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Exposure of Nile Tilapia ( Oreochromis niloticus ) Fingerlings to a Saxitoxin‐Producing Strain of Raphidiopsis ( Cylindrospermopsis ) raciborskii (Cyanobacterium) Reduces Growth Performance and Increases Mortality Rate
Author(s) -
De Bock Mariana Federica Sánchez,
Moraes Gláucia Sabrine de Oliveira,
Almeida Rômullo Guilherme dos Santos,
Vieira Karla Daniele da Silva,
Santoro Kleber Régis,
Bicudo Álvaro José de Almeida,
Molica Renato José Reis
Publication year - 2020
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.4728
Subject(s) - nile tilapia , cylindrospermopsis raciborskii , saxitoxin , oreochromis , biology , aquaculture , cyanobacteria , fishery , eutrophication , toxicology , zoology , veterinary medicine , ecology , fish <actinopterygii> , toxin , microbiology and biotechnology , bacteria , medicine , genetics , nutrient
Blooms of toxin‐producing cyanobacteria have been more frequent and lasting because of the eutrophication of freshwater ecosystems, including those used for aquaculture. The aim of the present study was to investigate the effects of chronic exposure to a saxitoxin‐producing strain of Raphidiopsis ( Cylindrospermopsis ) raciborskii on the performance of Nile tilapia ( Oreochromis niloticus ) fingerlings over a 60‐d period. The fingerlings were cultivated under the following conditions: 1) water without cyanobacterium (WATER), 2) R. raciborskii in ASM‐1 culture medium (CYANO), and 3) ASM‐1 culture medium without cyanobacterium (ASM). Exposure to the CYANO treatment led to a significant increase in the mortality rate ( p < 0.05) and a significant reduction in growth ( p < 0.05) compared to fingerlings submitted to the ASM and WATER treatments, in which similar survival and growth were found ( p > 0.05). Saxitoxin toxicity was dependent on the weight of the fingerling ( p < 0.05), with maximum mortality caused by the ingestion of 13.66 μg saxitoxin equivalent L −1 g −1 . The present results clearly show the harm caused by saxitoxins to the production of Nile tilapia fingerlings in the early growth phase. These findings underscore the importance of maintaining adequate water quality in aquaculture activities to minimize the risk of saxitoxin‐producing cyanobacterial blooms and avoid economic losses among producers. Environ Toxicol Chem 2020;39:1409–1420. © 2020 SETAC