Grade 12th passZoology

How do penial setae help in copulation in roundworms??

Tara Gurung

6 Years agoGrade 12th pass

2 Answers

Arun

6 Years ago

The cloacal opening is associated with a pair of curved chitinoid spicules called penial setae, each of which is provided with a muscular penial sac. The spicules are cuticular structures which serve to open the female genital pore during copulation and help in the transference of sperms.

Vikas TU

6 Years ago

Dear student

The male reproductive organs are unpaired, monodelphic and lie in the posterior half of the body. The testis is a long and single thread like structure occupying the anterior part of pseudocoel. Presence of a single testis produces a condition known as Monorchic
Male is smaller

The posterior aperture is cloacal aperture into which digestive and genital tubes open. A pair of curved chitinoid rods or copulatory spicules or pineal spicules protrude beyond the cloacal aperture.

The tail-end is curved ventrally in the form of a hook with a conical tip.

No vulval aperture in the mid-ventral line, one third from the anterior end.