Osmo-ionic regulation and carbonic anhydrase, Na+/K+-ATPase and V-H+-ATPase activities in gills of the ancient freshwater crustacean Aegla schmitti (Anomura) exposed to high salinities.
Comp Biochem Physiol A Mol Integr Physiol
; 231: 201-208, 2019 05.
Article
em En
| MEDLINE
| ID: mdl-30818018
ABSTRACT
Aeglidae anomuran crabs originated in the sea, but invaded and diversified in southern South American freshwater (FW) streams. We here aimed at examining their tolerance of increased salinity, after a long time of evolution in FW (~33 million years). Aegla schmitti were exposed to FW and dilute seawater of salinities 15, 20, and 25 for 1, 5 and 10â¯days. Mortality in 35 was also assessed. Hemolymph osmolality, Na+, K+, Cl-, and Mg2+ ions, and hydration levels of the abdominal muscle were assayed. The activities of the Carbonic Anhydrase (CA), Na+/K+-ATPase (NKA) and V-H+-ATPase (VHA) were also assayed in the gills. A. schmitti preserves osmoregulatory mechanisms of its marine ancestors. It is able to survive in high salinities (25) for at least 10â¯days. Mortality in 35 was of 56% after 1â¯day, and of 100% after 7â¯days. In 25, NaCl is apparently hyporegulated at all times, while hemolymph osmolality rises after 5â¯days. CA and NKA activities remained unchanged in all experimental conditions, while VHA activity decreased after 10â¯days in 25. Hemolymph NaCl data was compatible with either hyporegulation and/or putative influx of NaCl into cells for regulatory volume increase (RVI). Further studies should deepen the understanding of the roles of low permeabilities and saturation of high affinity uptake systems in truly FW decapods, in their responses to high salinities. Moreover, the fate of extracellular NaCl as secretion in true hypo-regulation and/or influx into cells for RVI should also be investigated.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Anidrases Carbônicas
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ATPases Translocadoras de Prótons
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ATPase Trocadora de Sódio-Potássio
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Crustáceos
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Salinidade
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Osmorregulação
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Brânquias
Limite:
Animals
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article