In the present study the zooplankton fauna of Lake İznik (Bursa) was investigated during January-December 2006. A total of 54 taxa-35 taxa from rotifers, 14 taxa from cladocerans, and 5 taxa from copepods-were identified in Lake İznik. Brachionus calyciflorus, B. angularis, Notholca squamula, N. acuminata, Euchlanis dilatata, E. deflexa, Platyias quadricornis, Trichocerca similis, T. cylindrica, T. chattoni, T. lophoessa, T. bicristata, Asplanchna girodi, Conochiulus dossuarius, Synchaeta pectinata, Lecane luna, L. bulla, L. stenroosi, L. clostrocerca, L. lunaris, Lepadella patella, Dicranophorus forcipatus, Mytilina mucronata, Lophocharis salpina, Trichotria tetractis, T. pocillum, Testudinella patina, Hexarthra fennica, and Collotheca sp. from the rotifera species; Diaphanosoma lacustris, D. orghidani, Daphnia cucullata, Ceriodaphnia quadrangula, Macrothrix laticornis, Alona rectangula, Leydigia leydigi, Graptoleberis testudinaria, Cyhdorus sphaericus, Pleuroxus aduncus, P. trigonellus, Alonella excisa, and Phrixura rostrata from the cladocera species; and Eucyclops macruroides, Paracyclops fimbriatus, Cyclops vicinus, and Thermocyclops crassus from the copepoda species are new records for Lake İznik. According to the QBrachionus/Trichocerca index (Q = 0.8) used for the determination of trophic level, the lake is oligotrophic.

In the present study the zooplankton fauna of Lake İznik (Bursa) was investigated during January-December 2006. A total of 54 taxa-35 taxa from rotifers, 14 taxa from cladocerans, and 5 taxa from copepods-were identified in Lake İznik. Brachionus calyciflorus, B. angularis, Notholca squamula, N. acuminata, Euchlanis dilatata, E. deflexa, Platyias quadricornis, Trichocerca similis, T. cylindrica, T. chattoni, T. lophoessa, T. bicristata, Asplanchna girodi, Conochiulus dossuarius, Synchaeta pectinata, Lecane luna, L. bulla, L. stenroosi, L. clostrocerca, L. lunaris, Lepadella patella, Dicranophorus forcipatus, Mytilina mucronata, Lophocharis salpina, Trichotria tetractis, T. pocillum, Testudinella patina, Hexarthra fennica, and Collotheca sp. from the rotifera species; Diaphanosoma lacustris, D. orghidani, Daphnia cucullata, Ceriodaphnia quadrangula, Macrothrix laticornis, Alona rectangula, Leydigia leydigi, Graptoleberis testudinaria, Cyhdorus sphaericus, Pleuroxus aduncus, P. trigonellus, Alonella excisa, and Phrixura rostrata from the cladocera species; and Eucyclops macruroides, Paracyclops fimbriatus, Cyclops vicinus, and Thermocyclops crassus from the copepoda species are new records for Lake İznik. According to the QBrachionus/Trichocerca index (Q = 0.8) used for the determination of trophic level, the lake is oligotrophic.