%0 Journal Article
%T Reproductive Biology and Fishery-Related Characteristics of the Malabar Grouper (Epinephelus malabaricus) Caught in the Coastal Waters of Mafia Island, Tanzania
%A Lydia Gaspare
%A Ian Bryceson
%J Journal of Marine Biology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/786589
%X The reproductive biology and fishery-related characteristics of the Malabar grouper (Epinephelus malabaricus) (Bloch and Schneider, 1801) specimens were investigated. The size of females ranged from 25 to 113£¿cm total length ( ), with 50% sexually mature at 79£¿cm , and the males (97£¿cm to 114£¿cm ) were larger than the females. Due to the sex ratios and size distribution of the sample, it appeared that the groupers change sex between 97 and 113£¿cm . However, the gonadal histology data lacked specimens in the transitional stage. The spawning peak occurred in November, as defined by the presence of ripe females, and the spawning season lasted from September to February. The size of the fish correlated positively with the water depth at capture, which is also related to oxygen levels in deep water being more favourable for larger fish. Larger specimens (>100£¿cm ) were targeted by fishers between December and February, when the northeast monsoon coincides with calmer weather and the spawning season. Fishers were interviewed, and observations were made on fishing gear, vessels, and grounds. There was no indication that small-scale fishers targeted spawning aggregations; therefore, fisheries independent research is recommended in order to verify the time, location, and behaviour of the spawning of Malabar groupers for management and conservation purposes. 1. Introduction The population size structure, mode of reproduction, maturity, and fisheries characteristics (fishing gear, vessels, and fishing grounds) of various Epinephelinae are well documented in the Western Atlantic, the Caribbean, Southeast Asia, and Australian waters [1¨C4]. In contrast, virtually no such data is available for the same species in Tanzanian waters, despite their frequent presence in local fish markets (pers. observations). Being highly priced fish, the Epinephelinae are heavily exploited in many tropical areas of the world for commercial purposes, aquaculture ventures (e.g., Epinephelus malabaricus and Epinephelus coioides) and for recreational and local consumption [4¨C6]. The increasing exploitation is attributed to growing markets, especially worldwide export markets for the fish [7, 8]. Groupers have long lifespans, are slow growing, relatively large in size, and have a low natural mortality rate. The larger species form breeding aggregations, and most species are protogynous hermaphrodites. Among the Epinephelinae, monandry protogynous hermaphroditism is the most common sexual pattern [9]. A few species, such as the Epinephelus coioides and the Epinephelus andersoni, are diandry,
%U http://www.hindawi.com/journals/jmb/2013/786589/