Bradleycypris foresteri, Külköylüoğlu & Hutchins & Yavuzatmaca & Schwartz, 2021

Külköylüoğlu, Okan, Hutchins, Benjamin T., Yavuzatmaca, Mehmet & Schwartz, Benjamin F., 2021, Hyporheic ostracods (Crustacea, Ostracoda) from Texas (USA) with six new species, Zootaxa 5046 (1), pp. 1-63 : 6-12

Bradleycypris foresteri n. sp.

( Figs 2–5 )

Type locality. San Antonio River Basin , San Antonio River hyporheic zone, Bexar County, Texas, USA (Lat: 29.311 96, Lon: -98.4432), Elevation ~ 149 m ASL .

Etymology. The species is named after late Dr. Richard M. Forester for his invaluable contribution to North American ostracod studies.

Material examined. Holotype: Female dissected in lactophenol solution with soft body parts slide mounted and sealed with translucent nail polish (no: OK-TX-SA160701-H3-1); valves in micropalaeontological slides (no: OK-TX-SA160701-H3-2). Collected from type locality on 01 July 2016 by Benjamin T. Hutchins and Aaron P. Swink.

Dissected paratypes: Seven females from type locality (no: OK-TX--SA160701-H3-3-9). Collected by Benjamin T. Hutchins and Aaron P. Swink .

Non-dissected paratypes: Thirty-four females and 12 juveniles in 70% ethanol. Collected from type locality by Benjamin T. Hutchins and Aaron P. Swink.

Other materials: 1) Type locality: Forty-six females and 27 juveniles (sample H2 on 01 July 2016), 54 females and 23 juveniles (sample H3 on 01 July 2016). 2) Guadalupe River Basin , San Marcos River hyporheic zone at Scull Road crossing (Lat: 29.849 43, Long: -97.8568, ~ 154 m ASL), Texas : 39 females and 6 juveniles (sample H1 on 01 September 2016), 16 females and 9 juveniles (sample H3 on 01 September 2016), 12 females and 4 juveniles (sample H2 on 01 September 2016), 32 females and 4 juveniles (sample H1 collected on 02 December 2016), 2 females (sample H2 on 02 December 2016).

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

Description: Measurements (μ m). Female (n=11): LV: L=653–715 (mean=685), H=300–325 (mean=313); RV: L=650–683 (mean=667), H=293–323 (mean=308); W=207–306 (mean = 257).

Carapace ( Figs 2 & 3 ): Translucent to opaque white, length> ½ of height in lateral view, with normal pores, greatest height in front of mid-length, margins almost equally rounded, surface smooth, subelliptical in dorsal view, anterior and posterior margins rounded, oblique in anterior and posterior view; LV overlapping RV anteriorly, ventrally and posteriorly, without inner list, with internal groove along valve edge; RV overlapping LV dorsally; hinge adont (without teeth); marginal pore canals short; inner lamella wide anteriorly, narrow posteriorly in both valves.

A1 ( Fig. 4A ): Seven-segmented. First segment with short Wouters organ, two long ventro-apical smooth setae extending to the terminal segment and short dorso-subapical seta; second segment with smooth dorso-apical seta slightly shorter than Rome organ; third segment with one smooth spike-like dorso-apical seta about size of fourth segment; fourth segment with two long dorsal setae, extending to terminal segment; fifth segment with one short (about as long as segment) and three long setae, reaching to end of long terminal setae; sixth (penultimate) segment with one medium (about half as long as aesthetasc ya) and two long setae; terminal segment with two long and one medium apical setae and one medium size aesthetasc ya slightly longer than the terminal segment.

A2 ( Fig. 4B ): Four-segmented. First segment (protopodite) with one long smooth postero-distal seta reaching about middle of penultimate segment. Second segment with exopodite plate with two short and one medium sized seta, not reaching to the end of the third segment, aesthetasc Y strong with about three segments and anteriorly plumose, a smooth posterior seta long extending to the terminal segment, natatory setae very short reaching almost one third of the penultimate segment (diagnostic character). Third (penultimate) segment with two medium sized and one long smooth posterior setae, t1 and t3 setae short about one third length of t2 seta, t4 seta not apparent, a medium smooth seta postero-dorsally, z1–3 setae three times longer than terminal segment, G1 and G3 claws equal in size, G2 claw short. Terminal segment with GM and Gm claws, Gm seta-like about half as long as GM. Aesthetasc y1 not seen, y2 short, about half as long as penultimate segment, seta y3 twice the length of y2, g seta thin. All claws serrated.

Md-palp ( Fig. 4C ): Md-coxa well-developed. First segment with three large setae (S1 and S2, and one slender), and a smooth alpha seta, vibratory plate with six plumose setae; second segment dorsally with two unequally long apical setae, extending to end of terminal segment, ventrally with four smooth setae and a cone-shaped plumose beta seta; penultimate segment with three dorsal setae, an apical y-seta thin and long (ca. twice as long as terminal segment) and four smooth apical setae; terminal segment with three unequally long smooth claws.

Mx1 ( Fig. 4D ) with two-segmented Mx1-palp and three endites; vibratory plate with 13 slightly setose setae; third endite with two serrated bristles and five to six smooth seta; first segment of Mx1 palp with four equally long and one shorter smooth setae; second segment of Mx1-palp approximately rectangular in shape, ending with four unequally long claws.

T1 ( Fig. 5A ): with two very small a setae and one b and d setae, c seta not apparent. Length of setae h: h2>h1>h3. Seta h3 smooth and about one third length of seta h2. Vibratory plate with five setose setae.

T2 ( Fig. 5B ): five-segmented. Both d setae smooth, d1 twice the length of d2; setae e, f, g smooth (e ≈ f> g); h1 seta not seen; h3 seta very small, about size of penultimate segment; h2 seta claw-like.

