Eusarsiella eli, Churchill & Ellis & Pique & Oakley, 2014

Churchill, Celia K. C., Ellis, Emily A., Pique, Alannah E. & Oakley, Todd H., 2014, Two new sympatric species of Eusarsiella (Ostracoda: Myodocopida: Sarsiellidae) from the Florida Keys with a morphological phylogeny of Sarsiellinae, Zootaxa 3802 (4), pp. 444-458 : 451-454

Eusarsiella eli sp. nov.

Etymology. Named by the authors for Elizabeth Ansier Oakley, who has provided critical assistance and support during numerous expeditions to collect myodocopids.

Holotype: SBMNH # 235522 one ovigerous female on five slides, and carapaces in ethanol. Type locality: (24.850002, -80.816925) off Long Key , Monroe County, Florida, USA. Collected by hand nets in algae, coarse sand, shells, 3–4 m depth. Collected by authors ( CKCC, EAE, and THO).

Material examined. Holotype (adult female).

Distribution. Known only from the type locality.

Diagnosis. A Eusarsiella species , with a prominent, triangular caudal process and minute anterior incisure. Shell ornamented with many fossae and posterior processes bearing short bristles and one long bristle. Posterior processes decrease in size dorsally. Valve margin extremely hirsute. Short, anterior processes along the perimeter of the valve, bearing minute bristles. The carapace of Eusarsiella eli closely resembles the Caribbean E. paniculata , especially in the placement of processes and bristles ornamenting the carapace. The caudal process of E. eli is pointed postero-ventrally, whereas that of E. paniculata points posteriorly. The two species also differ in adult female size; E. paniculata (1.24–1.32 mm length and 0.95–1.03 mm height; Kornicker 1986) is relatively longer than E. eli (1.15 mm length and 1.11 mm height). Internal diagostic characters between the two species are as follows: The second podomere of the first limb is bare in E. eli , but bears a dorsal bristle in E. paniculata ( Kornicker 1986) . The endopodite of the second limb is monomeric in E. eli but dimeric in E. paniculata . Finally, the exopodite of the fourth limb has three bristles in E. eli , whereas E. paniculata has two.

Description of holotype —Adult female. Carapace ( Figure 4 ): Length 1.15 mm, height 1.11 mm (holotype). Carapace slightly oval in lateral view with truncated postero-dorsal margin. Distinct caudal process pointing postero-ventrally.

Ornamentation ( Figure 4 ): Prominent, triangular caudal process and distinct processes circling the valve. Processes along the valve margin hirsute, with two rows along the ventral margin. Carapace with shallow fossae concentrated in the center. Posterior processes, decreasing in size dorsally, each with numerous short bristles and one long bristle. Valve margin hirsute.

Limb 1/Antennula ( Figure 5A ): First and second podomeres bare. Long third and short fourth podomeres fused without a suture; third podomere bare; fourth podomere with one distal medium-length, ventral bristle and one longer, distal dorsal bristle. Fifth through eighth podomeres are fused. Fifth podomere with one large terminal bristle with one setula and one terminal spine. Sixth podomere bare. Seventh podomere bears the a-, b-, and c- bristles, eighth podomere bears d-, e-, f-, and g-bristles. Bristles a through g are of typical length for genus; f-bristle has few, sparse setulae.

Limb 2/Antenna ( Figure 5B ): Protopodite bare. Endopodite monomeric with two short proximal bristles and one small terminal node bearing one minute apical bristle. Exopodite nonomeric. First podomere about the length of podomeres 2–9, bare. Second podomere bears one long distal bristle, with proximal ventral filaments and distal natatory setulae. Podomeres 3–8 follow the same fashion, though decreasing in length. Ninth podomere with two terminal bristles; dorsal bristle short and bare, ventral bristle long with sparse proximal filaments.

Limb 3/Mandibula ( Figure 5C ): Coxa with dense minute stout spines along ventral margin. Coxale endite reduced to single spine. Basis with one dorsal, distal, stout bristle at the dorsal margin. Two lateral, proximal, ventral bristles proximal to the dorsoventral margin. Ventral margin bears one minute bristle. Endopod trimeric: First podomere with numerous short, stout spines on the medial surface; ventral margin with stout terminal claw and short dorsal bristle. Second podomere with one ventral claw, slightly longer than the terminal claw on the first podomere. Third podomere with long terminal claw about twice the size of the terminal claw on the first podomere; one minute dorsal bristle and one larger ventral bristle.

Limb 4/Maxillula ( Figure 5D ): Precoxa bare. Coxa with dorsal process bearing a short, anterior bristle along the distal, antero-dorsal margin. First endite appears bare, but was not observed clearly. Second endite bears three very stout bristles. Third endite bears two distinct clusters of three bristles: posterior group with one short, one medium, and one longer, stout bristles with spines; anterior group has one stout bristle with spines and two medium bristles. Exopodite bears three medium-sized bristles. Endopod dimeric: first podomere with stout, spinous and pectinate alpha- and beta-bristles. Second podomere with two small a-bristles and five pectinate end bristles.

Limb 5 ( Figure 5E ): Epipodial appendage with 13 pectinate bristles; single endite present with one single bristle. Exopodite with five podomeres: first podomere with two bristles. Podomeres 2–5 are fused. Second podomere with three spinous bristles. The remaining podomeres have four bare bristles, though the distinction among joints is uncertain.

Limb 6 ( Figure 5F ): Single endite with one stout, short bristle. Terminal podomere with about 11 slender, hirsute bristles along the ventral margin. Short spines are followed by two hirsute, stout, posterior bristles.

Limb 7 ( Figure 5G ): Each limb with eight bristles: six terminal (three on each side) and two proximal (one on each side). Each bristle bears four to seven bells; terminal bristles bear more bells than proximal. Proximal bristles are located about 80 % down the full limb length. Terminus with opposing combs of about four teeth distally on each margin.

Furca ( Figure 5H ): Each lamella with five claws; each claw curved with pointed tip. Claw 1 is the longest and fused with lamella; claws 2–5 are separated by a suture. Claws are followed by several small spines.

Eyes: Lateral eyes with reddish pigment and about eight ommatidia, but was difficult to see. Medial eye with light amber pigment.

γ -sclerite ( Figure 5I ): Typical for the family.

Eggs: Holotype SBMNH # 235522 with three embryos in the domicilium.

Figures

FIGURE 4. Eusarsiella eli, holotype, SMBNH #253222. Adult female. Photograph of carapace. Scale bar = 0.5 mm.

FIGURE 5. Eusarsiella eli, holotype, SBMNH #235522. Adult female. A, first limb, right side, medial view, bristles labeled from podomere 5 to terminus; B, second limb, right side, lateral view, long bristles on podomeres 3–9 truncated (appearance is similar to bristle on podomere 2); C, third limb, right lateral view; D, fourth limb, left lateral view, labels: ex, exopodite, II; second endite, III, third endite, α, alpha bristle, β, beta bristle, a, a-bristle; E, fifth limb, left medial view, long bristles on epipod truncated (appearance is similar to single hirsute bristle); F, sixth limb, right lateral view; G, seventh limb, right; H, furca, right lamella lateral view; I, γ-sclerite. Scale bar = 100 µm.