Matt Tank, Australien
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Sea squirts of the genus Botryllus (order Stolidobranchia, family Styelidae) are a group of more than 53 recognized colonial species, some of which are widespread in temperate or tropical and subtropical waters, others even in cold Arctic waters.
Sea squirts have colonized almost every part of the world's oceans, partly through their own reproduction and ocean currents, and partly through anthropogenic factors (introduction by shipping, emptying of ballast water tanks).
Reproduction in sea squirts occurs in three forms:
(1) asexual reproduction by budding, which occurs only in a few families,
2) division of colonies, a process observed in a few species, and
3) sexual reproduction or propagation, in which fertilized eggs develop into lecithotrophic larvae before transforming into benthic adults.
Botryllus stewartensis usually forms colonies on sandy lobes about 10 mm high, which sit densely on a basal mat.
Each lobe has a central common exhalant opening with a circle of zoids.
Morphology and color vary depending on sediment content and exposure. The color when alive is sandy violet or cream-colored.
The shell is delicate and soft, with sediment found only on the outside of the shell, if present.
Botryllus stewartensis occurs occasionally in reefs in sheltered bays and on fjord walls in southern New Zealand.
This species has been recorded in Lyttleton Harbor, Stewart Island, the Foveaux Strait, and Fiordland, and is also known from southern, eastern, and western Australia.
The links below also provide evidence of the species in the central Indian Ocean.
Etymology: The species name “stewartensis” refers to the place where it was first described, Stewart Island, an island in New Zealand.
Botrylloids (order Stolidobranchia, family Styelidae) are a group of more than 53 colonial species, some of which are widespread in temperate or tropical and subtropical waters.
Synonym: Parabotryllus nemorus Kott, 1975 · unaccepted (original combination)
Sea squirts have colonized almost every part of the world's oceans, partly through their own reproduction and ocean currents, and partly through anthropogenic factors (introduction by shipping, emptying of ballast water tanks).
Reproduction in sea squirts occurs in three forms:
(1) asexual reproduction by budding, which occurs only in a few families,
2) division of colonies, a process observed in a few species, and
3) sexual reproduction or propagation, in which fertilized eggs develop into lecithotrophic larvae before transforming into benthic adults.
Botryllus stewartensis usually forms colonies on sandy lobes about 10 mm high, which sit densely on a basal mat.
Each lobe has a central common exhalant opening with a circle of zoids.
Morphology and color vary depending on sediment content and exposure. The color when alive is sandy violet or cream-colored.
The shell is delicate and soft, with sediment found only on the outside of the shell, if present.
Botryllus stewartensis occurs occasionally in reefs in sheltered bays and on fjord walls in southern New Zealand.
This species has been recorded in Lyttleton Harbor, Stewart Island, the Foveaux Strait, and Fiordland, and is also known from southern, eastern, and western Australia.
The links below also provide evidence of the species in the central Indian Ocean.
Etymology: The species name “stewartensis” refers to the place where it was first described, Stewart Island, an island in New Zealand.
Botrylloids (order Stolidobranchia, family Styelidae) are a group of more than 53 colonial species, some of which are widespread in temperate or tropical and subtropical waters.
Synonym: Parabotryllus nemorus Kott, 1975 · unaccepted (original combination)
