Nassariid whelks hitch-hiking on Cancer pagurus: phoresis, commensalism or fouling?. (5th October 2015)

• Record Type: Journal Article
• Authors: Davenport, John; McCullough, Sheila; Thomas, Robert W.; Harman, Luke; McAllen, Rob
• Is Part Of: Marine biodiversity records. Volume 8(2015)
• Publication Date: 2015-10-05
• Subjects: phoresy/phoresis, -- commensalism, -- fouling, -- whelks, -- Nassarius, -- Cancer pagurus, -- hitch-hiking; Marine biodiversity -- Periodicals; Marine biology -- Periodicals; 578.77
• DOI: 10.1017/S1755267215001232
• Languages: English
• ISSNs: 1755-2672

Abstract

Abstract : The behavioural responses of scavenging animals to mackerel ( Scomber scombrus ) baits were studied by short-term video photography in shallow water (16–18 m depth) at Lough Hyne, Ireland. Earliest arrivals (after seconds/minutes) at baits were small fish or swimming crabs ( Liocarcinus depurator ), followed by crawling portunid crabs. After tens of minutes, juvenile whelks 2–4 mm shell length ( Nassarius reticulatus and/or Nassarius incrassatus ) sometimes arrived to feed. They moved at a mean speed of 1.24 (SD 0.392) mm s −1 . After tens of minutes or hours, single large scavengers arrived, consuming most of the bait; the most common of these were Cancer pagurus that fed in a wasteful fashion, generating large quantities of mackerel scraps. Cancer pagurus moved into view at a mean speed of 48.7 (SD 16.9) mm s −1 (39 times the whelk speed). A single individual of C. pagurus (197 mm carapace width) arrived at a bait carrying 24 juvenile whelks on the dorsal surface of its carapace. No whelks were present on walking legs or chelipeds. The crab fed for 6.8 min and 3 whelks fell off before it departed. The nature of this crab/whelk association is discussed; on balance it appears that it is a previously unreported example of phoresy/phoresis. No whelks were observed being carried by other edible crabs or upon large numbers of scavenging portunid crabs.