Bradleycypris vittata ( Sars, 1903 )

Savatenalinton, Sukonthip & Martens, Koen, 2010, On the subfamily Cypricercinae McKenzie, 1971 (Crustacea, Ostracoda) from Thailand, with the description of six new species 2379, Zootaxa 2379, pp. 1-77 : 59-64

Bradleycypris vittata ( Sars, 1903) ( Figs 38–41)

1903 Cypris vittata Sars : 22, Fig. 3.

1916 Cypris (Strandesia) vittata — Gurney: 339.

1937 Strandesia vittata — Tressler: 197.

2009 Bradleycypris vittata — Savatenalinton & Martens: 3.

Material examined. Eleven dissected females, two dissected males and several undissected specimens (both females and males, in 70% ethanol) from 2 localities: 1) Nong Naree swamp, Muang district , Phetchabun Province, 28 September 2005 (TH051), 9 October 2007 (TH149), coordinates: 16° 26´23.7˝ N and 101° 08´29˝ E; 2) Lopburi River, Muang district , Lopburi Province, 5 October 2007, coordinates: 14° 47´55.5˝ N and 100° 38´29.8˝ E (TH140) .

Diagnosis. Carapace in lateral view subovate (length c. 1.6 times height), greatest height situated slightly in front of mid-length, anterior and posterior margins broadly rounded; carapace in dorsal view subelliptical, greatest width situated at mid-length, anterior and posterior extremity equal, rounded; LV overlapping RV anteriorly; carapace in posterior view oblique; LV with internal groove along valve margin; inner lamella without inner list; RV with large marginal selvage; Wouters and Rome organs on A1 long, aesthetasc ya considerably long; longest seta of A2-exopodite short, aesthetasc Y on A2 short; two large bristles on third endite of Mx1 serrated; d-seta on T1 present; length of distal claw of caudal ramus less than half of that of ramus; caudal ramus attachment stout, with Triebel’s loop situated at middle of distal part of main branch, dorsal and ventral branches well-developed; hemipenis with medial shield rounded, lateral shield small, subtriangular and with pointed tip; Zenker organ with distal and proximal ends forming cone-shaped chitinous sheet.

Differential diagnosis. Bradleycypris vittata ( Sars, 1903) differs from Bradleycypris obliqua (Brady, 1868) in the shape of the carapace in dorsal view (rounded anterior margin in B. vittata , asymmetrically beaklike anterior margin in B. obliqua ), the morphology of the A2-exopodite, the length of the shortest natatory seta on the A2 and of the proximal seta of the caudal ramus.

Measurements (in µ m). Female: LV (n=2), L=849–891, H=534–559; RV (n=2), L=826–874, H=540– 568; Carapace (n=4), L=871–905, W=516–548. Male: LV (n=2), L=810–828, H=510–532; RV (n=2), L=790–810, H=514–534.

Ecology. This species was originally described from dried mud samples collected from fishponds and inundated ricefields in China ( Sars 1903). Gurney (1916) found this species in a pond, while it was recorded from lakes by Tressler (1937). In the present study, several specimens were encountered from a swamp and a river, in a pH range of 6.79–7.20 and a temperature range of 27.6–29.2° C.

Abbreviated redescription of female. Carapace in lateral view ( Fig. 38A) subovate (length c. 1.6 times height), greatest height situated slightly in front of mid-length, dorsal margin arched, anterior and posterior margins broadly rounded, ventral margin almost straight.

Carapace in dorsal view ( Fig. 38C) subelliptical, greatest width situated at mid-length, anterior and posterior extremities equally rounded; LV overlapping RV along anterior, ventral and posterior margins.

Carapace in posterior view ( Fig. 38B) oblique, LV larger and lower than RV.

LV in interior view ( Fig. 38E) subovate, with groove along valve margin; calcified inner lamella wide anteriorly, without inner list, posteriorly more narrow.

RV in interior view ( Fig. 38F) with large marginal selvage, without inner list.

A1 ( Fig. 39A): first segment with long, tube-like proximal Wouters organ, long dorso-subapical seta and two long ventro-apical setae; second segment with long Rome organ and short dorso-apical seta, aesthetasc ya on terminal segment long (length c.1.6 times length of short apical seta).

A2 ( Fig. 39B) with longest seta of exopodite c. half of length of first endopodal segment; aesthetasc Y short, shortest natatory seta reaching beyond mid-length of penultimate segment; distal claws on penultimate segment serrated, long (length c. 1.2 times length of penultimate segment), aesthetasc y2 long (c. 3/4 of length of terminal segment).

Md-palp as in Fig. 39 C–D, Md-coxa as in Fig. 39 E.

Basal segment of Mx1-palp ( Fig. 40A) with long subapical seta (reaching tip of terminal segment), two large bristles on third endite serrated, sideways directed bristles unequal, short one c. 3/4 of length of long one.

T1 ( Fig. 40B–C) with a-, b- and d-setae.

T2 ( Fig. 40D) with d1 c. 1.6 times length of d2.

T3 as in Fig. 40E–F.

Caudal ramus ( Fig. 40H) stout, ventral margin weakly serrated, claws serrated, length of distal claw less than half of that of ramus, length of proximal claw c. 3/4 of that of distal claw, distal seta slightly shorter than proximal claw, proximal seta long (reaching slightly beyond tip of ramus). Caudal ramus attachment ( Fig. 40G) stout, with Triebel’s loop situated at middle of distal part of main branch, dorsal and ventral branches well-developed.

Abbreviated (first) description of male. Carapace and valves ( Fig. 38G–H) as in female, somewhat smaller. All limbs as in female, except for the last two segments of A2 ( Fig. 41A) and T1 ( Fig. 41B–C).

Setae z1 and z2 of the penultimate segment of A2 transformed in to claws; claws G1 and G3 reduced to setae; Gm on terminal segment of A2 reduced, appearing smaller and shorter (length c. 1/4 of that of claw GM).

T1 with asymmetrical prehensile palps (endopodites); right prehensile palp ( Fig. 41C) anteriorly with large subquadrate lobe and two apical spines; left palp ( Fig. 41B) bearing large, elongated, curved lobe and two unequal apical spines.

Hemipenis ( Fig. 41D) with medial shield rounded; lateral shield small, pointed and subtriangular, internal postlabyrinthal spermiduct with one large loop. Zenker organ ( Fig. 41E) elongated, length c. 2.5 times width, set with c. 20 chitinous spiny whorls, distal and proximal ends set with cone-shaped chitinous sheet.

Remarks. Strandesia vittata ( Sars, 1903) was recently allocated to Bradleycypris , because of the morphology of valves and soft parts, e.g. the carapace shape and features of the hemipenis ( Savatenalinton & Martens 2009c). This species was earlier recorded from China ( Sars 1903), Sri Lanka ( Gurney 1916), Celebes ( Indonesia) ( Tressler 1937) and Thailand ( Savatenalinton & Martens 2009c). The Thai specimens, both males and females, are found in three samples. This is the first report of a sexual population of this species.

Tribe Bradleystrandesiini Savatenalinton & Martens, 2009

Genus Bradleystrandesia Broodbakker, 1983