How are brittle stars classified?
brittle star, also called serpent star, any of the 2,100 living species of marine invertebrates constituting the subclass Ophiuroidea (phylum Echinodermata). Their long, thin arms—usually five and often forked and spiny—are distinctly set off from the small disk-shaped body.
How many species of brittle stars are there?
2,000 species
There are around 2,000 species of brittle star — more than any other group of sea stars.
What are some characteristics of brittle stars?
Brittle stars are nocturnal scavengers that can be found in ecosystems throughout the world’s oceans. These animals consist of a clearly defined circular or pentagonal central disk surrounded by five long, slender arms. Sizes can vary by species and can range from 8 inches in diameter to 20 inches in diameter.
Is commonly called brittle star?
Ophiothrix fragilis is a species of brittle star in the order Ophiurida. It is found around the coasts of western Europe and is known in Britain as the common brittle star. It is also found along the coast of South Africa where it is known as the hairy brittle star.
What is a group of brittle stars called?
Ophiuroids are a large group (over 1600 species) of echinoderms that includes the brittle stars (Ophiurida) and basket stars (Euryalida).
What is the name of the only hermaphroditic brittle starfish?
The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars)….Brittle star.
| Brittle star Temporal range: Ordovician to Present | |
|---|---|
| Phylum: | Echinodermata |
| Superclass: | Asterozoa |
| Class: | Ophiuroidea Gray, 1840 |
| Type species |
What class and characteristics do the brittle stars share?
What class and characteristics do the brittle stars share? Ophiuroidea: slender legs, single set of organs, feed on detritus/small animals.
Do brittle stars have a central disk?
Brittle stars have a distinct central disc and (usually) five skinny, flexible arms. The central disk (approximately 2.5 cm in diameter in the species Ophiura sarsii) consists of a skeleton of calcium carbonate and contains all the brittle stars’ internal organs.
What color is a brittle star?
Brittle stars can be as large as 2 ft (0.6 m) in diameter or as small as a few millimeters. Ophioroids are usually a drab green, grey, or brown, but some have variegated color patterns. Some species of brittle stars glow in the dark-a bright green luminescence appears if they are disturbed.
How do brittle stars breathe?
Brittle stars are bottom feeders, consuming small organic material found on the sea floor. Respiration occurs through cilia-line sacs located between the arm bases on the central disk.