Details

Autor(en) / Beteiligte

• Appeldoorn, R S

Titel

Growth, mortality and dispersion of juvenile, laboratory-reared conchs, Strombus gigas and S. costatus, released at an offshore site

Ist Teil von

• Bulletin of marine science, 1985, Vol.37 (3), p.785-793

Ort / Verlag

University of Miami - Rosenstiel School of Marine and Atmos

Erscheinungsjahr

1985

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Hatchery-reared juvenile Strombus gigas and S. costatus were used in a series of field release experiments to determine rates of growth, mortality and dispersion. These experiments, each approximately 8 weeks long, were conducted throughout the year at an offshore site, 17 m deep. Average shell length at release ranged from 3 cm to 4 cm.S. gigas was found to be considerably more active than S. costatus. The former showed greater rates of diffusion away from the release site, and noticeable migrations: inshore during late winter, offshore during autumn. Movement of S. costatus was insufficient to detect directed migration. S. gigas consistently grew faster than S. costatus. Growth varied seasonally, being negligible in late winter and highest in autumn when temperature was maximum. Mortality was similar between species and varied over the year, being higher in summer and lower in winter. A simple sine function fitted to the combined data yielded an integrated average instantaneous annual mortality rate of z = 8.62 or 2.3% mortality/day.