NOAA's Office of Ocean Exploration and Research
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The black coral is currently only known from the Musician Seamounts and the northwestern Hawaiian Islands between Nihoa and Lisianski,
Colonies of the azooxanthellate coral have been found in association with glass sponges (so far only on Farrea occa and an unidentified sponge from the Tretodictyidae family).
Unfortunately, deep-sea corals are often snatched and landed with trawls. In the case of Antipathes sylospongia, the observation was made with the help of a NOAA Ocean Exploration Operations (NOAA) ROV.
The holotype of the coral was found on a Farrea occa sponge that was about 15 cm high and 20 cm wide at the time of collection.
The sponge broke into several pieces after removal. A large part of the outer surface of the Farrea occa sponge is overgrown with coral.
A loose network of coral branches covers the surface and penetrates the tissue to bind with the very fine siliceous matrix of the sponge.
The colony is shrubby to bushy with very thin, short branches extending from the sponge in all directions.
Based on the in situ photos, it is estimated that the branches extend 5 to 10 cm from the surface of the sponge.
The branches are irregularly arranged on all sides of the lower order branches.
Due to the growth habit of the colony, it is difficult to determine if there is a main stem or how many branching orders are present.
The terminal branches are up to 2 cm long and have a basal diameter of 0.08 mm.
A 1 cm long terminal branch has a diameter of 0.047 mm in the middle and a diameter of 0.066 mm near the base. Some of the smallest terminal branches are arranged in pairs next to each other. These pairs of branches are 4-5 mm apart.
The polyps usually have a transverse diameter of about 1.5 mm (range: 0.7-2 mm) and are arranged unilaterally with five polyps per cm.
In situ photographs of apparently fully expanded polyps show that all tentacles are cylindrical and unequal in length and usually not much longer than the transverse diameter of the polyps. This can also be seen in the preserved polyps of the holotype.
The members of the class Anthozoa are either gonochoric or hermaphroditic. The mature gametes are released into the coelenteron and spawned through the mouth.
Life cycle:
The zygote develops into a planktonic planula larva. Metamorphosis begins with the early morphogenesis of tentacles, septa and pharynx before the larva settles at the aboral end.
Etymology. The species name "sylospongia" is derived from the Greek prefix "syl" for "with", the connecting vowel "o" and "spongia" for the sponge hosts. To date, all known records of this species are closely associated with hexactinellid sponge hosts, either Farrea occa or an unidentified species from the family Tretodictyidae .
Litearure reference:
Opresko, Dennis M. & Wagner, Daniel, 2020,
New species of black corals (Cnidaria: Anthozoa: Antipatharia) from deep- sea seamounts and ridges in the North Pacific,
Zootaxa 4868 (4), pp. 543-559 : 550-553
https://doi.org/10.11646/zootaxa.4868.4.5
Colonies of the azooxanthellate coral have been found in association with glass sponges (so far only on Farrea occa and an unidentified sponge from the Tretodictyidae family).
Unfortunately, deep-sea corals are often snatched and landed with trawls. In the case of Antipathes sylospongia, the observation was made with the help of a NOAA Ocean Exploration Operations (NOAA) ROV.
The holotype of the coral was found on a Farrea occa sponge that was about 15 cm high and 20 cm wide at the time of collection.
The sponge broke into several pieces after removal. A large part of the outer surface of the Farrea occa sponge is overgrown with coral.
A loose network of coral branches covers the surface and penetrates the tissue to bind with the very fine siliceous matrix of the sponge.
The colony is shrubby to bushy with very thin, short branches extending from the sponge in all directions.
Based on the in situ photos, it is estimated that the branches extend 5 to 10 cm from the surface of the sponge.
The branches are irregularly arranged on all sides of the lower order branches.
Due to the growth habit of the colony, it is difficult to determine if there is a main stem or how many branching orders are present.
The terminal branches are up to 2 cm long and have a basal diameter of 0.08 mm.
A 1 cm long terminal branch has a diameter of 0.047 mm in the middle and a diameter of 0.066 mm near the base. Some of the smallest terminal branches are arranged in pairs next to each other. These pairs of branches are 4-5 mm apart.
The polyps usually have a transverse diameter of about 1.5 mm (range: 0.7-2 mm) and are arranged unilaterally with five polyps per cm.
In situ photographs of apparently fully expanded polyps show that all tentacles are cylindrical and unequal in length and usually not much longer than the transverse diameter of the polyps. This can also be seen in the preserved polyps of the holotype.
The members of the class Anthozoa are either gonochoric or hermaphroditic. The mature gametes are released into the coelenteron and spawned through the mouth.
Life cycle:
The zygote develops into a planktonic planula larva. Metamorphosis begins with the early morphogenesis of tentacles, septa and pharynx before the larva settles at the aboral end.
Etymology. The species name "sylospongia" is derived from the Greek prefix "syl" for "with", the connecting vowel "o" and "spongia" for the sponge hosts. To date, all known records of this species are closely associated with hexactinellid sponge hosts, either Farrea occa or an unidentified species from the family Tretodictyidae .
Litearure reference:
Opresko, Dennis M. & Wagner, Daniel, 2020,
New species of black corals (Cnidaria: Anthozoa: Antipatharia) from deep- sea seamounts and ridges in the North Pacific,
Zootaxa 4868 (4), pp. 543-559 : 550-553
https://doi.org/10.11646/zootaxa.4868.4.5
