пятница, 8 марта 2019 г.
Female Reproductive System of Pheretima Posthuma
womanish reproductive system of earthworm- It consists of sideline parts 1. Ovary 2. Oviducal funnel 3. Oviducts 4. Female genital aperture 5. Spermathaceae 1. Ovary- They be the white lobate structures which argon posit in the inter instalment of 12/13. They consist of ova secreting cells. The ova are commonly generated by the process of oogenesis. They are generally arranged on the bum of maturation. The matured ones are contained in the distal end whereas the immature ones are concentrated in the proximal end. 2.Oviducal funnel- A pair of funnel-like structure is present beneath the ovary in the 13th segment. They are the ciliated structures which allow the ova to be passed through a pair of tubular structures called oviducts. The regular beating of cilia helps to pull to positionher the ova inside it. 3. Oviducts- The ovducal funnel leads to a narrow pair of tubular structures called oviducts. They are internally ciliated and allows the ova to pass through it. These pair o f oviducts run ventrally to meet at the 14th segment where it forms the female genital aperture. . Female genital aperture- They are the mid- ventrally located apertures in the 14th segment of the earthworm. Through these apertures, the ova which are passing through the oviducts are passed during the cocoon formation. 5. Spermathatheceae- there are four pairs of spermatheca located ventro- laterally in the 6th, 7th, 8th and 9th segments. in that respect openings are located in the intersegments of 6/7, 7/8 8/9 and 9/10. They are the sites for reserving the sperms during the copulation phase.The male genital aperture and the spermatheceae get fused during copulation where the sperms from the male genital pore are transferred to spremathaceae. structurally the spermathaceae consists of a pear-shaped ampulla, a neck and a nose- like physical process called diverticulum. In Pheretima, the sperms are stored in the diverticulum and the nourishment is provided by the ampulla. Unlikely i n other earthworms, they are stored in the ampulla itself. Fig. Reproductive system of Pheretima posthuma Fig. OvaryFig. Spermathaceae