The Diversity of Vibrios Related To Vibriosis In Mud Crabs (Scylla Serrata) From Extensive Brackish Water Pond Surrounding of Semarang Bay, Indonesia
Vibriosis is frequently found as a problem in crustacean farming, including on the mud crab culture. The aims of this study were to determine the clinical sign of mud crab that was infected by vibrios and to identify bacterial agent of vibriosis in mud crabs Twenty two isolates were collected from hepatopancreas, gills, hemolymph and injured carapace of moribund mud crabs that were collected from extensive brackish water pond of Kendal and Demak, Indonesia. Thiosulfate Citrate Bile Salts Sucrose (TCBS) medium was used to isolate suspected vibrios. Based on the morphological characteristics of the twenty two isolates, six isolates, designated SJK1, SJK5, SJK6, SJK11, SJD3 and SJD6, were selected for further Koch’s postulate test. The results showed that the clinical sign of mud crab that was infected with the isolated vibrios are red spots on the carapace, wounds in the abdomen, and weak conditions. The postulate koch test result of the six isolates demonstrated 100% incidence of vibriosis, whilst the mortality was in the range of 77.78 – 100%. Therefore, these isolates could be potentialy to the causative agent of vibriosis in mud crab. Based on the morfological and biochemical results, it was showed that the vibrios isolated from mud crab (S. serrata) of extensive brackish water pond surrounding of Semarang Bay, Indonesia were V.harveyi (SJK1; SJD6. ), V. fischeri (SJK5) and V. Ordalii (SJK6, SJK11,SJD3).