Silverstripe Chromis, Chromis alta
Silverstripe Chromis, Chromis alta. Fish caught from coastal waters off Point Palmilla, Baja California Sur, March 2018. Length: 11 cm (4.3 inches).
Silverstripe Chromis, Chromis alta. Fish caught from coastal waters off Point Palmilla, Baja California Sur, February 2018. Length: 12 cm (4.7 inches).
Silverstripe Chromis, Chromis alta. Fish caught from coastal waters off Point Palmilla, Baja California Sur, January 2014. Length: 15.5 cm (6.1 inches).
The Silverstripe Chromis, Chromis alta, is a member of the Damselfish or Pomacentridae Family, that is also known as the Oval Chromis and in Mexico as castañetas alta. Globally, there are eight-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 Silverstripe Chromis has a deep oval compressed body that has a depth that is 48% to 52% of standard length, thus similar in nature to freshwater bluegills. They vary from tan to dark brown in color with a broad silver band along the base of their dorsal fin (that fades quickly with death) that joins a diffuse pale bar running across their upper caudal fin base. Their fins are the same color as the body. They also have a prominent tan lateral line. Their head has a steep profile and a small protrusible mouth that opens in the front with 2 rows of teeth. Their anal fin has 2 spines and 12 or 13 rays, their caudal fin is forked with 2 or 3 projecting spines; and, their dorsal fin is continuous and singular with 13 spines and 12 to 14 rays. They have 27 to 33 gill rakers. Their body is covered with large rough scales. Their lateral line is incomplete and ends under the edge of their dorsal fin base.
The Silverstripe Chromis is a non-migratory species normally found in shallow water within rocky reef structure, but they are also found at depths up to 200 m (655 feet). They reach a maximum of 17.3 cm (6.8 inches) in length, established by a fish that I caught. They are diurnal feeders consuming primarily algae, plankton, and benthic invertebrates. Reproduction is oviparous with pairing of individuals; eggs are distributed demersal and adhere to the substrate due to their stickiness. The Silverstripe 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 Silverstripe Chromis is a resident of all Mexican waters of the Pacific Ocean.
The Silverstripe Chromis is most likely confused with the Scissortail Chromis, Chromis atrilobata (narrow body; caudal fin with sharp dark lobes; white spot at rear base of dorsal fin).
From a conservation perspective the Silverstripe Chromis is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature and rare and of limited interest to most. They are classic nibblers, thus difficult to catch by hook and line.