Streblocerrus serricaudatus S. LAT.

Streblocerrus serricaudatus (Fischer, 1849) S.LAT. 1849. Daphnia serricaudata Fischer. Bull. Soc. Imp. Nat. Mosc. 22: p.45-50, tab. IV, figs. 2-3. 1862. Streblocerus minutus Sars, Forhandl. Vidensk. Selesk. Christinia (1861), p. 284-285. 1988. Streblocerrus serricaudatus Michael & Sharma, Fauna of India. Indian Cladocera. P. 113-114, figs. 35, D-E. 3.1 Materials Examined 4 EXS., 04-vi-2015, Pechiparai dam, Lowerkodayaar, Mylaar, coll. S. Prabakaran; 3exs., 05-XII-2018, Lower Kodayaar, Power House II, Mothiramalai, Kanyakumari dist., coll. J. Thilak. 3.2 Diagnostic Characters The genus Streblocerus comprises of the smallest Macrothricids characterised by a bent antennule bearing laterally a few long setae, convolutions in the gut and a short bilobed postabdomen. Small, rounded-oval shaped body with dorsum evenly arched, ventral surface produced in the middle, posterior end with indistinct protuberance. Valves reticulate, dorsal margin smooth and ventral margin with setae. Post abdomen with rounded anal part and with spines, preanal part serrate and bearing rows of fine setules on inner edge, claws small, curved and bears setae on its concave margin. Only females were recorded during the present study. Length-0.91- 0.90mm. 3.3 Earlier Report From India it is from Rajasthan (Biswas, 1971) [2], Manipur (Patil, 1976) [4]. It is Holarctic, predominantly in its northern portion, but some unrevised populations are found in Chile, New Zealand, Australia (Paggi 1976; Smirnov, 1992) [4, 12]. 4. Distribution Assam, Meghalaya, Manipur, Rajasthan, India. 5. Elsewhere Europe and North America.