Pila is a unisexual animal.Males and females are separate. Male is smaller than female. Male will show penis at the end of vas deferens.

 Male reproductive system : It shows testis, vas deferens and penis.

1. Testis : Only one testis is present. It is present in the visceral mass.

2. Vas deferens : From testis a number of vas efferentja will arise. They unite to form vas deferens. This is divisible into 3 parts.

a) Proximal tubular part : It is thin tube, it is narrow.

b) Middle curved part : It is curved. It is bulged. It will store sperms.

c) Distal glandular part: The last part is glandular. It will open on the genital papilla.

d . Penis : In front the anus from the edge of mantle a curved penis will arise ii is called Penis. It shows a groove. Through this groove sperms will travel


Hypo branchial gland : Near the base of penis a big hypo-branchial gland is present. Its functions are not clearly known.

 Sperms : In pila two types of sperms are formed.

1. Enpyrene type: They are thin. They show head, middle piece and tail. They are 25 microns in length. They can swim. The tail has a cilium. These sperms can fertilize the ovum.

2. Oligopyrene sperms ; These are sickle shaped. They show 4 to 5 cilia. They are 32.5 microns in length. Specific head is not seen. They cannot move They can never fertilise.

Female reproductive system : In the female reproductive system ovary, oviJ. ict, seminal receptacle and uterus are present.

1. ovary : It is present above the hepato-pancreas. It is branched. It is light orange coloured. When it is mature it becomes black. It gives oviduct.

2. oviiduct : It is a narrow duct. It opens into seminal receptacle.

3. seminal receptacle : It is bean shaped bulged organ. It will receive the sperr s from male during copulation.

4. Utirus : It is a big yellow coloured sac. Seminal receptacle will open into it. At it a 2X vagina is present. It opens out through female genital aperture near the anus.

Copulation : In the rainy season copulation will take place between male and female >ilas. Male and female will attach in opposite directions. Male will inject sperms through penis into the seminal receptacle of the female.

Fertilisation : In the uterus fertilization is carried on. They are liberated on moist places by female. They hatch and give small organism which resemble the adult pila.

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