GENERAL HISTOLOGY

Detailed explanation-1: -Male and female sea stars release their gametes through gonopores, located on the top (dorsal aspect) of the animal (Figure 2), and fertilization occurs externally in the seawater.

Detailed explanation-2: -External fertilization in animals usually occurs in water or in damp areas in a process called spawning. Moisture in the environment keeps the gametes from drying out. Moisture is also important so the eggs and sperm can move around freely, which lets them meet and fuse.

Detailed explanation-3: -Sea stars can reproduce sexually and asexually. In sexual reproduction, fertilization occurs in the water with males and females releasing sperm and eggs into the environment. The fertilized embryos, which are free-swimming animals, become part of the zooplankton in most species.

Detailed explanation-4: -External fertilisation can occur both in water and on land.

Detailed explanation-5: -Descriptive external fertilization examples are that of salmon, trout fish, and codfish. Both the female and male release their eggs and sperms respectively into the water where they diffuse and fertilize. In the list of external fertilization examples, aquatic animals such as mammals and sharks are exceptions.