Numerical variations and spontaneous malformations in the early embryos of the Korean salamander, Hynobius leechii, in the farmlands of Korea

Abstract

Embryo sacs of the Korean salamander, Hynobius leechii, were collected from nine farmlands in Gyeongsangnam-Do, Korea, in early spring of 2002 and 2004. The variations in the number of embryos within each embryo sac and the mortality and abnormality rates among the embryos were investigated. We also analyzed the patterns of spontaneous embryonic malformations and the residual chemicals in the soil of the habitats using multiple-residue GC/MS. A total of 79,195 embryos were obtained from 1933 embryo sacs. There were regional variations in the length of individual embryo sacs and the number of embryos in each. The longest embryo sac averaged by region measured 20.67 cm ± 3.51 and was obtained from 2-Banseong in 2002. Of the embryos collected, 13.71% either died or stopped developing, and 3.54% of the hatched embryos developed abnormally; the latter were classified according to the patterns of malformation. External gill dysplasia was the most frequent malformation, and caudal dysplasia, abdominal blisters, and dysplasia of the fin were also observed frequently. Histopathological analysis showed neural tube abnormalities, acrania, curved notochords, thyroid teratoma, and various other kinds of endodermal developmental abnormalities. In the analysis of the residual pesticides in the soil, carbofuran, endosulfan-sulfate, and endosulfan-β were detected in the regions with high mortality and malformation rates. These results indicate that various agricultural chemicals and other unknown factors may cause the aforementioned forms of spontaneous malformations in the embryos of Hynobius leechii.

Co-Treatment of Copper Oxide Nanoparticle and Carbofuran Enhances Cardiotoxicity in Zebrafish Embryos

“…These conditions make it harder to obtain accurate measurements of cardiac physiology and the data accountability would be compromised if the experiment continued, and so the carbofuran concentration was lowered to the point where accurate measurements are still achievable. Several malformation cases after exposure to carbofuran have been reported in several animals like Hynobius leechii (Korean salamander), Bufo gargarizans (Asiatic toad), and even in zebrafish, which is in line with the findings of this study [ 16 , 49 , 50 ].…”

Vertebral anomalies in a natural population of Taricha granulosa (Caudata: Salamandridae)

“…polydactyly) are relatively common in lissamphibians and have been reported in the scientific literature for more than 200 years (among many others: De Superville 1740 ;Meteyer 2000;Ouellet 2000;Johnson et al 2002;Blaustein and Johnson 2003;Lunde and Johnson 2012;Rothschild et al 2012;Silva-Soares and Mônico 2017). Reports on developmental deformities of the spine, however, are less frequent as they can only be diagnosed via radiographic examination, dissection, histological sections or different clearing and staining techniques (Adolphi 1893(Adolphi , 1895(Adolphi , 1898Trueb 1977;Martinez et al 1992;Alvarez et al 1992Alvarez et al , 1995Gamble et al 2005;Maglia et al 2007;Park et al 2010;Pugener and Maglia 2009;Perpiñán et al 2010;Buckley et al 2013;Liu et al 2016;Danto et al 2020).…”