Northern Quahog

Overview

The Northern Quahog, also known as the hard clam, is a robust bivalve mollusk native to the Atlantic coast of North America. These clams are highly valued in commercial and recreational fisheries and are frequently categorized by size, ranging from small "littlenecks" to large "chowder clams."

Distribution & habitat

This species is native to the eastern shores of North America, spanning from the Gulf of St. Lawrence in Canada down to the Gulf of Mexico. They inhabit intertidal and subtidal zones, typically burying themselves in sandy, muddy, or gravel-mixed sediments within bays and estuaries. While they have been introduced to various regions, including parts of California and Europe, their establishment success varies by location.

Appearance

The Northern Quahog features a thick, heavy, and roughly triangular shell that is typically light brown or gray. The exterior displays concentric growth lines that are more widely spaced near the umbo and closer together toward the margins. The interior of the shell is smooth and often exhibits a distinct purplish-blue stain, particularly around the muscle scars.

Biology & behavior

Adults are generally sessile, remaining buried in the sediment with only their siphons exposed to the water column. However, researchers have observed individuals "walking" across the sediment surface, leaving behind distinct furrows. They are suspension feeders that filter phytoplankton from the water. As protandrous hermaphrodites, they typically mature between one and three years of age, with spawning cycles influenced by water temperature.