Latia
Latia is an endemic New Zealand species living in fresh water bowl-shaped worm from the order of snails ( Pulmonata ) and the only genus of the family Latiidae. There is not a recognized German name. The family is expected here to the subordination of water snails ( Basommatophora ).
Features
The housings are cup-shaped, more or less longitudinally oval and is blackish through the dark periostracum. The Apex is hook-shaped. The animals can be up to 12 mm long and remember through the shell (but not the soft body ) to the European river cap screw ( Ancylus fluviatilis), which is why they have been asked several times earlier in the ( now defunct ) Family Ancylidae.
At the back end of the shell a lamella is formed, which becomes ( a tongue- like appendage ) on the right side into a lingula. Lamella and lingula form attachment points for the muscles of the foot, so that the worm body is firmly attached to the shell, but is also very mobile. The animals may therefore when they enter once on the back, unlike other cup-shaped freshwater snails do not straighten up by itself and baste.
Anatomy and Physiology
The animals breathe by the penetration of dissolved oxygen in water. To this end, they have developed in the lung cavity, a secondary gill. They feed on periphyton (algae, bacteria, fungi ), which they rasp of the stone surface by means of the radula.
The animals secrete, especially if they are disturbed, with her mucus a luminescent substance that is released in the form of a light green, light emitting water cloud. Also the whole animals can luminesce. The underlying chemical reaction is based on a flavoprotein ( luciferase), which contains a light-emitting group flavin. These studies are based on the type Latia neritoides. It is thus currently the only known freshwater animal that shows without the aid of bacteria such luminous phenomena; such are otherwise known only from marine and terrestrial organisms.
Distribution and habitat
The members of this family are found only in the North Island of New Zealand. They are found on or under stones in rivers.
Although they are sensitive to pollution and also to disturbances of the subsurface waters, the representatives of the Latiidae are not considered endangered.
Paleontology and Evolution
The Latiidae are not yet known fossil. They form together with the occurring only in South America Chilinidae family of the superfamily Chilinoidea, which is a relatively original superfamily of Hygrophila (water snails in the narrow sense ).
System
The species (and the family ) is composed of three types:
- Latia climoi Starobogatov, 1986
- Latia lateralis ( Gould, 1852)
- Latia neritoides Gray, 1850