Diaphanosoma dubium Manuilova, 1964

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 : 783

Diaphanosoma dubium Manuilova, 1964

Specimen examined. Eight parthenogenic female (six Philippine specimens and two Chinese specimens). Three mounted Philippine specimens and one Chinese specimen ( UST-ZRC 0114 - Lake Sampaloc, Laguna; 0115, 0116 - Lake Tambo, Tarlac; Guangzhou City , Guangdong-0117). Four specimens were damaged beyond repair .

Description. This Diaphanosoma species is characterised by a very large cone-shaped head, almost ½ of its body size. Spine on the apical end of the antennal branch can either be curved or straight. Number of denticles in its carapace is increasing with body size with thin setules in between them. It commonly coexists with D. tropicum in tropical and sub- tropical Asia ( Korovchinsky, 2000). In the Philippines it also co-occurs with D. sarsi and D. excisum in several freshwater bodies in Luzon ( Fig. 24 ).

Distribution. Tarlac: Lake Tambo; Laguna: Lake Bunot, Lake Yambo, Lake Mohicap, Lake Palakpakin, Lake Pandin, Lake Sampaloc, Lake Caliraya, Laguna De Bay; Camarines Sur: Lake Baao, Bicol River; Agusan Del Norte: Agusan River ( Fig. 23 )

Remarks. Species can also be found in Russia, China, Mongolia, Bangladesh, Thailand, Sri Lanka, Vietnam and Malaysia. Comparative specimens collected from China (Ming Lake, Jinan University, Guangzhou City) have strongly curved apical antennal spine in comparison with Philippine specimens with straight spines. The species is common in lakes, reservoirs and fish ponds. It is primarily limnetic and can co-exist with other sidids and limnetic cladocerans. Species have bigger head in comparison with its two closely related species D. tropicum and D. modigliani . It has a variable spine on its antennal branches ranging from straight to strongly curved.

Figures

Fig. 24. Diaphamosoma dubium parthenogenic female.A, habitus; B, postero-ventral valve margin; C, distal part of second segment of upper 2-segmented antennal branch (Phil.); D, distal part of second segment of upper 2-segmented antennal branch (China); E, postabdomen.

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