The behavioural ecology of epibenthic scavenging invertebrates in the Clyde Sea area: laboratory experiments on attractions to bait in moving water, underwater TV observation in situ and general conclusions

Abstract

The attractions to bait of eight species of epibenthic scavenging invertebrates, i.e. Asterias rubens L., Buccinum undatum L., Cancer pagurus L., Ophiocomina nigra (Abildgaard), Liocarcinus depurator (L.), Pandalus montagui (Leach), Hyas araneus (L.) and Pagurus bernhardus (L.), were examined in current tank experiments at high (0.3 m s −1) and low (0.1 m s −1) water current velocities. The swimming crab L. depurator showed the greatest upstream response towards bait in the low current velocity trials, while the hermit crab P. bernhardus showed the greatest attraction to bait in the high current velocity trials. There was a significant association between the rank orders of the above species caught in baited traps in the field and their relative performance in the high current velocity experiments in the laboratory. Baited TV cameras in situ confirmed the importance of P. bernhardus and B. undatum as scavengers in the Clyde Sea area.