Panamic Cushion Star, Pentaceraster cumingi

Panamic Cushion Star, Pentaceraster cumingi. Underwater photographs taken in coastal waters off Loreto, Baja California Sur, May 2023. Photographs courtesy of Dr. Tom Bartol, Carlsbad, California.

Panamic Cushion Star, Pentaceraster cumingi. Sea Star provided by the commercial fishermen of the greater Los Cabos area, September 2015. Wingspan: 20 cm (7.9 inches).

Panamic Cushion Star, Pentaceraster cumingi. Underwater photographs taken in Zihuantanejo Bay, Guerrero, March 2017 and November 2018. Photographs courtesy of Ron Woheau, Zihuantanejo.

Panamic Cushion Star, Pentaceraster cumingi. Underwater photograph taken in Zihuantanejo Bay, Guerrero, November 2021. Photograph and identification courtesy of Maude Jette, Dive Zihuantanejo, www.Divezihuatanejo.com.

Phylogeny:  The Panamic Cushion Star, Pentaceraster cumingi (Gray, 1840), is a member of the Oreasteridae Family of Cushion Starfish and in the Class Asteroidea of Sea Stars. The Panamic Cushion Star is also know as the Cortez Starfish or Knobby Starfish, and in Mexico as Estrella Panámica de Colchón. There are fifteen global members of the Pentaceraster Genus.

Morphology:  The Panamic Cushion Star has a thick and inflated disc, with short, thick arms that almost appear to be webbed. Coloration of the aboral surface is variable and may be red-orange, reddish green, or gray with an overlying red network. They have stout, immovable,  spines on the upper surface of the disk and arms, but no spines along the margins.  The suckered tube feet are often hidden within the deep ambulacral grooves. The disc margin may be dark brown, orange brown, or reddish brown. Panamic Cushion Stars reach a maximum of 17.4 cm (6.8 inches) in diameter.

Habitat and Distribution:  The Panamic Cushion Star is found on cobbles, rocky reefs, and occasionally on sand.  They live in the lower intertidal zone, and to a depth of 200 m (656 feet). In the Eastern Pacific, Panamic Cushion Stars range from Mexico the Peru. They are also found in the southwestern Caribbean and Hawaii. The Panamic Cushion Stars is a resident of all Mexican waters of the Pacific with the exception that they are absent from Todos Santos, Baja California Sur, northward along the central and northwest coasts of Baja, and they are absent from the extreme northern portion of the Gulf of California.

Diet: The Panamic Cushion Star feeds on algae, detritus, echinoderms, barnacles, and other small invertebrates

Predators:  Panamic Cushion Stars are eaten by fish and crabs.

Reproduction:  Panamic Cushion Stars reproduce either sexually or asexually.  Asexual reproduction occurs by fission, splitting the central disc. Panamic Cushion Stars are known to form large aggregations at various locations throughout their range, including the Central and Southern Sea of Cortez. These aggregations, sometimes exceeding 2500 individuals, are thought to be related to reproduction. In the Sea of Cortez, these aggregations occur during the months of July, August, and September. The aggregations are short lived, usually dispersing after two days or so.

Ecosystem Interactions: The commensal Sea Star Shrimp, Periclimenes soror, is found in association with the Panamic Cushion Star.

Human Impact: The Panamic Cushion Star are sometimes collected, dried, and sold as souvenirs, which may have significant impacts on localized populations. They are utilized by the aquarium trade on a nominal level. From a conservation perspective they have not been formally evaluated however they have are common with a wide distribution and should be consider to be of Least Concern.

Synonyms:  Oreaster hawaiiensis, Oreaster occidentalis, Pentaceros cumingi, Pentaceros hawaiiensis, and Pentaceros cumingi.