Paralabrax clathratus

Lore & Background

Paralabrax clathratus has an elongate, relatively deep, compressed body with a pointed snout and a large, downturned mouth. The mouth extends back to the center line of the pupil, and the lower mandible protrudes. There are teeth on the roof of the mouth, and the preopercle margins have fine serrations. A large spine is present on the edge of the gill cover. The dorsal fin has 10 spines and 13–14 soft rays, with the 3rd and 4th spines longest. The anal fin has 3 spines and 7 soft rays. The caudal fin is truncated. Juveniles are light brown; adults are brown to olive-green fading ventrally, with mottled light yellow spots on the dorsal head and black, white, or olive-green blotches on the body. White, rectangular spots appear along the back. All fins are yellow at the tips. Males may develop an orange tint on the lower jaw and chin during mating season. The species can change color depending on surroundings, such as from dark green or brown to pale green when moving from kelp forest to open ocean. There is no sexual dimorphism, so males and females cannot be distinguished by sight. A distinguishing feature from other sea bass is piebald or multicolored spotting under the belly, giving the alternative name calico bass. It is the largest species in its genus.

Reader's Guide

Paralabrax clathratus is found in the eastern North Pacific Ocean off western North America, from central California south to the southern tip of Baja California. It was formerly found as far north as the mouth of the Columbia River but is now rare north of Point Conception. It inhabits depths from 0 to 61 meters, typically between 2.7 and 21.3 meters, and shows a strong association with kelp forests and estuaries, also residing in nearshore rocky reefs. Juveniles hide among kelp blades and seaweed in the intertidal zone; adults prefer deeper water. Spawning occurs from late spring to early autumn, peaking in summer, with aggregations of up to 200 fish (commonly around 50) forming around natural or man-made structures at depths of 8 to 18 meters. Mating involves courtship displays, and both sexes release sperm and eggs simultaneously, often multiple times in an evening. Spawning activity peaks around the full moon. Eggs hatch within 36 hours, followed by a pelagic larval phase of 25–36 days. Juveniles grow an average of 0.59 mm per day for the first 90 days. Males are sexually mature at 2–4 years (half at 22 cm), females at 2–5 years (half at 22.6 cm). Maximum lifespan is 34 years, but most do not live that long; about 17.6% die from natural causes annually. The species is largely diurnal, faithful to home ranges averaging about 3,000 square meters, and may remain in the same area for up to 3 years. Adults feed on small fish, crustaceans, mollusks, and other small primary consumers; in winter, they sometimes rely on kelp and algae. The primary predator of adults is the giant sea bass (Stereolepis gigas).

Did You Know?

• Approximately 40% of all kelp bass alive at any given time are 200 to 250 millimeters in length.
• Spawning activity tends to peak each month around the time of the full moon, though the reason remains a mystery.
• The primary predator of adult kelp bass is the giant sea bass (Stereolepis gigas).