Predation upon postlarval lobsters Homarus americanus by cunners Tautogolabrus adspersus and mud crabs Neopanope sayi on three different substrates: eelgrass, mud and rocks

Abstract

assess the anti-predator function and efficiency of burrows formed in different substrates, late Stage IV or early Stage V lobsters were placed in seawater tables with mud, rocks (some with algae), or eelgrass. They were allowed 4 d in which to settle and build burrows, after whlch predators were placed into half of the seawater table sections. The remaining sections served as predator-free controls. Censuses were taken of the number of lobsters without burrows during the 4 d preceding predator introduction. Following predator introduction, behavior of both lobsters and predators was observed to note how predators located and captured lobsters and how, if at all, lobsters escaped.The census data showed that more lobsters had burrows in the rock substrates than in either the eelgrass or mud substrates. Fewer lobsters had burrows in mud substrates than in eelgrass substrates. When subject to predation by cunners Tautogolabrus adspersus, no predation occurred in the rock substrate. However, significant predation occurred in the mud and eelgrass substrates. When subject to predation by mud crabs Neopanope sayi, predation occurred in all 3 of the substrates.