Sperm Supply from the Testes to the Seminal Vesicle over Consecutive Matings in the Sweetpotato Weevil, &amp;lt;i&amp;gt;Cylas formicarius&amp;lt;/i&amp;gt; (F&amp;lt;sub&amp;gt;ABRICIUS&amp;lt;/sub&amp;gt;) (Coleoptera: Curculionidae)

Satoshi Hiroyoshi

doi:10.11648/j.ajls.20170504.12

Abstract

The sweetpotato weevil, Cylas formicarius, stores free sperm in both the testes and the seminal vesicle, even though the primary function of the testes is sperm production. Here, it was investigated sperm storage in the testes in relation to mating frequency. In particular, it was examined the effect of the positional relationship between the testes and seminal vesicle, on sperm storage by counting the number of sperm in those organs. After mating, not only were the number of free sperm in the seminal vesicle reduced, but also was the number in the testes, suggesting that free sperm stored in the testes moved into the seminal vesicle during or immediately after mating. Since this weevil seems to not regulate the number of sperm in the seminal vesicle for ejaculation, the sperm supply system of the testes may contribute ejaculate to support consecutive, multiple matings by this weevil.

Highlights

The morphology of the male reproductive organs differs considerably among insect species [1]
The number of free sperm found in testes decreased significantly with the number of matings, and there was a significant difference between virgin males and males that had mated twice (H = 53.50961, df = 29, P
The male seminal vesicle had significantly smaller numbers of free sperm after the first one or two matings compared to virgin males (H = 50.480764, df = 29, P

Summary

Introduction

The morphology of the male reproductive organs differs considerably among insect species [1]. The positional relationship between the testis and the seminal vesicle, differs among species. To the best of our knowledge, few studies have examined the positional relationship between testes and seminal vesicles and the influence of their arrangement on sperm storage. The testes are connected with the seminal vesicle via the vas deferens. The length of the vas deferens differs in species, resulting in the differences of distance between the testes and the seminal vesicle. Cylas formicarius Fabricius) (Coleoptera: Curculionidae), both the testes and the seminal vesicle are very close to each other and both store free sperm [4] The vas deferens of this weevil is connected with ejaculatory duct. The positional relationship between the testes and the seminal vesicle, is unclear

Methods

Results

Conclusion