Xestoleberis gracilariaii, Chand, Prerna & Kamiya, Takahiro, 2016

Chand, Prerna & Kamiya, Takahiro, 2016, Seven new species of the genus Xestoleberis (Ostracoda: Podocopida: Cytheroidea) from the Fiji Archipelago, Zootaxa 4208 (4), pp. 325-348 : 332-334

publication ID	https://doi.org/ 10.11646/zootaxa.4208.4.2
publication LSID	lsid:zoobank.org:pub:6D3B4F32-7196-4DF9-B6E5-401FCF4A4CE6
DOI	https://doi.org/10.5281/zenodo.6078102
persistent identifier	https://treatment.plazi.org/id/8B57EE20-FFF3-B304-B4CC-3F0347088DFA
treatment provided by	Plazi
scientific name	Xestoleberis gracilariaii
status	sp. nov.

Treatment

Xestoleberis gracilariaii n. sp.

Type series. Holotype: male UMUT RA32531 ( Figs. 5 View FIGURE 5 H, L, 2E–F). Paratypes: male: UMUT RA32535 ( Fig. 13 View FIGURE 13 G, J1–J3), females: UMUT RA32533 ( Fig. 5 View FIGURE 5 A–G, I–K), UMUT RA32534 ( Fig. 5 View FIGURE 5 M), UMUT RA32536 ( Fig. 13 View FIGURE 13 I), UMUT RA32537 ( Fig. 13 View FIGURE 13 H). All type material was collected from the type locality. The holotype and paratypes are deposited at the University Museum , University of Tokyo, Japan . Valves on paleontological paper/cavity slides and soft parts mounted on glass slides. Additional paratypes preserved in 70% ethanol: one male UMUT RA32532.

Type locality. A sandy pocket beach along the open coastline of Korovou , Naviti Island in the Yasawa Group of Islands (P2, Fig. 1 View FIGURE 1 , Table 1); habitat: a short red alga ( Gracilaria maramae ).

Etymology. Gracilaria is the genus of the alga from which most of the specimens of this species were collected ( Gracilaria maramae South, 1995 —an edible red alga from Fiji).

Diagnosis. Posterior and anterior ends of carapace widely rounded. Valve edges lined with numerous simple marginal pores. Coloration in living specimens translucent valves, soft parts whitish to very light brown, some specimens with dark spots on posterior ends. BO short segment with numerous fine terminating setae. Ejaculatory duct forms O-shape loop before existing outwards through distal processes as hook-like projections. Furca reduced to short seta.

Description. Carapace ovate, and strongly inflated ( Figs. 2 View FIGURE 2 E–F, 5N, 13G–J3). Maximum valve length range: 407µm–480 µm, maximum valve height range: 245 µm–288 µm ( Table 2). Maximum height at mid-length. Dorsal margin convex, ventral margin slightly sinuous. Wide anterior and narrow posterior vestibula. Merodont hinge. Normal sieve pores scattered over carapace; those lining anterior and antero-ventral edges of carapace more recessed and with smooth circumferences. Scar pattern: posterior row of four adductor scars, and V-shaped anterior scar.

An1 with six podomeres; first two big, wide and rectangular, third–sixth small and quadrate ( Fig. 5 View FIGURE 5 A–A’). One short medial seta at junction of second and third podomeres, third and fourth podomeres with one dorsal apical seta each, fourth and fifth podomeres with one ventral apical seta each, fifth podomere with two dorsal apical setae, terminating setae of sixth podomere: one stout and pointed, one whip-like, one slender and round-tipped and one fine. An2 with one ventral apical seta on first podomere of endopodite, two dorsal and ventral medial setae and stout distal ventral apical seta on second endopodite podomere ( Fig. 5 View FIGURE 5 B–B’). One terminating claw with very fine serrations. Md coxa with six pointed and one lobate teeth and four fine setae ( Fig. 5 View FIGURE 5 C–E). Palp with four podomeres: second podomere with one dorsal and two ventral apical setae, third podomere with five dorsal and one ventral apical setae, two medial setae at junction of second and third podomeres, one medial seta at junction of third and fourth podomeres, two stout and one short terminating setae. Exopodite with at least two long setuled setae. Mx with two segmented palp; first segment with three distal dorsal-apical setae and second segment with three terminating setae ( Fig. 5 View FIGURE 5 F–G). Branchial plate with 14–15 setuled setae. BO symmetrical; short segment with numerous fine terminating setae ( Fig. 5 View FIGURE 5 H).

Basal setal formula for L5 1+1:2:1 and L6 and L7 1+1:1:1 ( Fig. 5 View FIGURE 5 I–K). Terminating claws of L5, L6 and L7 stout and slightly curved. Hp with asymmetrical sub-triangular distal processes; tips of distal processes wide and rounded ( Fig. 5 View FIGURE 5 L). Proximal ends of capsules sub-rounded and proximal support structure T-shaped. Furca, short fine seta on small base.

Distribution. Apart from the above-mentioned habitat of the holotype, a small number of specimens of X. graciliariaii n. sp. were also collected from Pterocladiella sp., a short red alga. Three specimens of X. gracilariaii n. sp. were also collected from the south east coast of Tavewa Island, which is situated close to Naviti Island (where majority of the specimens were collected) (P2, Fig. 1 View FIGURE 1 , Table 1). The collections were made from the green alga Bryosis penata.

Remarks. Xestoleberis gracilarii n. sp. is similar to Xestoleberis honiaraensis Titterton & Whatley, 2005 ( Fig. 4 View FIGURE 4 , Nos.16, 19, Pl. 3, 17–23, Titterton & Whatley 2005) reported from Honiara, Solomon Islands. Both species differ in the shape of the frontal muscle scars and anterior margin pores: X. gracilarii— V-shaped muscle scars and simple pore canals and X. honiaraensis —trefoil muscle scars and branching pore canals.