Neil McDaniel, Kanada
Info
Halocynthia igaboja is a solitary cold-water sea squirt whose distribution range extends from the Aleutian Islands to the Gulf of Alaska and California, with confirmed sightings also reported in Japan.
Halocynthia igaboja has an opaque, smooth body covering that is covered with branched, spiny projections, the largest of which have circles of curved branches and are so numerous that they almost completely cover the rest of the covering.
The dark brown mantle of this sea squirt is equipped with red or orange siphons.
At about 10 cm high and 2-5 cm wide, Halocynthia igaboja is one of the largest sea squirts on the American east coast.
Feeding:
Halocynthia igaboja has mouth siphons with 12-50 tentacles, which form a cross when closed, sometimes difficult to see.
The spines or conspicuous, flexible bristles often collect diatoms and deposits. In weak currents, Halocynthia igaboja can become so muddy that the sea squirt is almost impossible to recognize.
Halocynthia igaboja differs from all other sea squirts in the northeastern Pacific precisely because of these spines.
Symbiosis:
The pea crab Pinnotheres pugettensis Holmes, 1900, is regularly observed on the sea squirt. This symbiotic relationship is referred to in the literature as a symbiotic community, presumably because the crab cleans the sea squirt's dirty spines.
The copepod Doropygopsis longicauda often settles in the gill chamber of the sea squirt, presumably in a commensal relationship.
Studies have also shown that the sessile sea squirts provide a settlement substrate for the bryozoan Celleporella hyalina and encrust the spines of Halocynthia igaboja.
Environment:
Pollution from heavy metals (vanadium), see the article “Accumulation of heavy metals by some solitary tunicates” under further links, and microplastics drifting in are also making life increasingly difficult for these delicate sea creatures.
Synonyms:
Cynthia ritteri Oka, 1906 · unaccepted (original combination)
Halocynthia jakoboja Oka, 1906 · unaccepted (synonym)
Halocynthia owstoni Oka, 1906 · unaccepted (original combination)
Halocynthia ritteri (Oka, 1906) · unaccepted (new combination)
Pyura okai (Ritter, 1907) · unaccepted (new combination)
Tethyum igaboja (Oka, 1906) · unaccepted (new combination)
Halocynthia igaboja has an opaque, smooth body covering that is covered with branched, spiny projections, the largest of which have circles of curved branches and are so numerous that they almost completely cover the rest of the covering.
The dark brown mantle of this sea squirt is equipped with red or orange siphons.
At about 10 cm high and 2-5 cm wide, Halocynthia igaboja is one of the largest sea squirts on the American east coast.
Feeding:
Halocynthia igaboja has mouth siphons with 12-50 tentacles, which form a cross when closed, sometimes difficult to see.
The spines or conspicuous, flexible bristles often collect diatoms and deposits. In weak currents, Halocynthia igaboja can become so muddy that the sea squirt is almost impossible to recognize.
Halocynthia igaboja differs from all other sea squirts in the northeastern Pacific precisely because of these spines.
Symbiosis:
The pea crab Pinnotheres pugettensis Holmes, 1900, is regularly observed on the sea squirt. This symbiotic relationship is referred to in the literature as a symbiotic community, presumably because the crab cleans the sea squirt's dirty spines.
The copepod Doropygopsis longicauda often settles in the gill chamber of the sea squirt, presumably in a commensal relationship.
Studies have also shown that the sessile sea squirts provide a settlement substrate for the bryozoan Celleporella hyalina and encrust the spines of Halocynthia igaboja.
Environment:
Pollution from heavy metals (vanadium), see the article “Accumulation of heavy metals by some solitary tunicates” under further links, and microplastics drifting in are also making life increasingly difficult for these delicate sea creatures.
Synonyms:
Cynthia ritteri Oka, 1906 · unaccepted (original combination)
Halocynthia jakoboja Oka, 1906 · unaccepted (synonym)
Halocynthia owstoni Oka, 1906 · unaccepted (original combination)
Halocynthia ritteri (Oka, 1906) · unaccepted (new combination)
Pyura okai (Ritter, 1907) · unaccepted (new combination)
Tethyum igaboja (Oka, 1906) · unaccepted (new combination)
