Rare eggshell structure in Odonata: Lindenia tetraphylla (Van der Linden) (Anisoptera: Gomphidae).

Lindenia tetraphylla (Van der Linden, 1825) eggs exhibit an egg structure that is very rare in other Gomphidae species. They have a well-developed surface reticulation structure. The anterior pole of the egg has a small, rounded micropylar area consisting of seven orifices arranged radially around a central area. The posterior pole has a sessile, truncated cone that carries 55-65 coiled filaments. The filament structure found at the posterior pole of the egg has been observed in the gomphid species Lestinogomphus africanus (Fraser, 1926), Ictinogomphus australis (Selys, 1873), and I. rapax (Rambur, 1842). However, L. tetraphylla eggs differ from these species in both morphology and filament structure. This study provides a detailed analysis of the ultrastructure of L. tetraphylla eggs using scanning electron microscopy, and the functional and taxonomic significance of the eggshell are discussed. RESEARCH HIGHLIGHTS: The aim of this study is to examine the ultrastructure of the L. tetraphylla eggshell, emphasizing its function and taxonomic value. In this context, the general morphology of the egg, the reticulations on its surface, the micropylar region and micropylar structure, and the posterior filament coil were examined. In this study, the ultrastructure of L. tetraphylla egg was examined for the first time using scanning electron microscopy (SEM). As a result of the examination, it was detected for the first time that the posterior filament coil, which is rarely seen in odonate eggs, is also present in L. tetraphylla eggs. By comparing the L. tetraphylla egg with the eggs of I. ferox, I. rapax, I. australis, and L. africanus species, which are similar in terms of the posterior filament coil, the features that distinguish the L. tetraphylla egg.