Cheliped morphological variation of the intertidal crab Eriphia verrucosa across shores of differing exposure to wave action

Experimental predatory behavior of the stone crab Eriphia verrucosa (Forskål, 1775) (Decapoda, Brachyura, Eriphiidae)

“…According to the food habits of this intertidal predator (Rossi and Parisi 1973;Brazão et al 2009;Silva et al 2010), six prey species were chosen as potential food items. The oyster Magallana angulata (Lamarck, 1819), the mussel Mytilus galloprovincialis Lamarck, 1819 and the limpet Patella depressa Pennant, 1777 were used in representation of sessile preys, and the hermit crab Clibanarius erythropus (Latreille, 1818), the toothed top shell Phorcus lineatus (da Costa, 1778) and the rock sea urchin Paracentrotus lividus (Lamarck, 1816) as representatives of vagile prey.…”

“…Likewise, due to the human extraction of E. verrucosa specimens to use them as bait or for human consume, in the Gulf of Cádiz the species is currently not observed under the stones at some rocky habitats with free access of visitors and shellfish gatherers (as, for instance, Santibáñez beach), whereas it was very abundant at others with restricted human access as the military protected area of Torregorda (Stevčić et al, in press). Top predators as E. verrucosa could play a significant role in structuring intertidal communities (Rilov and Schiel, 2006;Silva et al, 2010). Indeed, using predatorexclusion experiments, Silva et al (2008) observed a significant reduction of limpet densities when crabs predation was occurring.…”

“…Crabs are highly mobile and are known to have an important role in structuring assemblages on rocky shores worldwide (Behrens Yamada and Boulding, 1996;Rilov and Schiel, 2006;Silva et al, 2008;Forsstrom et al, 2015). They are predators of intertidal hard-shelled prey such as limpets, mussels, gastropods and sea urchins (Turra et al, 2005;Silva et al, 2010;Laitano et al 2013). When they feed on these hard-shelled preys, many crabs are capable of extracting the meat by peeling the shell aperture and thus avoid spending more time and energy in shell crushing (Rossi and Parisi, 1973).…”

“…Nevertheless, other predators also feed on mollusks and will contribute to overall effects on these preys (Silva et al, 2010). According to Rossi and Parisi (1973), specimens of E. verrucosa carry their prey (especially those of larger dimensions) toward the shelter; then the predator may use the walking legs to subdue and kill their prey without necessarily breaking the shell, or may use its pair of chelae to break the shell by exerting pressure and prying action in the area of the margin of the shell aperture.…”

Ecomorphology of crabs and swimming crabs (Crustacea DecapodaBrachyura) from coastal ecosystems

“…Additionally, robust chelipeds may also assist in protecting crabs against the mechanical action of waves by improving the contact area and adherence of the body to the uneven substrate. This inference is based on the study of Eriphia verrucosa (FORSKAL, 1775) by SILVA et al (2010), who recorded individuals with stronger chelipeds in exposed biotopes of rocky shores than those found in protected areas of the same environments. These observations may explain the robust major cheliped of the crabs in the Complex Substrates of this study, which are composed of Eriphidae, Grapsidae, Menippidae, Panopeidae and Pilumnidae, found on rocky shores and in oyster lantern nets.…”