Creative Commons License 2023 Volume 10 Issue 3

Morphological Characterization of the Male Reproductive System of Mylabris cernyi Pan and Bologna, 2014 (Coleoptera: Meloidae)


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Abstract

An aedeagus, two seminal vesicles, two vasa deferentia, an ejaculatory duct, three pairs of accessory glands, and two testes make up the male reproductive system of Mylabris cernyi. The morphology of this system was investigated using both optical and electron microscopy. There are 14–15 testicular follicles in the testis, arranged radially. In these testicular follicles, 3 different zones (growth, maturation, and differentiation) are distinguished from the periphery of the testis to its center. The testis emerges as a vas efferens later joining to form a vas deferens and seminal vesicle. Mature sperm masses are distinguished in their lumens. In M. cernyi, there are three pairs of accessory glands (Ag1, Ag2, and Ag3). Ag1 is short, tubular, and light yellow. It has columnar epithelial cells and a muscle layer. Its lumen contains basophilic secretory materials. Ag2 is long, coiled, tubular, and whitish, and its lumen has basophilic and fibrous secretory materials. A single layer of squamous epithelium envelops it. Ag3 is a long, tubular, coiled gland that secretes chemicals that are eosinophilic. The accessory gland opens into an ejaculatory duct. The ejaculatory duct wall is composed of a thick layer of muscle, epithelium, and intima. The intima layer's lumen-facing surface is covered in spines. The aedeagus is the opening of the ejaculatory duct. The findings offer the first morphological description of the male reproductive system of M. cernyi, which may be helpful for further investigation and investigations.


How to cite this article
Vancouver
Koçakoğlu NÖ, Candan S, Güllü M. Morphological Characterization of the Male Reproductive System of Mylabris cernyi Pan and Bologna, 2014 (Coleoptera: Meloidae). Entomol Appl Sci Lett. 2023;10(3):33-41. https://doi.org/10.51847/UHEzG4Ullx
APA
Koçakoğlu, N. Ö., Candan, S., & Güllü, M. (2023). Morphological Characterization of the Male Reproductive System of Mylabris cernyi Pan and Bologna, 2014 (Coleoptera: Meloidae). Entomology and Applied Science Letters, 10(3), 33-41. https://doi.org/10.51847/UHEzG4Ullx
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Morphological Characterization of the Male Reproductive System of Mylabris cernyi Pan and Bologna, 2014 (Coleoptera: Meloidae)

 

Nurcan Özyurt Koçakoğlu1*, Selami Candan1, Mustafa Güllü2

 

1Department of Biolog, Faculty of Science, Gazi University, 06500 Ankara, Türkiye.

2Department of Plant Protection, Faculty of Agriculture, Bingöl University, Bingöl, Türkiye.


ABSTRACT

An aedeagus, two seminal vesicles, two vasa deferentia, an ejaculatory duct, three pairs of accessory glands, and two testes make up the male reproductive system of Mylabris cernyi. The morphology of this system was investigated using both optical and electron microscopy. There are 14–15 testicular follicles in the testis, arranged radially. In these testicular follicles, 3 different zones (growth, maturation, and differentiation) are distinguished from the periphery of the testis to its center. The testis emerges as a vas efferens later joining to form a vas deferens and seminal vesicle. Mature sperm masses are distinguished in their lumens. In M. cernyi, there are three pairs of accessory glands (Ag1, Ag2, and Ag3). Ag1 is short, tubular, and light yellow. It has columnar epithelial cells and a muscle layer. Its lumen contains basophilic secretory materials. Ag2 is long, coiled, tubular, and whitish, and its lumen has basophilic and fibrous secretory materials. A single layer of squamous epithelium envelops it. Ag3 is a long, tubular, coiled gland that secretes chemicals that are eosinophilic. The accessory gland opens into an ejaculatory duct. The ejaculatory duct wall is composed of a thick layer of muscle, epithelium, and intima. The intima layer's lumen-facing surface is covered in spines. The aedeagus is the opening of the ejaculatory duct. The findings offer the first morphological description of the male reproductive system of M. cernyi, which may be helpful for further investigation and investigations.

Keywords: Testicular follicles, Spermatozoa, Accessory glands, Light microscope, Electron microscope


INTRODUCTION

 

Meloidae (bubble or oil bugs) have 177 species in Turkey and more than 3000 species in the world and cause great economic damage by feeding on the leaves and shoots of many fruits and vegetables [1-3].

The family Meloidae has been the subject of numerous taxonomic, biological, systematic, and faunistic studies and has received great attention worldwide [2]. LM and SEM were used in this study to examine the morphology of the male reproductive system of M. cernyi (Meloidae), as there have been few investigations on the reproductive system of Meloidae [4].

A pair of testes, a pair of vasa deferentia, three pairs of accessory glands, an ejaculatory duct, and an aedeagus are the main organs of the male reproductive system in Meloidae [4]. The testis consists of many follicles, the number of which varies according to the species, where sperm development occurs. Accessory glands form the spermatophore, which allows the sperm to move and feed, and at the same time ensures the safe transport of the sperm to the female. The testis peritoneal sheath color, the testis shape, the testis follicle numbers, and the accessory gland shape and number vary interspecifically [4-9].

This study looked at the morphology of M. cernyi's male reproductive system in an effort to learn more about blister beetles in general.

MATERIALS AND METHODS

Mylabris cernyi (n=20) were collected in July 2019 from Keklikdere, Bingöl, Türkiye. The adults' organs were dissected under a stereo microscope (SM) after they had been sedated with ethyl acetate steam. After being moved to formalin, certain organs were embedded in paraffin. For light microscope (LM), slices (5–6 μm) stained with hematoxylin and eosin (H and E). The other organs were transferred HMDS (Hexamethyldisilazane) and then dried with air. The organs examined with a scanning electron microscope (JEOL JSM 6060 LV).

RESULTS AND DISCUSSION

The male reproductive system of Mylabris cernyi comprises a pair of testes (Te), a pair of vasa deferentia, a pair of seminal vesicles (Sv), three pairs of accessory glands (Ag 1- first pair of accessory gland, Ag 2- second pair of accessory gland, Ag 3- third pair of accessory gland), an ejaculatory duct (Ed) (Figure 1a), and an aedeagus (Ae) (Figure 7d) as in many other blister beetle species [4].

The testis

The testis of M. cernyi has a light yellow-colored (Figure 1a) globule-like structure (Figures 1b and 1c). There is a trachea (Tr) in some places on the testis surface (Figure 1c). The testis of M. cernyi is spherical (Figures 1a-1c) and the testis consists of testicular follicles (Tf), which have a radial arrangement. The size of the testis and the follicle number of tests may differ interspecifically. The testis of M. cernyi is ~12 mm (Figure 1c) and has 14–15 follicles (Figure 1d). Each testis of Meloe proscarabaeus Linnaeus, 1758 (Meloidae) contains 100–120 follicles [4].

 

a)

b)

c)