''Nucella ostrina'', the northern striped dogwinkle, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Muricidae Muricidae is a large and varied taxonomic family of small to large predatory sea snails, marine gastropod mollusks, commonly known as murex snails or rock snails. With over 1,700 living species, the Muricidae represent almost 10% of the Neog ...

, the murex snails or rock snails. Other common names for this mollusk include emarginate dogwinkle, short-spired purple dogwinkle, striped dogwinkle, ribbed dogwinkle, emarginate whelk, ribbed rock whelk, rock thais, short-spired purple snail and rock whelk.

Description

This dogwinkle has a robust shell with three indistinct whorls. It can be in length, but a more typical length is or less; the

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is less than half the diameter of the shell and can be closed by a brown, horny operculum. The exterior of the shell is spirally ridged, often with heavy ridges alternating with more delicate ones. The heavy ridges may bear coarse nodules, but in more exposed locations these, and the ridges themselves, may be partially smoothed. The ridges tend to be pale in color and the furrows between them dark, typically brown, gray, black, orange or yellow. The interior of the shell is purple.

Distribution and habitat

''N. ostrina'' is native to the northeastern Pacific Ocean. Its range extends down the western coast of North America from the

Aleutian Islands The Aleutian Islands ( ; ; , "land of the Aleuts"; possibly from the Chukchi language, Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before Alaska Purchase, 1867, the Catherine Archipelago—are a chain ...

, Alaska, to Cayucos, California. It is found in the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

on rocky coasts, often in the vicinity of

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...

beds, and particularly in wave-exposed positions.

Ecology

Like the other members of its family, this dogwinkle is a

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

. Each individual has its own food preferences, but the population as a whole feeds predominantly on

s and

barnacle Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...

s (''Balanus glandula''), but sometimes on periwinkles ('' Littorina sitkana'' and '' Littorina planaxis''), or

limpet Limpets are a group of aquatic snails with a conical gastropod shell, shell shape (patelliform) and a strong, muscular foot. This general category of conical shell is known as "patelliform" (dish-shaped). Existing within the class Gastropoda, ...

s ('' Collisella scabra''). The bay mussel (''Mytilus trossulus'') is usually preferred as prey over the

California mussel The California mussel (''Mytilus californianus'') is a large edible mussel, a Marine (ocean), marine bivalve mollusc, mollusk in the family Mytilidae. This species is native to the west coast of North America, occurring from northern Mexico to ...

(''Mytilus californianus''). Having selected its prey, the dogwinkle drills into the shell with its

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

, injects digestive

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s which liquefy the tissues, and sucks out the contents. The dogwinkle is itself eaten by the purple sea star (''Pisaster ochraceus'') and the red rock crab (''Cancer productus''). It lays its eggs in clusters of stalked capsules, known as "sea oats", which are attached to rocks high up in the intertidal zone. Although there are around 550 eggs in each capsule, most of the eggs are infertile and are consumed by the developing juveniles, 10 to 20 of which hatch from the capsule after three or four months, without an intermediate larval stage.

References

{{DEFAULTSORT:Nucella Ostrina Muricidae Gastropods described in 1852 Molluscs of the Pacific Ocean