Parasites and pathological conditions in the edible oyster, Crassostrea madrasensis (Preston), from the east and west coasts of India

• Published in: Parasitology research (1987) Vol. 116; no. 9; pp. 2569 - 2579
• Main Authors: Suja, G., Kripa, V., Sunil Mohamed, K., Lijo, J., Mini, K. G., Sanil, N. K.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-09-2017; Springer; Springer Nature B.V
• Subjects: Atrophy; Biomedical and Life Sciences; Biomedicine; Ciliates; Environmental aspects; Health aspects; Immunology; Medical Microbiology; Microbiology; Original Paper; Oysters; Parasites; Pollution levels; Protozoa; Seasonal variations; India; Histopathology; Host physiology; Pathological conditions; Protozoan parasites; Crassostrea madrasensis
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-017-5566-z

A detailed pathological survey was carried out on the commercially important edible oyster,
Crassostrea madrasensis
(Preston), from two distinct coastal/brackish water ecosystems of south India. Samples were collected twice a year during wet and dry seasons from 2009 to 2012. Bacterial colonies in the form of prokaryotic inclusions, protozoans (
Perkinsus beihaiensis
,
Nematopsis
sp. and ciliates
Sphenophrya
sp. and
Stegotricha
sp.), metazoans (trematodes, turbellaria, cestodes and crustaceans) and shell parasites (
Polydora
spp. and
Cliona
spp.) along with various pathological conditions (digestive tubule atrophy, ceroid bodies, haemocytic infiltration, tissue necrosis and neoplastic disorders) were observed in
C. madrasensis
collected from two sites. Intensity, spatial and seasonal variations in infection prevalence and pathological effects on the host were studied. The protozoan parasite,
P. beihaiensis
; shell parasite,
Polydora
spp. and pathological condition, digestive gland atrophy were most prevalent in occurrence. High-intensity infections with
P. beihaiensis
, larval trematodes and
Polydora
spp. were found to cause significant impact on host physiology. All other parasites were observed with low mean prevalence and intensity. Karapad in Tuticorin bay, the site reported with marked pollution levels, exhibited higher number of parasitic taxa and high mean prevalence and intensity for pathological conditions.