dorsal corner. Second endopodial joint: ventral margin with short subterminal bristle; dorsal margin with spines forming rows. End joint with long, stout, unringed claw, 2 short ventral bristles, and 1 small medial bristle near dorsal margin. Exopodite well-developed, hirsute; although base of exopodite present on lateral side of basale, distal tip tends to twist onto medial side of first endopodial joint.

Maxilla: Reduced.

Fifth Limb (Figure 34e): Single endite with 1 small bristle. Exopodite: first joint with 2 hirsute bristles; second joint with 2 bristles hirsute proximally; third joint with 3 bristles (1 very small) on inner lobe and 1 long bristle on outer lobe; fused fourth and fifth joints with 4 bristles.

Sixth Limb (Figure 34f): Single endite with 3 bristles. End joint with 12 spinous or hirsute bristles followed by space and then 2 stout hirsute bristles.

Seventh Limb: Not observed.

Furca (Figure 34g,h): Each limb with 5 slender pointed claws; claw 1 fused to lamella, remaining claws separated from lamella by suture; right lamella anterior to left (Figure 34h); each lamella with 2 or 3 pointed processes following posterior claw; claws with long and short teeth along posterior margin.

Bellonci Organ: Broken off.

Eyes (Figure 34i): Medial eye bare with light amber pigment. Lateral eye about same size as medial eye, with light amber pigment and about 10 ommatidia.

Copulatory Organs (Figure 34j): Each of paired copulatory organs with several lobes; distal lobe with sclerotized curved process having peg and bristles on inner edge of curvature.

DESCRIPTION OF INSTAR IV Male (Instar A–1 Figure 35).—Carapace oval in lateral view, with small caudal process and without rostrum or incisur (Figure 35a).

Ornamentation: Similar to that of adult female.

Infold: Not examined.

Size: USNM 158595, length 0.83 mm, height 0.70.

First Antenna (Figure 35b): First joint without bristles. Second joint with 1 dorsal bristle. Third and fourth joints fused; third joint with 2 bristles (1 ventral, 1 dorsal); fourth joint with 3 bristles (2 ventral, 1 dorsal). Remaining joints not examined in detail, but in general similar to those of adult female.

Second Antenna (Figure 35c): Protopodite bare. Endopodite 3-jointed: first joint with 1 proximal anterior bristle; second joint elongate with 3 ventral bristles; third joint elongate with 2 small terminal bristles (Figure 35c). Exopodite similar to that of adult female.

Mandible, Maxilla, Fifth and Sixth Limbs: Not examined in detail but well developed and, in general, similar to those of adult female.

Seventh Limb (Figure 35d,e): Faint, small, bare.

Furca: Not examined in detail but, in general, similar to that of adult female.

Bellonci Organ (Figure 35b): Elongate with rounded tip.

Eyes (Figure 35b): Medial eye with light amber pigment. Lateral eye with light amber pigment and 7–11 ommatidia, some indistinct and small.

Upper Lip (Figure 35b): Similar to that of adult female

Copulatory Organs: Consisting of weakly developed lobes.

Y-Sclerite: Typical for genus.

Eusarsiella costata (Kornicker, 1958)

Sarsiella costata Kornicker, 1958:251, figs. 47:4A,B, 80A–E, 81A–E, 88B,C,G.

Eusarsiella costata.—Poulsen, 1965:83.—Kornicker, 1986a: 61, figs. 31–35.

HOLOTYPE.—USNM 122912, dry specimen, length 1.02 mm, (Kornicker, 1958:252, number 156-2).

TYPE LOCALITY.—Bimini Islands, Bahamas.

MATERIAL.—Exuma Sound: Sta 94-018, transect AA: USNM 194489, adult male in alcohol.

DISTRIBUTION.—Bahamas: Bimini Islands, San Salvador Island, the Wall off Lee Stocking Island, Exuma Cays (depth 67 m). Known depth range 1–100 m.

SUPPLEMENTARY DESCRIPTION OF ADULT MALE (Figure 26).—Carapace Size (length, height in mm): USNM 194489, 0.91, 0.68.