Eusarsiella bryanjuarezi, 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 : 448-451

Eusarsiella bryanjuarezi sp. nov.

Etymology. Named by the authors for Bryan Juarez, who provided critical assistance during the collection of these specimens.

Holotype: None designated.

Syntypes: SBMNH # 235521 two ovigerous females, “A” and “B” on five slides, and carapaces in ethanol. We chose to designate syntypes because given the low number of individuals available for morphological examination (2), we were not able to describe the species from a single individual. 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. Syntypes (two ovigerous females).

Distribution. Known from the type locality and Indian River (a brackish lagoon, not a freshwater river), Fort Pierce, Florida, USA (27.462063, -80.312713).

Diagnosis. A Eusarsiella species , with a small, rounded caudal process and minute anterior incisure on the inner carapace margin. Shell ornamented with many fossae. The carapace of E. bryanjuarezi resembles both E. dominicana (known from the Dominican Republic) and E. absens (known from Bermuda). E. bryanjuarezi is nearly circular in lateral view, whereas both E. dominicana and E. absens are distinctly oval. The posterior margin of E. bryanjuarezi is flat in lateral view where that of E. absens is concave. E. bryanjuarezi and E. absens have different carapace sculptures: the former has a single rib extending from above the central adductor muscle attachments to the posterodorsal bulge, whereas the latter has an additional horizontal rib below the central adductor muscle attachments (see Kornicker 1986). E. absens in Kornicker 1986 (Figure 25) also has three to four weakly developed radiating ribs on the anterior portion of the carapace ( Kornicker 1981a as Sarsiella absens ), whereas E. bryanjuarezi has none. E. bryanjuarezi (1.03–1.05 mm) adult females are of a similar size to E. dominicana (1.08 mm) but E. absens (1.17–1.22 mm) are around 10 % larger ( Kornicker 1986). Internal diagnostic features of the three species are as follows: On the first limb, the third and fourth fused podomeres have differing number of bristles. E. bryanjuarezi has a total of six bristles and one spine (see below), E. dominicana has a total of four bristles, and E. absens has a total of three ( Kornicker 1986). Finally, adult female E. bryanjuarezi have about 10 ommatidia while E. dominicana have four ( Kornicker 1986) and E. absens have five ( Kornicker 1981a).

Description of syntypes —Adult females. Carapace ( Figure 2 ): Syntypes A and B. Length 1.05 mm, height 0.95 mm. Carapace oval but nearly circular in lateral view with flat posterior. Caudal process present, but highly reduced and round.

Ornamentation ( Figure 2 ): Syntypes A and B. Carapace with many fossae; valve lined with bristles. One ridge present immediately medial to the valve margin, beginning dorsally above the caudal process and following the valve margin around to the ventral side of the caudal process.

Limb 1/Antennula ( Figure 3A ): Syntype A. First podomere bare. Second podomere with one dorsal bristle. Long third and short fourth podomeres fused; third podomere with one long dorsal bristle and one short ventral bristle; fourth podomere with one distal lateral spine, one short dorsal bristle and group of three ventral bristles: one short, one medium, and one long. Fifth podomere with long distal, ventral sensory bristle; sensory bristle of fifth podomere with minute proximal filaments and terminal spine. Short sixth podomere fused to fifth podomere with one short, medial, bare bristle. Seventh podomere: a-bristle half-length of b-bristle, bare; b-bristle half the length of c-bristle, bare; c-bristle long, with one proximal filament, one distal filament, and one terminal spine. Eighth podomere: d-bristle half-length of c-bristle, bare; e-bristle slightly longer than b-bristle, bare, appears open at tip; f-bristle long with terminal spine; g-bristle similar to f-bristle.

Limb 2/Antenna ( Figure 3B ): Syntype A. Protopodite with one lateral, stout, blunt bristle. Endopodite monomeric with one short proximal bristle and small terminal node bearing one minute bristle. Exopodite nonomeric. First podomere about length of podomeres 2–9, bare. Second podomere bearing one long distal ventral bristle with proximal ventral filaments and distal natatory setulae. Third podomere bearing one long distal ventral bristle with distal natatory setulae. Podomeres 4–6 decreasing slightly in length and width, each bearing one long distal ventral bristle resembling bristle of third podomere. Seventh and eighth podomeres each bearing one long distal ventral bristle with proximal filaments and distal natatory setulae. Ninth podomere with two terminal bristles; dorsal bristle short and bare, ventral bristle long with sparse proximal filaments and distal natatory setulae.

