REPRODUCTIVE SYSTEM OF PERIPLANETA AMERICANA
Periplaneta is diecious, or unisexual .Both the sexes have well developed reproductive organs. They show sexual dimorphism both externally and internally. The female is different from the male in respective of short and broad abdomen, presence of brood pouches and absebce of anal styles.
MALE REPRODUCTIVE SYSTEM
1.The male reproductive system of periplaneta consists of a pair of testes, a pair of vasa deferentia, an ejaculatory duct, a pair of seminal vesicles, a mush room shaped gland and a phallic gland.
2.A pair of lobed and elongated testes are present. They are located in the fourth to sixth segments , one on each side . They are embedded in the fat bodies.
3.A thin duct called vas deferens begins from the posterior end of each testis.
4.The two vasa deferentia run backwards and open into a wide median duct, the ductus ejaculatorius in the seventh segment.
5.The ejaculatory duct is a muscular tube that extends posteriorly and opens at the gonopore or the male genital pore.
6.The male genital pore is surrounded by chitinous and asymmetrical structures called phallic organs or gonapophyses or phallomeres . They help in copulation . These are the male external genitalia.
These are the ventral , left and right phallomeres. The male genital aperture is present at the base of the ventral phallomere. The left phallomere bears a pseudo penis , a titillator , a aspirate lobe and inner acculobolus lobe. The phallic duct opens between acculobous and aspirate lobe. The right phallomere bears a hook and a serrate lobe.
7.A mushroom shaped gland is present in the sixth and seventh abdominal segments. It functions as an accessory reproductive gland. This gland consists of two types of tubules : They are
A.Long slender tubules, the utriculi majors or peripheral tubules.Their secretions forms the inner layer of the spermatophore.
B.Short tubules, the utriculi brevores. Their secretions nourishes the sperms.
8. A phallic or the conglobate gland is also associated with the male rproductive system of the periplaneta. Theduct of this glnad opens near the gonopore. Its function is still not known.`
FEMALE REPRODUCTIVE SYSTEM OFPERIPLANETA
1.The female reproductive system of periplaneta consists of
a pair of oviducts ,
spermathecal papilla and
2.A pair of large ovaries lie laterally in 2-6 abdominal segments.
They are light yellow in colour surrounded by fat bodies.Each ovary consists of eight tubules called ovarian tubules or ovarioles. Each ovariole consists of a
Tapering anterior anterior filament called germarium , and
A wide posterior end vitellarium.
The germarium contains various stages of developing ova , and
The vitellarium contains mature ova with yolk.
The tapering ends of ovarioles of each ovary unite to form a single thread which attaches to the dorsal body wall.
The ovarioles , at their posterior end unite to form a short wide oviduct.
3. The oviducts unite to form a very short median vagina.
4. Vagina opens into a large genital pouch on the eighth sternum through a vertical opening called female genital pore.
5. Genital pouch is formed by 7th , 8th , and 9th abdominal sterna.
The sternum of the segment is boat shaped and forms the floor and side walls of the genital pouch.
The sterna of the eighth and ninth segmants constitute the anterior wall and the roof of the genital pouch , respectively.
The genital pouch has two chambers the anterior Gynatrium or genital chamber , and the posterior Vestibullum or oothecal chamber.
6. A spermatheca or receptaculum seminis , is present in the 6th segment.It opens by a median aperture on a small spermathecal papilla in the dorsal wall of the genital pouch on the ninth sternum.
The spermatheca consisting of a left-sac like and a right filamentous caecum.
7.Three pairs of plate like chitinous structures called gonapophyses are present around the female genital aperture. These gonapophyses guide the ova into ootheca as ovipositors.These are the female external genitalia.
The eighth sternum bears one pair of gonapophyses called first basivalvulae. The ninth sternum bears two pairs called valvifers and second basivalvulae respectively.
8. A pair of branched colleterial glands is present behind the ovaries. These glands open in to the genital pouch separately , just above the spermathecal aperture. Secretion of the two collaterial glands forms a hard egg case called ootheca around the eggs .