Question

Describe the reproductive systems of male and female squid. Describe how and where fertilization takes place. Where do the larvae develop?

Answer 1

Squids are a diverse group of cephalopods known for having eight arms, two tentacles, and the ability to change their colors to protect themselves from predators.

The female squid reproductive system consists of

ovary where the eggs are produced

single oviduct a transparent tube through which the eggs travel

Nidamental glands which secrete a gelatinous cover that protects the eggs and provides the structure of the egg mass

Oviducal gland that releases a gelatinous layer that covers the eggs with a jelly capsule, as they go through the oviduct and facilitates their development,

Buccal membrane that is the area of tissue surrounding the mouth, where the sperm is stored until it is used to fertilize and

Funnel through which the eggs pass from the ovary to the oviduct.

The male squid reproductive systems consist of

Testis where sperm is produced
Vas Deferens an open-end chamber that receives and stores sperms,

Spermatophores A Long tube packets where sperm is stored,

Spermatophoric organ where the spermatophores are formed.
Hectocotylus A Long specialized arm used to deliver the sperm into the female.

Initiation of matting process starts with attracting female squid by male squid. In order to do so, males squids change their colors and swim rapidly in very large circles to attract female squid. They also fight against each other to win the interest of the females.After finding interest, female squid joins them and start to swim in pairs called "nuptial dance". That is the time when mating takes place.

During the mating process, the male transfer spermatophores using hectocotylus into the female's mantle cavity or around her mouth that are then stored in the buccal membrane of female squid until they are mature enough to be spawned. When the eggs are ready to be spawned, the female uses the stored sperm to fertilize its eggs within the oviduct or in the egg clusters. First, the eggs are produced in the ovary and passed to the oviduct through the ciliated funnel. Next, the eggs are covered with a gelatinous mass produced by the oviducal glands, which are inside the oviduct. Then, they continue to pass through the oviduct, now with the shape of egg clusters and the nidamental glands add them another gelatinous layer for protection. Finally, at least 50,000 fertilized eggs are immediately released in white, gelatinous clusters, at the bottom of the sea.