Snails, or as they are called still, Gastropoda mollusks, belong to the class of rakovinny mollusks. This class includes about 100 thousand species of invertebrate animals.
The body of snails asymmetric, consists of the head, a trunk and a leg with a special polzatelny sole. Reducing special muscles, the snail creeps. Emitting slime, she facilitates to herself the movement. The leg and the head are completely pulled in in a sink which has the spiral building. At slugs the sink is absent.
Love game
Snails breed no more once a year. Desire to find couple is expressed in special behavior of a mollusk: moving, the snail begins to do frequent stops, periodically fades. When there is a meeting of two individuals ready to reproduction, they begin a love game. So, both snails extend the heads, being shaken from one party in another and adjoining the soles. They touch each other a mouth and tentacles. Then snails prikachivatsya densely by soles and lie so some time. After the long game the pairing process begins.
Coition
Snails hermaphrodites, have at the same time both male genitals, and women's. At a coition there is a mutual fertilization. Snails shoot at the partner's body the "love arrows" consisting of lime. They are pushed out at a tension of a certain muscle from a sexual opening, piercing the partner's body. After that arrows are dissolved, there is, directly, a fertilization process. Some species of snails diclinous, but it is impossible to distinguish them on appearance.
Emergence of posterity
Overland snails lay eggs to the earth in a small pole. Usually their number from 30 to 40 pieces. Aquarian snails for reproduction creep out of water on aquarium walls. Eggs are attached to glass on air in the form of a bunch. You watch that the snail did not creep out, without water she will quickly die. Some species of snails viviparous. For example, Melanija do not lay some eggs. They breed in two ways: - parthenogenetic – one female suffices; - amfimiktny – the male participates. In an aquarium it is necessary to control population number, under favorable conditions reproduction process very fast. Snails from open reservoirs cannot be lodged in an aquarium. Slime will quickly pollute water, and the snail will eat all vegetation.
As process of pregnancy influences a snail
During pregnancy growth of a snail slows down or stops at all. The shell of eggs and a sink of posterity consist of calcium which of a maternal organism. After reproduction one third of all snails perishes.