Prowfish, Zaprora silenus

The prowfish (Zaprora silenus) is a subtropical species of a perch-like fish found in the northern Pacific Ocean. The range of the prowfish is from the Aleutian Islands, Alaska to Kamchatka, Russia, from Navarin Canyon in the Bering Sea to Hokkaido, Japan and Monterey, California. The preferred habitat of the prowish is rocky bottom at a maximum of 2,200 feet in depth where they spend most of their adult life.

Prowfish can grow to a length of 40 inches or more having an elongated body that is laterally compressed and stout. The dorsal fin (top) runs almost the entire length of its back and contains 54-58 spines. The anal fin (bottom rear) is also quite long and the tail is large but short and rounded. The pectoral fins (sides behind the head) are large and the prowfish is absent of the pelvic fins (bottom front). It has a slightly upturned mouth that contains small, sharp teeth which are set close together. Its head is slightly convex and has blue and white fringes. The scales are small and the typical colors of the prowfish are a bluish-gray to an olive brown with small dark spots at the head and gradually becoming lighter toward the tail.

Adult prowfish will feed mainly on jellyfish by tearing chunks from the bells, but will also eat smaller fish and crustaceans, while the juveniles feed exclusively on jellyfish. Skates and halibut are predators of prowfish.

While the adult will spend most of its life on the bottom, the juvenile will swim at the middle level of the water column. Although the young eat jellyfish, they will also hide within the bells of them to escape predators.

The female will reach maturity in five years. Although there is little difference between the male and female fish, the female tends to be a little heavier.

Image Caption: Prowfish (Zaprora silenus). Credit: Jan Haaga, NOAA/Wikipedia (public domain)