Oreaster reticulatus (Linnaeus, 1758)
Family: Oreasteridae
Common names: Cushion Star,  more...
Oreaster reticulatus image
Oreaster reticulatus  

Species Description: Oreaster reticulatus is a member of the family Oreasteridae. It was once the most common seastar in the shallow waters of the Caribbean (Anderson 1978, Wulff 1995, Metaxas et al. 2002). The cushioned star is large with a central disc surrounded by five short, tapered arms. The thick body of O. reticulatus is covered by a hard shell with raised knobby spines. The color of adult cushioned stars can be brown, orange, red, or yellow. The juveniles are mottled green in color that affords them camouflage in their seagrass bed refuge (Scheibling 1980a).

Regional Occurrence: The cushioned star occurs in the eastern and western Altantic, from North Carolina to Brazil and Cape Verde Islands in western Africa. Adult Oreaster reticulatus are usually found in calm shallow waters (depths from 1 - 37 m) and more commonly occur on calcareous sandy bottoms (Anderson 1978, Guzman and Guevara 2002). Larvae and juveniles are usually found in seagrass beds (Guzman and Guevara 2002).

IRL Distribution: Oreaster reticulatus occurs in the Indian River Lagoon.

Age, Size, Lifespan: The cushioned star reaches sexual maturity at approximate radius of 12 cm (Guzman and Guevara 2002). Individuals can grow up to 50 cm in diameter. The growth potential of an individual is thought to be limited by food availability, usually caused by intraspecific competition in large aggregations. During times of low food availability, O. reticulatus will reabsorb its body tissues to prevent starvation and as a result decrease in size (Scheibling 1980a).

Abundance: Adults occur in dense aggregations called 'fronts' of 200 to 4000 individuals (Guzman and Guevara 2002, Metaxas et al. 2002). The size of the fronts is dependent upon the available substratum and higher densities of the fronts are correlated with the annual reproductive cycle. Oreaster reticulatus can occur at densities of 14 individuals per m2 ensuring reproductive success (Scheibling 1980a and b, Guzman and Guevara 2002). There are mass migrations of the cushioned star to calmer offshore habitats in the winter months to avoid turbulence (Scheibling 1980a, Scheibling 1985).

Reproduction: Oreaster reticulatus have separate sexes and reproduce annually in summer in subtropical regions. In more tropical areas where water temperatures are high nine months out of the year, there is asynchronous spawning year round (Guzman and Guevara 2002).

Embryology: The planktonic larvae of the cushioned star are dispersed over long distances in water currents. Larvae will settle and metamorphose in seagrass beds. Recruitment to adult populations of Oreaster reticulatus from nursery grounds occurs when individuals enter the last juvenile stage, measuring 6-12 cm in length (Scheibling 1980a).

Temperature: Sea water temperatures regulate the spawning cycles of Oreaster reticulatus (Guzman and Guevara 2002).

Salinity: There are no studies specifically addressing the salinity tolerance of Oreaster reticulates.

Trophic Mode: The cushioned star, a deposit feeder, has a complex digestive system that allows considerable variability in its feeding habits (Anderson 1978, Scheibling 1982). It is an omnivore, feeding on epiphytic microorganisms, echinoids, holothuroid juveniles and invertebrates including polychaetes, copepods, ostracods, crab larvae, and sponges (Wulff 1995, Guzman and Guevara 2002). Oreaster reticulatus uses its arms to rake piles of sediments and then everts its large cardiac stomach, enveloping the food in its folds. (Anderson 1978, Wulff 1995). O. reticulatus can turn over sediment 1.9 times within 24 hours (Scheibling 1980b).

Fishery: Fishery: The cushioned star has been overharvested for souvenirs and the aquarium trade and are no longer common in areas of high human populations (Metaxas et al. 2002, Guzman and Guevara 2002).

Anderson JM. 1978. Studies of the functional morphology in the digestive system of Oreaster reticulatus (L.) (Asteroidea). The Biological Bulletin 154:1-14.

Guzman HM and CA Guevara. 2002. Annual reproductive cycle, spatial distribution, abundance, and size structure of Oreaster reticulatus (Echinodermata: Asteroidea) in Bocas del Toro, Panama. Marine Biology 141:1077-1084.

ITIS. Integrated Taxonomic Information System. Available online.

Metaxas A, Scheibling RE, and CM Young. 2002. Estimating fertilization success in marine benthic invertebrates: a case study with the tropical sea star Oreaster resticulatus. Marine Ecology Progress Series 226:87-101.

Reef Life. Available online.

Scheibling RE. 1980a. Abundance, spatial distribution, and size structure of populations of Oreaster reticulatus (Echinodermata: Asteroidea) on sand bottoms. Marine Biology 57:107-119.

Scheibling RE. 1980b. Dynamics and feeding activity of high-density aggregations of Oreaster reticulatus (Echonodermata: Asteroidea) in a sand patch habitat. Marine Ecology Progress Series 2:321-327.

Scheibling RE. 1982. Habitat untilization and bioturbation by Oreaster reticulatus (Asteroidea) and Meoma ventricosa (Echinoidea) in a subtidal sand patch. Bulletin of Marine Science 32:624-629.

Scheibling RE. 1885. Directional movement in a sea star (Oreaster reticulates): Adaptive significance and ecological consequences. Contributions in Marine Science 27, Supplemental: 244-256.

Wulff JL. 1995. Sponge-feeding by the Caribbean starfish Oreaster reticulates. Marine Biology 123:313-325.

