Fourspined

The term "fourspined" most commonly refers to a group of small, ray-finned fish belonging to the family Aulorhynchidae. These fish are characterized by having four spines preceding their dorsal fin. They are slender, elongated, and have a tube-like snout. Fourspined fish are typically found in marine environments, inhabiting coastal waters, kelp forests, and rocky reefs. Their diet usually consists of small crustaceans and plankton.

There are several species within the fourspined family, with the most well-known being the fourspine stickleback (Apeltes quadracus) found in the North Atlantic. These fish are relatively small, often measuring only a few centimeters in length. Their coloration can vary, often providing camouflage against their surroundings. Reproduction in fourspined fish typically involves the male building a nest to attract a female, after which he guards the eggs until they hatch.

In some contexts, "fourspined" might also be used descriptively for other organisms or objects that possess four prominent spines. However, without further context, the fish are the primary subject associated with this descriptor. Their ecological role is generally as small prey for larger fish and seabirds, contributing to the marine food web.