Tamarisk Sea Star, Linckia columbiae

Tamarisk Sea Star, Linckia columbiae. Star provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, December 2013. Pictured stars wingspan: 18 cm (7.1 inches).

Phylogeny: The Tamarisk Sea Star, Linckia columbiae (Gray, 1840), is a member of the Ophidiasteridae Family of Ophidiasterid Sea Stars. The genus Linckia is one of twenty-three in this family, and there are nine species in this genus. This species is also known as the Burgundy Sea Star, the Comet Star, the Fragile Star, the Purple Linkia Star, the Rough Purple Sea Star and the Variable Starr. In Mexico they are known a estrella de mar tamarisk or estrella de mar cometa. Until 2022 this species was known as the Purple Linckia Starfish, Tamaria stria. It was included in this preexisting name even though there are morphological differences. There is some confusion in the available literature as to this new classification.

Morphology:  Tamarisk Sea Stars have a small disk and cylindrical arms that are marked by rows of pores, through which gill papillae protrude. There are two rows of ambulacral plates that distinguish this species from the very similar Common Comet Star,  Linckia guildingi, which has three rows of ambulacral plates. Tamarisk Sea Stars can have from one to nine arms, though they usually have five. The arms are seldom of equal length. They have a granulate texture on their aboral (dorsal) surface. Depending on their diet, they may be uniform maroon, purple, gray, or red in color. Tamarisk Sea Stars have a maximum wingspan of 17.5 cm (6.8 inches).

Habitat and Distribution: The Tamarisk Sea Star is found on rocks and rubble, and on sand at deeper depths. They live at depths between 12 m (40 feet) and 100 m (328 feet). The Tamarisk Sea Star is a resident of all Mexican waters of the Pacific Ocean, including the Gulf of California. Because of the recent reclassification of this species there is some confusion between sources as to habitat and range.

Diet:  Tamarisk Sea Stars are detritivores. They use their tube feet to move detritus to their mouth while they move across the sea floor.

Predators:  Predation of Tamarisk Sea Stars has not been documented. Other species within this genus are eaten by crabs, fish, gastropods and shrimp. This species is quick to shed an arm to escape from a predator, hence the alternative common name Fragile Star.

Reproduction:  Tamarisk Sea Stars are gonochoric (male or female for life). They reproduce either asexually or sexually. Asexual reproduction is done through autotomy, where a detached arm can grown a new individual. While most sea stars can regrow a detached arm, sea stars within this genus are among the few sea stars that can reproduce a new sea star from a detached arm. While this arm begins to regrow, it looks like a comet, hence the alternative common name Comet Star. The regrowth of a new body is what results in the unequal length of arms, so prevalent in this species. Regrowth take about six months. Sexual reproduction consists of broadcast spawning and external fertilization. The resulting larva are planktonic until they settle to the bottom to begin their benthic existence.

Ecosystem Interactions:  Tamarisk Sea Stars host Cleaner or Glass Shrimp from the genus Periclimnes. In this commensal relationship the shrimp eat detritus and mucous from the sea star. The sea star is not harmed or benefitted by this relationship.

Human Interactions:   Recent reclassification of this species has generated conflicting information in the literature. Some sources indicate that the Tamarisk Sea Star is utilized by the aquarium trade on a limited basis, can be purchased via the internet, and they are popular as they are easy to maintain. Other sources say that they have not yet been kept successfully in an aquarium. Tamarisk Sea Stars have no direct impact on human activities. From a conservation perspective they have not been formally evaluated however they are fairly common with a wide distribution and should be consider to be of Least Concern.

Synonyms: Phataria fascialis and Tamaria stria.