Scaled Sardine, Harengula jaguana
The Scaled Sardine, Harengula jaguana, whose common Spanish name is sardinita vivita escamuda, is a member of the Herring or Clupeidae Family, known collectively as sardinas in Mexico. Globally, there are only four species in the genus Harengula, all of which are found in Mexican waters, three in the Atlantic and one in the Pacific.
The Scaled Sardines have deep fusiform compressed bodies with a depth that is 33 to 37% of standard length. Both their upper and lower body profiles are convex. They are bluish-black with faint horizontal streaks dorsally and transition to silvery ventrally. They have a black spot behind their gill covers. Their fins are clear with the exception that the tip of their caudal fin is dusky. Their mouth opens at the front and their lower jaw is slightly projecting. Their anal fin has a short base with 15 to 19 rays and originates well behind the dorsal fin; their caudal fin is deeply forked; their dorsal fin has 17 to 19 rays and originates slightly before the center of the body; their pectoral fins are long; and their pelvic fins are located halfway between the anal fin origin and the pectoral fin base. They have 32 to 39 gill rakers. Their belly is covered with bony scales.
The Scaled Sardines are a pelagic coastal species that form very large schools in coastal waters. They are found over sandy and muddy bottoms in estuaries and lagoons at depths up to 30 feet. They reach a maximum length of 27.5 cm (10.8 inches). They are fast-growing and have a very short lifespan, living less than three years. They are planktivores feeding on a variety or prey including copepods, mysids, amphipods, isopods, ostracods, insect larvae, and small mollusks. In turn they play an important role as a food source (including their eggs and larvae) for a wide variety of marine fish, marine mammals, and sea birds. Reproduction is oviparous with each female releasing 5,500 to 52,000 eggs per annum. They are more active nocturnally and make vertical migrations in pursuit of crustacean prey. They are prone to rapid death under low oxygen conditions.
In Mexican waters the Scaled Sardines are found in all waters of the Atlantic.
The Scaled Sardine is most likely confused with the False Pilchard, Harengula clupeola (body depth 30 to 33% of standard length; 30 to 32 gill rakers; pelvic fins closer to pectoral base than anal base) and the Redear Sardine, Harengula humeralis (lacks black spot on shoulder) and is found in mixed schools with both.
When available, the Scaled Sardines make excellent live bait fish but otherwise are of limited interest to most.
Scaled Sardine, Harengula jaguana. Fish caught off coastal waters in Tampa, Florida, December 2013. Length: 18.0 cm (7.1 inches). Catch, photo, and identification courtesy of Ben Cantrell, Peoria, IL.