Predation on Recent Turritelline Gastropods from the Indian Subcontinent and Comparison with a Revised Global Database

Subaerial naticid gastropod drilling predation by Natica tigrina on the intertidal molluscan community of Chandipur, Eastern Coast of India

“…Unsuccessful and multiple (MULT) drillholes generally indicate for prey effectiveness against predation (Kelley et al, 2001;Mallick et al, 2013Mallick et al, , 2014Paul et al, 2013). Frequency of unsuccessful drillholes (PE) was defined as a ratio between number of incomplete drillholes and total number of attempted holes (e.g., both complete and incomplete holes combined) (Vermeij, 1987).…”

“…Drilling frequencies were calculated for all species separately, as well as for all bivalve and gastropod species together (Table 1). Moreover, because drilling frequency highly varies with prey size (Dudley and Vermeij, 1978;Allmon et al, 1990;Tull and Bohning-Gaese, 1993;Mondal et al, 2010;Paul et al, 2013; press), DFs were calculated for three different size classes: >1.5-10mm, >10.1-20mm,…”

“…For the gastropod prey, along with radial distribution on a four, equal-area grids, vertical position of the drillholes with respect to shell base was also documented and positions of drillholes were described on the basis of percentage of total shell height (Allmon et al, 1990;Paul et al, 2013;Das et al, 2014) (Fig. 7).…”

“…It has been shown that shell ornamentation can deter drilling predation (Arua and Hoque 1989;Kelley and Hansen, 1996;Klompmaker 2011; but see Signor, 1985;Paul et al, 2013;Klompmaker and Kelley, 2015;Sarkar et al, in press). To test the influence of external shell ornamentation on drilling predation in Chandipur, we have subdivided our six molluscan species into two subcategories -smooth-shelled (Sunetta scripta, Natica tigrina, and Donax incarnatus) and ornamented (Cerithidae cingulata, Timoclea imbricata, and Nassarius stolatus) -to test the hypothesis that smooth-shelled forms will have high DF as compared to their ornamented counterpart.…”

Shell ornamentation as a likely exaptation: evidence from predatory drilling on Cenozoic bivalves

“…Bivalve ornamentation has been postulated to be important for a variety of functions including maintaining a stable life position in the sediment, burrowing, shell strengthening, directing inhalant and exhalant currents, and protecting against predators (e.g., Trueman et al 1966;Carter 1967Carter , 1968Kauffman 1969;Stanley 1970Stanley , 1981Stanley , 1988Aller 1974;Thomas 1975;Arua and Hoque 1987;Harper and Skelton 1993;Kelley and Hansen 1996;Stone 1998;Harper and Kelley 2012). An anti-predatory function of ornamentation has also been suggested for Paleozoic and Mesozoic brachiopods (Leighton 2001(Leighton , 2003Vörös 2010;Johnsen et al 2013), Cretaceous and Paleogene ostracods (Reyment 1967;Reyment et al 1987), Jurassic nautiloids and ammonoids (Bardhan and Halder 2000;Kröger 2002), modern barnacles (Palmer 1982), and modern and fossil marine and continental gastropods (e.g., Bertness and Cunningham 1981;Arua and Hoque 1987;Donovan et al 1999;Paul et al 2013;Liew and Schilthuizen 2014), although Yochelson et al (1983) suggested that predation intensity on the sub-Holocene scaphopod Dentalium laqueatum increased with more ribs.…”