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Longevity and Change in Shell Condition of Adult Male Snow Crab Chionoecetes opilio Inferred from Dactyl Wear and Mark‐Recapture Data
Author(s) -
Fonseca Duane B.,
SainteMarie Bernard,
Hazel François
Publication year - 2008
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/t07-079.1
Subject(s) - longevity , population , biology , snow , mark and recapture , zoology , fishery , ecology , demography , geography , meteorology , genetics , sociology
Postmolt longevity and changes in the shell condition and body integrity of male snow crab Chionoecetes opilio after their terminal molt were assessed through a mark‐recapture experiment and population censuses in a commercially unfished locality of eastern Canada. The experiment explored the value of dactyl wear as a quantitative measure and shell condition (SC; measured on a five‐stage scale) as a relative index of shell age. Males were recaptured up to 6 years after release. Much of the extensive variation in observed dactyl wear was explained by time at liberty (Δ t ) and male size, and the extent of change in SC was positively correlated with Δ t . The conservative wear‐based estimate of male longevity was 7.7 years, a value 1‐3 years greater than previously estimated. Dactyl wear and recapture data confirmed that SC is a relative, albeit rough, index of shell age. Shell hardness was positively correlated with male size and peaked in stage 3 about 3.5 years after the terminal molt. The number of missing pereopods increased with shell age and SC stage and overall was negatively correlated with male size. The commercial value of adult males may be highest at 1‐4.5 years post‐terminal molt and the reproductive value at 2‐5.5 years.