Some information on the biology of Illex coindetii Verany, 1839 (Cephalopoda, Ommastrephidae) in the South-Western Adriatic Sea (Central Mediterranean)

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“…ML50 of males was calculated as 121.2 mm ML and that of females was 148.5 mm ML. The similar results observed in different parts of the Mediterranean Sea; Arvanitidis et al (2002) from the neighboring Greek Seas (ML50, males 113 mm ML; females 179 mm ML), Ceriola et al (2006) from Adriatic (ML50, males 137 mm ML; females 146 mm ML), Jereb and Ragonese (1995) from Sicilian Channel (ML50, males 120 mm ML; Females 150 mm ML) and Perdichizzi et al (2011) from Southern Tyrrhenian Sea (ML50, males 105 mm ML; Females 150 mm ML).…”

“…I. coindetii had bi-modal length frequency distribution in the first group mantle lengths showed intensity between 40 and 90 mm and in the second group were ML between 140 and 180 mm ML ( Figure 2). Also, bi-modal length distribution of I. coindetii was reported previously by Sanches et al (1998) from the Catalan Sea and by Ceriola, Ungaro, and Toteda (2006) from the Adriatic Sea. Sanchez et al (1998) reported that growth of summer spawners were faster than that of autumn spawners after hatching periods, following two distinct reproductive peaks within the year.…”

“…Although there were reports from other areas of the Mediterranean such as Sanchez (1995) and Sanchez et al (1998) from Catalan Sea, Jereb and Ragonese (1995) from Sicilian Channel, Ceriola et al (2006) from Adriatic, and Arvanitidis et al (2002) from Greek Seas that mature animals were observed throughout the year, in this study, there were mature animals from all year round except March. This might be the result of the limited sampling scheme of this study.…”

“…Also since small sized animals were found throughout the year, it might be suggested that the reproduction occurs all year round with intensification in some seasons. Ceriola et al (2006) also reported that the spawning of I. coindetii in the Adriatic Sea occurred throughout the year.…”

“…I. coindetii was the most abundant at 350 m depth according to the data of this study. Although D'Onghia et al (1991) from Eastern coasts of Aegean Sea, Salman et al (1997) from Aegean Sea, and Salman and Katagan (2004) from North eastern Levant Sea reported that the fishing effort was higher at 100-200 m depths, it was also reported that fishing effort and abundance were higher at 100-200 m depths in other areas of the Mediterranean Sea such as Catalan Sea (Mangold-Wirz, 1963;Sanchez & Martin, 1993), Northern Tyrrhenian Sea (Belcari & Sartor, 1993), Southern Tyrrhenian (Perdichizzi et al, 2011), Sicilian Channel (Jereb & Ragonese, 1995), and Southern Adriatic (Ceriola et al, 2006). This vertical distribution differences between areas, and seasonal vertical difference on abundance observed in this study suggested that I. coindetii has vertical migrations depending on variations in bottom water temperature.…”