Indiacypris dispar Hartmann, 1964

George, Sunny & Martens, Koen, 2004, On the taxonomic position of Indiacypridinae (Crustacea, Ostracoda), with the description of a new species of Indiacypris Hartmann, 1964 from Chalakkudy River (Kerala, India), Journal of Natural History 38 (5), pp. 537-548 : 539-541

Indiacypris dispar Hartmann

( figures 1A–D, F–H , 2A–J )

Material investigated

About 20 parthenogenetic females from Chalakkudy River, about 50 m downstream of the confluence of Kannankuzhi Thodu and the main river, Kerala, India. All specimens, along with those of I. chalakkudensis n. sp., were collected with a hand net on 4 July 1999 from the benthic region along the river bank. Illustrated specimens are presently curated in the Ostracod Collection of the Royal Belgian Institute of Natural Sciences (Brussels, Belgium): six females either dissected or stored dry in micropalaeontological slides (nos OC.2435–2441), five females in ethanol (no. OC.2450) .

Abbreviated re-description

Valves strongly asymmetrical ( figure 1F, G ), with RV ( figure 1B ) with an asymmetrical indentation of the antero-ventral valve margin and with ventral margin rather sinuous. LV ( figure 1A ) with caudal margin asymmetrically produced in the lower two-thirds, anterior inner margin matching the curve of the anterior margin of the RV, thus allowing tight closure ( figure 1C, D, H ).

Natatory setae on A1 ( figure 2A ) and on A2 ( figure 2B, C ) of medium length, natatory seta 3 on A2 being the longest and not reaching middle of the endclaws. T2 ( figure 2F ) with endclaw rather short. Penultimate segment of T3 ( figure 2D, E ) approximately three times as long as its greatest width, distally clearly dilated. Caudal ramus ( figure 2G ) with proximal seta inserted close to the attachment, at about one-third of the total length of the ramus.

Male ( figure 2H–J , redrawn after Hartmann, 1964): hemipenis with largest lobe beak-shaped, rather pointed and with rounded distal margin, smaller lobe with short thumb-like process, distal margin concave. Left prehensile palp with distal segment rounded, relatively wide; right prehensile palp with distal segment very narrow, almost tubular, carrying long sensory organ.

Measurements (female, all in µm)

LV: Le=916, H=493. RV: Le=850, H=482. Cp: Le=901–940, W=282–292 (N =2).

Remarks

The parthenogenetic specimens illustrated here are nearly identical to the sexual ones illustrated by Hartmann (1964). The species thus constitutes a cluster of both sexual and asexual lineages. It is rather common in India and can be found in caves and wells, as well as in pools and rivers.

Figures

FIG. 1. Indiacypris dispar (A–D, F–H, all females) and I. chalakkudensis n. sp. (E, I–K). I. dispar: (A) LV, interal view (OC.2435); (B) RV, internal view (OC.2435); (C) Cp, right lateral view (OC.2438); (D) Cp, right lateral view (OC.2440); (F) Cp, dorsal view (OC.2436); (G) Cp, ventral view (OC. 2437); (H) Cp, right lateral view, detail anterior (OC.2438). I. chalakkudensis: (E) female, Cp, right lateral view (OC.2452); (I) female, Cp, right lateral view, detail anterior (OC.2452); (J) male, Cp, right lateral view, detail anterior (OC.2434); (K) male, Cp, right lateral view, total view. Scale: (H–J) 259µm; (A–G, K) 649 µm.

FIG. 2. Indiacypris dispar (A–G) female, OC.2436; (H–J) male (redrawn after Hartmann, 1964). (A) A1; (B) A2, detail of distal chaetotaxy; (C) A2; (D) T3; (E) T3, detail of distal segments; (F) T2; (G) caudal ramus; (H) left prehensile palp; (I) right prehensile palp; (J) hemipenis. Scale: (A, C, D, F, G) 53µm; (B, E) 132 µm; (H–J) unknown.