Zooplankton succession of the Asi River (Hatay-Turkey)

Abstract

In the study, zooplankton succession and zooplankton species diversity of Asi River were researched with weekly sampling between 12.05.2005 and 05.05.2006, and in the study, totally 89 taxa were identified including 58 species from Rotifera, 16 species from Cladocera and 15 species from Copepoda. During the study period, Rotaria rotatoria (Pallas, 1766), Brachionus calyciflorus, Cephalodella gibba (Rotifera), Ilyocryptus sordidus (Cladocera) were found each month. The most species of zooplankton were found in March (50 species) and the second most species with 45 species was found in September, while the minumum species (20 species) was found in August. Also, it was found that the most common genus in the study were Brachionus (9 sp), Lecane (8 sp), Keratella (5 sp). The most abundant species in the present study was B. angularis (188 ± 17.68), Euchlanis dilatata (150 ±23.33), B. calyciflorus (129 ±14.14) (Rotifera), Moina micrura (143 ±3.54), Chydorus sphaericus (101 ±27.58), Simocephalus vetulus (100 ±46.67) (Cladocera), Eucyclops speratus ( 218 ±6.36), Nitocra hibernica (91 ±7.78) (Kopepoda). Total zooplankton was the most abundant in May with 1897 induvidual/20L, the second abundance was in September with 1514 ind/20L and the least abundance was found in January (379 adet/20L). It was seen that there were significant and positive relationship between temperature and abundance of some zooplankton species, R. neptunia (R2 = 0.65), B. angularis (R2 = 0.71), B. calyciflorus (R2 = 0.77), B. urceolaris (R2 = 0.82), B. quadridentatus (R2 = 0.58), Asplanchna sieboldi (R2 = 0.82), Polyartra dolichoptera (R2 = 0.56), Cephalodella gibba (R2 = 0.54), F. longiseta (R2 = 0.85) (Rotifera); Alona rectangula (R2 = 0.66) (Kladosera); and Megacyclops viridis (R2 = 0.57), Eudiaptomus drieschi (R2 = 0.81) and Nitocra hibernica (R2 = 0.59) (Kopepoda).