engleski

Life –history traits of a Blackspotted smooth‐ hound (Mustelus punctulatus) in the northern and central Adriatic Sea

Blackspotted smooth‐hound (Mustelus punctulatus Risso, 1827) is frequently recorded and commercially exploited demersal shark, classified by IUCN Red List as Data Deficient. We used histological and morphometrical techniques on reproductive organs and vertebrae to analyse demographic and reproductive traits of blackspotted smooth‐hound. We sampled 220 specimens (108 females and 112 males) caught by demersal trawls between years 2005 and 2007 in the northern and central Adriatic Sea. Catches were equally distributed throughout the year, except during summer season when only 7 animals were sampled. In average, females had larger body lengths (BL) (average BL: 77.1±22.1 cm) than males (76.9±20.4 cm) and were older (average: 7.2±4.6 years) than males (6.7±4.0 years). Estimated age of the oldest female was 22 years, while the oldest male was aged 16. Majority of analysed sample (74 %) were specimens aged between 2+ and 9+ years. Estimated age of the smallest pregnant female (BL: 114.9 cm) was 12 years, while the smallest male (BL: 74.3 cm) with developed testes was 7 years old. These results suggest that blackspotted smooth‐hound is a k‐selected species, with slow growth rate, late age at sexual maturity and long life cycle, therefore highly vulnerable to exploitation. Hence, sustainable management and providing action plans for protection of the species will be crucial for maintaining populations in the Adriatic Sea.

somatic growth rate; sexual maturity; sharks; k‐selected species

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