How to raise shellfish

Primitive gastropods lay their eggs directly in the sea for fertilization, and the number of eggs is large, such as abalone, which can lay more than 100,000. However, the fertilized and hatched species such as snails (Viviparus) only produce dozens of eggs and snails. (Margarya) only produces 3 to 5. Some species of shellfish reach sexual maturity at the first anniversary and have a life span of only one year, such as some species in nudibranch and cephalopod. Some species have a longer life span, but most of them reach sexual maturity within 1 year. The growth rate varies with species and environmental conditions.

The temperature is suitable, the food is sufficient, the growth is fast, otherwise, the growth is slow. The life span of shellfish is highest in bivalves. Mussels and sea worms (Mya arenaria) can live for 10 years, and Pinctada martensi can live for 12 years. Mussels have a longer life span. Pearl mussels (Margari- Tana margaritifera can live for 80 years, and Tridacna can live for even a century.

Shellfish's feeding methods are divided into predation and filter feeding. Predatory species can be divided into herbivorous and carnivorous. Many primitive gastropods such as abalone, horseshoe snails, snails, etc. and many lung snails such as Lymnaea, snails, and Clausilia are herbivorous. Some species of Mesogastropods that have water pipes, such as Strombus and Neogastropods, are mostly carnivorous. Some of them feed on the carcasses of animals, and some eat polyps, ringworms, and bivalves. , Crabs, fish and other foods. Cephalopods are also carnivorous, they prey on bivalves, crabs, and even chase fish to prey on fish. The vast majority of bivalves are filter feeders.