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How does it look like?
It is a colonial ascidian. This means that what we see are many individuals (zooids) that live together and are enveloped by a common perforated tunic. We find two types of orifices, smaller ones (inhalant siphons) with 8 white lobes around them through which the water enters, and larger ones (exhalant siphons) through which it exits. It measures between 3 and 8 centimeters approximately. It has a fleshy appearance and its color varies from orange to pink.
Where does it live?
This colony lives attached to hard substrates such as rocks, either horizontally or vertically. It is normally found between 5 and 25 meters but specimens have been found up to 50m deep. It can be found at the western Mediterranean and along the Atlantic coast.
How does it feed?
All ascidians are filter feeders. The water enters through the inhalant siphon thanks to hairs that surround it and create a current. Then the water passes through a basket-shaped gill where the transported particles are retained and exits through the exhalant siphon. They have the same system for feeding, breathing and reproduction.
How do they reproduce?
They have two ways of reproduction, sexual and asexual. Sexual reproduction is based on hermaphroditism, each individual has both sexes but cannot self-fertilize. Fertilization is internal and indirect, which means that we can find a phase of swimming larvae that will later become ascidian. Asexual reproduction is by budding. The colony grows and reaches a point where it fragments voluntarily; this fragment gives rise to a new colony.
Is a confusion possible?
It can be confused with a species of the same genus called Aplidium nordmanni. They differ because Aplidium nordmanni forms more tubular structures and is larger (measuring 20cm in diameter and about 10cm in height). Also, the inhalant siphons of Aplidium nordmanni have six lobes and those of Aplidium elegans have 8. It also resembles Morchellium argus, but is easily differentiated because it is a pedunculate ascidian.
Curiosities
· The genus of seaslugs Berghia eats Aplidium elegans when placed in aquaria.
· It is also known as Sydnyum elegans.
· At first glance ascidians look like sponges but they are totally different groups. Ascidians are part of the urochordates, a sister group of vertebrates.
Taxonomy
Phylum: Chordata, Subphylum: Urochordata, Class: Ascidiacea, Order: Enterogona, Family: Polyclinidae, Genus: Aplidium |
