Implantation date, growth rate, and allometric relationships in foetal Northwest Atlantic harp seals ( Phoca groenlandica )

Using a sample of 150 female and 141 male foetal Northwest Atlantic harp seals (Phoca groenlandica) collected between October and February of 1980-1995, we determined that the allometric relationship between total body mass and standard length did not differ between sexes and did not differ from the...

Full description

Bibliographic Details
Published in:Canadian Journal of Zoology
Main Authors: Chabot, Denis, Stenson, Garry B
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2000
Subjects:
Online Access:http://dx.doi.org/10.1139/z99-227
http://www.nrcresearchpress.com/doi/pdf/10.1139/z99-227
Description
Summary:Using a sample of 150 female and 141 male foetal Northwest Atlantic harp seals (Phoca groenlandica) collected between October and February of 1980-1995, we determined that the allometric relationship between total body mass and standard length did not differ between sexes and did not differ from the relationship calculated for foetal harp seals from the study of Stewart and co-workers (R.E.A. Stewart, B.E. Stewart, D.M. Lavigne, and G.W. Miller. 1989. Can. J. Zool. 67: 2147-2157). Combining the data for foetuses from both studies, the exponent of the mass-length relationship was 2.75, significantly different from 3. Except for very small foetuses (<20 cm) standard length and mass 1/2.75 increased linearly as gestation progressed. Equations are provided to estimate standard length and total mass of foetuses in the period August-February and to estimate sculp mass, core mass, and axillary girth from length for the period October-February. The most reliable estimate of implantation date (day 223, 11 August) was obtained by regressing sampling date 1/2 on mass 1/2.75 .