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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.