Eucypris denktasi, Külköylüoğlu & Özdilek, 2024

Külköylüoğlu, Okan & Özdilek, Ahmet, 2024, Two new species of the genus Eucypris (Crustacea: Ostracoda) from Northern Cyprus, Zootaxa 5506 (1), pp. 58-78 : 60-66

Eucypris denktasi n. sp.

( Figs. 2–6 )

Etymology. The species is named after Rauf Raif DenktaŞ, the first president of Northern Cyprus.

Type locality: Temporary creek , Yılmazköy district , LefkoŞa, Northern Cyprus (35˚12’93.2’’N, 033˚10’76.7’’E). Elevation ca 136 m. a.s.l.

Material examined. Holotype: one female dissected in lactophenol solution with soft body parts on one slide mounted and sealed with translucent nail polish (no: OK-CYP1); valves in micropalaeontological cavity slides (no: OK-CYP-V1). Collected from type locality on 21 May 2022 by Okan Külköylüoğlu, Ahmet Özdilek and Ali Özdilek.

Dissected paratypes: six females from type locality (no: OK-CYP2-7). Collected by Okan Külköylüoğlu, Ahmet Özdilek and Ali Özdilek.

Non-dissected paratypes: forty-eight females kept in 70% ethanol. Collected from type locality by Okan Külköylüoğlu, Ahmet Özdilek and Ali Özdilek.

Repository. Holotype and all paratypes stored at the Limnology Laboratory of the Biology Department, Bolu Abant İzzet Baysal University, Bolu, Türkiye.

Measurements (mm). Female (n=7): Length: 1.12–1.32 (mean= 1.22), Height: 0.61–0.78 (mean= 0.71), Width: 0.53–0.63 (mean= 0.58).

Description: Carapace ( Figs. 2–3 ): In lateral view carapace ovoid, in dorsal view carapace anteriorly beak-shaped, LV> RV, carapace surface smooth without wart-like elevations, selvage present in RV, LV with inner list close to the outer margin, hinge adont, greatest height in the middle of carapace, rounded margin present anteriorly and posteriorly, valve surface with normal pores and setae.

A1 ( Fig. 4A ): Seven-segmented. Wouters organ and Rome organ absent. Four setae on first segment: a thin dorsal smooth seta, a long and smooth seta ventrally, extending to the end of the second segment, one of the two unequally long and smooth ventro-apical setae reaching to the tips of sixth segment, short seta slightly extending beyond the third segment. The second segment partially quadrangular with a medium-sized smooth dorsal seta. The third segment with one dorsal and one ventral apical setae. The fourth segment with two very long dorso-apical setae, twice the total length of the last three segments and with two equally long smooth apical setae. The fifth segment with two very long dorso-apical setae and with two ventro-apical setae. Penultimate (sixth) segment with rather long four setae. Terminal segment with three long setae, aesthetasc ya smooth, twice the length of the terminal segment.

A2 ( Fig. 4B ): Five-segmented. First protopodal segment with two short postero-distal setae. Second protopodal segment with one long basal seta on the ventro-apical part. First endopodal segment with one long and two short exopodal setae (long seta reaching to the end of second segment) postero-apical seta plumose about the length of second segment, two-segmented aesthetasc Y smooth about one fourth of the segment in length, first five natatory setae long, extending the tips of the terminal claws, the sixth natatory seta short, about the length of second segment. Penultimate segment undivided with four unequally long t-setae (t4>t3>t2>t1, t2 plumose) present, z-setae (z3>z2>z1) smooth, and two equally long smooth setae. Aesthetasc y2 absent. Claws (G1>G3>G2) well developed and serrated. Terminal (third endopodal segment) segment with one long GM and one Gm (shorter than GM), length of the y3 aesthetasc about the length of the terminal segment.

Md ( Fig. 4C ): Md-coxa with seven strong teeth and a thin inner seta and long, thin dorsal seta. Md-palp with four segments. First segment with two unequally long S1 and S2 setae plumose and a thin α seta, vibratory plate with six unequally long smooth setae; second segment with four plumose setae, a thick plumose β seta, and three long external setae; penultimate (third) segment with four dorsal setae, one thick cone-shaped plumose γ seta, three apical setae smooth and two ventral setae; terminal segment with three claw like smooth setae.

