Specialist spearfishers’ ecological knowledge provides accurate information that improves the description of the reproduction of a data-deficient species, Oplegnathus conwayi in South Africa

Fishers’ ecological knowledge (FEK) has become a popular method for collecting fisheries data. Yet, standard biological sampling by researchers is still the most commonly used method. South Africa’s recreational fishing sector currently has a wealth of biological and demographic information on species captured with hook and line, while several species targeted in the spearfishery are data limited. The aim of this study was to incorporate specialised spearfisher FEK to improve the understanding of the reproductive biology of Oplegnathus conwayi in South Africa. This was achieved using standard biological sampling and FEK data collected from specialist spearfishers using a questionnaire. A total of 305 O. conwayi were collected along the South African coastline. Fish were dissected, sexed and staged macroscopically and gonad staging was verified histologically. One hundred and three survey responses were received, of which 90 were regarded as being from specialised spearfishers. The combination of both traditional sampling and FEK data complemented each other well, with key reproductive data such as spawning season, length-at-maturity and spawning locality being collected. The combination of these methods is strongly advised for future life history studies, particularly, in countries with data-deficient species and limited research funding.