<span style="font-size:14.0pt;line-height: 115%;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; color:black;mso-ansi-language:EN-IN;mso-fareast-language:EN-IN;mso-bidi-language: HI" lang="EN-IN">Bacterial and protozoan (Ciliate) diseases of <span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:HiddenHorzOCR;color:black;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI" lang="EN-IN">praw <i><span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:black;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI" lang="EN-IN">Penaeus indicus </span></i><span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:black;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI" lang="EN-IN">(Decapoda: Crustacea)</span></span></span>

Abstract

285-296A survey was carried out on the prevalence of bacteria and ciliate protozoan of Penaeus indicus obtained from Ennore estuary, Chennai (Madras), India from November 1989 to July 1992. The study revealed the occurrence of Vibrio parahaemolyticus, V.vulnificus, V. harveyi; V. anguillarum, V. damsela, Pseudomonas sp., P. aeruginosa and a filamentous bacterium Leucothrix sp. This study also revealed the occurrence of three different peritrichous ciliates viz .. Zoothamnium sp., Epistylis sp. and Vorticella sp. and a loricate ciliate Lagenophrys sp. Zoothamnium  sp ., Epistylis sp. and Vorticella sp. were recorded on the body surface, gills, appendages and pleopods. Trophonts of Zoothamnium sp. occurred as branched colonies with contractile stalk with myoneme. Epistylis sp. also consisted of branched colonies but was lacking myoneme. In contrast the Vorticella sp. occurred as individual trophonts with a contractile stalk. Scanning electron microscopy of Epistylis sp. revealed the surface topography, convoluted ridges over the trophont surface and stalk. Both Pseudomonas spp. and Vibrio spp. caused darkening of cuticle, loss of appendage setae and their hairs in the pleopods and uropods, blister in the gills and accumulation of hemocytes at the infected sites. Minimum inhibitory concentration of acriflavin, ampicillin, furazolidone, kanamycin and prefuran required to control the growth of Vibrio spp. and Pseudomonas spp. were found to be higher than the recommended limits. Intramuscular inoculation of bacterial cells of Vibrio spp. and Pseudomonanas spp. into P. indicus caused mortalities from 30% to 80% but drug treatment with neomycin sulphate (20 μg ml-1 of culture tank)/ streptomycin (10 <span style="font-size:14.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:hiddenhorzocr;="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">μg <span style="font-size:14.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">ml-1 of culture tank) reduced the mortality (0% - 30%). Drug therapy of P. indicus infected with peritrichous ciliates revealed that formalin and a flavonoid flavone effectively killed the ciliates whereas methylene blue was ineffective. The present study revealed that the populations of the prawn P. indicus suffer from bacterial and epibiont protozoan diseases reflecting the quality of the environment which is polluted with industrial effluents and sewage discharge.</span