Brown Chromis, Chromis multilineata

Brown Chromis, Chromis multilineata. Underwater photograph taken in coastal waters of Bonaire, December 2019. Photograph and identifications courtesy of Bob Hillis, Ivins, Utah.

The Brown Chromis, Chromis multilineata, is a member of the Damselfish or Pomacentridae Family, and is known in Mexico as castañetas parda. Globally, there are eighty-four species in the genus Chromis, of which eight are found in Mexican waters, five in the Atlantic and three in the Pacific Ocean.

The Brown Chromis has an elongated oval fusiform compressed body that is similar in nature to freshwater bluegills. They are gray-green in color. The margins of their anal, caudal and dorsal fins are yellow. They have a prominent white spot just below the rear of the dorsal fin, a large black spot on the inside of the pectoral base and the upper and lower edges of the caudal fin are black. The caudal fin is deeply forked with sharp tips. The head has a small protrusible mouth that opens in the front with 2 rows of teeth. Their anal fin has 2 spines and 11 to 13 rays; their dorsal fin has 13 spines and 12 or 13 rays, and their pectoral fin has 18 to 20 rays. The body s covered with large rough scales. Their lateral line is incomplete and ends under the edge of the dorsal fin base.

The Brown Chromis is found in large schools which can include the Blue Chromis. They are a non-migratory species with the adults normally found in steep slopes and patch reefs at depths up to 91 m (300 feet). They reach a maximum of 20.0 cm (7.9 inches) in length. They are found on the surface of the reefs but will move into the water column to feed on plankton. They feed on aggregations of small zooplankton, primarily copepods, mysis and shrimp larvae, fish eggs and algae. Reproduction is oviparous with distinct pairing of individuals. The eggs are distributed demersally and adhere to the substrate and are guarded by the males. The eggs hatch into planktonic larvae in three days. The Brown Chromis is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Brown Chromis is a resident of all Mexican waters of the Atlantic Ocean including the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean.

The Brown Chromis is very easy to identify due to its markings, with the most similar appearing fish being the Crescent Damselfish, Neopomacentrus cyanomos (black shoulder blotch).

From a conservation perspective the Brown Chromis is currently considered to be of Least Concern with stable, widely distributed populations. Their long-term viability is strongly dependent upon the potential loss of habitat. Degradation of coral reef habitats in the Caribbean has led to a significant decline in the density of coral reef fish for more than a decade. The recent invasion of the Caribbean by the Red Lionfish, Pterois volitans, with its aggressiveness and population explosion has reduced the abundance of coral reef fishes. The Brown Chromis is not considered to be a quality food fish but they are retained by subsistence fishermen. They are not utilized by the aquarium trade at significant level as they are fairly large in stature, generally unattractive and become territorial over time.