Abstract

MUNOZ-ESCOBAR, Eliana M.  and  PALACIO-BAENA, Jaime A.. EFFECTS OF MERCURY CHLORIDE (HGCL₂) ON THE SURVIVAL AND GROWTH OF TADPOLES OF DENDROSPHUS BOGERTI. Actu Biol [online]. 2010, vol.32, n.93, pp.189-197. ISSN 0304-3584.

Frog larvae (Dendrosophus bogerti) were exposed to five lethal (0.25, 0.3, 0.36, 0.43, and 0.51 mg/l) and four sublethal concentrations (0.02, 0.04, 0.08, and 0.10 mg/l) of mercury chloride (HgCl₂), in order to determine the LC₅₀ and effects on growth and development rates. The LC₅₀ at 96 h of HgCl₂ was 0.41 mg/l. There was evidence for an effect of Hg on growth (weight and length) at 10 and 20 days of exposure to 0.04, 0.08, and 0.1 mg/l HgCl₂ with a P < 0.001. In contrast, weight and length of tadpoles exposed to 0.02 mg/l HgCl₂ showed no significant differences with the negative control (P = 0.77 and P = 0.1, respectively). The highest growth inhibition was observed at 30 days (P < 0.001). The time to reach Gosner stage 36 was significantly different in all specimens treated with Hg compared to controls (H = 35.4, P < 0.001). The delay in development may be related to an enzymatic alteration and in nature may have a negative impact on the survival of tadpoles due to rapid drying of temporary ponds and increased vulnerability to predators. The species D. bogerti is sensitive to mercury exposure in aquatic environments, with adverse effects on growth and development rate.

Keywords : Dendrosophus bogerti; growth; mercuric chloride; metamorphosis; tadpoles.

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