Toxicity of cobalt (C02+) and tin (Sn2+) to the embryos and juveniles of the freshwater snail, Radix quadrasi

Date

6-2017

Degree

Bachelor of Science in Biology

Major Course

Major in Zoology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Emmanuel Ryan C. De Chavez

Abstract

VARGAS, JOSHUA GABRIEL P. 2017. Toxicity of Cobalt (Co2+) and Tin (Sn2+) to the embryos and juveniles of the freshwater snail, Radix quadrasi. University of the Philippines, Los Banos. B. S. Biology Major in Zoology.

Adviser: Emmanuel Ryan C. de Chavez, Ph.D.

ABSTRACT

Heavy metals, a major environmental toxicant from industrial, agricultural and household sources, are usually disposed into freshwater ecosystems affecting resident invertebrates like snails. To investigate this problem, the trochophore larvae and juveniles of the freshwater snail, Radix quadrasi was used to examine the effects of Co' and Se. Static renewal acute toxicity was conducted for 96h. The median lethal (LCso-96h) and sublethal (LC,96h) concentrations were calculated using probit analysis. Sublethal toxicity test based on LC,„-96h was conducted to embryos and juveniles. For embryos, abnormality, heart rate, incubation period, hatchability and heart rate were determined; while for juveniles, growth rate was calculated. The LC50-96h for the embryos were 1.41 mg/L and 1.54 mg/L; and 0.17 mg/L and 6.07 mg/L for juveniles. Growth retardation was the most common abnormality, while edema and shell thinning were only observed in Ce-exposed embryos. Only Co2+ lowered the heart rate after 10-day exposure. Hatchability was reduced and incubation period was prolonged. Growth rate was reduced in juveniles. Maximum Allowable Toxicant Concentration of Co2+. and Sn2+ were 1.75mg/L and 1.27mg/L, respectively, was higher than acceptable WHO standards. The present study demonstrated the potential of R. quadrasi embryos and juveniles as bioindicator for Co2+ and Sn2+ contamination.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2017 B4 V37

Document Type

Thesis

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