''Ophionereis reticulata'', the reticulated brittle star, is a

brittle star Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomo ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Ophionereididae Ophionereididae are a family of brittle stars. Systematics Ophionereididae has been placed (along with Ophiocomidae) to the Taxonomic rank, superfamily Ophiocomidea and infraorder Chilophiurina or suborder Chilophiurina in different classificati ...

. It is found in shallow parts of the western Atlantic,

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

and

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

Description

Like other brittle stars, ''Ophionereis reticulata'' has a small flattened, pentagonal disc and five narrow, elongated arms. The disc can grow to a diameter of and the arms to a length of . The aboral (upper) surface of the disc is covered with small plates and is pale grey with a network of fine reddish-brown lines, giving it its common name. The arms have a large number of short joints and are fringed on either side with short spines. They are white or pale grey and have a band of chocolate brown approximately every fourth joint. This colouration makes the brittle star inconspicuous when viewed against its typical background.

Distribution and habitat

''Ophionereis reticulata'' is found in the western Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. Its range extends from the West Indies and Bermuda to Mexico, Belize, Honduras, Venezuela and Brazil. The type locality is the

Florida Keys The Florida Keys are a coral cay archipelago located off the southern coast of Florida, forming the southernmost part of the continental United States. They begin at the southeastern coast of the Florida peninsula, about south of Miami, and e ...

. It is found on sandy or shingle bottoms, among boulders and under rocks at depths of between .

Behaviour

''Ophionereis reticulata'' moves about on its arms with the disc clear of the substrate. Unlike many other brittle stars, it uses its tube feet in locomotion. These are long and pointed and are the only part of the arm to come in contact with the seabed. For bodily movement, the tips of the tube feet are extended forwards by bending them at right angles at the base. They are then straightened as the brittle star raises itself onto the points. By repeating these actions, the brittle star can creep forward at up to per minute. Any arm or pair of arms can be in the lead. ''Ophionereis reticulata'' is an

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

and

filter feeder Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

, but detritus and fragments of

polychaete Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that ...

worm have also been found in its stomach. It mainly consumes

red Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondar ...

and

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

and

diatom A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...

s which it catches by raising one or more of its arms into the passing water current while keeping its disc concealed. If an arm is attacked by a

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

it can easily break off in a process known as

autotomy Autotomy (from the Greek language, Greek ''auto-'', "self-" and ''tome'', "severing", wikt:αὐτοτομία, αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards one or more of its own appendages, usual ...

, and the brittle star can later regenerate a new limb. The sexes are separate in ''Ophionereis reticulata'' and spawning takes place once a year. The ophiopluteus larvae are

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic and after passing through several larval stages, settle on the seabed and undergo

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

into juveniles.

References

{{Taxonbar, from=Q1936985 Ophionereididae Animals described in 1825