Are there any terrestrial molluscs?
All terrestrial molluscs belong to the class Gastropoda. Terrestrial molluscs occur across most of the planet, with the exception of Antarctica and some islands.
What special adaptations do terrestrial gastropods like slugs need in order to get oxygen from the environment?
The original breathing organ of snails is the comb gill (Ctenidium). As this type of gill is only able to acquire oxygen from water, all terrestrial and numerous fresh water snail species have reduced it. Oxygen from dry air now had to be acquired directly trough the tissues of the pallial cavity wall.
What are terrestrial gastropods?
Land snail is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as slugs). Like other mollusks, land snails have a mantle, and they have one or two pairs of tentacles on their head. Their internal anatomy includes a radula and a primitive brain.
How do terrestrial gastropods breathe?
Like insects, gastropods are ectotherms that utilise various modes of respiration: all gastropods breathe through their skin but some species also use gills to retrieve oxygen from the water (e.g. caenogastropods), while others have a lung which they use to breathe air (pulmonates).
How do pulmonate snails breathe?
Pulmonata, or “pulmonates”, is an informal group (previously an order, and before that a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includes many land and freshwater families, and several marine families.
What does pulmonate mean in a marine snail?
Pulmonate, (subclass Pulmonata), any of various land, freshwater, and marine snails belonging to the class Gastropoda (phylum Mollusca) that have lost their ancestral gills and breathe instead by means of a “lung”—a highly vascularized saclike modification of the mantle cavity. Some snails lack an
What kind of animal is a pulmonate gastropod?
Pulmonate, fresh water Planorbina from the Oligocene of the Isle of Wight. Living species of this basommatophorean gastropod are able to secrete threads, which are attached to objects and used by the animal to ascend and descend through the water.
Where is the gill located in a pulmonate gastropod?
This current is U-shaped, so that it also flushes waste products away from the anus, which is located above the animal’s head, and would otherwise cause a problem with fouling. In the pulmonate gastropods, which are found on both land and in freshwater, the gill has been replaced by a simple lung .
What kind of snails have lungs and gills?
According to different characters, terrestrial snails can be divided into two different groups: the pulmonate snails (Pulmonata), i.e. snails breathing with lungs, and close relatives of prosobranch sea snails(Prosobranchia), originally breathing with gills.