Limb 3/Mandibula ( Figure 3C ): Syntype A. Coxa with minute, dense stout spines along ventral margin and covering the medial ventral surface. Coxale endite reduced to a single spine. Posteroventral margin with two short, stout bristles and small clump of minute setulae dorsal to the shorter stout bristle. Large, flat spine covering medial coxale-basic joint. Basis with two distal ridges bearing one short stout bristle at the dorsal margin. Ventral margin with cluster of two or three bristles: one minute, two short and stout. Exopod absent. Endopod trimeric: First podomere with numerous spines on the medial surface, increasing in length distally; ventral margin with stout terminal claw. Second podomere with short dorsal bristle and stout terminal claw, slightly longer than terminal claw on first podomere. Third podomere with short dorsal bristle and ventral strout terminal claw, about twice as long as claw on first podomere.

Limb 4/Maxillula ( Figure 3D ): Syntype A. First endite with four bristles, two short, one long, one stout and medium length; dorsal fringe of short setulae. Coxa with dorsal process bearing one short bristle. Precoxa/coxa boundary difficult to discern. First endite with three bristles, two short and one long. Second and third endites bearing several bristles each. Exopod not observed. Endopod dimeric: first podomere with stout spinous and pectinate alpha and beta bristles. Second podomere with one small a-bristle, one small c-bristle, and five pectinate end bristles.

Limb 5 ( Figure 3E ): Syntype A. Epipodial appendage with about 27 pectinate bristles; single endite present and bare. Exopodite with five podomeres: first podomere with two bristles, one long with few minute, marginal filaments, one shorter and bare. Podomeres 2–5 fused. Second podomere with bristles bearing minute marginal filaments. The remaining podomeres have three bare bristles, though the distinction among joints is uncertain.

Limb 6 ( Figure 3F ): Syntype A. Single endite with one short, bare bristle. Terminal podomere projecting posteriorly with 10 or 11 bristles along the ventral margin. The most posterior of these bristles is the most hirsute. Some of the other bristles with terminal filaments and minute, marginal filaments. Bristles are followed by a space, and then two thick, long, and hirsute bristles.

Limb 7 ( Figure 3G ): Syntype B. Each limb with 10 bristles: six terminal (three on each side) and four proximal (two on each side). Each bristle bears four to seven bells; terminal bristles bear more bells than proximal. Distal third of the limb with medial and lateral ridges heading to the V-shaped opening of the terminus. Terminus with opposing combs, each with about six teeth distally on each margin.

Furca ( Figure 3H ): Syntype B. Each lamella with five claws; each claw curved with pointed tip. First claw is the longest and continuous with lamella; claws 2–5 are separated by a suture. First two claws have repeated rows of spines increasing in length distally along the posterior margin. Claws 3 and 4 have spines along the posterior margin. Claw 5 is short and bare.

Eyes: Lateral eyes with reddish pigment and about 10 ommatidia. Medial eye with very light brownish pigment.

γ -sclerite ( Figure 3I ): Syntype B. Typical for the family.

Eggs: Syntypes SBMNH # 235521 with five and four embryos in the domicilia of syntypes A and B, respectively .

Figures

FIGURE 2. Eusarsiella bryanjuarezi, syntype, SBMNH #253221. Adult female. Photograph of carapace. Scale bar = 0.5 mm.

FIGURE 3. Eusarsiella bryanjuarezi, syntype, SBMNH #253221. Adult female. A, first limb, right side, lateral 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, left side, medial view; D, fourth limb, right side, medial view, labels: ex, exopodite, II; second endite, III, third endite, α, alpha bristle, β, beta bristle, a, a-bristle, c, c-bristle; E, fifth limb, right side, medial view, long bristles on epipod truncated (appearance is similar to single hirsute bristle); F, sixth limb, right side, lateral view; G, seventh limb, terminal end, right side; H, furca, right lamella, lateral view; I, γ-sclerite. Scale bar = 100 µm.