Abstract
ABSTRACT Feeding behavior of various life stages of the carnivorous copepods Tortanus spp. (mixture of T. forcipatus and T. glacilis) was investigated. Tortanus can capture prey copepods having up to approximately 100% of its own prosome length, but it only partially consumes larger prey copepods. Larger developmental stages of Tortanus tend to select larger prey. The functional response of various developmental stages of Tortanus was determined at 25, 20, and 15°C, using Oithona davisae CV and CVI, numerically dominant small copepods in Fukuyama Harbor, as prey. Ingestion rate increased with increasing prey density up to maximum rate. Maximum ingestion rate was highest at 25°C and decreased with decreasing temperature. Maximum specific ingestion rate at a given temperature was highest for CI―CIII and decreased for the later stages. Based on abundances of various developmental stages of Tortanus and small planktonic crustaceans (O. davisae, Parvocalanus crassirostris, and others) and the variation in water temperature in Fukuyama Harbor, the calculated predatory impact of Tortanus is small. Less than 2.7% of the prey populations are consumed per day by Tortanus.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call