The toxic dinoflagellate Alexandrium minutum impairs the performance of oyster embryos and larvae

Mar 2, 2020Harmful algae

The harmful algae Alexandrium minutum reduces oyster embryo and larva performance

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Alexandrium minutum exposure resulted in up to 68% decreased survival in oyster larvae.

Bioactive extracellular compounds (BEC) from A. minutum play a significant role in its toxicity to oyster development.
Embryos were the most sensitive life stage, with BEC exposure causing lysis.
The non-PST-producing A. minutum strain inhibited hatching and disrupted larval behavior, growth, and survival.
PST accumulation was observed in oyster larvae, potentially affecting their development and settlement.
A. minutum blooms may hinder shellfish settlement and recruitment.

AI simplified

The dinoflagellate genus Alexandrium comprises species that produce highly potent neurotoxins known as paralytic shellfish toxins (PST), and bioactive extracellular compounds (BEC) of unknown structure and ecological significance. The toxic bloom-forming species, Alexandrium minutum, is distributed worldwide and adversely affects many bivalves including the commercially and ecologically important Pacific oyster, Crassostrea gigas. In France, recurrent A. minutum blooms can co-occur with C. gigas spawning and larval development, and may endanger recruitment and population renewal. The present study explores how A. minutum affects oyster early development by exposing embryos and larvae, under controlled laboratory conditions, to two strains of A. minutum, producing only BEC or both PST and BEC. Results highlight the major role of BEC in A. minutum toxicity upon oyster development. The BEC strain caused lysis of embryos, the most sensitive stage to A. minutum toxicity among planktonic life stages. In addition, the non-PST-producing A. minutum strain inhibited hatching, disrupted larval swimming behavior, feeding, growth, and induced drastic decreases in survival and settlement of umbonate and eyed larvae (9 and 68 %, respectively). The findings indicated PST accumulation in oyster larvae (e.g. umbonate stages), possibly impairing development and settlement of larvae in response to the PST-producing strain. This work provides evidences that A. minutum blooms could hamper settlement of shellfish.

Full Text

Full text is available at the source.

View full text (XML) ↗View full text ↗

The toxic dinoflagellate Alexandrium minutum impairs the performance of oyster embryos and larvae

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief