Eusarsiella fax, Kornicker & Iliffe & Harrison-Nelson, 2007

Kornicker, Louis S., Iliffe, Thomas M. & Harrison-Nelson, Elizabeth, 2007, Ostracoda (Myodocopa) from Anchialine Caves and Ocean Blue Holes, Zootaxa 1565 (1), pp. 1-151 : 123-128

Eusarsiella fax , new species

Figs. 69–72

Etymology. From the Latin fax (torch, firebrand).

Holotype. USNM 1021474 , A- 1 female on slide and in alcohol.

Type locality. Sta 00-025, Conch Sound Blue Hole, Andros Island, Great Bahama Bank.

Paratypes. USNM 1021475 , undissected A-1 instar (sex unknown) in alcohol . USNM 1021476 , undissected A-1 instar (sex unknown) in alcohol . USNM 1021477 , A- 1 male on slide and in alcohol .

Distribution. Type locality.

Description of A- 1 female ( Figs. 69–71 a,b ). Carapace oval in lateral view with triangular pointed caudal process ( Figs. 69 , 70 c ). Surface with 2 lateral ribs with pebbly surface and several nodes bearing a long bristle but no short broad bristles ( Fig. 69 ).

Ornamentation ( Figs. 69 , 70 a–c ): Very short spines covering caudal process and remainder of valves,

appearing pebble-like along valve edges and on ridges. Surface of holotype with fossae with irregular outline, some with inward-pointing minute spines along edges. Surface coated with gel-like substance.

Infold: Anterior infold with minute bristle at midheight. Infold of caudal process with 3 bristles ( Fig. 70 c ). Two setal bristles present dorsal to caudal process.

Selvage: Lamellar prolongation with smooth outer edge along valve margins. Prolongation with serrated margin extends well past tip of caudal process.

Carapace size ( length, height in mm): Holotype, USNM 1021474 , length including caudal process 0.94, length without caudal process 0.83, height 0.72.

First antenna ( Fig. 70 d ): 1st segment bare. 2nd segment with dorsal bristle and 2 spines. 3rd and 4th segments fused: segment 3 with 2 bristles (1 ventral, 1 dorsal); 4th segment with 2 or 3 bristles (1 (right limb) or 2 (left limb) ventral, 1 dorsal). 5th segment with long ventral bristle with minute filament near midlength (not shown). 6th segment with short medial bristle. 7th segment: a-bristle short, b-bristle about same length as abristle, c-bristle as long as bristle of 5th segment, with minute distal filament (not shown). 8th segment: d- and e-bristles slightly shorter than c-bristle, bare with blunt tips, f-bristle shorter than c- bristle, g-bristle about same length as c-bristle.

Second antenna: Protopod bare. Exopod: 1st segment with small recurved medial spine; segments 2–8 with long bristle with proximal spines and distal natatory hairs; 9th segment with 2 bristles (1 long with proximal spines and distal natatory hairs, 1 short bare). Endopod with 2 fused segments: 1st segment with 1 (right limb) or 2 (left limb) ringed dorsal bristles; segment 2 tapering distally, bare ( Fig. 70 e ).

Mandible ( Fig. 70 f ): Coxa endite consisting of short stout spine; ventral margin of coxa with short hairs. Basis: medial side near ventral margin with 4 short bristles; ventral margin with 2 minute bristles; dorsal margin with 2 small distal bristles. Exopod absent. Endopod: 1st segment with distal medial spines, row of minute medial spines along distal margin (row extends to stout spine on dorsal edge of segment), and stout ventral claw with proximal row of minute teeth along dorsal edge; minute medial spine-like bristle at base of stout claw. 2nd segment with minute dorsal bristle and stout ventral claw. 3rd segment with 2 minute bristles (1 ventral, 1 dorsal) and stout terminal claw.

