Preprint volume - SIBM

Pre-print Volume –Invited presentations
Topic 4: THE ELASMOBRANCHS
G. RELINI, A. MANNINI, S. DE RANIERI 1 , I. BITETTO 2 , M.C. FOLLESA 3 ,
V. GANCITANO 4 , C. MANFREDI 5 , L. CASCIARO 2 , L. SION 6
Centro Biolmar - DIP.TE.RIS., Università di Genova, Viale Benedetto XV, 3 - 16132, Genova, Italia.
biolmar@unige.it
1 CIBM - Centro Interuniversitario di Biologia Marina, Viale N. Sauro, 4 - 57128 Livorno, Italia.
2 COISPA Tecnologia & Ricerca, Stazione sperimentale per lo studio delle risorse del mare,
Via dei Trulli, 18/20 - 70126 Torre a mare (BA), Italia.
3 Dipartimento Biologia Animale ed Ecologia, Università di Cagliari, Viale Poetto, 1 - 09126 Cagliari, Italia.
4 IAMC-CNR, Sezione Territoriale di Mazara, Via L. Vaccara, 61 - 91026 Mazara del Vallo (TP), Italia.
5 Laboratorio di Biologia Marina e Pesca di Fano, Dip.to B.E.S., Univ. di Bologna,
Viale Adriatico, 1/N - 61032 Fano (PU), Italia.
6 Dipartimento di Zoologia, Università di Bari, Via Orabona, 4 - 70125 Bari, Italia.
CHONDRICHTHYES CAUGHT DURING THE MEDITS SURVEYS
IN THE ITALIAN WATERS
I PESCI CARTILAGINEI PESCATI DURANTE LE CAMPAGNE MEDITS
NELLE ACQUE ITALIANE
Summary
Data on Chondrichthyes fished during 16 surveys of MEDITS project carried out from
1994 to 2009 on trawlable bottom up to 800m depth in all seas around Italy are
presented and discussed.
From the overall 7 GSAs involved during the 16 years surveys (10255 hauls) 40
elasmobranch species including 23 rays and skates, 16 sharks and 1 chimaera have
been identified (Tab.1).
Only 9 species of which 5 sharks, occurred in all GSAs, and other 10 were present in
85,7% of GSAs (6 on a total of 7).
The highest number of species was found in Sicily Channel (30 species) the lowest (20
species) in the South Adriatic Sea. Ten species of which 1 shark were found only in
one GSA and five of them during one year only: they are Galeorhinus galeus (GSA10,
1995 and 2001), Dasyatis centroura (GSA19, 2002) Pteroplatytrygon violacea
(GSA10, 2000 and 2002), Gymnura altavela (GSA19, 2006) Pteromylaeus bovinus
(GSA17, ten years), Dipturus batis (GSA9, 1996) Leucoraja melitensis (GSA16, all
years excluding 1994 and 2003), Raja radula (GSA17, 1994), Rostroraja alba
(GSA16, 1995, 2000, 2003, 2005, 2007, 2008 and 2009) and Rhinoptera marginata
(GSA17, 1994).
The number of species caught per year was 30 in 1995 and decreased to 23 in 1997
than increased with some oscillation to 31 in 2008 and 2009.
In each GSA and in each stratum the species with more than 20% occurrence (number
of hauls in which the species was fished against the total hauls in the stratum
considered) have been selected for data dealing with kg/km 2 , n/km 2 and mean weight
(g). In GSA9 only 4 species have been considered Galeus melastomus showed biomass
up to 100kg/km 2 and 850 n/km 2 . Lower catch were reached in GSA10. At GSA11 ten
species were selected of which 6 are rays; Raja clavata reached 120 kg/km 2 and 130
n/km 2 . Also GSA16 is rich in species (12) and rays (6) with quite high values of
biomass and density. In GSA17 there were 4 species no rays, with low values. In
GSA18 three species were selected Chimaera monstrosa, Etmopterus spinax and G.
melastomus (up to 80 kg/km 2 ). In GSA19 only 3 species with lower values.
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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