Page 4 - Castriota_alii_2014

Biologica/ date on Fistularia commersonii CASTRIOTA ET AL.

100

E'
5
.rcg::o. 80

60

g y = l .3773x - 52.62 1
r = 0.74; p<O.OI
!2 40 •• Il= 17
·;~;;
80
>. 20

f:!

0..

o

70 90 100 IlO
Total length (c m)

Figure 3. - Regression analysis performed between prey size and
bluespotted cornetfish size.

30

"5' 25 Figure 5. - Example of age reading in a vertebra of an estimateci
3-years old specimen of Fistularia commersonii.
E
'() 20 120

&. 100
'O"' 15
"c.".,"
.....,.

E IO

z::l
5

E 80

~
<;:
60 70 80 90 100 IlO 120
Total length classes (cm, without filament) o::l
-5 60
Figure 4. - Length-frequency distribution of bluespotted cornetfish
considered for age analysis. ·~

Table Il. - Age-length key of Fistularia commersonii in centrai E =TLt 102.39 (l - e o"'9'1(Ho.s7Jt))
Mediterranean Sea.
~ 40 n=46

~

TL(cm) Age classes Total o
Classes 23 n
Range 6 4 6 o
70 10 17 28 o 2 34 s
80 66-75 l 8
90 76-85 4 4 2 Age
100 86-95 l l 2
110 96-105 2 Figure 6. - Von Bertalanffy curve determined from groMh incre-
106-115 ment interpretation in Fistularia commersonii vertebrae.

n 16 22 8 46
MeanTL
75.77 82.62 94.35 for the age analysis ranged from 73 .O to 107 .5 cm TL

SD 1.75 4.29 9 .83 (82.3 ± 8.1 cm). Figure 4 shows the 1ength frequency dis-
tribution of these specimens; 6 1% of samp1es belong to the
labrids, followed by clupeids and sparids in the diet of blues- 80 cm TL class (75-85 cm).
potted cornetfish (Fig. 2). Prey size ranged from 30.5 to
9 1.3 mm TL. Regression analysis performed between prey Out of 200 vertebrae ana1ysed, on1y three were consid-
size and predator size revealed a high1y significant corre1a- ered unreadab1e . The thoracic vertebra of F. commersonii
shows a conica1centrum with bands made of wide1y spaced
tion (tJs = 4.25; p< 0 .0 1), with Pearson's coefficient r =0.74 rings in the inner part, becoming progressive1y narrow in
the outer part. Age readings allowed to identify three age
(Fig. 3). groups, presumab1y be1onging to fish of 2, 3 and 4 years
o1d. The age composition of the individua1s considered in
Age this study in re1ation to 1ength (age-1ength key) is summa-
The specimens of b1uespotted cornetfish considered

18 Cybium2014, 38(1 )