Detection of Baculovirus penaei and cases of vibriosis in Litopenaeus vannamei and L. stylirostris on a farm on the west coast of Venezuela.
Penaeid shrimp culture is an established industry in many tropical countries of Asia and America. In Venezuela it began with the native species Litopenaeus schmitti [Penaeus schmitti] and L. braziliensis [P. braziliensis] and then in 1986, with the exotic species L. vannamei [Penaeus vannamei]. Since 1989 the productive marine shrimp industry grew very fast but was characterized by many constraints in its production, including diseases. In the present study cultured shrimp from the western region of Venezuela were microbiologically evaluated. The specimens were grouped into apparently healthy and diseased individuals, with the second group showing many melanized areas in the exoskeleton. Low levels of infestation of Epistylis sp., Zoothamnium sp., Acineta sp. and trichomas of Leucothrix sp. Baculovirus penaei was detected in fresh squash preparations and histological sections of hepatopancreas and intestines of diseased shrimp. Trophozoites and gametocysts of Nematopsis sp. were observed in the animal intestines. In apparently healthy shrimp, Aeromonas spp., Vibrio spp., V. campbellii, V. carchariae, V. fluvialis, V. harveyi and V. parahaemolyticus were identified, and in diseased ones, Vibrio spp., V. harveyi and V. furnisii were isolated from hepatopancreas and intestines, while only Vibrio spp. and V. harveyi were identified from the lesions. B. penaei was detected in a group of diseased animals but not from the rest when in situ hybridization was applied. A sanitary evaluation is recommended when new specimens are introduced in a farm, either of national or international origin.