Comparative investigation of Sididae (Crustacea: Branchiopoda: Cladocera) of Northern and Western Thailand, with additional notes on Diaphanosoma Senegal isanensis Korovchinsky et Sanoamuang, 2008

摘要

The first extensive investigation of Cladocera from Northern and Western Thailand has revealed eight species of the family Sididae (Diaphanosoma excisum Sars, 1885, D. dubium Manuilova, 1964, D. sarsi Richard, 1894, D. volzi Stingelin, 1905, D. Senegal isanensis Korovchinsky et Sanoamuang, 2008, D. elongatum Korovchinsky et Sanoamuang, 2008, Latonopsis australis Sars, 1888, Pseudosida sza-layi (Daday, 1898)) among which two former species, Diaphanosoma excisum and D. dubium, were most widely distributed and abundant; while, D. Senegal isanensis and D. elongatum were rare or extremely rare, found only in four and one locality, respectively. Sididae species were often observed co-occurring in different combinations, among them up to three species of Diaphanosoma have been recorded as sympathise. A few species of the Sididae of northern origin found earlier in Northeastern Thailand were not encountered in the regions under consideration, probably due to their comparatively higher elevation and isolation from the influence of large rivers flowing from the north and promoting the migration of aquatic species to the south. Additional investigation of D. Senegal isanensis, including its representatives from Laos and Cambodia, has allowed to analyze size-frequency distribution and age-dependent morphological variability, to describe males of the subspecies for the first time and to summarize data of subspecies distribution throughout Southeast Asia.