CLASSIFICATION OF LIMPET OR PATELLA
PHYLUM :- MOLLUSCA (Unsegmented bilaterally symmetrical and provided with visceral mass, foot and mantle. )
CLASS :- GASTROPODA (Visceral hump twisted.)
SUB-CLASS :- PROSOBRANCHIATA (Gills in front of heart.)
ORDER :- ASPIDOHRANCHIATA (Gills bipectinate.)
SUB-ORDER :- DOCOGLOSSA (Ctenidium replaced by secondary gills.)
GENUS :- Patella
- It is found along Pacific coast, Atlantic coast, Europe and U.S.A. (California).
HABIT AND HABITAT
Patella is found on rocky beaches between tidemarks. It feeds on smaller sea-weeds and other marine vegetation.
GENERAL CHARACTERSTICS OF LIMPET OR PATELLA
- Commonly called as true limpet.
- Small, oval and sluggish creature.
- Dorsal side of the body is enclosed by a roundish shell, which is raised into a conical elevation by which it is easily recognized.
- Shell forms the miniature volcanic cone and dorsally it contains lines of growth. Operculum absent.
- Underside of the limpet shows a large foot with a broad creeping sole which acts as attachment organ to rocks.
- Head contains 2 stout, sensory tentacles. There are 2 ospbradia, 2 nephridia and a simple heart (1 auricle).
- True mantle cavity is restricted anteriorly and true ctnidia are replaced by pseudotenidia or secondary gills.
- Radula docoglossate with 3 marginals and 3 laterals but no central teeth. There is no siphon.
- A secondary pallial cavity extends all round between the foot and mantle.
- Nervous system shows little concentration towards the head region.
Patella has food value as it is generally eaten in France, Italy and Ireland.
Contains radiating ribs and all above features, hence it is Patella.