Comparative Studies Of The Skeleton System Of Two Groupers

Epinephelus malabaricus and Epinephelus coioides both belong to Perciformes, Percoidei, Serranidae, Epinephelinae,Epinephelus. Both of them are considerably important to the commercial fishery and aquaculture wherever in China or in the world. Biologists and farmers are all need to accurately identify the commercial species. For the proper management of a fishery resource, it is essential to correctly distinguished these two species concerned.The basic structure of fish is their skeleton. Due to its stability and complexity,it can be used as a key characteristics to recognize different species and genus. Therefore, it is the important basis for studying the classification and evolutionary relationships of fishes.There are certain difficulties and confusions in the identification of E. malabaricus and E.coioides, because they change color,bars and stripes on their skin at different stages,living environments and various stress status. They look similar and have the same local name"Qingban"in China. The argument on whether or not E. malabaricus and E.coioides belong to one specie has being lasted for a long time. To answer all these questions, the taxonomic characters and the skeleton system of the two groupers were compared in the present paper.The results revealed that detailed differences were as the following: 1)E. malabaricus have spots in the chin which are absent in E.coioides;2)The spots on the head and the whole body of E. malabaricus is dark brown or black with irregular white spots and blotches. E.coioides have no white spots or blotches on the body but orange or reddish brown spots;3)The number of E. malabaricus's pyloric caeca is more than 100. These pyloric caeca divde into three parts, each of them have multiply branches looking like a tree. E. coioides has only 30～50 pyloric caeca which is big and long.They encircle the intestines looking like an umbrella;4)Although most of skeletons of the two groupers are very similar, E. malabaricus's fin formulas of dorsal fin is XI.16, 24 vertebra, the sawtooth at the corner of Preoperculare was unconspicuous and small, its low angle in the back of Operculare is wider than E. coioides;5)The shape of their Suboperculare are different too.E. malabaricus and E.coioides have a very close relationship,they can even cross-fertilize, but they are still different in the molecule biological study results.As a conclusion, we consider that E. malabaricus and E.coioides are different species in the same genus.