Maxilla ( Fig. 70 g,h ): Endite I with 6 bristles; endite II with 4 bristles; endite III with 6 bristles. Coxa with short dorsal bristle. Basis with single bristle near exopod. Exopod with 2 bristles. Endopod with 2 segments: segment 1 with alpha- and beta-bristles; segment 2 with 2 a-bristles, 1 c-bristle, and 5 pectinate end bristles.

Fifth limb ( Fig. 70 i ): Coxa endite with 1 short bristle. Basis with 2 endites: endite I with 2 bristles; endite II with 3 bristles. Endopod with 2 fused segments: segment 1 with 3 bristles (1 short); segment 2 with 2 bristles. Exopod represented by short bristle. Limb hirsute. Epipod with about 34 plumose bristles.

Sixth limb ( Fig. 70 j ): Single endite with 3 bristles (1 terminal and 2 shorter proximal). End segment with 11 bristles plus 2 posterior plumose bristles.

Seventh limb ( Fig. 71 a ): Each limb with 6 tapered bristles (2 proximal with 3 or 4 bells; 4 terminal with 4 or 5 bells). Tip with small opposing teeth. Each limb with about 62 annulae plus a terminal segment.

Furca ( Fig. 71 b ): Each lamella with 5 claws; claw 1 with stout teeth and smaller teeth between them; claws 2 to 4 with small teeth; claw 1 with long medial spines near base; claw 4 of left lamella with long thin spines along anterior edge. Anterior edge of right lamella with small spine proximal to claw; left lamella with few spines along ventral edge following claw 5. Right lamella anterior to left by width of claw 1 at base.

Bellonci Organ ( Fig. 70 k ): Elongate with rounded tip.

Eyes: Lateral eye with 5 amber ommatidia; brown pigment between ommatidia ( Fig. 70 l ). Medial eye larger than lateral eye, with brown pigment ( Fig. 70k ).

Genitalia: None observed.

Y-Sclerite: With ventral branch ( Fig. 71 b ).

Posterior of body: Evenly rounded.

Gut content: Unidentified fragments.

Eggs: Absent.

Description of A- 1 male ( Figs. 71 c–k , 72 ). Carapace similar in shape and ornamentation to that of A- 1 female ( Fig. 71 c,d ). Surface with gel-like coating.

Infold: Anterior infold with minute bristle near midheight. Infold of caudal process with 3 small bare bristles plus paired bristles closer to inner margin of infold ( Fig. 71 e ). Posterior infold with 2 setal bristles.

Selvage: Similar to that of A- 1 female.

Carapace size (length, height in mm): USNM 1021477, length including caudal process 0.86, length without caudal process 0.77, height 0.64.

First antenna: 1st segment bare. 2nd segment with bare dorsal bristle. 3rd and 4th segments fused: 3rd segment with 2 bristles (1 ventral, 1 dorsal); 4th segment with 3 bristles (2 ventral, 1 dorsal). 5th segment with long ventral bristle with 3 minute filaments. 6th segment with short medial bristle. 7th segment: a-bristle short, b-bristle about same length as a-bristle, c-bristle about same length as bristle of 5th segment, with 3 minute filaments, d- and e-bristles slightly shorter than c-bristle, bare with blunt tips; f-bristle shorter than cbristle, with 2 minute filaments; g-bristle about same length as c-bristle, with 3 small filaments.

Second antenna: Protopodite bare. Exopodite similar to that of A- 1 female. Endopod with 2 (possibly 3) fused segments ( Fig. 71 f,g ): 1st segment with 2 ringed anterior bristles; terminal segment small, tapered, with short terminal pointed process.

Mandible ( Fig. 71 h ): Similar to that of A- 1 female.

Maxilla ( Fig. 71 i,j ): Similar to that of A- 1 female.

Fifth limb ( Fig. 71 k ): Epipod with about 32 plumose bristle. Coxa endite with 1 small bristle. Basis: endite I lobate with 2 bristles; endite II with 3 bristles. Endopod: 1st segment with 3 bristles; 2nd segment with 2 bristles. Exopod represented by 1 bristle.

