Population biology of the common pandora Pagellus erythrinus (Pisces :Sparidae) off the Canary Islands

摘要

Common pandora Pagellus erythrinus (N = 957) were caught off the Canary Islands from January 1991 to September 1993. Total length ranged from 75 to 371 mm. The species was characterized by protogynous hermaphroditism. The overall ratio of males to females was 1 : 2.63. The reproductive season extended from April to September, with a peak in spawning activity in June-July. Fifty percent maturity was reached at 174 mm total length by females and 232 mm by males. The length-weight relationship for all individuals was described by the following parameters: a = 0.01279 and b = 3.01338. Fish aged 0-10 years were found. The von Bertalanffy growth parameters for the whole population were: L-infinity = 417.8 mm, k = 0.205 year(-1) and t(0) = -0.550 year. Growth parameters differed between males and females. For all fish, the rates of mortality were: Z = 1.06, M = 0.30 and F = 0.76, and the exploitation ratio E = 0.71. The length at first capture for all individuals was 155 mm. The stock is being heavily exploited. Measures such as closed season or changes in fishing pattern would be desirable to safeguard the spawning stock and the recruits.