Astroboa cf. nuda
(Lyman, 1874)
Enter the name for this tabbed section: Description
Astroboa cf. nuda is the only representative of the family Gorgonocephalidae in Oman. So far, it has only been observed near Mirbat in Dhofar, on rocky outcrops, between 17 and 25 meter deep. It is easily confused with some kind of plant-like growth form because of the complexity of its 10 fractal arms, particularly during the day when the animal is rolled upon itself in a dense mass of branches and branchlets of all sizes.
The species identification is still tentative as no specimens were collected (it is rare) for a more accurate identification that requires observation of the central disk of the animal. The name of the family Gorgonocephalidae, literally means "with the head of the gorgone", a mythological creatures whose head was covered with numerous snakes and who transformed anyone who look at her into stone. In English, they are often called "basket stars" because at night, they extend their 10 fractal arms in a large plankton net, looking like a basket.
Most gorgonocephalids are deep water species that rarely venture in "divable" depths; a few species however, including Astroboa nuda live in the lower part of coral reef communities, typically between 15 and 40m.
The species identification is still tentative as no specimens were collected (it is rare) for a more accurate identification that requires observation of the central disk of the animal. The name of the family Gorgonocephalidae, literally means "with the head of the gorgone", a mythological creatures whose head was covered with numerous snakes and who transformed anyone who look at her into stone. In English, they are often called "basket stars" because at night, they extend their 10 fractal arms in a large plankton net, looking like a basket.
Most gorgonocephalids are deep water species that rarely venture in "divable" depths; a few species however, including Astroboa nuda live in the lower part of coral reef communities, typically between 15 and 40m.
Enter the name for this tabbed section: Distribution
Astroboa cf. nuda is so far restricted to Dhofar and was only observed a few times near Mirbat.
Worldwide, this species is widespread, from the western Indian Ocean to Japan and the central pacific islands (New Caledonia, Fiji).
Worldwide, this species is widespread, from the western Indian Ocean to Japan and the central pacific islands (New Caledonia, Fiji).
IUCN status
Data deficient (DD)
Data deficient (DD)
Enter the name for this tabbed section: Ecology and Biology
Astroboa cf. nuda, like all species of Gorgonocephalids are planktivorous. At night, they extend their extremely subdivided arms into a large (often > 1m in diameter) plankton net into the current and capture drifting plankton. These organisms are pretty faithful to their "home" rock or crevice and can be observed for month or years. After sunset, they crawl out of their hiding place and progressively unfurl their arms and extend them into the current. Once extended, the mutable collagen locks the arms in place and allow them to filter without expenditure in energy.