''Lottia instabilis'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a

true limpet The Patellogastropoda, common name true limpets and historically called the Docoglossa, are members of a major phylogenetic group of marine gastropods, treated by experts either as a clade or as a taxonomic order. The clade Patellogastropoda ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Lottiidae Lottiidae is a family of sea snails, specifically true limpets, marine gastropod mollusks in the superfamily Lottioidea and the clade Patellogastropoda (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). Subfamilies 20 ...

. Common names include the unstable limpet, the unstable seaweed limpet and the rocking chair limpet. It is native to the northern Pacific Ocean where it feeds on

kelp Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "underwat ...

in the intertidal zone and the shallow sub-littoral zone.

Description

The shell of ''Lottia instabilis'' is specially adapted by the shape of its rim to adhere to the holdfasts and stipes of

. The sides of the rim are elongated and nearly parallel, but both anterior and posterior end are raised up; this means it cannot lie flat and seal itself to a level surface but it can seal to a curved surface. The shell is smooth with an even margin. It is often mainly brownish, and may be paler near the apex, which is somewhat towards the anterior end of the shell. The interior of the shell is bluish-white, sometimes with a dark margin and a dark blotch near the apex. Individuals in the northern part of the range tend to have solid shell colors and be larger than those in the south, which tend to have tesselated patterns of brown and gray on their shells.

Distribution and habitat

Native to the northeastern Pacific Ocean, ''L. instabilis'' is present from

Kodiak Island Kodiak Island (Alutiiq: ''Qikertaq''), is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second larges ...

, off the coast of Alaska, to

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the List of United States cities by population, eigh ...

, California. It is often found on the holdfasts and stipes of kelp, at depths ranging from the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

down to about . It also occurs on bare rock and sometimes on the shells of gastropod mollusks, including those occupied by

hermit crab Hermit crabs are anomuran decapod crustaceans of the superfamily Paguroidea that have adapted to occupy empty scavenged mollusc shells to protect their fragile exoskeletons. There are over 800 species of hermit crab, most of which possess an a ...

Ecology

''L. instabilis'' is a herbivore and feeds directly on kelps such as ''

Saccharina dentigera ''Saccharina dentigera'' is a species of brown algae (class Phaeophyceae), in the family Laminariaceae. It is native to shallow water in the northeastern Pacific Ocean from the Gulf of Alaska to Baja California. Taxonomy This seaweed was first ...

'' and '' Pterygophora californica''. Being such a specialised feeder, it can essentially be considered to be a

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

of the kelp host. It is part of a genus whose rock-associated members are distributed widely in the Pacific Ocean and this species probably evolved in the Pacific, alongside its kelp

hosts A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places *Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman *Michel Host ( ...

. The purple seastar (''Pisaster ochraceus'') is a predator of this limpet, and when the seastar approaches, the limpet flees.

References

{{taxonbar, from=Q3802326 Lottiidae Molluscs of the Pacific Ocean Gastropods described in 1846