A Mating Aggregation of the Spider Crab ( Libinia emarginata )

• Published in: Journal of Northwest Atlantic fishery science Vol. 13; pp. 77 - 82
• Main Authors: Degoursey, R E, Auster, P J
• Format: Journal Article
• Language: English
• Published: Dartmouth Dartmouth, Canada :Northwest Atlantic Fisheries Organization,1980 1992; Northwest Atlantic Fisheries Organization, NAFO
• Subjects: Aggregation; Crustacea; Crustaceans; Eggs; Females; Fishers; Libinia emarginata; Majidae; Males; Marine; Marine crustaceans; Reproductive behaviour; Scuba diving
• ISSN: 0250-6408; 1682-9786; 1813-1859
• DOI: 10.2960/j.v13.a6

Observations made while SCUBA diving report for the first time in the spider crab (Libinia emarginata) the occurrence of a mating aggregation in Fishers Island Sound, Connecticut, USA. Observations between 30 April and 20 May 1986 showed the aggregation covered a depth range of 5-8 m and an area of approximately 5 000 m2 at a density of approximately 1 crab/m2 . There was no significant difference between the sizes of mature females and ovigerous females. Paired males were significantly larger than unpaired males in the overall population, while paired females were not significantly larger than unpaired females in the overall population. There was no correlation between male and female size in paired crabs. Observations of agonistic bouts between males, and male-female pairs exhibiting "obstetrical" behaviour, supplement previously published laboratory observations. However, the observations of "obstetrical" behaviour showed it has a wider context that involved mature, nonovigerous females as well as females with newly extruded eggs, and suggested that this behaviour should instead be called "protective" behaviour.