The biology and ecology of tropical marine sardines and herrings in Indo-West Pacific fisheries: a review

Tropical sardines and herrings (Family Clupeidae) form important fisheries resources in the Indo-West Pacific region. However knowledge of their biology and ecology is largely scattered across diverse localised studies. In addition, their challenging taxonomy due to numerous, morphologically similar species, coupled with data collected from dispersed, often small-scale and mixed species fisheries, creates difficulties for comparing species-level research and fisheries statistics across the region. This review considers four main groups of tropical marine clupeid species important for Indo-West Pacific fisheries—Sardinella (subg. Sardinella) species (‘Round-bodied Sardinellas’), Sardinella (subg. Clupeonia) species (‘Flat-bodied Sardinellas’), Amblygaster species (‘Tropical Pilchards’), and Herklotsichthys and Escualosa species (‘Tropical Herrings’)—and collates and synthesises existing knowledge on early life history, reproduction, trophic biology, habitat associations and population dynamics. Most research on tropical clupeid biology and ecology in the Indo-West Pacific is concentrated on the Round-bodied Sardinellas (S. longiceps and S. lemuru) from a few major fishery locations; other species-groups have been studied sporadically across their distributions. Characteristics such as maximum size, life span, size at first maturity and some habitat associations are generally similar within species-groups and differ between groups. However differences within the same reported species highlight the importance of continued work to improve taxonomic identification. There remain substantial gaps in knowledge on all species-groups. Regular critical review of specific research topics, such as reproductive parameters and population dynamics, would assist to standardise methods and terminology used, enable consolidation and comparison of findings, identify local research agenda, and help build and improve research on these important tropical species.