Chydorus cf. sphaericus (Mueller, 1785)

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 : 774-776

Chydorus cf. sphaericus (Mueller, 1785)

Specimen examined. Six parthenogenic female.One mounted specimens (UST-ZRC 0120-Lake Malbato, Palawan). Four were not mounted due to rarity of specimens collected. One specimen was damaged beyond repair.

Description. Chydoridae is the largest family in Anomopoda and the largest family under Superorder Cladocera . It has two recognised sub families: Chydorinae and Aloninae ( Dumont & Negrea, 2002) . Chydorus sphaericus is one of the most common species of chydorids found worldwide. It is characterised by a subglobular body with valves having polygons. It has a well pointed rostrum and a very short antennule. Its labral plate is cuneiform and has an elongated tip. It has a short post abdomen with 8–10 anal teeth. It occurs in both the littoral and the limnetic zones. It has limited distribution in the Philippines found mostly in freshwater bodies with good macrophyte cover in the littoral zones. ( Fig. 8 )

Distribution. Palawan: Lake Malbato; Misamis Oriental: Lake Danao; Bukidnon: Lake Pinamaloy ( Fig. 7 ).

Remarks. It has a possible worldwide distribution but are less morphologically variable in the tropics. Recognised as a species complex and possibly be separated into several genera and species. It occurs in both littoral and limnetic zones. It is dominant in highly eutrophic waters with dense macrophyte cover.

Figures

Fig.8.Chydorus cf.sphaericus parthenogenic female.Lake Malbato, Coron, Palawan. A, habitus; B, antennae; C, post abdomen.

Fig.7. Distribution of family Chydoridae based on recently collected samples (2013) and stored samples in the UST ZRC.