Résumé:
Biology and population dynamics of sea bream Pagellus acarne (Risso, 1827) an
economically interesting species, were studied. The evidence provided by the biological
study and monthly monitoring of length frequencies were used in an attempt to determine
the reproduction period, fecundity, size at first maturity and an assessment of the status of
its stock.
The overall sex ratio is in favor of females while its evolution over months showed
significant differences (χ2, p<0.05
Following the monthly evolution of the three parameters (GSI, HSI and K) of
Algerian west coast seabream showed that this sparidae has two spawning periods the first
covering spring from April until mid- June with a peak in May, the second from October to
December
The parameters of the von Bertalanffy equation for the entire population of P.
acarne off Oran bay are equal to: L∞ = 20.63 (Cm), K = 0.99 (year-1), t0 = -0.28 (year), W∞
= 91.11 (g), Φ =2.625. Growth parameters K and Φ are clearly superior to other
Mediterranean areas indicating a rapid growth of the species in Mostaganem Bay.
Parameter b of the length-weight relationship seems > to 3 (3.181 both sexes, 3.218
for males, and 3,187 for females), which reflects a positive allometry for the species (t-test,
P<0.05).
The minimum landing size (MLS) set for P. acarne is equal to 15 cm Lt, the size is
greater than the length at first sexual maturity of females of the species evaluated at 12.75
cm, but it seems to be insufficient and it would be advisable to increase the MLS and set it
at 17 cm ensuring renewal of the resource.
