三种蚤生殖系统的细微结构:雄性外生殖器的发育

FINE STRUCTURES OF THE REPRODUCTIVE SYSTEM OF THREE FLEA SPECIES: DEVELOPMENT OF MALE GENITALIA

本文研究了缓慢细蚤Leptopsylla segnis(Sch?nherr),不等单蚤Monopsyllus anisus(Ro-thschild)和猫栉首蚤指名亚种Ctenocephalides felis felis(Bouche)雄性外生殖器的结构,观察了从幼虫、前蛹、蛹至成虫各发育时期的雄性外生殖器的内部结构变化。对有争议的雄蚤上抱器的起源,雄蚤生殖孔的位置,雄性外生殖器芽内陷的腹节以及射精管横切面的细胞数目和阳茎背、腹杆的结构等问题进行了详细的观察和探讨。

The result of a study on the internal structures during the development of the male genitalia from first instar larva to adult of Leptopsylla segnis, Monopsyllus anisus and Cte-nocephalides felis jelis is reported and summarized as follows:1. The development of the male genitalia of these fleas is essentially the same.2. The first genitalia rudiments appear in the early third instar larva as a pair of primary phallic lobes with the rudiments of the vasa deferentia sunken into a pocket of the anterior venter of the tenth abdominal segment. In the early prepupa a second pair of the rudiments is formed as the foldings of anterior venter of the ninth abdominal segment, and it will become the lower clasper of the adult; each primary phallic lobe is divided into a lateral branch, the paramere, and a mesal branch, the mesomere; and the anterior parts of the mesomeres unite to form the lumen of the endophallus; the rudiments of the vasa deferentia unite to form the ejaculatory duct, the opening of which is the gonopore on the anterior wall of the lumen of the endophallus; but the opening at the posterior of the lumen of the endophallus is the phallotreme. In the late prepupa the rudiments of aedeagal apodeme and the capsule appear in the dorsal wall of the aedeagus and the posterior dorsal wall of the lumen of the endophallus. In the pupa the folding tissues of the aedeagus with the phallotreme are everted, and the genital passage, the penis, the endophallus and the apical part of the aedeagus are gradually formed; and the parameres become bi-segmented, the basal segment being the body of the clasper, the basimere, and the distal one being the movable process, the telomere.3. Discussions have been brought forth concerning: (1) the development of the upper clasper; (2) the situation of the gonopore: (3) the structures of the ejaculatory duct and the penis rod; and (4) the situation of the development of the first genitalia rudiments.