Sergeant Major, Abudefduf saxatilis
The Sergeant Major, Abudefduf saxatilis, whose common Spanish name is petaca rayada, is a species in the family Pomacentridae, the Damselfis or Pomacentridae Family, known collectively as castañetas and jaquetas in Mexico. Globally, there are twenty-five species in the genus Abudefduf, four of which are found in Mexican waters, two in the Atlantic and two in the Pacific.
The Sergeant Majors have deep oval compressed bodies with a depth that is 60 – 64% of standard length, thus similar in nature to freshwater bluegills. They are whitish to pale silver in color with a bright yellow back and five dark bars on their sides which are narrower than the interspaces. Their head has a steep profile and a small protrusible mouth that opens in the front with a single row of teeth. Their caudal fin is forked with broad and very symmetrical lobes. They have two anal spines with 10 to 13 rays and a single continuous dorsal fin with 13 spines and 12 or 13 rays. Their lateral line is incomplete and ends under the edge of the dorsal fin base. Their body is covered with rough scales.
The Sergeant Majors are a non-migratory species found in shallow water over and within rocky reef structure buffeted by wave action at depths up to 140 feet. They reach a maximum length of 23.0 cm (9.1 inches). 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. While breeding, males turn a very dark metallic blue to attract females to the nesting site, then guard and aerate the eggs.
In Mexican waters the Sergeant Majors are found in all waters of the Atlantic.
The Sergeant Major is not easily confused with any other species due to its barring pattern and yellow coloration, however, it is virtually identical to the Panamic Sergeant Major, Abudefduf troschelii (found only in the Pacific Ocean). It has a similar body profile as the Night Sergeant, Abudefduf taurus (lacks yellow coloration on back) and similar barring pattern as the Sheepshead, Archosargus probatocephalus (six or seven bars; lacks yellow collation on back).
The Sergeant Majors are rather small but considered an excellent food fish. They are classic nibblers, thus difficult to catch by hook and line.
Sergeant Major, Abudefduf saxatilis. Fish caught off the Vidanta Grand Luxx Resort Pier, Playa del Carmen, Riviera Maya, Quintana Roo, February 2016. Length: 14.0 cm (5.5 inches). Catch and photo courtesy of George Brinkman, Guelph, Ontario, Canada.
Sergeant Major, Abudefduf saxatilis. Fish caught from coastal waters off Key Largo, Florida, December 2013. Length: 11 cm (4.3 inches). Catch, photo and identification courtesy of Ben Cantrell, Peoria, IL.