Preferential prey and attacking strategy of the purple dye murex (Bolinus brandaris) on three common bivalve species from Tunisia (Central Mediterranean Sea)

ABSTRACT

The purple dye murex (Bolinus brandaris) is an active predator that feeds mainly on bivalves, barnacles and other gastropods, further supplying its generalist diet through scavenging and cannibalism. The present study investigated B. brandaris feeding behaviour on three bivalves commonly found in the Bizerte lagoon (northern Tunisia): the unexploited lagoon cockle (Cerastoderma glaucum), and the harvested and commercially valuable carpet shell (Ruditapes decussatus) and Mediterranean mussel (Mytilus galloprovincialis). The purple dye murex showed a clear preference for feeding on C. glaucum and R. decussatus, distantly followed by M. galloprovincialis. Signs of attack were clearly visible in R. decussatus shells, but not in the other two bivalve species. Overall, B. brandaris attacked bivalves mainly by chipping and/or drilling their shells, but opening the valves was the most common feeding strategy. The present study provides a brief description of the predatory behaviour of the purple dye murex, together with the quantification and illustration of the attack patterns (chipped, drilled and/or broken valves) on these bivalve prey. Besides improving the current knowledge on the feeding ecology of the purple dye murex, this study provides helpful information for small-scale fisheries targeting this species and to further assess the aquaculture potential of B. brandaris.

KEYWORDS:

• Predator gastropod
• Muricidae
• Bolinus brandaris
• bivalve prey
• prey preference
• prey attack

Acknowledgements

The present study was undertaken within the framework of the bilateral cooperation project ‘The purple dye murex (Bolinus brandaris) – a valuable fishery in Portugal and a potential fishing resource in Tunisia: Baseline information for sustainable exploitation and management’ (Proc° 441.00), co-funded by the Fundação para a Ciência e Tecnologia – FCT (Portugal) and by the Ministère de l’Enseignement Supérieur et de la Recherche Scientifique (Tunisie). The authors also acknowledge Dr Carolin Löscher (Editor), Dr Jamileh Javidpour (Subject Editor) and two anonymous reviewers for their helpful comments that contributed for improving the present article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The present study was undertaken within the framework of the bilateral cooperation project ‘The purple dye murex (Bolinus brandaris) – a valuable fishery in Portugal and a potential fishing resource in Tunisia: Baseline information for sustainable exploitation and management’ (Proc° 441.00), co-funded by the Fundação para a Ciência e Tecnologia – FCT (Portugal) and by the Ministère de l’Enseignement Supérieur et de la Recherche Scientifique (Tunisie).