Toxic Effects of the Methanol Extracts of some Tunicate Species

Abstract

The toxicities of the methanol extracts of seven tunicates (Phallusia sp., Eudistoma obscuratum, Atriolum robustum, Didemnum sp., D. molle, Clavelina picta and Aplidium sp.) on brine shrimp and the 4^th instar larvae of four vector mosquitoes (Culex quinquefasciatus, Anopheles maculatus, Aedes aegypti and Ae. albopictus) were investigated. The extracts were very toxic to the brine shrimp with Lc₅₀ values ranging from 0.8 -26.0 µg/ml and the most toxic being the extract from Aplidium sp. The extracts were also effective against the mosquito larvae with LC₅₀ values ranging 1.2 - 55.6 µg/ml. Larvicidal activity of the extracts was most significant on An. maculatus with LC₅₀ values ranging from 1.2 -6.2 µg/ml and of these, the most toxic was the extract of E. obscuratum.