''Patiria miniata'', the bat star, sea bat, webbed star, or broad-disk star, is a species of

sea star Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...

(also called a starfish) in the family

Asterinidae The Asterinidae are a large family of sea stars in the order Valvatida. Description and characteristics These are generally small sea stars, flattened dorsally and bearing very short arms, often giving a pentagonal shape in the body ;exampl ...

. It typically has five arms, with the center disk of the animal being much wider than the stubby arms are in length. Although the bat star usually has five arms, it sometimes has as many as nine. Bat stars occur in many colors, including green, purple, red, orange, yellow and brown, either mottled or solid. The bat star gets its name from the webbing between its arms, which is said to resemble a bat's wings. The bat star is usually found in 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 ...

to a depth of . Its range extends from

Sitka russian: Ситка , native_name_lang = tli , settlement_type = Consolidated city-borough , image_skyline = File:Sitka 84 Elev 135.jpg , image_caption = Downtown Sitka in 1984 , image_size ...

, Alaska to

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

. It is most abundant along the coast of

Central California Central California is generally thought of as the middle third of the state, north of Southern California, which includes Los Angeles, and south of Northern California, which includes San Francisco. It includes the northern portion of the San Jo ...

and the

Monterey Bay Monterey Bay is a bay of the Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica ...

Classification

The genus of this species has transitioned back and forth between '' Asterina'' and ''Patiria'' since its inclusion in Fisher's 1911 North Pacific Asteroidea monograph. However, recent revisions based on molecular systematics have constrained ''Asterina'' and identified ''Patiria'' as a

complex Complex commonly refers to: * Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe ** Complex system, a system composed of many components which may interact with each ...

of three closely related species in the Pacific, including ''P. miniata'', '' P. pectinifera'' in Asia and '' P. chilensis'' in South America.

Anatomy

Bat stars can be many different types of colors. The bat star breathes through

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

-like structures on its back that perform as respirators. It lacks the pincers or pedicellariae that most starfish use to clean the skin surface of debris, but its small, moving hairs or

cilia The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...

may create enough of a water current to keep the surface of its skin clean. It has visual sensors at the end of each ray that can detect light and note prey. To eat its prey, it covers the prey with its stomach and oozes digestive juices over it; this liquefies the food, enabling the bat star to ingest it. It is

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

, eating both plants and animals alive or dead.

Reproduction

3D projection of a Patiria miniata bipinnaria

The bat stars reproduce through

spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aqua ...

. The male casts sperm and the female drops eggs; each has pores at the base of the rays for this purpose. The sperm and egg unite at sea and are carried away by ocean currents.

Behavior

Bat stars may gently "fight" with each other if they meet. Fighting behavior consists of pushing and laying an arm over the other. Bat stars are important as

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrate ...

s and

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

s, collecting

algae Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from ...

and dead animals from the ocean floor.

References

{{Taxonbar, from1=Q3468311, from2=Q2406146 Asterinidae Fauna of the Pacific Ocean Starfish described in 1835 Taxa named by Johann Friedrich von Brandt