Vol. 45 No. 3, 2006

Kin Recognition during Intraspecific Predation by Harpacticus sp. (Copepoda: Harpacticoida)

Hans-Uwe Dahms* and Pei-Yuan Qian

Department of Biology and Coastal Marine Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China

Hans-Uwe Dahms and Pei-Yuan Qian (2006) Female predation on developmental instars of its own as well as on conspecific alien offspring is reported for a new species of Harpacticus sp. from Hong Kong waters. The intensity of predation by Harpacticus females on their own offspring compared to that on offspring of conspecific females did not differ which indicates that females do not spare their individual offspring. The nutritional status of females affected the intensity of their predation on nauplii. When starved, they consumed about twice as many nauplii as they did when being fed algae. Intraspecific predation was found to be density-dependent. Enhanced predation with increasing female/nauplius ratios could be explained by the increasing probability of female/nauplius encounters. Feeding ratios were determined and a functional ingestion response is discussed with findings from the literature.

Key words: Kin recognition, Intraspecific predation, Density, Nauplius, Copepods.

*Correspondence: Tel: 852-23588417. Fax: 852-23581559. E-mail: boqianpy@ust.hk