A COMPARISON OF THE FISHERY BIOLOGY OF THREE ILLEX COINDETII VÉRANY, 1839 (CEPHALOPODA: OMMASTREPHIDAE) POPULATIONS FROM THE EUROPEAN ATLANTIC AND MEDITERRANEAN WATERS

Autor: Christos Arvanitidis, Drosos Koutsoubas, Jean-Paul Robin, João Pereira, Ana Moreno, Manuela Morais da Cunha, Vasilis Valavanis, Anastasios Eleftheriou
Přispěvatelé: Hellenic Center for Marine Research (HCMR), National Marine Park of Zakynthos, Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Technical University of Lisbon, ROBIN, Jean-Paul
Jazyk: angličtina
Rok vydání: 2002
Předmět:
Zdroj: Bulletin of Marine Science
Bulletin of Marine Science, University of Miami, Rosenstiel School of Marine and Atmospheric Science, 2002, 71, pp.129-146
ResearcherID
CIÊNCIAVITAE
HAL
Scopus-Elsevier
ISSN: 0007-4977
Popis: International audience; Three populations of the short-finned squid Illex coindetii were simultaneously sampled and studied from the Southern Celtic Sea and Bay of Biscay, Portuguese waters and Greek Seas, during a EU funded project (FAIR CT 1520). Dorsal mantle length (DML) ranged from 24 mm to 360 mm and body weight (BW) from 2.4 g to 1630 g. Modal progression analysis (MPA) indicated a female life span of 13-18 mo and in male life span of 11 mo. Length-weight relationship was found to be positively allometric for males and negatively allometric for females in all three populations. Sex ratio did not differ significantly from 1:1 over the entire sampling period. Differences among the three populations were observed for the following life-cycle parameters: (1) males from the Portuguese waters had significantly different length-weight slopes from those from the remainder areas; (2) size at full recruitment was determined at 110 mm in females from the Portuguese waters whereas in females from the Southern Celtic Sea and Bay of Biscay and from the Greek Seas was 170 mm; (3) female recruitment peaks were recorded only during autumn in samples from the Southern Celtic Sea and Bay of Biscay while in those from the Portuguese waters and the Greek Seas the recruitment peaks were recorded at various seasons; (4) maturing and mature males were found abundantly over the entire sampling period in the samples from the Southern Celtic Sea and Bay of Biscay and the Greek Seas whereas in those from the Portuguese waters maturing and mature males were at higher percentages than immature ones only during spring and summer; peaks of the Gonadosomatic index, calculated for mature females from the Southern Celtic Sea and Bay of Biscay, were scored from (5) L50 (mantle length at which 50% of the individuals are mature) values estimated for both females and males from the three studied areas were gradually decreased from the North Atlantic to the Mediterranean; (6) length data suggest that females from the Greek Seas potentially mature at two modal sizes while those from the remainder areas show only one modal size at maturity. Environmental variables (sea surface temperature and chlorophyll-a concentration) were correlated with some of the biological indices of the I. coindetii populations. Finally, results on biological indices of the I. coindetii are compared with those calculated for its conge-neric species I. illecebrosus, I. argentinus as well as with another European ommastrephid species Todaropsis eblanae. The ecological importance of ommastrephid squids has been recently summarized in a number of papers (e.g., Mangold, 1983; Lordan et al., 1998). Ommastrephids are characterized by high food intake and high conversion rates (Mangold, 1983) thus increasing rates of energy transformation and accumulating high quality protein, available to higher consumers. Consequently, terms such as 'ecosystem accelerators' and 'ecosystem en-zymes' can fully explain the essential role they play in the oceanic system.
Databáze: OpenAIRE
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