''Protoreaster lincki'', the red knob sea star, red spine star, African sea star, or the African red knob sea star, is a species of
starfish
Starfish or sea stars are Star polygon, star-shaped echinoderms belonging to the class (biology), class Asteroidea (). Common usage frequently finds these names being also applied to brittle star, ophiuroids, which are correctly referred to ...
from the
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...
.
Description
''P. lincki'' grows to a maximum diameter of . It has numerous tubercles located along its five arms. These tubercles are bright red and extend upward from the arms. It has a gray body with red stripes that connect the tubercles. This creates an appearance of a grid made of interconnecting wires.
The skeleton is composed of many calcareous ossicles and spicules. They are located inside the layer of connective tissue. This skeleton supports the large central disk.
File:Starfish in Mombassa.JPG, Off the coast of Kenya
Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...
.
File:Asteroidea 01.jpg, Close to a dead '' Astropyga radiata''
File:Diani Beach 10.jpg, Drying
Distribution
It is distributed in the western
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...
.
The red-knobbed starfish can only be found in the Indian Ocean, mostly along the African coast and Madagascar, north to India and Sri Lanka. A small population is also present in
Coral Bay, Western Australia.
They prefer sandy or muddy seabeds because it is easier for them to search and forage for food. While they are most often seen in shallow tidal pools, they can live in a variety of depths, down to deep. Red-knobbed starfish are carnivorous animals that eat a number of sea creatures.
Behaviour and diet
''P. lincki'' is active in both daytime and nighttime. It is a popular aquarium specimen, but is considered incompatible with many other invertebrates, as it will eat
soft corals,
sponge
Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and a ...
s,
tube worms,
clam
Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...
s, other starfish, and the like.
[ ]
It is also a heavily fished species for the curios trade, which contributes to the decline of the species.
References
Bibliography
*
External links
Image
Oreasteridae
Echinoderms described in 1834
{{Asteroidea-stub