Sixth limb ( Fig. 72 a ): Single endite with 3 bristles (1 terminal, 2 smaller and proximal). End segment with 11 bristles followed by 2 posterior plumose bristles (marginal spines not shown).

Seventh limb ( Fig. 72 b ): Each limb with 4 tapered terminal bristles with 3 or 4 bells. Tip smooth.

Furca (72 c): Similar to that of A- 1 female.

Bellonci Organ ( Fig. 72 d ): Elongate with rounded tip.

Eyes ( Fig. 72 d ): Lateral eye with 5 amber-colored ommatidia and brown pigment between ommatidia. Medial eye larger than lateral eye, with brown pigment.

Lips: Stippled in Fig. 71 h ; also shown in Fig. 72 e .

Posterior of body ( Fig. 72 c ): Evenly rounded and bare ventral to girdle.

Genitalia ( Fig. 72 f ): A single tapered lobe on each side of body; 3 minute bristles near tip of each lobe.

Y-Sclerite ( Fig. 72 c ): With ventral branch.

Gut content: Unidentified crustacean fragments.

Description of A-1 instar (sex unknown) ( Fig. 71 l ). Carapace similar in shape and ornamentation to those of A- 1 female and male.

Carapace size (length, height in mm): USNM 1021475, length including caudal process 0.99, length without caudal process 0.85, height 0.73; USNM 1021476, length including caudal process 0.93, length without caudal process 0.81, height 0.68.

Central adductor muscle attachments: USNM 1021476 with about 16 ovoid attachments ( Fig. 71 l ).

Comparisons

The irregular outlines of fossae on the carapace of E. fax are unusual; the fossae of previously described species having fossae are evenly rounded. The carapace of the new species resembles that of Eusarsiella cornuta Poulsen 1965 , which is known only from an adult female collected in the Virgin Islands ( Poulsen 1965:106). The edges of the fossae on the carapace of that species are crenulate, but the fossae are more rounded than those of E. fax .

Figures

FIGURE 69. Eusarsiella fax, new species, holotype USNM 1021474, A-1 female, complete specimen from right side, length with caudal process 0.94 mm.

FIGURE 70. Eusarsiella fax, new species, holotype USNM 1021474, A-1 female: a, detail of fossae on right valve; b, fragment of valve edge showing fossae and bristles; c, caudal process right valve, iv; d, right first antenna, mv; e, endopod right second antenna, mv; f, left mandible, mv; g, left maxilla, lv (nabs); h, endites right maxilla, mv; i, fifth limb; j, left sixth limb, mv; k, medial eye and Bellonci Organ; l, right lateral eye, mv. Scale equals 0.05 mm (a–c, e–l) and 0.10 mm (d).

FIGURE 71. Eusarsiella fax, new species, holotype USNM 1021474, A-1 female: a, seventh limb; b, left lamella of furca, mv and right Y-sclerite. Paratype, USNM 1021477, A-1 male: c, complete specimen from right side, length with caudal process 0.86 mm; d, detail of fossae from "c"; e, caudal process of left valve, iv; f,g, endopods of right and left second antenna, mv; h, left mandible, mv; i, endite II right maxilla, mv; j, endites I and III of maxilla; k, fifth limb. Paratype, USNM 1021476, A-1 instar (sex unknown); l, central adductor muscle attachments of right valve. Scale equals 0.02 mm (a,f,g,i), 0.10 mm (b,d,e,l), and 0.05 mm (e,h,j,k).

FIGURE 72. Eusarsiella fax, new species, paratype USNM 1021477, A-1 male: a, left sixth limb, lv; b left seventh limb; c, left lamella of furca and left Y-sclerite, lv; d, medial eye, Bellonci Organ, and left lateral eye; e, view of lips and esophagus from left side, anterior to left; f, left and right copulatory organs, anterior to right. Scale equals 0.05 mm (a,b,d–f) and 0.10 mm (c).