Sensory organs of gastropods

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Gastropod eye
)

The

olfactory organs, eyes, statocysts and mechanoreceptors.[1] Gastropods have no sense of hearing.[1]

Olfactory organs

Aplysia californica
.
of the tentacles.

In terrestrial gastropods the most important sensory organs are the olfactory organs which are located on the tips of the 4

anemotaxis).[2]

In

mucopolysaccharides in the slime trails of prey, and of potential mates.[3]

The

chemoreception, and of closing its operculum to avoid predation.[4]

The deepwater snail

Bathynerita naticoidea can detect mussel beds containing the mussel Bathymodiolus childressi, because it is attracted to water that has cues in it from this species of mussel.[5]

Eyes

In terrestrial pulmonate gastropods, eye spots are present at the tips of the tentacles in the

ocelli that cannot project an image (simply distinguishing light and dark), to more complex pit and even lens eyes.[6] Vision is not the most important requirement in terrestrial gastropods, because they are mainly nocturnal animals.[1]

Some gastropods, for example the freshwater apple snails (family Ampullariidae)[7] and marine species of genus Strombus[8] can completely regenerate their eyes. The gastropods in both of these families have lens eyes.

Morphological sequence of different types of multicellular eyes exemplified by gastropod eyes:[9]

Eye pit of Patella sp.
Scheme of pit eye.
Eye cup of Pleurotomaria sp.
Pinhole eye of Haliotis sp.
Turbo coronatus
.

Lens eyes

Lens eye of Bolinus brandaris.
Nucella lapillus
.
Scheme of lens eye.
Eye of a snail.
1 - anterior chamber,
2 - lens,
3 - retina,
4 - optic nerve.
fibrous connective tissue layer
8 - nerve
of the eye
Drawing of cross sections of the extracted tentacle (left) and constricted tentacle (right) with and eye of Helix pomatia.
1 - nerve of an eye
2 -
3 -
4 - eye
5 - tentacle ganglion
6 - epidermis
7 -
8 - nerve of an tentacle
9 - retractor muscle
10 -
Eustrombus gigas on eyestalk has a black iris. There is a small tentacle
on the eyestalk also.

another drawing of eye of Helix pomatia

Statocysts

Statocysts (ss) and statolith (sl) inside the head of Gigantopelta chessoia.

In the statocysts of Haliotis asinina was found the expression of a conserved gene (Pax-258 gene), which is also important for forming structures for balance in eumetazoans.[10]

Mechanoreceptors

The mechanoreceptors are very crucial to the snail's sensory.

See also

References

This article incorporates CC-BY-2.0 text from the reference[9]

Further reading

External links