How Do River Snails Reproduce? Reproduction Methods and Key Technical Points

River snails reproduce their offspring through eggs. River snails are dioecious with sexual dimorphism and are an ovoviviparous animal, with a unique mode of reproduction. Mature eggs meet sperm at the top of the oviduct and are fertilized, and the fertilized eggs undergo embryonic development inside the mother snail's uterus. Both the embryonic development and the development of the young snails of the river snail are completed within the mother's body. From fertilized egg to the birth of the young snail, it takes about one year of gestation within the mother's body.

I. Living Habits of the River Snail

The main feeding organ of the river snail is the radula, which is used to scrape food from the bottom of the water and from attached surfaces. The river snail has an omnivorous diet; in the natural environment, it mainly eats tender stems and leaves of aquatic plants, algae, bacteria and organic debris, etc., and also filter-feeds on plankton, and it likes to be active and feed at night.

The river snail begins activity and feeding at a water temperature of around 15°C, and the most suitable temperature for growth is 20-28°C. Above 30°C, the river snail will retract its body into its shell, gather in shady places or burrow into the mud to escape the heat, and when the water temperature exceeds 40°C the river snail will die. It has strong adaptability to drought and cold; when the water temperature is below 8°C, the river snail burrows into mud holes to hibernate, and only when the water temperature rises back to around 15°C in the following spring does the river snail emerge again to be active and feed. The river snail is very sensitive to dissolved oxygen in the water; when the dissolved oxygen level in the water drops to 3.5 mg/L, they feed poorly; at 1.5 mg/L, they begin to die.

II. Reproductive Characteristics of the River Snail

The river snail is dioecious with sexual dimorphism. The method of distinguishing female and male river snails is mainly based on the morphology of their tentacles: the two tentacles of the female river snail are bilaterally symmetrical and identically shaped; the two tentacles of the male river snail are asymmetrical, with the right tentacle short and thick, curving inward and specialized into a copulatory organ (the curved part being the male reproductive organ). In addition, female snails are large and round, while male snails are small and long. In natural waters there are generally more females than males.

The river snail is an ovoviviparous animal with a unique mode of reproduction. Mature eggs meet sperm at the top of the oviduct and are fertilized, and the fertilized eggs undergo embryonic development inside the mother snail's uterus. Both the embryonic development and the development of the young snails of the river snail are completed within the mother's body. From fertilized egg to the birth of the young snail, it takes about one year of gestation within the mother's body. The river snail gives birth in batches, beginning to reproduce in March to April each year; while producing young snails, the female and male parent snails mate and fertilize, and then the young snails to be produced the following year are gestated in the mother's body. Mating behavior generally takes place during the day, and mating can last as long as 12 hours; the young snails are mostly born at night. One mother snail produces about 100-150 young snails in a year. Newborn young snails have a shell height of 4-7 mm, and after one year of growth, the gonads mature. During the reproductive period, the uterus of the female snail often contains young snails at different stages of development.