Pseudosida szalayi ( Daday, 1898 )

Korovchinsky, Nikolai M. & Sanoamuang, La-Orsri, 2008, Overview of Sididae (Crustacea: Cladocera: Ctenopoda) of Northeast and East Thailand, with description of a new species of the genus Diaphanosoma, Zootaxa 1682, pp. 45-61 : 55

Pseudosida szalayi ( Daday, 1898)

( Figs 30–32 )

Daday, 1898: 64–66, Fig. 33a–d ( Parasida ); Korovchinsky, 1992: 67, figs 330–335, 337–342; 2004: 339, Fig. 134, 135 (2–7).

Material: numerous specimens (females) from 53 localities in Northeast and East Thailand.

Diagnosis. Antennules long with sensory papillae on a small lateral prominence of its basal part ( Fig. 30 ). One spine at the end of proximal segment of upper 2-segmented antennal branch much longer and thinner than neighbouring one. Formula of antennal setae (5–6)–(9–11) / 0–1–3. Postabdomen with noticeable dorsal acute outgrowth of different shape and size near base of terminal claws ( Figs 31, 32 ). One row of 8–14 clusters of anal teeth on each side of postabdomen (each cluster with 3–6 thin lanceolate teeth).

Remarks. The erroneous tradition to identify pseudosidas from southern Asia as P. bidentata Herrick , originally describing from North America, had been established in some recent decades ( Rajapaksa & Fernando 1982; Idris 1983; Boonsom 1984; Michael and Sharma 1988; Sanoamuang 1998; Maiphae et al., 2005) though it was not based on solid grounds. Meanwhile, all Thai specimens studied during the present investigation had diagnostic features of another species— P. s z a l a y i, originally describing from Sri Lanka, which has proved to be abandoned for a long time. They have the characteristic long antennules with small lateral prominence with sensory papillae and long thin dorsal outgrowth between postabdominal claws.

Figures

FIGURES 30 – 32. Pseudosida szalayi, female, canal in Hui Nong Nam Jun, Akat Amnuai dt., Sakon Nakhon Province. 30) antennule, 31) distal part of postabdomen, lateral side, 32) the same, ventral side. Scale bars in mm.