TY - JOUR
T1 - External morphology of the short-beaked common dolphin, Delphinus delphis
T2 - Growth, allometric relationships and sexual dimorphism
AU - Murphy, Sinéad
AU - Rogan, Emer
PY - 2006/10
Y1 - 2006/10
N2 - Growth, allometric relationships and sexual dimorphism are described from measurements of 105 male, 149 female and 38 unsexed specimens of short-beaked common dolphin, Delphinus delphis, stranded along the Irish coastline (53.8% of the sample) or by-caught in fisheries (46.2% of the sample), from 1990 to 2003. For each dolphin, 24 external body length measurements were recorded. Ages were determined for 183 dolphins by analysis of growth layer groups in the dentine. Males ranged in total body length (TBL) from 105 to 231 cm and females from 93 to 230 cm, with a maximum age of 25 years obtained for both sexes. Using a single Gompertz growth curve, asymptotic values obtained for TBL were 211.6 cm and 197.4 cm for males and females, respectively. Asymptotic lengths were attained at 11 years in males and 9 years in females. The gestation period was estimated to last approximately 11.5 months. Sexual size dimorphism (SSD) was evident, with males being significantly larger than females for 20 of the characters measured, and an SSD ratio of 1.06 was obtained. Sexual shape dimorphism was lacking, except for the presence of prominent postanal humps in mature males.
AB - Growth, allometric relationships and sexual dimorphism are described from measurements of 105 male, 149 female and 38 unsexed specimens of short-beaked common dolphin, Delphinus delphis, stranded along the Irish coastline (53.8% of the sample) or by-caught in fisheries (46.2% of the sample), from 1990 to 2003. For each dolphin, 24 external body length measurements were recorded. Ages were determined for 183 dolphins by analysis of growth layer groups in the dentine. Males ranged in total body length (TBL) from 105 to 231 cm and females from 93 to 230 cm, with a maximum age of 25 years obtained for both sexes. Using a single Gompertz growth curve, asymptotic values obtained for TBL were 211.6 cm and 197.4 cm for males and females, respectively. Asymptotic lengths were attained at 11 years in males and 9 years in females. The gestation period was estimated to last approximately 11.5 months. Sexual size dimorphism (SSD) was evident, with males being significantly larger than females for 20 of the characters measured, and an SSD ratio of 1.06 was obtained. Sexual shape dimorphism was lacking, except for the presence of prominent postanal humps in mature males.
KW - Cetaceans
KW - Common dolphin
KW - Delphinus delphis
KW - Gompertz growth curve
KW - Morphometrics
UR - http://www.scopus.com/inward/record.url?scp=33748916003&partnerID=8YFLogxK
U2 - 10.1111/j.1463-6395.2006.00245.x
DO - 10.1111/j.1463-6395.2006.00245.x
M3 - Article
AN - SCOPUS:33748916003
SN - 0001-7272
VL - 87
SP - 315
EP - 329
JO - Acta Zoologica
JF - Acta Zoologica
IS - 4
ER -