Northern sea robin.
Northern sea robin.
Courtesy: Marine Biological Laboratory, Woods Hole, MA

Northern Sea Robin (Prionotus carolinus)

Alternate common name: Common Sea Robin.
Color: Combination of red, grey, and brown, with dark blotches along its back; underside is dirty white or pale yellow.
Size: 12 to 16 inches long.
Habitat: Smooth, hard-packed bottom of open Bay.
Seasonal appearance: May to October.


The northern sea robin is distinguishable by a large, spiny head and tapering body. It can be easily identified by its rounded, fanlike pectoral fins that are so large they overlap the anal and second dorsal fins when laid back. The three lower rays of the northern sea robin's pectoral fins are long, broad feelers used to walk along the bottom, stirring up bottom sediments to find food. The head of the northern sea robin is encased in bony plates, which it uses as a shovel to dig up invertebrates from the mud. The front part of its upper jaw is concave, and there is a small spine in its nostrils. The northern sea robin's eyes are a distinctive peacock blue. The features of its head distinguish this species from a similar-looking fish, the sculpin.

Life History and Behavior

Northern sea robins typically inhabit areas of hard, smooth bottom habitats, but are not often seen among rocks or in the mud. These active swimmers are often found close to the surface. When threatened, they will bury themselves in the sand, revealing only their eyes and the top of their heads.

The northern sea robin feeds on a wide variety of invertebrates, including shrimp, crabs, amphipods, squid, bivalve mollusks, and segmented worms. It has also been known to bite readily on any bait, suggesting a fairly nonselective feeding habit.

Special Notes

Adapted from The Uncommon Guide to Common Life on Narragansett Bay. Save The Bay, 1998.