TY - JOUR
T1 - Growth and reproduction in spiny dogfish Squalus acanthias L. (Elasmobranchii
T2 - Squalidae), from the west coast of Ireland
AU - Henderson, Aaron C.
AU - Flannery, Kevin
AU - Dunne, James
PY - 2002/12/19
Y1 - 2002/12/19
N2 - The age, growth characteristics, maturity, and reproductive cycle of commercially caught spiny dogfish Squalus acanthias were investigated over a 12 month period. The specimens ranged in age from 4 to 30 years, with asymptotic lengths of 79 and 112 cm estimated for males and females, respectively. The lower age range reported here when compared with previous North Atlantic studies is attributed to fishing pressure. Fifty per cent maturity was estimated at 57.5 cm in males and 78.2 cm in females, and fecundity was positively correlated with female size. Although recently formed candles and full-term embryos were observed throughout the year, parturition occurred mainly from August to January. The minimum fecundity recorded was four (determined from developing ova/candled embryos), while the maximum was 16 (determined from embryo counts), and fecundity was found to increase by up to four between pregnancies. The overall sex ratio of embryos was 1:1, although this balance was rarely observed in any one female. The results presented here indicate that neither growth rate, size at maturity, nor fecundity have significantly changed due to fishing pressure.
AB - The age, growth characteristics, maturity, and reproductive cycle of commercially caught spiny dogfish Squalus acanthias were investigated over a 12 month period. The specimens ranged in age from 4 to 30 years, with asymptotic lengths of 79 and 112 cm estimated for males and females, respectively. The lower age range reported here when compared with previous North Atlantic studies is attributed to fishing pressure. Fifty per cent maturity was estimated at 57.5 cm in males and 78.2 cm in females, and fecundity was positively correlated with female size. Although recently formed candles and full-term embryos were observed throughout the year, parturition occurred mainly from August to January. The minimum fecundity recorded was four (determined from developing ova/candled embryos), while the maximum was 16 (determined from embryo counts), and fecundity was found to increase by up to four between pregnancies. The overall sex ratio of embryos was 1:1, although this balance was rarely observed in any one female. The results presented here indicate that neither growth rate, size at maturity, nor fecundity have significantly changed due to fishing pressure.
KW - Dogfish
KW - Growth
KW - Northeast Atlantic Ocean
KW - Reproduction
KW - Shark
UR - http://www.scopus.com/inward/record.url?scp=0037137760&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037137760&partnerID=8YFLogxK
U2 - 10.1080/0036482021000155805
DO - 10.1080/0036482021000155805
M3 - Article
AN - SCOPUS:0037137760
SN - 0036-4827
VL - 87
SP - 350
EP - 361
JO - Sarsia
JF - Sarsia
IS - 5
ER -