Astenocypris papyracea ( 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 : 5-7

Astenocypris papyracea ( Sars, 1903) ( Fig. 1)

1903 Leptocypris papyracea G.O. Sars : 29, Pl. 3, Fig. 4

1912 Astenocypris papyracea — G.W. Müller: 203.

Material examined. Two females from two samples: 1) one female from Chiangsan lake, Chiangsan district , Chiang Rai Province, 11 February 2006, coordinates: 20° 15´40.5˝ N and 100° 02´45.7˝ E (TH092); 2) one female from Kwan Phayao lake, Muang district , Phayao Province, 6 October 2007, coordinates: 19° 09´32.6˝ N and 99° 54´36.2˝ E (TH142) .

Diagnosis. Carapace in lateral view elongated, subquadrate; anterior margin broadly rounded, posterior margin truncate; valve surface striated; carapace in dorsal view narrow; LV in interior view without groove along valve margin, inner lamella weakly calcified, without inner list; RV in interior view without selvage; Wouters organ on A1 long, Rome organ short, aesthetasc ya short; b and d setae on T1 absent; T2 with d1 large, d2 short and slim (d1 c. 1.7 times d2); caudal ramus stout, ventral margin set with strong, but few, serrations, claws strongly serrated, distal seta long, set with a row of fine setulae; caudal ramus attachment stout, Triebel’s loop situated at middle of distal part of main branch, dorsal branch short, pointed-end, ventral branch short, blunt.

Differential diagnosis. Astenocypris papyracea ( Sars, 1903) has several unique characters of both valves and soft parts, e.g. subquadrate carapace in lateral view, striated ornamentation, stout caudal ramus with strongly serrated claws, absence of b and d setae on T1, morphology of d1 and d2 of T2. It cannot be confused with any other cypricercine species.

Measurements (in µ m). LV (n=2), L=1360–1660, H=685–770; RV (n=2), L=1350–1660, H=688–777. For full redescription, see George & Martens (1993).

Ecology. Sars (1903) reported Astenocypris papyracea from dried mud collected from a swamp in Sumatra. Subsequently, it was found from paddyfields (Kerala, India) by George & Martens (1993). In the present study, this species was only found from 2 lakes with pH 6.5–7.1 and temperature 22.5–26.8° C.

Remarks. Astenocypris papyracea , which was originally raised and described from dried mud from Sumatra ( Indonesia) by Sars (1903), was redescribed by Victor & Fernando (1981a) on the same material and by George & Martens (1993), the latter based on new material from India. This species is rare. We found only 2 specimens from 2 samples. This is the first record from Southeast Asia after its original description more than 100 years ago.

Tribe Cypricercini McKenzie, 1971

Genus Strandesia Stuhlmann, 1888