2
Fig. 1. Bou Ismail Bay on the central coast of Algeria, SW Mediterranean
where TL: fish total length (cm); L ∞ : asymptotic total
length (cm); K: growth coefficient (yr
-1
) and t 0 : theoretical
age when fish has zero length (yr
-1
).
L ∞ and K were calculated on the basis of sizefrequency distribution with a class interval of 2 cm in total
length (Fig. 2), using the ELEFAN I routine integrated
into FiSAT II program (Gayanilo et al., 2005).
Fig. 2. Seasonal evolution of size-frequency polygons of S. cabrilla in Bou Ismail Bay, SW Mediterranean. (a) Winter;
(b) Spring; (c) Summer and (d) Autumn
Pauly’s equation (1983) calculates t 0:
log (- t 0 ) = - 0.3922 - 0.2752 × log L ∞ -1.038 × log K
The phi-prime (ϕ′) growth performance index,
proposed by Munro and Pauly (1983), compares the
growth parameters with previous studies:
ϕ = log K + 2 log L ∞
Fadhila Ailane et al.
45
40
35
30
25
20
15
10
5
0
45
40
35
30
25
20
15
10
5
0
45
40
35
30
25
20
15
10
5
0
45
40
35
30
25
20
15
10
5
0
n %
n %
n = 373
n = 388
n = 580
n = 227
8 10 12 14 16 18 20 22 24 26 28
TL (cm)
8 10 12 14 16 18 20 22 24 26 28
TL (cm)
8 10 12 14 16 18 20 22 24 26 28
TL (cm)
8 10 12 14 16 18 20 22 24 26 28
TL (cm)
n %
n %
(a)
(b)
(c)
(d)