Effects of tributyltin oxide on embryonic and larval development of giant freshwater prawn Macrobrachium rosenbergii de Man

Abstract

Acute and subacute toxicities of tributyltin oxide (TBTO) were determined in embryos and larvae of giant freshwater prawn, Macrobrachium rosenbergii de Man, with static water renewal condition every 24 h. The 96 h LC₅₀s for early and late stage embryos were 583 and 720 µg 1⁻¹, respectively. The tolerance to TBTO trend increase with increasing developmental stage. For larvae, the 24 h LC₅₀s were ranging from 10.9 to 12.8 µg 1⁻¹, respectively for first and fifth stage larvae. The 48 h LC₅₀s compised between 5.8 and 7.7 µg 1⁻¹ for fifth and sixth stage larvae, respectively. There appear to be no difference among the 24 h LC₅₀s of first six stages larvae and also 48 h LC₅₀s for second to sixth stage. As regards sublethal effects, hatching success reduced with increasing concentration by 15 days of exposure between 250-1000 µg 1⁻¹. Growth was significantly retarded (P<0.05) in larvae treated with 0.6 or 1.2 µg 1⁻¹ for 30 days without significant difference between the two concentration.