The importance of dietary calcium consumption in two species of semi-terrestrial grapsoid crabs

Iheringia. Série Zoologia

Flavia P. Zanotto²  Felipe Pinheiro¹  Marina G. E Sá¹ 

[1] ,Universidade Presbiteriana Mackenzie Centro de Ciências Biológicas e da Saúde São Paulo SP ,Brazil

关键词: Diet;    semi-terrestrial crabs;    feeding behavior;    Sesarma rectum;    Neohelice granulata;    Dieta;    caranguejo semi-terrestre;    comportamento alimentar;    Sesarma rectum;    Neohelice granulata;   

DOI  :  10.1590/S0073-47212009000300011

来源: SciELO

【 摘 要 】

Calcium (Ca) is essential for crustaceans, due to calcium carbonate (CaCO3) deposition in the new exoskeleton to harden it. The purpose of this work was to study short term Ca balance in terms of dietary Ca ingestion in two phylogenetically related crabs (Superfamily Grapsoidea) showing different degrees of terrestrial adaptations: Sesarma rectum Randall, 1840 and Neohelice granulata (Dana, 1851). Dietary Ca ingestion was studied using purified diets with different Ca concentrations (0, 2.2 and 6.66 % Ca), together with measurements of Ca excretion and Ca hemolymph levels. The results showed that both crabs had the same response to foods containing different levels of Ca, with both species eating more of the high Ca diet. However, S. rectum consumed more per mg body mass at all Ca concentrations (6 mg.g-1 for S. rectum against 3 mg.g-1 for N. granulata). Both species excreted/egested Ca differently: S. rectum excreted Ca proportionally to ingestion, whereas N. granulata maintained constant faecal Ca output at all dietary Ca levels. Moreover, Ca hemolymph levels for crabs fed the different diets were independent of dietary Ca. In conclusion, both S. rectum and N. granulata seem to regulate the consumption of diets containing more Ca, which suggests a fine balance for Ca intake.

【 授权许可】

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