''Morchellium argus'', the red-flake ascidian, is a
species of
colonial
Colonial or The Colonial may refer to:
* Colonial, of, relating to, or characteristic of a colony or colony (biology)
Architecture
* American colonial architecture
* French Colonial
* Spanish Colonial architecture
Automobiles
* Colonial (1920 a ...
sea squirt, a
tunicate in the
family Polyclinidae
Polyclinidae is a family of tunicates in the order Enterogona. It describes a group of marine animals.
Genera
The World Register of Marine Species lists the following genera:
*'' Aplidiopsis'' Lahille, 1890
*'' Aplidium'' Savigny, 1816
*'' Fraga ...
. It is native to shallow water in the northeastern Atlantic Ocean, especially round the coasts of Britain.
Description
A colony of ''Morchellium argus'' consists of a clump of vase-shaped
zooids up to long, each supported by a conical stalk about wide, to which sand adheres. Each zooid has a buccal siphon with eight flaps and a tongue-like process underneath. This siphon opens into a large
pharynx through which water is drawn into the interior, but the colony has a single exit siphon through which the water from several zooids is expelled. The zooids are translucent white, pale pink or red and there are four small red spots at the entrance to the pharynx, which distinguishes this tunicate from similar species.
Distribution and habitat
''Morchellium argus'' is native to the northeastern Atlantic Ocean. It is common round the coasts of Britain, as far north as the
Shetland Isles. It is also known from the west of France including
Arcachon Bay. It is found at depths down to about mainly in caves, under overhangs and on vertical surfaces, often among foliose algae.
Biology
''Morchellium argus'' draws in water through its buccal siphon, filters out zooplankton and other food particles and then expels the water. Gas exchange takes place at the same time.[
''Morchellium argus'' is a ]hermaphrodite
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes.
Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...
. The gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...
s are in the body cavity and sperm passes out with the exhalent water. When this sperm is drawn into another individual zooid, internal fertilisation can occur. The early developmental stages take place inside the zooid and the larvae are later liberated into the sea. After a short free-living stage, these attach themselves to a surface, undergo metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...
, and start a new colony. Further development is by budding of new zooids. The function of the red spots in the pharynx is unclear.[
]
References
External links
*
{{Taxonbar, from=Q4919381
Enterogona
Animals described in 1841