Search results
Results from the WOW.Com Content Network
The mantle cavity is a central feature of molluscan biology. This cavity is formed by the mantle skirt, a double fold of mantle which encloses a water space. This space contains the mollusk's gills, anus, osphradium, nephridiopores, and gonopores. The mantle cavity functions as a respiratory chamber in most mollusks. In bivalves it is usually ...
Terrestrial molluscs or land molluscs (mollusks) are an ecological group that includes all molluscs that live on land in contrast to freshwater and marine molluscs. They probably first occurred in the Carboniferous , arising from freshwater ones .
The most frequently used measurements of a gastropod shell are: the height of the shell, the width of the shell, the height of the aperture and the width of the aperture. The number of whorls is also often used. In this context, the height (or the length) of a shell is its maximum measurement along the central axis.
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where the head-foot part of the body of the animal emerges for locomotion, feeding, etc. The term aperture is used for the main opening in gastropod shells, scaphopod shells, and also for Nautilus and ammonite shells.
Gastropods (/ ˈ ɡ æ s t r ə p ɒ d z /), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (/ ɡ æ s ˈ t r ɒ p ə d ə /). This class comprises snails and slugs from saltwater, freshwater, and from the land.
The bivalve's two siphons are situated at the posterior edge of the mantle cavity. [11] There is an inhalant or incurrent siphon, and an exhalant or excurrent siphon. [12] The water is circulated by the action of the gills. Usually water enters the mantle cavity through the inhalant siphon, moves over the gills, and leaves through the exhalant ...
In cuttlefish, activation of a chromatophore can expand its surface area by 500%. Up to 200 chromatophores per mm 2 of skin may occur. In Loligo plei , an expanded chromatophore may be up to 1.5 mm in diameter, but when retracted, it can measure as little as 0.1 mm. [ 56 ] [ 58 ] [ 59 ]
Helix pomatia using a simple transparent epiphragm made of dried mucus. An epiphragm (from the Ancient Greek ἐπί, epi " upon, on, over " and φράγμα, -phrágma "fence") is a temporary structure which can be created by many species of shelled, air-breathing land snails, terrestrial pulmonate gastropod mollusks.