stellatorii

Stellatorii are a proposed group of deep-sea echinoderms distinguished by star-shaped body plans and bioluminescent organs. They inhabit the bathyal to abyssal depths of the Pacific and Indian Oceans, where they occur around hydrothermal vent and cold seep ecosystems. The group has attracted interest because of its unusual morphology and potential insight into echinoderm evolution.

Etymology and taxonomy: The name derives from Latin stella "star" and the Latin plural suffix -ii; in literature stellatorii refers to the collective group, with singular form stellatorius in some proposals. Taxonomically, stellatorii are described as an early-diverging echinoderm lineage, though formal recognition by major taxonomic authorities has not been achieved. Some researchers place them within Asteroidea (starfish) as a highly divergent clade; others propose a separate order Stellatorida.

Morphology: Adults display a central disk with radiating, tapering arms that range from five to twelve; the arms are lined with calcareous ossicles and soft connective tissue. The skin hosts photophores or chromatophores enabling bioluminescent displays. Pedicellariae and tube feet support detritivorous and micro-suspension feeding.

Ecology and behavior: They are benthic or near-benthic, often associated with microbial mats and vent fluids. They may harbor symbiotic bacteria and utilize luminescence for mate recognition, camouflage, or predator deterrence. Reproduction is presumed to be broadcast or clutch-based, with free-swimming larvae.

Discovery and status: First described in a 2092 expedition report by Lian Kaur, genetic data suggest a distinct lineage within echinoderms, though data remain limited. The taxonomic status is debated, and further specimens and molecular analyses are needed.