Multiple tail-like structure induced by nitrogen fertilisers in Hoplobatrachus rugulosus embryos

Abstract

© 2020 by Chulalongkorn University. Agrochemical contamination is claimed as one of the most important factors in amphibian decline. Although many researchers previously focused on pesticide toxicity, fertiliser toxicity is also a prominent issue due to the massive amounts applied to fields by farmers each year. Therefore, the present study aimed to investigate acute toxicity of nitrogen fertilisers (ammonium sulphate and urea) on mortality and development of gastrula and neurula in the East Asian bull frog (Hoplobatrachus rugulosus) using the frog embryo teratogenesis assay. The results revealed lethality, malformation, and negative developmental effects induced by ammonium sulphate and urea fertilisers in H. rugulosus gastrulae and neurulae. Ammonium sulphate produced more severe effects on H. rugulosus embryos compared to urea for all measures in the same stage of embryos. Gastrulae were more sensitive to the exposure of the two nitrogen fertilisers. Moreover, the present study is the first report of a multiple tail-like structure caused by fertilisers in frog embryos. The two fertilisers also produced oedema and kinking of tail and body in both stages. This study suggests that the abnormality occurred due to interference with cell movements during gastrulation.