Document Type

Article

Date of Original Version

1992

Department

Zoology

Abstract

Postlarval Homarus arnericanus were collected from Block Island Sound, Rhode Island, USA, during 5 diel neuston sampling periods in summer 1988 and 1989. The foregut contents of the postlarvae were determined and compared with the relative abundances of potential prey groups in the plankton. Nine taxonomic prey groups were identified in the gut contents (N = 802). The composition of the prey groups and their relative frequencies of occurrence in the guts did not differ with time of day or sampling period. The frequent occurrence of copepods, decapod larvae, fish eggs and insect parts indicates a predominantly carnivorous feeding habit. Furthermore, the disproportionate frequency of occurrence of large copepod species and decapod larvae in the guts relative to their densities in the plankton suggests a preference for larger sized prey. Contrary to expectations, the mean gut fullness and condition of gut contents of individuals at different molt stages were not significantly different. Likewise, there was no significant difference in the incidence of guts with newly ingested prey between postlarvae in the premolt stages and those in the post and intermolt stages. Completely empty guts were rare. In addition, the variability in gut fullness and the condition of gut contents among individuals was high during all sampling periods. These indicate that postlarvae in the field forage successfully throughout the day. However, the significantly higher incidence of newly ingested prey in the guts of postlarval lobsters at night indicates a higher feeding activity during this time.

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