Supiyanit Maiphae

Species richness of the Cladocera (Branchiopoda: Anomopoda and Ctenopoda) in southern Thailand, and its complementarity with neighboring regions

Seventy-two cladoceran species from southern Thailand include eleven first records. Species accumulation curves were used to estimate the total number of species present, and Chao’s estimator was used to extrapolate the species number observed in 212 samples to the total number present. This S*max amounted to 76.06 species, with a low ratio of variance/estimator. Cladoceran faunas were compared by a complementarity index at three levels: between habitat types, between different zones of Thailand, and between Thailand and other countries. The geographical gradient was quite strong, but because not all areas have been studied to the same degree and with the same taxonomic accuracy, some comparisons are robust while others are not.

Two new species of genus Limnias from Thailand, with keys to congeners (Rotifera, Gnesiotrocha)

Abstract Two new species and two morphological variant taxa of sessile rotifers found during a survey of Thai rotifers are reported upon. Living specimens were collected and identified from twelve sampling sites. The specimens were photographed, and prepared for SEMs of dorsal plates and trophi. Two new species of genus Limnias are recognized. Limniaslenissp. n. possesses a corona with a relatively shallow ventral sinus, and a dorsal plate without any projection, whereas Limniasnovemcerassp. n. carries a corona with a deep and wide ventral sinus, and a dorsal plate with nine projections. Two morphological variants of Limniasmelicerta are discussed, which are designated as L.melicerta SH and L.melicerta LH on the basis of the length of the horns on their dorsal plates. Moreover, both a dichotomous key and a formula key are provide including all Limnias species known to date.