Bat star
Encyclopedia
The Bat star also known as Sea bat, Webbed star and Broad-disk star, is an echinoderm
of class Asteroidea (commonly known as sea stars). It typically has five arms or starms, 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 of 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
at an average depth of 79 metres (259.2 ft). Its range extends from Sitka, Alaska to Baja California
in the Pacific Ocean
. It is most abundant along the coast of Central California
and the Monterey Bay
.
-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 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, eating both plants and animals alive or dead.
. 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.
s and scavenger
s, collecting algae
and dead animals from the ocean floor and helping keep the ocean healthy.
Echinoderm
Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
of class Asteroidea (commonly known as sea stars). It typically has five arms or starms, 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 of 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
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
's wings.
The bat star is usually found in the intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
at an average depth of 79 metres (259.2 ft). Its range extends from Sitka, Alaska to Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. It is most abundant along the coast of Central California
Central California
Central California, sometimes referenced as Mid-State, is an area of California south of the San Francisco Bay Area and north of Southern California...
and the Monterey Bay
Monterey Bay
Monterey Bay is a bay of the Pacific Ocean, along the central coast of California. The bay is south of San Francisco and San Jose, between the cities of Santa Cruz and Monterey....
.
Anatomy
The bat star breathes through gillGill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
-like structures on its back that perform as respirators. It lacks the pincers or pedicellariae
Pedicellariae
A pedicellaria is a small wrench or claw-shaped structure commonly found on Echinoderms, particularly in sea stars and sea urchins...
that most starfish use to clean the skin surface of debris, but its small, moving hairs or cilia 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, eating both plants and animals alive or dead.
Reproduction
The bat stars reproduce through spawningSpawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
. 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.Importance
Bat stars are important as detritivoreDetritivore
Detritivores, also known as detritophages or detritus feeders or detritus eaters or saprophages, are heterotrophs that obtain nutrients by consuming detritus . By doing so, they contribute to decomposition and the nutrient cycles...
s and scavenger
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
s, collecting algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
and dead animals from the ocean floor and helping keep the ocean healthy.