Aboral: In a direction away from the mouth; the part of the body opposite the mouth.

Anal Cone: In crinoids and echinoids, a fleshy projection bearing the anus at its apex; also known as an anal tube.

Apical System: In echinoids, a ring of specialized skeletal plates, including the genital plates and ocular plates; usually located on the highest point of the test.

Arm: In asteroids, crinoids, and ophiuroids, a movable, jointed ambulacral projection, distal to the disk or calyx that carries a radial branch of the water vascular system and the nervous system; sometimes called a ray.

Basket: One of several types of microscopic skeletal ossicles in holothuroids; minute cup-shaped ossicle, usually with four projections.

Button: One of several types of microscopic skeletal ossicles in holothuroids; minute ossicle with four perforations; may be smooth or knobbed.

Disk: The round or pentagonal central body region of ophiuroids and asteroids; see also Terminal Disk.

Distal: In a direction away from the center of the body; for example, toward the tip of the arm in asteroids or the tip of a spine in echinoids.

Dorsal: In echinoderms, this term is variously applied; in asteroids, ophiuroids and echinoids it usually refers to the surface of the body that is opposite the mouth, the surface that is uppermost; in holothuroids, with mouth and anus opposite ends of the cylindrical body, the uppermost surface is considered dorsal; in crinoids, the surface opposite the mouth in considered dorsal by convention, even though it is functionally the ventral (lower) side.

Echinulate: Something spiny or prickly, usually referring to the microscopic texture of a skeletal element such as a spine.

Hermaphrodism: A condition in organisms whereby one individual possesses both functional male and female reproductive structures; hermaphroditic individuals may express both sexes simultaneously, alternately, or sequentially.

Interambulacral Area: An oral or aboral section of the body lying between two ambulacra; in interradius; also known as an interambulacrum.

Interradial: Referring to interambulacral areas of the body; interradius and interradii also commonly used.

Oral: In a direction toward the mouth; a part of the body on the same surface as the mouth.

Oral Papillae: In ophiuroids, small plates at the edge of the mouth, attached to the edges of the jaw plate and/or to the aboral shield; may be variously shaped, from spine-like to scale-like.

Papillae: In holothuroids, specialized dorsal tube feet that lack a suckered tip; in ophiuroids, certain skeletal elements of the jaws or disk.

Papillate: Covered with papillae.

Papillose: Covered with papillae.

Pedicellariae: Small stalked or unstalked pincer-like organs on the body of asteroids and echinoids, used for defense and grooming.

Peltate: Shield-shaped; used to describe the tentacles of some holothuroids.

Perforated Plate: One of several types of microscopic skeletal ossicles in holothuroids; sieve-like and widespread; may also be found in other echinoderm classes, especially in juvenile individuals.

Periproct: In echinoids, a flexible region surrounding the anus, which consists of a membrane containing embedded plates and often bearing spines and pedicellariae.

Plates: One of several types of skeletal elements in echinoderms; tabular structures with a characteristic shape and a fixed position.

Primary Plates: The first-formed plates on the dorsal side of the disk; in ophiuroids, these are the central and five radial plates; in adults, they may form a rosette of scales near the center of the disk, or they may be separated by numerous secondarily developed scales.

Radial: In a direction toward the central axis of an arm or ambulacrum; a part of the body near an arm or ambulacrum.

Radial Shields: Pairs of plates on the dorsal surface of the ophiuroid disk, which lie near the base of each arm; usually relatively large and conspicuous, but may be hidden by granules or superficial scales.

Rods: One of several types of microscopic skeletal ossicles in holothuroids; commonly found as supporting structures in tentacles or tube feet.

Scales: One of several types of skeletal elements in echinoderms; flat, thin structures that are overlapping, tessellate, or haphazardly arrayed.

Sole: In some holothuroids, the flattened ventral part of the body, either covered with or surrounded by tube feet.

Spines: One of several skeletal elements in echinoderms; movable, articulating structures that are long, slender and attenuated.

Teeth: In ophiuroids, small plates or spines attached to the dental plate on the inner edge of the jaw, a series of them extending into the mouth; in echinoids, the five hard, sharp, and movable ossicles incorporated in Aristotle’s lantern; the term also refers to five movable ossicles that surround the anus of some holothuroids.

Tentacle Scales: Small, movable spines or scales, associated with ophiuroid tube feet, which are attached to the ventral arm plate and/or lateral arm plate; may cover the tentacle pores and protect the retracted tube feet.

Tentacles: In holothuroids, feeding structures in the form of highly modified tube feet arranged in a ring around the mouth.

Terminal Disk: Round portion on the end of the tube foot in many echinoderms; usually employed for attachment to substrates.

Tube Feet: Fluid-filled, fingerlike extensions of the water vascular system that protrude through the openings in the skeleton or between skeletal elements; muscles and nerves in the shaft of the tube feet control their movements; glands, and sometimes a muscular sucker, at the tip function in adhesion; specialized tube feet are used for locomotion, feeding, burrowing, respiration, and a combination of functions.

Ventral: In echinoderms, this term is variously applied; in asteroids, echinoids and ophiuroids, it is the surface of the body that carries the mouth; this surface is in contact with the substrate; in holothuroids, with mouth and anus at opposite ends of a cylindrical body, the ventral surface is lowermost, in contact with the substrate; in crinoids, the ventral surface carries the mouth and is functionally the uppermost surface.

Oreaster reticulatus image
Oreaster reticulatus