Preprint volume - SIBM

Pre-print Volume –Posters
NECTON AND FISHERY COMMITEE
V. GANCITANO, C. BADALUCCO, P. RIZZO, S. GANCITANO, G. SIELI,
S. CUSUMANO, F. FIORENTINO
National Research Council (CNR) – Insitute for Costal Marine Enviromnent (IAMC)
Via Luigi Vaccara, 61 – 91026 Mazara del Vallo (TP), Italy.
vita.gancitano@iamc.cnr.it
DIFFERENCES IN GROWTH OF COMMON PANDORA, PAGELLUS
ERYTHRINUS (L., 1758) (PISCES: SPARIDAE), CAUGHT BY DIFFERENT
FISHING GEARS IN THE STRAIT OF SICILY
DIFFERENZE NELLA CRESCITA DEL PAGELLO FRAGOLINO, PAGELLUS
ERYTHRINUS (L., 1758) (PISCES: SPARIDAE), CATTURATI DA DIVERSI
ATTREZZI DA PESCA NELLO STRETTO DI SICILIA
Abstract – The von Bertalanffy growth curves (VBGC) of Common pandora, Pagellus erythrinus (L., 1758)
were estimated using data from commercial trawling and artisanal fisheries. The difference in VBGC
checked by the Chen‘s test was significant, confirming that the two métiers exploit different fractions of the
stock. This difference suggests to be cautious in adopting growth parameters for stock assessment purposes
and in integrating information coming from different sources in a proper way.
Key-words: Common pandora, growth, fishing gears, Strait of Sicily.
Introduction - The Common pandora, Pagellus erythrinus (L., 1758), is one of the
most important demersal resources in the Strait of Sicily (GSA 16). According to
IREPA data, during the last three years the mean annual yields amount to 43 t and 467
t, by artisanal and trawl fisheries respectively. Andaloro & Giarritta (1985) described
firstly the growth of the species in the area on the basis of trawling catches. Orsi Relini
& Romeo (1985) reported difference in growth patterns between specimens caught by
trawling and those caught by long lines. Therefore one of the aims of this study is to
check the existence of differences in growth curves of P. erythrinus in GSA 16 based
on data from commercial trawling and artisanal fisheries (trammel net and long lines).
Materials and methods – Biological sampling of landings were carried out monthly
from 2002 to 2008 in GSA 16 (Italian National Program of DCR - Module H). Each
specimen was measured as total length (TL, cm) and total weight (g) and the sex was
assigned. A total of 2647 otoliths (1073 from trawling; 944 from artisanal fisheries)
was sampled. Age was estimated by readings of whole sagitta under transmitted light.
Since this species is a protogynous hermaphroditic species (Giordano et. al., 1999), the
von Bertalanffy growth curves (VBGC) were estimated by combined sex and separate
métiers using the “Length at Age” routine as implemented in Fisat II. Differences in
growth curves between métiers were checked by means of the Chen’s test (Chen et al.,
1992), which is based on the analysis of the residual sum of the squares (ARSS).
Results and conclusions – The difference in VBGC by métier (Tab. 1) was significant
(p