Comparative ultrastructure of the fertilized egg envelope in Corydoras adolfoi and Corydoras sterbai

[Horlack]

Comparative ultrastructure of the fertilized egg envelope in Corydoras adolfoi and Corydoras sterbai, Callichthyidae, Teleostei
Authors : Eun‐Kyung Choi, Joon Hyung Sohn, Sung Sik Han, Dong Heui Kim
First published: 20 June 2018
HTML : https://onlinelibrary.wiley.com/doi/abs ... jemt.23057
DOI : https://doi.org/10.1002/jemt.23057

In teleost, the structural characteristics of fertilized egg and egg envelope are very important for classification of genus or species. The structures of fertilized egg and egg envelope from Corydoras adolfoi and Corydoras sterbai, Callichthyidae, Siluriformes in teleost were examined by scanning and transmission electron microscopes to confirm whether these morphological structures have specificities of species and family or not. The fertilized eggs of C. adolfoi and C. sterbai were non‐transparent, spherical, demersal, and strong adhesive. There were no structural differences between two species through the light microscope. The size of the fertilized eggs of C. adolfoi was 1.95 ± 0.03 mm (n = 20), and that of C. sterbai was 1.92 ± 0.03 mm (n = 20). The perivitelline space was almost not developed in both species. In both species, the adhesive protuberances structures were on the outer surface of egg envelope. And fibrous structures were specially located at attachment part of spawning bed. And the egg envelope consisted of two layers, an inner lamellae layer and an outer strong adhesive layer with high electron dense protuberances structures in cross section. Consequentially, the fertilized eggs, outer surface on the egg envelope and cross section of egg envelope have identical structure. So, these structural characteristics of fertilized eggs and egg envelope show genus Corydoras specificity.

[Bas Pels]

In more plain words, this technique is not usable to separate eggs to species in Corydoras

[Horlack]

In more plain words, this technique is not usable to separate eggs to species in Corydoras

False. Look better pictures




Even if general or global structure is the same, the density and height of the protuberances is not the same.
You dont see, on (c), that there is a lot more protuberances than (a), included height ?

it's like mathematics, 2 triangles, which are 2 structures of 3 sides, does not mean that they are identical
There is triangle and triangle. They can be characterized in different ways: area, surface, angle, length, median, center of gravity, etc.