Diaphanosoma tropicum Korovchinsky, 1998

Pascual, Jhaydee Ann F., Rizo, Eric Zeus C., Han, Boping, Dumont, Henri J. & Papa, Rey Donne S., 2014, Taxonomy and distribution of four Cladoceran families (Branchiopoda: Cladocera: Moinidae, Bosminidae, Chydoridae and Sididae) in Philippine inland waters, Raffles Bulletin of Zoology 62, pp. 771-794 : 787

Diaphanosoma tropicum Korovchinsky, 1998

Specimen examined. Five parthenogenic female, two mounted (UST ZRC 0112-0113-Lake Pandin, Laguna), One specimen with decapitated head with two damaged beyond repair.

Description. Separated from D. modigliani by ( Korovchinsky, 1998) after re-assessing its occurrence outside Lake Toba in Indonesia, it is characterized by a cone shaped head almost 1/3 of its body size. Its first record in the Philippines is in Lake Taal ( Papa & Zafaralla, 2011). It exists in several lakes in Luzon Island and co-existing with the more common D. sarsi and D. excisum . Ends of the distal segment of its swimming antennae have a noticeable curved spine often having hook like appearance. The postero-ventral margin of its carapace have noticeable differing denticles as they progress dorsally and long thin setules between them. Its post abdomen prominently dorsal and have a strong convex curve. Outside of the country it is found in Malaysia, Thailand, India, Sri Lanka and China ( Fernando, 2002) ( Fig. 29).

Distribution. Ilocos Norte: Lake Paoay; Tarlac: Lake Tambo; Laguna: Lake Bunot, Lake Palakpakin, Lake Pandin, Lake Lumot-Mahipon, Laguna De Bay; Batangas: Lake Taal; Camarines Sur: Lake Bato, Lake Baao, Lake Buhi ( Fig. 23 ).

Remarks. Recent re-evaluation of localities of D. modigliani outside Lake Toba by Korovchinsky in 1998 where the species is commonly associated with have shown that the species is also present in India, Sri Lanka, China, Thailand and Malaysia. Found in lakes and reservoirs co-existing with other limnetic cladocerans with aquaculture. It is an adaptive species that can survive slightly brackish water and a wide range of varying physico-chemical parameters. It is differentiated from D. modigliani and D. dubium from its strongly curved antennal spine and prominently curved post abdomen.

Figures

Fig. 23. Distribution of family Sididae based on recently collected samples (2013) and stored samples in the UST ZRC.