Calliaster hystrix
A spiny sea star from the Coral Sea and New Caledonia.
Calliaster hystrix, a sea star from the family Goniasteridae, lives in the waters off New Caledonia and the Coral Sea. Its many marginal spines give it its species name, which comes from the Greek word for "porcupine."
This species has a thick, star-shaped body with long, upturned arms. The upper surface plates are smooth and bare, with distinct spines along the center of the arms but none in the spaces between the arms on the central disk. Along each arm, 10 to 15 pairs of upper marginal plates sit edge to edge, with 5 to 8 of these pairs free on the disk. Large conical spines appear on all these upper marginal plates, arranged in two rows on the disk. Nearly every plate on the underside carries small, hinged pincer-like structures called bivalve pedicellariae. The furrow spines, which line the groove on each arm, number 8 to 11, most often ten.
Calliaster hystrix differs from the Australian *Calliaster erucaradiatus* in having many bivalve pedicellariae on almost every actinal plate, far fewer spines on the interradial areas of the upper surface, and 8 to 11 furrow spines instead of 6 to 7. It resembles *Calliaster kanak* in its numerous, closely packed upper marginal plates and prominent spines, but it is set apart by its abundant bivalve pedicellariae, which *C. kanak* appears to lack. The spines on the upper and lower marginal plates are also arranged in more regular rows in *C. hystrix* than in *C. kanak*.
This sea star is found at depths between 140 and 428 meters.
Quick Facts
- Genus
- Calliaster
- Species
- hystrix
Facts from the source article.
Lore & Background
The species epithet hystrix is derived from the Greek for 'porcupine,' alluding to the many marginal spines present on this species. Its body is strongly thick and stellate with elongate, upturned arms. Abactinal plates are smooth and bare, with no surficial accessories, and distinct carinal spines are present, though interradial areas on the disk are spineless. Superomarginal plates, numbering 10 to 15, are abutted along the arm, with 5 to 8 free on the disk, and large conical spines are present on all superomarginal plates, with two series present on the disk. Bivalve pedicellariae are present on nearly all actinal plates, and furrow spines number 8 to 11, mostly ten.
Reader's Guide
Calliaster hystrix is distinguished from the Australian Calliaster erucaradiatus by the presence of multiple bivalve pedicellariae on nearly every actinal plate, significantly fewer spines on the interradial abactinal regions, and by having 8 to 11 furrow spines versus 6 to 7 in C. erucaradiatus. It is similar to Calliaster kanak in sharing numerous abutted supermarginal plates and prominent spines but differs in displaying numerous bivalve pedicellariae, which appear to be absent in C. kanak. The spination on the superomarginal and inferomarginal plates is also more serial in C. hystrix than in C. kanak. Known from depths of 140 to 428 meters off New Caledonia and in the Coral Sea, this species contributes to understanding the diversity and morphological variation within the family Goniasteridae, particularly in spine and pedicellariae patterns that help differentiate closely related species.
Did You Know?
- The species epithet hystrix is Greek for 'porcupine,' referencing its many marginal spines.
- It has 8 to 11 furrow spines, mostly ten, compared to 6 to 7 in Calliaster erucaradiatus.
- Bivalve pedicellariae are present on nearly all actinal plates, a feature absent in Calliaster kanak.
Frequently Asked Questions
What is Calliaster hystrix?
It is a spiny sea star in the family Goniasteridae, native to deep waters off New Caledonia and the Coral Sea. Its thick, star-shaped body and dense covering of conical spines make it one of the more striking members of its group.
Why is it called Calliaster hystrix?
The species epithet 'hystrix' comes from the Greek word for porcupine, a reference to the numerous marginal spines that give the animal its bristly, armored appearance.
Where and how deep does Calliaster hystrix live?
It is found in the waters off New Caledonia and across the Coral Sea, typically at depths ranging from about 140 to 428 meters below the surface.
What does Calliaster hystrix look like?
It has a thick, star-shaped body with long, upturned arms, smooth bare upper surface plates, and large conical spines running along the center of each arm. Along every arm, 10 to 15 pairs of upper marginal plates sit edge to edge, with 5 to 8 of those pairs free on the central disk.
What makes Calliaster hystrix stand out among other sea stars?
Its dense array of large conical spines, combined with free marginal plates on the disk, gives it a distinctly armored, porcupine-like profile. It also carries 8 to 11 furrow spines (most commonly ten), a detail that helps distinguish it from close relatives in the Goniasteridae family.
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