Abstract
In this work, parasites associated with the mangrove oyster Crassostrea rhizophorae were studied at a cultivation unit in the estuary of the Graciosa River in Taperoá, Bahia. On a monthly basis, between April 2011 and March 2012, 20 oysters were collected, measured and fixed in 10% formaldehyde. In order to identify the parasites, routine histological techniques were used. The specimens were embedded in paraffin and sections, 7 µm thick, were cut. These were then stained with Harris hematoxylin and eosin and were examined using an optical microscope. The parameters analyzed to investigate water quality showed that the temperature ranged from 23.9 °C to 29.3 °C, water salinity from 0.4 to 24.2 Practical Salinity Units PSU and recorded rainfall from 80 mm to 406.4 mm/month. During the parasitological analyses, infestation of the polychaete Neanthes succinea was observed in 41% of the oysters. Through histological techniques, the following parasites were identified: colonies of Rickettsia-like organisms (RLOs); the protozoa Nematopsis sp. and Ancistrocoma sp.; the turbellarian Urastoma sp.; the metacestode Tylocephalum sp. and an unidentified tapeworm. The data collected showed that there was low-intensity infection with and prevalence of parasites, except for Nematopsis sp., thus attesting that these cultivated oysters were in a healthy condition.
Highlights
Bivalve mollusks are filter feeders and they feed on particles that are suspended in water
Studies looking at parasites in bivalve mollusks have provide an insight into the extent of the problems caused during bivalve mollusk production (SILVA et al, 2002; SABRY & MAGALHÃES, 2005)
The same happened with the European oyster (Ostrea edulis), which was severely affected by the protozoa Marteilia refringens and Bonamia ostrea (SILVA & VILLALBA, 2004)
Summary
Bivalve mollusks are filter feeders and they feed on particles that are suspended in water Because of this characteristic, they are considered to be carriers of numerous pathogens for humans, given that they primarily bioaccumulate bacteria such as those from the genera Salmonella and Shigella, along with enteric viruses and protozoa. The same happened with the European oyster (Ostrea edulis), which was severely affected by the protozoa Marteilia refringens and Bonamia ostrea (SILVA & VILLALBA, 2004). These parasites spread during the 1970s and 1980s, dramatically reducing production in the main bivalve cultivation areas in Europe. There were no methods available to eradicate them, and these diseases endemically persisted in most natural oyster beds and oyster farming areas, making any production enterprise impossible (ABOLLO et al, 2008; FAO, 2013)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.