T3 ( Fig. 5C ): four-segmented. d-setae present. Length of d-setae: dp> d1 ≈ d2; seta dp long about the length of third segment; e seta smooth (two times as long as seta f); h setae as in Fig. 3C .

Rake-like organ ( Fig. 5D ): with a strong tooth, base with short setae.

Uropod ( Fig. 5E ): caudal ramus stout; ventral margin continuously and weakly serrated; claws (Ga, Gp) weakly serrated; length of anterior claw (Ga) slightly less than half the length of ramus; length of posterior (Gp) claw about 3/4 length of Ga; anterior seta (Sa) smooth and slightly longer than Gp; posterior seta (Sp) plumose, short, about half as long as Gp. Uropodal attachment with Triebel’s loop situated approximately between dorsal and ventral branches and well-developed.

Genital organ: without process.

Male: unknown.

Accompanying ostracod species. See Appendix 2.

Differential diagnosis. Bradleyscypris foresteri n. sp. is distinguished from the two known species of the genus ( B. obliqua (Brady) and B. vittata (Sars)) by several characteristics (see details in Table 1). Bradleycypris foresteri n. sp. has a smooth carapace, short apical seta on A1, medium size exopodial seta and very short natatory setae on A2, and a sixth seta longer than the other five setae and barely reaching the midpoint of the same segment. Several additional chaetotaxy differences are illustrated in Figures 2–5 .

Remarks. The genus Bradleycypris was first described from vernal pools in San Diego (California, USA) by McKenzie (1982). Since then, relatively few occurrences have been reported in the literature. Most recently, two species were listed by Meisch et al. (2019). This is the first published report of the genus from Texas, USA. Bradleycypris obliqua also occurs in Texas (Külköylüoğlu, unpublished data). Ma & Yu (2018) reported B. vittata from ponds and puddles in eastern China but indicated a couple of differences (e.g., carapace length) between their specimens and previously described specimens ( Savatenalinton & Martens 2010; Zhai & Zhao 2014). However, there are additional differences between the drawings of Ma & Yu (2018) and Savatenalinton & Martens (2010). For example, the longest seta on the exopodial plate of A2 is much longer than figured by Savatenalinton & Martens (2010), and the f seta of T2 is also much longer. Additionally, h1 and h3 setae are almost equal in Savatenalinton & Martens (2010) but h1 is almost 2x longer than h 3 in Ma & Yu (2018). These differences could be variation among populations but this needs to be confirmed.

Ecology: Bradleycypris foresteri n. sp. was collected from a mid-channel Bou-Rouch sample at the downstream end of a riffle in the San Antonio river where water temperature was 29.6°C, dissolved oxygen was 2.07 mg /L, specific conductance was 788 µS/cm, and pH was 7.72. In addition to other ostracod species (Appendix 2), B. foresteri occurred with the following stygobiont invertebrates in the San Antonio River: the snail Phreatodrobia nugax (Pilsbry & Ferriss) and the isopod Mexistenasellus coahuila, (Cole & Minckley) . In the San Marcos River, it occurred with the following stygobiont invertebrates: Erimidrilus worms, the snail Phreatodrobia micra (Pilsbry & Ferriss) , harpacticoid copepods, the isopod Lirceolus hardeni (Lewis & Bowman) , an undetermined parabathynellid, a Stygobromus amphipod, the beetle Haideoporus texanus (Young & Longley) and mites of the genera Stygomomonia, Meramecia, Uchidostygacarus , and Arrenurus . A number of epigean, benthic invertebrates were also collected at both sites ( Hutchins et al. 2020). The type species B. obliqua seems to have a wider distribution in Europe, North America, North Africa, the Azores islands, and Madeira ( Meisch 2000) where the species appears to prefer littoral and/or shallow zones of lakes and ponds ( Meisch et al. 2019). Sars (1903) raised B. vittata from dry mud samples sent to him from China. Tressler (1937) reported females from two lakes (Akemboeala at Timampoe, Towoeti at Celebes) in Groot Sanghir ( Indonesia). According to Savatenalinton & Martens (2010) the species was encountered from two localities (Nong Naree swamp, Muang district, Phetchabun Province and Lopburi River, Muang district, Lopburi Province, Thailand) in warm waters (27.6–29.2°C) with pH of 6.79–7.20. Additionally, the species has a relatively narrow distribution in South East Asia ( Karanovic 2012). Most recently, Ma & Yu (2018) reported B. vit- tata from puddles and ponds with mud or vegetation located at about 56 to 390 m elevation where the range of water temperature was 18.2–26.5°C and dissolved oxygen ranged between 1.45 and 11.28 mg /L.

Figures

FIGURE 2. Bradleycypris foresteri n. sp. (A) RV (note to ventral margin damaged) and (B) LV external views, (C) Dorsal view, (D) Ventro-lateral view, (E) Muscle scars internal view. Scale bar: 100 µm for A–D, 20 µm for E.

FIGURE 3. Bradleycypris foresteri n. sp. (A) LV and (B) RV (note to dorsal margin damaged), internal views, (C) RV posterior and (D) anterior margins with internal groove, internal views; (E) normal pore opening with seta. Scale bar: 100 µm for A and B, 50 µm for C and D, 10 µm for E.

FIGURE 4. Bradleycypris foresteri n. sp. (A) A1, (B) A2, (C) Md, (D) Mx1. Scale bar: 20 µm.

FIGURE 5. Bradleycypris foresteri n. sp. (A) T1, (B) T2, (C) T3, (D) Rake-like organ, (E) Ur with genital organ and furcal attachment. Triangle shows Triebel’s loop. Scale bar: 20 µm.