Abstract
Fish predation upon two species of caprellid amphipods was measured in the laboratory with the aid of microcomputer analysis of video-images. This technique allowed determination of prey preferences when the predator was exposed to multiple prey specimens exhibiting multiple prey behaviors. Shiner perch Cymatogaster aggregata (Gibbons) were used as visual predators, Caprella laeviuscula Mayer represented caprellid prey which frequently move, and Deutella californica Mayer represented caprellid prey which seldom move. Time intervals between the release of fish into the test aquarium and predatory strikes were measured during four caprellid behaviors: free in the water column, crawling on hydroids, filter-feeding by pulling the antennae through the water, and remaining stationary. There are three levels of fish selectivity in decreasing importance: 1. (1)fish selected active species over the sedentary species, 2. (2) fish selected caprellids that were overtly moving: swimming > crawling or filtering > stationary, and 3. (3) fish preferentially selected caprellids by size (larger body length).
Sign-in/Register to access full text options 
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
