Gulf Sierra, Scomberomorus concolor
The Gulf Sierra, Scomberomorus concolor, whose common Spanish name is sierra golfina, is a member of the Mackerel or Scombridae Family, known collectively as macarelas in Mexico. This fish is also known as the Monterrey Spanish Mackerel. Globally, there are eighteen species in the genus Scomberomorus, five of which are found in Mexican waters, three in the Atlantic and two in the Pacific.
The Gulf Sierras have elongated, fusiform, and strongly compressed bodies. They exhibit sexual dimorphism as males are metallic blue dorsally, transition to silvery ventrally, and have no bars, spots or stripes, whereas females are darker metallic blue dorsally, transition to silvery ventrally, and have two series of alternating gold spots on their sides. Their ventral fins are clear to transparent and their other fins are dusky to very dark. Their snout is short and less than half the length of the head. Their mouth is equipped with a set of strongly compressed teeth that are triangular and knife-like. Their anal fin has 19 to 23 rays followed by 6 to 8 finlets; they have two dorsal fins set close together, the first with 15 to 17 spines and the second with 16 to 20 rays followed by 6 to 9 finlets. Their pelvic fins are relatively short. They have 21 to 27 gill rakers. Their body is covered with small scales and their lateral line gradually curves down toward the caudal fin base.
The Gulf Sierras are a coastal highly migratory pelagic schooling species found from the surface to depths up to 50 feet. They reach a maximum length of 87 cm (34 inches) and 3.6 kg (7.9 pounds) in weight. I have a report of a 4.2 kg (9 pound 4 ounces) fish being caught in coastal waters off San Felipe in 2015. They inhabit coastal estuaries and marshes during the winter months and retreat to deeper cooler waters during the summer. They are voracious predators and consume small fish including anchovies, clupeids, and herrings. They are believed to have a lifespan of up to eight years. They are a very rare and poorly studied species that has been fished to extinction in some parts of their historical range. Very little is known about their reproductive and behavioral patterns .
In Mexican waters the Gulf Sierras have a limited range being found only in the northern two-thirds of the Sea of Cortez ranging south as far as Bahia Concepcion.
The Gulf Sierra is easy to recognize. It is very similar to the Spanish Mackerel, Scomberomorus maculatus, found in the Atlantic. Females can possibly be confused with the Pacific Sierra, Scomberomorus sierra (3 to 8 rows of yellow spots; 12 to 17 gill rakers).
The Gulf Sierras are caught on a very limited basis by artisanal fishermen in the central and northern portions of the Sea of Cortez. They are considered an excellent food fish if consumed the day of catch as they have a short shelf-life. From a conservation perspective they are currently classified as Vulnerable to extinction with an 80% reduction in their population over the last 40 years accompanied by a significant range reduction. Historically they were targeted and caught in great quantity by commercial gill net fishermen. Such practices continue today without any effective form of regulation in place. Efforts to introduce this fish to the Salton Sea in 1950 failed.
Gulf Sierra, Scomberomorus concolor, Juvenile, Female. Fish caught from coastal waters of Bahia de Los Angeles, Baja California, November 2010. Length: 25 cm (10 inches). Catch, photo, and identification courtesy of Chris Wheaton, Fullerton, CA.
Gulf Sierra, Scomberomorus concolor, male. Fish caught from coastal waters of Gonzaga Bay, Baja California, June 2017. Length: 61 cm (24 inches). Catch courtesy of Earl Roberts, Mexicali, Baja California. Photo, and identification courtesy of Chris Wheaton, Fullerton, CA.
Gulf Sierra, Scomberomorus concolor, Female. Fish caught from coastal waters of Gonzaga Bay, Baja California, June 2016. Length: 75 cm (30 inches). Catch, photo, and identification courtesy of Chris Wheaton, Fullerton, CA.
Gulf Sierra, Scomberomorus concolor, Female. Fish caught from coastal waters off San Felipe, Baja California, May 2015. Length: 78 cm (31 inches). Catch, photo, and identification courtesy of Chris Wheaton, Fullerton, CA.