Fish Identification Photos: Panamic Sergeant Major, Abudefduf troschelii: The Panamic Sergeant Major is characterized by its five dark bars on a yellow background, reminiscent of an army sergeant major's chevron. The Panamic Sergeant Major has a small mouth and a body similar to a freshwater bluegill.

While breeding, Panamic Sergeant Major males try to attract females to a nesting site by turning a very dark metallic blue coloration. Panamic Sergeant Majors are very easy to identify, with the only possible confusion coming from the Graybar Grunt, Haemulon sexfascitum, which has six or seven bars on a yellow background.

The Panamic Sergeant Major is normally found in large aggregations in the surge zone around rocky structure in the first 50 feet of the water column. It is a diurnal feeder, and it reaches a length of approximately 10 inches.

The Panamic Sergeant Major is one of a group of small, very colorful reef fishes of the Pomacentridae or Damselfish Family. These differ from nearly all other marine reef fishes by possession of a single nostril that occurs on each side of the snout that is a blind pouch. Most Pomacentridae are strongly territorial and solitary. They are omnivores, feeding on bethic algae, crustaceans, plankton, and fish eggs. There are a total of 321 species of the Pomacentridae known globally, of which 13 are found in the Sea of Cortez.

In Mexico, the Panamic Sergeant Major occurs on the Pacific side of the Baja California peninsula south of Magdalena Bay, on the southeastern side of the Baja, and along the mainland Mexico, and around all oceanic islands.

Panamic Sergeant Major, Abudefduf troschelii: Caught from shore in the last hour of daylight in December 2001 in 72-degree water, along the rock line and in the surge zone with pounding surf, utilizing a 15-pound test, two dropper loop rig, no swivels, 1.5-ounce bank sinker, and Mustad 92553 hooks, size #6, on cut squid at Km. 21, Cabo Real, between Cabo San Lucas and San Jose del Cabo, Baja California Sur, Mexico. Size approximately 6 inches and one-half pound and for its size an energetic fighter. The fish in this photo is showing signs of stress as it comes out of the water, without the grey tinge. Due to the small size a “catch and release.” A true classic nibbler that is exceedingly difficult to hook and at times can quite rapidly becomes a major pest. Description and photo courtesy John Snow. Panamic Sergeant Major, Abudefduf troschelii: Caught from shore in the last hour of daylight in June 2003, in 77-degree water along the rock line and in the surge zone with pounding surf. This fish is a breeding male. Description and photo courtesy John Snow.