Barnes LM, Gray CA and Williamson JE (2011) Divergence of the growth characteristics and longevity of coexisting Platycephalidae (Pisces). Marine & Freshwater Research, 62: 1308–1317.

Summary

More than 65 species of Platycephalidae, commonly referred to as flatheads, occur globally. The majority of species from this family are found throughout the Indian and Pacific Oceans while a few species inhabit the Atlantic Ocean and the Mediterranean Sea. Several flathead species including Eastern Bluespotted flathead, Tiger flathead, Longspine flathead, Freespine flathead and Mud flathead exist throughout the inner continental shelf waters of south-eastern Australia. In this region, these species are specifically targeted or caught as by-catch by both commercial and recreational fishers. With the exception of Tiger flathead, there is a lack of basic information available about the age and growth of these species. Knowledge of age and growth characteristics is fundamental in determining how species coexist and understanding the potential influence fishing pressures may have on populations.

The objectives of this study were to investigate whether the age and growth characteristics of Eastern Bluespotted flathead, Tiger flathead, Longspine flathead, Freespine flathead and Mud flathead differ where they coexist along the inner continental shelf of south-eastern Australia. We compared growth parameters between species at Yamba and Newcastle and whether there was any relationship between growth, sex and location.

Results from this study revealed that each species exhibited unique growth characteristics with the maximum observed sizes of each species ranging between 20.6 cm for Mud flathead and 62.3 cm for Eastern Bluespotted flathead. The oldest individual sampled was a 16 year old male Longspine flathead. Females of each species grew larger than males however the maximum ages of females and males were similar. Overall, the differential growth characteristics observed for each of the five Platycephalidae species suggests that size may play a key role in the ability of these species to coexist in the inner continental shelf waters of south-eastern Australia.