Feeding Ecology and Seasonal Trophic Dynamics of the Spadenose Shark (Scoliodon laticaudus) from Veraval, Northwest Coast of India

The spadenose shark, Scoliodon laticaudus, is a commercially significant and Near-Threatened species that dominates shark landings along India’s northwest coast. This study investigated its feeding ecology, focusing on seasonal feeding intensity and dietary composition, to inform sustainable management. A total of 360 specimens were collected monthly from April 2024 to March 2025 at Veraval Fishing Harbour, Gujarat. Feeding intensity was assessed through the Gastro-Somatic Index (GaSI), stomach fullness categories, and the Empty Stomach Ratio (ESR). Diet composition was quantified using the Index of Relative Importance (IRI). Results revealed significant seasonal variation in feeding activity. The highest GaSI values were recorded in winter (February: 6.88), indicating peak feeding intensity, while the lowest values occurred in pre-monsoon months (May: 2.794). ESR was highest in May (85%) and November (78%), reflecting reduced feeding during these periods. Dietary analysis confirmed a generalist carnivorous diet. Crustaceans were the most important identifiable prey (IRI: 21%), followed by teleosts (IRI: 16%) and cephalopods (IRI: 14%). However, semi-digested material dominated the overall diet (IRI: 49%), highlighting challenges in precise prey identification. S. laticaudusis a mesopredatory coastal shark that feeds mainly on crustaceans, small fishes, and benthic invertebrates. It acts as an important link between lower trophic consumers and higher predators, thereby helping to maintain balance and energy flow in coastal food webs. The species exhibits seasonal, opportunistic foraging behavior, with higher feeding activity during pre- and post-monsoon periods and a shift in diet during the monsoon in response to changes in prey availability. These findings elucidate the trophic role and seasonal foraging strategy of S. laticaudus, providing critical baseline data for ecosystem-based fisheries management and conservation of this vulnerable species in the region.