Reproductive Biology of Scombrids Occurring along the Indian Coast: A Brief Review

The present article reviews the reproductive biology of scombrids inhabiting Indian waters, a family comprising 54 species across 15 genera including commercially significant mackerels, bonitos and tunas. Scombrids are a vital pelagic resource, contributing approximately 13.21% to India's total marine fish landings. Reproductive studies indicate wide inter-specific and regional variability in life history traits. Size at first maturity (Lm) ranges from 16.65-25.9 cm in the Indian mackerel to 79.9-81.3 cm in yellowfin tuna, with larger seerfishes like S. commerson maturing between 62.5 and 80.0 cm. Sex ratios vary from near parity to significant sex biased dominance depending on the species and size class. Fecundity estimates are high, ranging from approximately 13,800 ova in R. kanagurta to over 2.5 million ova in S. commerson and E. affinis, reflecting their high reproductive potential. Spawning seasons are prolonged and often bimodal; while many species spawn year round, peak activity is frequently associated with the pre-monsoon and monsoon periods (January-April and June-October). GSI and ova diameter frequency analyses suggest that most scombrids are asynchronous, multiple spawners. The review highlights the need for standardized methodologies and further research on the impacts of climate change to formulate adaptive management strategies for the sustainable exploitation of these resources.