''Linckia laevigata'' (sometimes called the "blue ''Linckia''" or blue star) is a species of
sea star
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish a ...
in the shallow waters of tropical
Indo-Pacific
The Indo-Pacific is a vast biogeographic region of Earth.
In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
.
Description and characteristics
The variation ("polymorphism", in this case, a "
color morph
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the s ...
") most commonly found is pure, dark, or light blue, although observers find the aqua, purple, or orange variation throughout the ocean. These sea stars may grow up to 30 cm (11.8 in) in diameter, with rounded tips at each of the arms; some individuals may bear lighter or darker spots along each of their arms. Individual specimens are typically firm in texture, possessing the slightly tubular, elongated arms common to most of other members of 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 ...
Ophidiasteridae, and usually possessing short, yellowish
tube feet
Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on britt ...
.
An inhabitant of
coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Co ...
s and
sea grass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...
beds, this species is relatively common and is typically found in sparse density throughout its range. Blue stars live
subtidal
The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth.
From the point of view of marine biology it forms a relatively stable and well-illuminated ...
ly, or sometimes
intertidal
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of Marine habitat, habitats with var ...
ly, on fine (sand) or hard substrata and move relatively slowly (mean locomotion rate of 8.1 cm/min).
Image:Linckia laevigata Tonga.jpg, In Tonga
Image:Aguirangan Blue Sea Stars.jpg, In Aguirangan Island, Philippines
Image:Blue Star Fish (6244737028).jpg, In Bali
Image:Linckia laevigata x2.jpg, In some places non-blue color morphs can be frequent, such as pink (here in Mayotte
Mayotte (; french: Mayotte, ; Shimaore: ''Maore'', ; Kibushi: ''Maori'', ), officially the Department of Mayotte (french: Département de Mayotte), is an overseas department and region and single territorial collectivity of France. It is loc ...
)
Image:Reef4075 - Flickr - NOAA Photo Library.jpg, 4-armed specimen
The genus ''Linckia'', as is true of other species of starfish, is recognized by scientists as being possessed of remarkable regenerative capabilities, and endowed with powers of defensive
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 ...
against predators: Although not yet documented, ''L. laevigata'' may be able to reproduce asexually, as does the related species ''
Linckia multifora
''Linckia multifora'' is a variously colored starfish in the Family (biology), family Ophidiasteridae that is found in the Indian Ocean and Red Sea. Its common names include the Dalmatian Linckia, mottled Linckia, spotted Linckia, multicolor sea ...
'' (another denizen of tropical seas, but of differing coloration, i.e., pink or reddish mottled with white and yellow, which has been observed reproducing asexually in
captivity).
''Linckia multifora'' produces 'comets', or separated arms, from the mother individual; these offspring proceed to grow four tiny stubs of arms ready for growth to maturity. ''L. laevigata'' is apparently not an exception to this behavior, as many individuals observed in nature are missing arms or, on occasion, in the comet form.
Some species of other reef inhabitants prey on this species of sea star. Various
pufferfishes, ''
Charonia
''Charonia'' is a genus of very large sea snail, commonly known as Triton's trumpet or Triton snail. They are marine gastropod mollusks in the monotypic family Charoniidae.
Etymology
The common name "Triton's trumpet" is derived from the Gr ...
'' species (triton shells),
harlequin shrimp, and even some
sea anemone
Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...
s have been observed to eat whole or parts of the sea stars. The Blue Linckia is also prone to parasitization by a species of the parasitic gastropod ''Thyca crystallina''.
Commensal
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...
associations sometimes play part on this echinoderm's life; animals such as ''
Periclimenes
''Periclimenes'', commonly known as glass shrimp or cleaner shrimp, is a commensal and often symbiotic genus of semi-transparent shrimp within the family Palaemonidae. Species of this large genus feature a wide variety of coloration and patterns, ...
'' shrimp are sometimes found commensally on the oral or aboral surface of the animal, picking up mucus and detritus.
This sea star is fairly popular with
marine aquarium
A marine aquarium is an aquarium that keeps ocean, marine plants and animals in a contained environment. Marine aquaria are further subdivided by hobbyists into fish only (FO), fish only with live rock (FOWLR), and reef aquarium, reef aquaria. Fi ...
hobby
A hobby is considered to be a regular activity that is done for enjoyment, typically during one's leisure time. Hobbies include collecting themed items and objects, engaging in creative and artistic pursuits, playing Sport, sports, or pursu ...
ists, where it requires a proper, slow
acclimatization
Acclimatization or acclimatisation ( also called acclimation or acclimatation) is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude, temperature, humidity, photoperiod, or pH), ...
before entering the tank system, and an adequate food source similar to that found in its natural habitat. Generally thought of as a
detritivore
Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...
, many sources maintain that this species will indefinitely graze throughout the aquarium for organic films or sedentary, low-growing organisms such as
sponges
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...
and
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
. In the marine aquarium hobby, they have been seen to consume Asterina Starfish,
which are commonly introduced into such aquaria on the ubiquitous "live rock" used in such settings. In 2021 pictures surfaced on reddit of a linckia eating an Asternia it takes roughly 45 mins to fully devour the starfish. It's a worthy pest control depending on how abundant the food source is, as well as such factors as the conditions of shipping, acclimatization, and water quality, this species has been kept in captivity with variable success. This species has yet to be bred in captivity for
sustainable harvest
The sustainable yield of natural capital is the ecological yield that can be extracted without reducing the base of capital itself, i.e. the surplus required to maintain ecosystem services at the same or increasing level over time. The term only ...
.
This species has long been a staple of the sea-shell trade, which involves marketing dried sea star tests (skeletons) for curios or decoration. Some regions of their habitat have seen significant population decline due to the continuous harvesting by the sea-shell and tourism industries.
See also
* ''
Leptasterias pusilla''
References
* Shimek R.L.; Marine Invertebrates: 500+ Essential-to-Know Aquarium Species; T.F.H. Publications; New Jersey;
External links
An essay on the biology, taxonomy and captive-keeping by Rob Toonen
* ttps://web.archive.org/web/20060901174659/http://www.edge-of-reef.com/asteroidi/ASTLinckialaevigataen.htm Information about ''Linckias habitat and associationsbr>ReefCorner - Blue Linckia Database Entry
*
{{Taxonbar, from=Q882716
Linckia
Animals described in 1758
Taxa named by Carl Linnaeus