Some species of known pathogenic bacteria isolates in tropical aquaculture produces hemolysin. Hemolysin can be identified based on its ability to break down red blood cells in vitro. Some hemolysin is a pore-shaped poison that can damage cell membranes and kill host cells. The character of the 13 sequences of hemolysin protein in several pathogenic bacterial isolates in tropical aquaculture was analysed using the NCBI protein bioinformatics database. The phylogenetic tree was generated, and the analysis was conducted using the base character method (Maximum Parsimony) of Mega 6.06 software. The result showed that there are two big family of hemolysin from the known pathogenic bacteria. The closest characteristics of protein sequences were hemolysin of Streptococcus agalacticae and of S. iniae.

Penelitian ini dilakukan untuk mengetahui pola pemberian pakan yang tepat dalam pemeliharaan larva rajungan skala massal. Penelitian menggunakan bak beton berbentuk bulat volume 3.000 liter yang dilengkapi dengan sistem aerasi, dan ditebar larva (zoea-1) dengan kepadatan 75 ind./L

ABSTRAKPenelitian dilakukan untuk dapal mengontrol lingkungan secara biologis dalam produksi massal melalui penggunaan bakteri probiotik serta meningt

The wide exploration of interferon (IFN)s in vertebrates for medical purposes has attracted researchers to investigate the existence of a similar role of interferon in other organisms such as invertebrates, including insects, and crustacea. A review of the literature indicates that there is no evidence of interferon existing either in insects such as D. melanogaster and A. gambiae which have had their genomes fully sequenced or in crustacea. However, a nonspecific antiviral state in crustacean, such as P. monodon can be efficiently triggered by both dsRNA and siRNA. The evidence suggests that anonymous cytokines, similar to interferon and not identical to any vertebrate IFNs, related to antiviral protection, do exist in crustacea. However, how widely spread of interferon immune response inducer or interferon-like molecules in this group is an important issue that remains to be explored.

A regular surveillance of marine fish diseases was conducted from March to November 2019 in order to determine the occurrence time of the diseases within the mariculture centre of the North of Bali, Indonesia. The monthly surveillance was conducted by collecting 15 fish samples from each of the three hatcheries in Gerokgak and Penyabangan villages and of the two floating net cages in Pegametan Bay, Sumberkima village. Bacterial concentrations were grouped into 4 categories including low, moderate, high and very high. Surveillance data were analyzed using bivariate descriptive statistical methods. The results showed some important findings. First, the results of the study showed that NNV infection was found during the transitional seasons in March to June and September to November. Parasite infection were more frequent observed in fish with high and very high bacterial population. Second, high concentration of total bacteria in fish-feces occurred throughout the year. The prevalence of NNV infection and bacterial populations at the high to very high concentration were mostly occurred in the cultured fish in hatcheries at the size of 1-10 g, while in cultured fish at the net cages were mostly occurred at the size of > 50 g.