Common Sea Star (also known as starfish or common starfish, though technically an echinoderm rather than a true mollusk/shell)
Phylum: Echinodermata, Class: Asteroidea, Order: Forcipulatida, Family: Asteriidae, Genus: Asterias, Species: Asterias rubens · Asteriidae (Common Sea Star family) · Echinoderm exoskeleton (often collected and dried alongside seashells; not a mollusk, but features a calcareous skeletal test)
Species
Asterias rubens (or similar common sea star species depending on exact locality)
Shell Type
Echinoderm exoskeleton (often collected and dried alongside seashells; not a mollusk, but features a calcareous skeletal test)
Family
Asteriidae (Common Sea Star family)
Size
Approximately 4 to 5 inches across, which is typical for a medium-sized adult specimen. Adults can range from 2 to 12 inches.
Color & Pattern
Pale off-white to light gray due to drying and sun bleaching, with subtle darker central lines running down the length of each of the five tapering arms.
Rarity
Very Common, frequently found washed ashore or in shallow coastal waters, though intact dried specimens are popular decorative items.
Habitat
Found in marine environments, predominantly in intertidal and shallow subtidal zones down to moderate depths, preferring rocky shores, sandy bottoms, and kelp beds.
Geographic Range
Widely distributed across temperate marine waters, particularly common along coasts of the North Atlantic, including both European and North American shores.
Description
A classic five-armed echinoderm with a central disc and tapering rays. The surface exhibits a rough, granular texture composed of calcareous ossicles and minute spines. The central aboral surface shows clear structural symmetry with characteristic central channels along each arm.
Key Features
Symmetrical five-armed star body plan, rough calcareous skeletal structure, distinct central disc, and rows of tube feet visible on the underside (oral side).
Collector Value
Low monetary value; extremely common in souvenir shops and coastal gift stores. Prized more as a natural craft item or educational specimen than a high-end conchological collectible.
Condition Notes
Dried specimen in generally good, intact condition with all five arms present. Moderate fading and bleaching typical of dried beach finds; collectibility grade is Good.
Interesting Facts
Sea stars are not fish or mollusks, but echinoderms closely related to sea urchins and sand dollars. They possess an amazing ability to regenerate lost arms and feed by everting their stomachs outside their bodies to digest prey.
Ecological Role
Acts as a prominent marine predator controlling populations of bivalves like mussels and clams. They serve as an important keystone species in rocky intertidal ecosystems.
Similar Species
Spiny Sunstar (Crossaster papposus) and bat stars (Asterina), which can be distinguished by having more than five arms or a more webbed, compact body shape.
Beach Finding Tips
Look along sandy or rocky beaches at low tide, especially after a storm or strong offshore winds. Often found high up on the strandline where seaweed and flotsam accumulate.