Cockroach: Reproductive System

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Reproductive System

  • The cockroaches are dioecius (unisexual).
  • They have well developed reproductive organs.

Male reproductive organ

  • Male reproductive system consists of a pair of testes. They are found on the lateral side of the body along the 4th -6th abdominal segments.

  • A thin tube called vas deferens arises from the testis.
  • Vas deferens opens into ejaculatory duct through seminal vesicle.
  • The sperms are stored in the seminal vesicles and are glued together in the form of bundles called spermatophores which are discharged during copulation.
  • The ejaculatory duct opens into male gonopore situated ventral to anus.
  • The accessory gland is mushroom-shaped and it is present in the 6th-7th abdominal segments.
  • The external genitalia are represented by male gonapophysis or phallomere (chitinous asymmetrical structures, surrounding the male gonopore).

Female reproductive organ

  • The female reproductive system is composed of two large ovaries, present in the lateral side of the body along the 2nd – 6th abdominal segments.
  • Each ovary is composed of a group of eight ovarian tubules (called ovarioles) which contain a chain of developing ova (or eggs).

  • Thin tubes called oviducts emerge from each ovary.
  • Oviducts of each ovary unite into a single median oviduct (also called vagina) which opens into the genital chamber.
  • A pair of spermatheca is present in the 6th segment which opens into the genital chamber.

Reproduction

  • Sperms are released in bundles called spermatophores.
  • These are transferred into the female genital chamber.

  • The fertilised eggs are covered in hard capsules called oothecae.
  • The color of Ootheca ranges from dark reddish to blackish brown. They are about 3/8″ (8 mm) long. They are dropped or glued to a suitable surface, usually in a crack or crevice of high relative humidity near a food source.
  • Females produce nearly 9-10 oothecae at a time, each containing 14-16 eggs.

  1. Copulation
  2. Laying of ootheca
  3. Ootheca
  4. Cross section of ootheca
  5. Embryo
  6. Hatching
  7. Nymph
  8. Late nymph

Development

  • The development of cockroach is indirect (or paurometabolous).
  • Development involves a nymphal stage. The nymphs look very much like adults.
  • There is metamorphosis. The nymph grows by moulting about 13 times to reach the adult form. Only the adult cockroaches have wings.