Littorina saxatilis
Small beach snail ( Littorina saxatilis )
The rocky beach worm, also Small or Rough beach snail ( Littorina saxatilis ), called a living in the sea snail from the family of Littorinidae is ( beach snails).
- 5.1 Literature
- 5.2 Notes and references
Features
The housing of the rocky beach worm is festschalig, conical and only moderately high. The outer edge is almost straight, the whorls are slightly curved outward. It is up to 1.7 inches high. The outside has spiral grooves and fine growth lines. The coloring of the little beach worm is variable, usually yellowish to brownish. The gill is degenerated, converted the mantle cavity into a kind of lung, which can also absorb oxygen from the atmosphere.
Similar Species
The little beach snail, the Shallow beach snail ( Littorina obtusata ) can be easily confused with the other smaller beach snails like the lace beach snail ( Littorina neritoides ) and. In comparison with the Great beach the screw whorls of the house are clearly curved.
Geographical distribution and habitat
The rocky beach worm is widespread on the North European and North American Atlantic coast. It also occurs in the North Sea and the western Baltic Sea ( to complaints ). She was dragged into the bay from San Francisco. She lives in the shallow waters of the upper intertidal zone, but also up to 2 m above the water level (flood and spray zone) in crevices and small cave systems.
Way of life
The rocky beach worm wanders at night from their resting places in crevices and small cave systems to their pasture, where they graze algae growth on rocks or young shoots of Tangen. In the morning they will return to their resting place. It tolerates low salinities up to 5 ‰.
As an adaptation to life in the flood zone of the beaches this Littorina species is viviparous. The fertilized eggs (from 40 to about 500 ) are borne by the mother in the jacket edge hatch to small, fully developed hatchlings from the eggs. This will then leave the mantle cavity of the mother. They can be up to about six years old
System
In classical systematics of this family is to the center screw ( Mesogastropoda ), an order of prosobranch ( Prosobranchia ) provided. In the used here ( new ) phylogenetic systematics, this classification has been abandoned, the Littorinidae be placed here in the order Sorbeoconcha.