Substrate-controlled naticid gastropod drilling predation on recent barnacles from Chandipur, India and its Palaeontological implications

ABSTRACT

The study of drilling predation has been largely limited to molluscs. Herein, we report drilling predation on Recent acorn barnacles by gastropods from Chandipur, eastern India. The aspects of predator-prey relation dealt here are the size and site preference of the predator; the interrelationship between barnacle shell morphology (e.g., shape, external ornamentation) and drilling intensity; and influence of substrate type on body size and shape of barnacles, as well as predation pressure on it. The study reveals that, barnacles are drilled by the naticid gastropods, which is otherwise an uncommon interaction. Drilling intensity on the barnacles attached to a semi-infaunal bivalve, Timoclea imbricata, is exceptionally high and is comparable to the drilling intensity on the host bivalve. Otherwise, predation pressure is very low on barnacles, supporting previous literature. The study implies that unique live-live associations can create opportunities such that even an unusual predator (e.g., Naticidae) can successfully feed on a novel prey (e.g., barnacles), suggesting dietary opportunism. Studies dealing with the fossil record of drillholes should consider these different ecological (e.g., prey selectivity by the predator, host selection by the epizoan, role of unusual predator on an uncommon prey) aspects of drilling predation on barnacles through space and time.

KEYWORDS:

• Semi-infaunal prey
• acorn barnacle
• bivalve as substrate
• anti-predatory adaptation
• muricid predation

Acknowledgments

SM received partial funding from his DST (SERB) Fast track project (SR/FTP/ES-133/2014), The UPE II Grant, 2018 CU, and the Department Research Grant for Teachers (RGT), CU. PG acknowledges Durgapur Government College for providing the funds and infrastructural facilities. Prof. Subir Mukherjee, Jadavpur University is acknowledged for logistic help. KB acknowledges Indian Statistical Institute, Kolkata for providing infrastructural facilities. S Mallick acknowledges Triveni Devi Bhalotia College for providing partial funding for the fieldwork. Greg Dietl and an anonymous reviewer provided valuable input.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Durgapur Government College; Triveni Devi Bhalotia College; Science and Engineering Research Board [Fast track project (SR/FTP/ES-133/2014)]; University of Calcutta [RGT,UPE II Grant, 2018].