{{Short description|Species of starfish}} {{Speciesbox | image = Estrella de mar de espinas rojas (Protoreaster linckii), Zanzíbar, Tanzania, 2024-06-01, DD 06.jpg | genus = Protoreaster | species = lincki | authority = (Blainville, 1834) }}
'''''Protoreaster lincki''''', the '''red knob sea star''', '''red spine star''', '''African sea star''',<ref>{{Cite web|url = http://www.fishdb.com/db/salt/specimen/Red_Knob_Sea_Star.php|title = FishDB - Red Knob Sea Star|website = www.fishdb.com|access-date = 2016-04-10|archive-url = https://web.archive.org/web/20120320152650/http://www.fishdb.com/db/salt/specimen/Red_Knob_Sea_Star.php|archive-date = 2012-03-20|url-status = dead}}</ref> or the '''African red knob sea star''',<ref>{{Cite web|url=http://www.peteducation.com/article.cfm?c=16+2158+2224&aid=2175|title=Ask a Vet Online 24/7 - PetCoach}}</ref> is a species of starfish from the Indian Ocean.<ref>{{Cite web|url = http://www.saltcorner.com/AquariumLibrary/browsespecies.php?CritterID=3062|title = View Protoreaster lincki|website = www.saltcorner.com|access-date = 2016-04-10}}</ref><ref>{{Cite web|url = https://www.biolib.cz/en/taxon/id311482/|title = BioLib: Biological library|last=Zicha|first=Ondrej|website = www.biolib.cz|access-date = 2016-04-10}}</ref>
==Description== [[Image:Star Fish, Market (7969950304).jpg|thumb|Mummified ''P. lincki'' for sale in Tanzania. Their sale contributes to the rarefaction of this species.]] ''P. lincki'' grows to a maximum diameter of {{convert|12|in|cm|abbr=on}}. 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.<ref>{{Cite web|url=http://www.peteducation.com/article.cfm?c=16+2158+2224&aid=2175|title=Ask a Vet Online 24/7 - PetCoach}}</ref>
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.<ref>{{Cite book|url = https://books.google.com/books?id=Zb3sTkJEwOwC|title = Biological Adhesive Systems: From Nature to Technical and Medical Application|last1 = Byern|first1 = Janek von|last2 = Grunwald|first2 = Ingo|date = 2011-01-27|publisher = Springer Science & Business Media|isbn = 9783709102862|language = en}}</ref>
<gallery style="text-align:center;" mode="packed"> File:Starfish in Mombassa.JPG|Off the coast of Kenya. File:Asteroidea 01.jpg|Close to a dead ''Astropyga radiata'' File:Estrella de mar de espinas rojas (Protoreaster linckii), Zanzíbar, Tanzania, 2024-06-01, DD 143.jpg|Detailview </gallery>
== Distribution == It is distributed in the western Indian Ocean.<ref>{{Cite book|url = https://books.google.com/books?id=DUq0NmhW1CcC|title = The Everything Aquarium Book: All You Need to Build the Aquarium of Your Dreams|last = Indiviglio|first = Frank|date = 2006-10-12|publisher = Everything Books|isbn = 1440523894|language = en}}</ref><ref>{{Cite web|url = http://www.freshmarine.com/red-knob-sea-star.html|title = FreshMarine.com - African Red-Knob Sea Star - Protoreaster lincki - Buy Cheap Red Knob at Wholesale|website = www.freshmarine.com|access-date = 2016-04-10}}</ref>
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.<ref name="Ducarme">{{cite journal |last1=Ducarme |first1=Frédéric |date=2022 |title=How to assess the absence of a species? A revision of the geographical range of the horned sea star, Protoreaster nodosus (Echinodermata; Asteroidea) |url=https://escholarship.org/uc/item/9hx8h1tk#main |journal=Frontiers of Biogeography |volume=14 |issue=3 |pages= |doi=10.21425/F5FBG56187 |access-date=|doi-access=free }}</ref>
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 {{convert|100|m|ft|abbr=on}} deep.<ref>{{Cite web|url=http://www.peteducation.com/article.cfm?c=16+2158+2224&aid=2175|title=Ask a Vet Online 24/7 - PetCoach}}</ref> 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.<ref>{{Cite web|url = http://www.fishdb.com/db/salt/specimen/Red_Knob_Sea_Star.php|title = FishDB - Red Knob Sea Star|website = www.fishdb.com|access-date = 2016-04-10|archive-url = https://web.archive.org/web/20120320152650/http://www.fishdb.com/db/salt/specimen/Red_Knob_Sea_Star.php|archive-date = 2012-03-20|url-status = dead}}</ref> It is a popular aquarium specimen, but is considered incompatible with many other invertebrates, as it will eat soft corals, sponges, tube worms, clams, other starfish, and the like.<ref>{{cite web |url=http://www.aquariumslife.com/sea-star/red-knob-sea-star-protoreaster-linckii/ |title=Red Knob Sea Star – Protoreaster linckii {{!}} Aquariums Life |website=www.aquariumslife.com |url-status=usurped |archive-url=https://web.archive.org/web/20101202021412/http://www.aquariumslife.com/sea-star/red-knob-sea-star-protoreaster-linckii/ |archive-date=2010-12-02}} </ref>
It is also a heavily fished species for the curios trade, which contributes to the decline of the species.<ref name="Ducarme"/>
==References== {{Reflist}}
== Bibliography == * {{cite journal |last1=Ducarme |first1=Frédéric |date=2022 |title=How to assess the absence of a species? A revision of the geographical range of the horned sea star, Protoreaster nodosus (Echinodermata; Asteroidea) |url=https://escholarship.org/uc/item/9hx8h1tk#main |journal=Frontiers of Biogeography |volume=14 |issue=3 |pages= |doi=10.21425/F5FBG56187 |access-date=|doi-access=free }}
==External links== *[http://www.meerwasser-lexikon.de/tiere/698_Protoreaster_linckii.htm Image]
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Category:Oreasteridae Category:Echinoderms described in 1834
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