Mx1 ( Figs. 5A, B ): with three endites and two-segmented palp; vibratory plate with 20 setose setae; first endite with 12 plumose and two smooth setae; second endite with nine setae; third endite with six setae and two serrated teeth bristles (Zahnborsten). First segment of Mxl palp with seven setae (one seta slightly plumose); second segment of Mxl-palp rectangular in shape with six (two claw-like and four smooth) setae.

T1 ( Fig. 5C ): with two unequally long a setae, setae b, c, and d present; length of setae h: h2>h1> h3. Vibratory plate with five long setose setae.

T2 ( Fig. 5D ): Five-segmented. First segment with a short d1 seta; d2 and dp setae absent. e seta smooth, f and g setae slightly plumose (length ratio: e> f> g); seta h1 short, slightly extending the length of terminal segment, seta h2 a well-developed serrated claw, longer than the terminal three segments together. Seta h3 ½ the length of the h1 seta.

T3 ( Fig. 6A, B ): Three-segmented. d1 and d2 setae smooth, dp seta plumose. Length ratio of d-setae: dp> d2> d1. Setae e and f plumose (length of seta f about half of seta e). Pincer organ present. Length ratio of h-setae: h3> h2> h1 (hook-like h2).

Hypostome ( Fig. 6C ): with a wide base covered with thin pseudochaetae.

Genital organ ( Fig. 6D ): smooth and rounded with a hook-shape structure inside.

Rake-like organ ( Fig. 6E ): with well-developed nine teeth.

Uropod ( Fig. 6F ): slightly curved, ventral margin smooth; Gp longer than half of Ga (both claws slightly serrated); posterior seta (sp) plumose and ca. sa = sp. Uropodal attachment smooth, thin and curved with a short ventral branch.

Male: unknown.

Accompanying ostracod species: Ilyocypris gibba ( Ramdohr, 1808) .

Diagnosis. In lateral view, carapace smooth, ovoid, and anterior margin beak shaped. A1 without Wouters and Rome organs. A2 length of t-setae: t4>t3>t2>t1, t-2 plumose, Aesthetasc Y and y3 present, y2 absent, natatory setae extending slightly beyond terminal claws. Md vibratory plate with six smooth setae. Terminal segment of Mx-palp rectangular with two well-developed claw-like and four smooth setae, vibratory plate with 20 plumose setae. Rake-like organ with nine teeth. T1 with five setae on vibratory plate (all plumose), length of h-setae: h2>h1>h3. T2 five-segmented, d1 seta short, d2 absent, length of e-g setae: e>f>g, f and g plumose. T3 three-segmented. Uropod well-developed, Gp more than 1/2 of the Ga, sp equals to sa.

Ecology: Eucypris denktasi sp. nov. was collected from a temporary creek water puddle with about 10 cm of depth. Physical variables of the type locality: elevation 136 m. a.s.l., water temperature 18.16 °C, pH 7.98, electrical conductivity 26.30 mS/cm, oxidation reduction potential 99.8 mV, total dissolved solids 13.16 ppt, atmospheric pressure 14.526 mmHg.

Figures

FIGURE 2. Eucypris denktasi sp. nov. Female. (A) RV, external view. (B) LV, external view. (C) carapace in dorsal view. (D) muscle scars. Scale bar: 133 µm for A and C. 145 µm for B. 94 µm for D.

FIGURE 3. Eucypris denktasi sp. nov. Female. (A) RV internal view. (B) RV internal view with enlarged anterior margin. (C) RV internal view with enlarged posterior margin. (D) LV internal view. (E) LV internal view with posterior margin extended. (F) LV internal view with anterior margin extended. Scale bars: 140 µm for A and D. 88 µm for B and C. 100 µm for E and F.

FIGURE 4. Eucypris denktasi sp. nov. (A) A1. (B) A2. (C) Md. Scale bar: 75 µm for A. 100 µm for B. 90 µm for C.

FIGURE 5. Eucypris denktasi sp. nov. (A) Mx1. (B) Mx1 vibratory plate. (C) T1. (D) T2. Scale bar: 100 µm for A. 70 µm for B. 460 µm for C. 40 µm for D.

FIGURE 6. Eucypris denktasi sp. nov. (A) T3. (B) Terminal part of T3. (C) Hypostome. (D) Genital organ. (E) Rake-like organ. (F) Uropod with attachment. Scale bar: 70 µm for A and B. 150 µm for C. 200 µm for D. 155 µm for E.80 µm for F.