Naslov
Drilling and chipping patterns of bivalve prey shell penetration by Hexaplex trunculus (Mollusca: Gastropoda: Muricidae)

Autori
Morton, Brian ; Peharda, Melita ; Harper, Elizabeth

Izvornik
Journal of the Marine Biological Association of the United Kingdom (0025-3154) 87 (2007), 4; 933-940

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
gastropod; whelk; Hexaplex trunculus; predation; Adriatic

Sažetak
The predatory caenogastropod Hexaplex trunculus employed different methods to access different species of bivalve prey characterized by different shell thicknesses. Hexaplex trunculus drilled Callista chione and Venus verrucosa at their shell margins but the latter species also laterally. It also attempted to drill two species of Tapes but successfully penetrated these only after chipping the shell margin. Chipping, whereby a labral spine is forcibly pushed between the prey's valves, especially posteriorly, to break them followed by proboscis insertion, was typically applied to access the thinner shelled prey Cerastoderma glaucum whereas Modiolus barbatus and Mytilus galloprovincialis were either chipped or drilled. The pattern of M. galloprovincialis shell penetration appears related to predator and prey size. Small (40mm shell height) H. trunculus tended to drill rather than marginally chip M. galloprovincialis. Medium sized (55mm shell height) H. trunculus either chipped or drilled M. galloprovincialis in approximately equal proportions but also at the valve margin. Larger (70mm shell height) H. trunculus tended to laterally drill average sized (35mm shell length) and the biggest (65mm shell length) M. galloprovincialis. When larger M. galloprovincialis are attacked it thus becomes increasingly more difficult for H. trunculus to chip and drill the shell margin, possibly because the periostracum is thicker here in such individuals, and the predator resorts to lateral drilling. This is possible because as the mytilid ages its surface periostracum becomes progressively eroded and thus thinner and easier to access. SEM identified shell microstructure damage shows that the chipping and drilling behaviours of H. trunculus result from labral spine damage and dissolutional etching, respectively, rather than mechanical radula rasping. These observations have implications for the use of such predation marks to identify the predator taxon implicated from holes in either empty recent shells or fossil material.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Poljoprivreda (agronomija)

POVEZANOST RADA