Silverstripe Chromis, Chromis alta
The Silverstripe Chromis, Chromis alta, whose common Spanish name is castañeta alta, is a species in the Damselfish or Pomacentridae Family, known collectively as castañetas and jaquetas in Mexico. This fish is also known as the Oval Chromis. Globally, there are eighty-four species in the genus Chromis, eight of which are found in Mexican waters, five in the Atlantic and three in the Pacific.
The Silverstripe Chromis have deep oval compressed bodies with 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 tan band along the base of their dorsal fin 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, however the tan coloration tends to fade to a uniform brown post collection (pictured below). Their head has a steep profile and a small protrusible mouth that opens in the front with two rows of teeth. Their caudal fin is forked with two or 3 projecting spines. They have two anal spines and 12 or 13 rays, a single continuous dorsal fin with 13 spines and 12 to 14 rays, and 27 to 33 gill rakers. Their lateral line is incomplete and ends under the edge of their dorsal fin base. Their body is covered with large rough scales.
The Silverstripe Chromis are a non-migratory species normally found in shallow water within rocky reef structure, but they are also found at depths up to 655 feet. They reach a maximum length of 17.3 cm (6.8 inches), 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.
In Mexican waters the Silverstripe Chromis are found in all waters of the Pacific.
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).
The Silverstripe Chromis are small and rare and of limited interest to most. They are classic nibblers, thus difficult to catch by hook and line.