Limpet
 

Limpet is a common name applied to aquatic snails with shells broadly conical in shape, rather like the conical Asian hat. The term "limpet" is purely informal, a term of convenience; it refers to any gastropod whose shell has no obvious coiling such as one sees in familiar garden snails or in winkles. Although all limpets are Gastropoda, the group is highly polyphyletic, meaning that the various lines that we call limpets have descended independently from different ancestral Gastropoda. This general category of conical shell is technically known as "patelliform", meaning dish-shaped.[1]

Some species of limpet live in fresh water, but by far the majority are marine.

All members of the large and ancient marine clade Patellogastropoda are limpets, and within that clade the family Patellidae in particular often are called the "true limpets". However, other groups, not in the same family, also are called limpets of one type or another because of the general shapes of their shells. Examples include the Fissurellidae; they are the keyhole limpet family, contained in the clade Vetigastropoda, though many of the members of the Vetigastropoda do not have the morphology of limpets at all.

few species are known to eat other inverts such as clams, or corals. most common limpet in aquaria is the keyhole limpet.

Keyhole limpets somewhat resemble true limpets because of the simple conical shape of their shells, but in reality they are not closely related to true limpets, which are in the clade Patellogastropoda. This conical shape of the shell allows keyhole limpets to withstand wave attack on exposed rocks. The shell has a reticulate (= net-like) sculpture with strong radial ribs and lacks an operculum. The shell ranges from 3 mm to 13.2 cm. The Great keyhole limpet (Megathura crenulata) measures up to 13.2 cm.

For respiration, the shells of fissurellids have a single apical or subapical perforation ("keyhole"). This opening at the top allows a direct exit of exhalant water currents together with waste products from the mantle cavity. The water enters under the edge of the shell near the head and passes over large paired gills. Most young species in this family have a marginal slit in the middle of the anterior end of the spiral shell. Some species possess just a short internal groove at the anterior end. The paired organs in the mantle cavity represent a primitive condition in gastropods.

The soft body consists of a well-developed head, a short muzzle. It has a broad and flat foot and a well-developed mantle. This foot exerts a strong suction, adhering the keyhole limpet to its hard substratum. The mantle extends in some species partly or completely (as in Megathura crenulata) over the shell. The tentacles at the epipodium (the lateral grooves between foot and mantle) are well developed. The species in Medusafissurella have numerous subequal tentacles at the propodium, while the species in Dendrofissurella have an outgrowth with main trunk and side branches at the propodium. The eyes are situated on rudimentaiy pedicels at their outer bases. The sides are ornamented with short cirri. There are two, symmetrical branchial plumes . The anal siphon occupies the anterior notch or perforated summit of the shell.[4]

In addition to the possession of this hole, slit or groove, keyhole limpets differ in several other ways both internally and externally from true limpets.[how?]

Keyhole limpets are in essence herbivorous, feeding primarily on algae, but are also detritus feeders. A few species in the genera Diodora and Emarginella are carnivorous, feeding on sponges. Puncturella has been reported to digest diatoms and detritus. Puncturella aethiopica feeds mainly on Foraminifera.[5]

Lee Shipley
Lee Shipley updated Limpet
2015-02-18 17:43:23 -0700
Limpet is a common name applied to aquatic snails with shells broadly conical in shape, rather like the conical Asian hat. The term "limpet" is purely informal, a term of convenience; it refers to any gastropod whose shell has no obvious coiling such as one sees in familiar garden snails or in winkles. Although all limpets are Gastropoda, the group is highly polyphyletic, meaning that the various lines that we call limpets have descended independently from different ancestral Gastropoda. This general category of conical shell is technically known as "patelliform", meaning dish-shaped.[1] Some species of limpet live in fresh water, but by far the majority are marine. All members of the large and ancient marine clade Patellogastropoda are limpets, and within that clade the family Patellidae in particular often are called the "true limpets". However, other groups, not in the same family, also are called limpets of one type or another because of the general shapes of their shells. Examples include the Fissurellidae; they are the keyhole limpet family, contained in the clade Vetigastropoda, though many of the members of the Vetigastropoda do not have the morphology of limpets at all.
Lee Shipley
Lee Shipley posted on Limpet
2015-02-18 17:43:22 -0700
Lee Shipley
Lee Shipley created Limpet on Limpet
2015-02-18 17:41:20 -0700
Limpet is a common name applied to aquatic snails with shells broadly conical in shape, rather like the conical Asian hat. The term "limpet" is purely informal, a term of convenience; it refers to any gastropod whose shell has no obvious coiling such as one sees in familiar garden snails or in winkles. Although all limpets are Gastropoda, the group is highly polyphyletic, meaning that the various lines that we call limpets have descended independently from different ancestral Gastropoda. This general category of conical shell is technically known as "patelliform", meaning dish-shaped.[1] Some species of limpet live in fresh water, but by far the majority are marine. All members of the large and ancient marine clade Patellogastropoda are limpets, and within that clade the family Patellidae in particular often are called the "true limpets". However, other groups, not in the same family, also are called limpets of one type or another because of the general shapes of their shells. Examples include the Fissurellidae; they are the keyhole limpet family, contained in the clade Vetigastropoda, though many of the members of the Vetigastropoda do not have the morphology of limpets at all.

Invertebrate Specs

Name
Scientific Name
Family
Patellidae
Environment
Salt
Diet
Herbivore
Difficulty
Easy