Details

Autor(en) / Beteiligte

• Rosa, Jheimison Junior da Silva
• Martinez, Claudia Bueno dos Reis

Titel

Short communication: Effects of acute copper exposure on ionic regulation of the freshwater crab Aegla castro

Ist Teil von

• Comparative biochemistry and physiology. Toxicology & pharmacology, 2021-10, Vol.248, p.109106, Article 109106

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2021

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Aeglids are unique freshwater decapods whose habitats are being impacted by metallic compounds, such as copper (Cu). Thus, we investigated the effects of acute Cu exposure on ionic regulation of Aegla castro. For this, male specimens in intermolt were collected from a reference stream and acclimated for 5 days in laboratory. After which, crabs were exposed to 11 μg L−1 Cu (Cu11) or only to water (CTR) for 24 h. Hemolymph samples were withdrawn for the determination of Na+, K+, Ca2+, and Mg2+ concentrations and the posterior gills removed for the analysis of Na+/K+-ATPase, Ca2+-ATPase, H+-ATPase, and carbonic anhydrase (CA) activities. Increased Ca2+ and Mg2+ hemolymph concentrations were observed in animals from Cu11, when compared with CTR group. In addition, decreased activity of CA was observed in animals exposed to Cu. In the current study, alterations in Ca2+ and Mg2+concentrations probably indicate that animals activated exoskeleton reabsorption mechanisms, characteristic of the premolt. Therefore, increased Ca2+ and Mg2+ concentrations in hemolymph may indicate that a biochemical signal associated with the molting cycle was triggered by Cu exposure. Despite the known harmful effects of Cu on osmoregulatory enzymes, here we observed decreased activity only in CA. However, decreased activity of CA could trigger both acid-base imbalance and ionic disruption, since CA provides H+ and HCO3− for intracellular pH maintenance, and underpins Na+ and Cl− for ionic regulation. Therefore, understanding how aeglids respond to metal contamination in laboratory conditions is crucial to assess their potential as an alternative biological model for aquatic ecotoxicology. [Display omitted] •Freshwater anomuran crab Aegla castro was exposed to Cu (11 μg L−1) for 24 h.•Acute Cu exposure increased hemolymph Ca2+ and Mg2+ concentrations.•Cu exposure may have triggered the start of a new molting cycle.•Cu inhibited gill activity of carbonic anhydrase.•Cu did not affect the hemolymph Na+ and K+ concentrations.