Giant california sea cucumber
Encyclopedia
The giant California sea cucumber (Parastichopus californicus) is a sea cucumber that can be found from the Gulf of Alaska
to Southern California
. It is found from the low intertidal zone
to a depth of 250 m. They are most abundant in areas with moderate current with cobbles, boulders or bedrock.
just below the skin. The mouth and anus are on opposite ends of the body. The mouth is surrounded by twenty retractable tentacle
s that are used to bring food in. Five rows of tube feet
extend from the mouth to the anus. Mobility is limited, though individuals can move up to 4 m per day while feeding. They use their tube feet located on the underside of their body.
.jpg)
The giant California sea cucumber is a scavenger that feeds on plankton
and other organic matter. They feed by sifting through sediments with their tentacles, or by positioning themselves in a current where they can use their tentacles to catch food flowing by.
These sea cucumbers have separate sexes, and egg
s are fertilized externally
. Spawning usually takes place in August, and each female can produce thousands of eggs. After fertilization, a larva is formed which metamorphoses into a sea cucumber after a few weeks.
Gulf of Alaska
The Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...
to Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
. It is found from the low 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...
to a depth of 250 m. They are most abundant in areas with moderate current with cobbles, boulders or bedrock.
Physical description
The giant California sea cucumber can grow to a length of 50 cm and a width of 5 cm. It has a soft, cylindrical body, with red-brown to yellowish leathery skin. It has an endoskeletonEndoskeleton
An endoskeleton is an internal support structure of an animal, composed of mineralized tissue. Endoskeleton develops within the skin or in the deeper body tissues. The vertebrate is basically an endoskeleton made up of two types of tissues . During early embryonic development the endoskeleton is...
just below the skin. The mouth and anus are on opposite ends of the body. The mouth is surrounded by twenty retractable tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
s that are used to bring food in. Five rows of tube feet
Tube feet
Tube feet are the many small tubular projections found most famously on the oral face of a sea star's arms, but are characteristic of the water vascular system of the echinoderm phylum which also includes sea urchins, sand dollars and sea cucumbers and many other sea creatures.Tube feet function in...
extend from the mouth to the anus. Mobility is limited, though individuals can move up to 4 m per day while feeding. They use their tube feet located on the underside of their body.
Feeding habits
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
and other organic matter. They feed by sifting through sediments with their tentacles, or by positioning themselves in a current where they can use their tentacles to catch food flowing by.
Behavior and reproduction
P. californianus is a solitary nocturnal animal. It has the ability to regenerate all parts of its body. When threatened, it can expel all its stomach contents through its anus until its next feed. It can also expel sticky filaments to ensnare or confuse predators. It undertakes seasonal migrations to different depths.These sea cucumbers have separate sexes, and egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s are fertilized externally
External fertilization
External fertilization is a form of fertilization in which a sperm cell is united with an egg cell external to the bodies of the reproducing individuals. In contrast, internal fertilization takes place inside the female after insemination through copulation....
. Spawning usually takes place in August, and each female can produce thousands of eggs. After fertilization, a larva is formed which metamorphoses into a sea cucumber after a few weeks.