Effects of metal contamination in situ on osmoregulation and oxygen consumption in the mudflat fiddler crab Uca rapax (Ocypodidae, Brachyura)

Author(s)

Capparelli, Mariana V. ^[1] ; Abessa, Denis M. ^[2] ; McNamara, John C. ^{[3, 1]}

Affiliation

^[1] Univ Sao Paulo, Fac Filosofia Ciancias & Letras Ribeirao Preto, Dept Biol, Ave Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Estadual Paulista, Campus Sao Vicente, BR-11380972 Sao Vicente, SP - Brazil

^[3] Univ Sao Paulo, Ctr Biol Marinha, BR-11600000 Sao Sebastiao, SP - Brazil

• Document type: Journal article
• Source: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY; v. 185, p. 102-111, JUL-AUG 2016.
• Web of Science Citations: 9

Abstract

The contamination of estuaries by metals can impose additional stresses on estuarine species, which may exhibit a limited capability to adjust their regulatory processes and maintain physiological homeostasis. The mudflat fiddler crab Uca rapax is a typical estuarine crab, abundant in both pristine and contaminated areas along the Atlantic coast of Brazil. This study evaluates osmotic and ionic regulatory ability and gill Na+/K+-ATPase activity in different salinities (<0.5, 25 and 60 parts per thousand S) and oxygen consumption rates at different temperatures (15, 25 and 35 degrees C) in U. rapax collected from localities along the coast of Sao Paulo State showing different histories of metal contamination (most contaminated Ilha Diana, Santos > Rio Itapanhau, Bertioga > Picinguaba, Ubatuba {[}pristine reference site]). Our findings show that the contamination of U. rapax by metals in situ leads to bioaccumulation and induces biochemical and physiological changes compared to crabs from the pristine locality. U. rapax from the contaminated sites exhibit stronger hyper- and hypo-osmotic regulatory abilities and show greater gill Na+/K+-ATPase activities than crabs from the pristine site, revealing that the underlying biochemical machinery can maintain systemic physiological processes functioning well. However, oxygen consumption, particularly at elevated temperatures, decreases in crabs showing high bioaccumulation titers but increases in crabs with low/moderate bioaccumulation levels. These data show that U. rapax chronically contaminated in situ exhibits compensatory biochemical and physiological adjustments, and reveal the importance of studies on organisms exposed to metals in situ, particularly estuarine invertebrates subject to frequent changes in natural environmental parameters like salinity and temperature. (C) 2016 Elsevier Inc All rights reserved. (AU)

• FAPESP's process: 11/08065-9 - A qualitative and quantitative analysis of metal pollution in the fiddler crab Uca rapax (Ocypodidae, Brachyura) evaluated using physiological, biochemical and genetic biomarkers
• Grantee: Mariana Vellosa Capparelli
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/22537-0 - Macroevolutionary implications of osmotic, thermal and metabolic homeostasis in inter-tidal, neotropical crabs
• Grantee: John Campbell McNamara
• Support Opportunities: Regular Research Grants