Abstract
AbstractWe examined the morphology of the fertilized egg and the fine structure of fertilized egg envelopes of Poropanchax normani belonging to the family Poeciliidae, also known as Norman’s lampeye using light and electron microscopes. The fertilized eggs with narrow perivitelline space were found to be spherical and demersal, additionally containing small oil droplets in the vitelline membrane. Further, a bundle of adhesive filaments was observed to be present on one side of the fertilized egg. These filaments possessed remarkably high elasticity and were approximately 1-3 mm in length. The size of the fertilized egg was determined to be about 1.49 ± 0.07 mm (n = 30). The outer surface appeared smooth, and adhesive filaments originating at different location of the surface of the envelope were found to be distributed around the egg envelope and were joined together to form a single long bundle in scanning electron microscopic observation. A peak-like structure formed of several straight wrinkles was observed around the micropyle. However, the complete structure of the micropyle could not be studied due to the depth at which it was located. Additionally, the total thickness of the egg envelope was ascertained to be approximately12.5–14.5 μm. The egg envelope consisted of two distinct layers, an outer electron dense layer and an inner lamellar layer, further consisting of 10 sublayers of varying thicknesses. Collectively, it was observed that the morphological characteristics of the fertilized egg, fine structures surrounding the micropyle, outer surface, adhesive structure consisting adhesive filaments, and sections of fertilized egg envelope displayed species specificity.
Publisher
Springer Science and Business Media LLC
Subject
Applied Microbiology and Biotechnology,Microbiology
Reference27 articles.
1. E. Ahl, LXXVII., Descriptions of two new cyprinodont fishes from Nigeria. Ann. Mag. Nat. Hist. 2(12), 600–602 (1928). https://doi.org/10.1080/00222932808672927
2. I.L. Cameron, K.E. Hunter, Regulation of the permeability of the medaka fish embryo chorion by exogeneous sodium and calcium ions. J. Exp. Zool. 231, 447–454 (1984)
3. B.S. Chang, E.K. Choi, H.W. Kim, D.H. Kim, Ultrastructure of the fertilized egg envelopes in Hemigrammus erythrozonus, Characidae. Teleostei. Appl. Microsc. 49, 8 (2019). https://doi.org/10.1186/s42649-019-0010-8
4. E.K. Choi, J.H. Sohn, S.S. Han, D.H. Kim, Comparative ultrastructure of the fertilized egg envelope in Corydoras adolfoi and Corydoras sterbai, Callichthyidae. Teleostei. Microsc. Res. Tech. 82, 33–38 (2019). https://doi.org/10.1002/jemt.23057
5. Y.K. Deung, D.S. Reu, D.H. Kim, Comparative ultrastructures of the fertilized egg envelopes in golden severum, convic cichlid and discus, Cichlidae, teleost. Kor. J. Electron Microsc. 27, 417–432 (1997)