||Harengula humeralis Cuvier, 1829
||Alosa apicalis Müller & Troschel, 1848
Clupea humeralis Cuvier, 1829
Harengula callolepis Goode, 1879
Harengula maculosa Valenciennes, 1847
Harengula sardina Poey, 1860
The red-ear sardine, Harengula humeralis, is one of several schooling bait fishes in Florida belonging to the family Clupeidae. Species from this group are characterized by several features, including: small, fusiform to subcylindrical bodies; pelvic scutes; and a terminal mouth with a short, deep lower jaw (Munroe & Nizinski 2002). As the name implies, the red-ear sardine is distinguished by a reddish spot near the opercle (top bone of the gill cover). The jaw is yellowish, the upper body is marked with 3-4 dark yellowish broken streaks or dotted lines, the tip of the dorsal fin is dusky, and the scales are easily shed (Robins et al. 1986; Munroe & Nizinski 2002). A series of ventral scutes (25-29, usually 27-28) line the abdomen on both sides of the pelvic fin, which bears 7 branched fin rays. Along with the dorsal fin, the pelvic fin is slightly anterior to the midpoint of the body.
Potentially Misidentified Species
Two other species of Harengula are present in local Florida waters: the false herring, H. clupeola; and the scaled sardine, H. jaguana. In H. clupeola, a pale yellow or orange spot is present near the opercle, the dorsal fin is a similar coloration throughout, the jaw lacks a yellowish tint, and the scales are not easily shed (Robins et al. 1986; Munroe & Nizinski 2002). Also in H. clupeola, the ventral scutes number 29-32 (usually 30-31), the body is silvery green and lacks yellow stripes characteristic of H. humeralis. The scaled sardine is similar to the red-ear sardine, but with unbroken and more inconspicuous lines on the back of the body (Robins et al. 1986; Munroe & Nizinski 2002). The opercle of H. jaguana is usually marked with a small dark spot lacking orange or reddish coloration, which is occasionally repeated near the shoulder. The belly is deep and lined with 28-31 ventral scutes.
HABITAT AND DISTRIBUTION
The range of H. humeralis extends from southern Florida through the Bahamas and Caribbean south to Brazil (Robins et al. 1986; Munroe & Nizinski 2002). Small schools are found in a variety of coastal habitats, from brackish estuaries to nearshore and coral reefs (Randall 1967; Robins et al. 1986; Ortaz et al. 1996; Munroe & Nizinski 2002). Studies have shown that larger individuals move offshore to feed and reproduce, while juveniles often occupy protected estuarine habitats such as mangroves and seagrass beds (Ortaz et al. 1996).
Indian River Lagoon (IRL) Distribution
Little information is available concerning the distribution of the red-ear sardine in the IRL, but schools can be found throughout the lagoon on submerged tidal flats, in seagrass beds and salt marshes, among mangrove roots and in shallow nearshore waters off nearby sandy beaches.
LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan
The maximum recorded length for red-ear sardine is 22 cm, although most adult specimens measure only about 12 cm (Munroe & Nizinski 2002). Lifespan varies with environmental conditions and other factors.
Detailed abundance records for H. humeralis populations within the IRL are scarce. However, red-ear sardines often form several small schools that contribute to the overall abundance of the species within its native range.
Reproduction & Embryology
Other than reported offshore spawning (see 'Regional Occurrence' above), little information is available concerning the reproduction and embryology of H. humeralis. However, laboratory studies have been conducted on eggs and larvae of the related scaled sardine, H. jaguana, and it is likely that the two species share similar developmental processes. Eggs of H. jaguana 1.6 to 1.8 mm in diameter were collected from populations in south Florida (Houde et al. 1974). Larvae measuring about 2.4 mm and bearing a large yolk sac emerged from the eggs within 24 hours post-fertilization. After about 48 hours, the yolk sac was absorbed and the larvae began to actively feed on plankton. Juvenile and adult characteristics developed when larvae reached a length of 22-24 mm. Concurrent studies by Houde et al. (1974) suggested that spawning occurs at night and extends from February through July near Miami, Florida. It is possible that spawning seasons are abbreviated for false herring populations in and around the IRL, where water temperatures may fluctuate seasonally on a larger scale than those in south Florida.
No information is available at this time
Red-ear sardines are nocturnal predators, consuming a variety of organisms, including plant and algal material, small fishes, polychaete worms, copepods, and larvae of shrimp, crabs and stomatopods (Randall 1967; Ortaz et al. 1996; Munroe & Nizinski 2002; Nagelkerken et al. 2006).
Gut content studies have revealed that H. humeralis is preyed upon by a variety of fishes, including the houndfish, Tylosurus crocodilus and the king mackerel, Scomberomorus cavalla (Randall 1967). Additional fish species, coastal birds and some marine mammals likely consume H. humeralis as part of their diet.
The red-ear sardine is documented as a host for the parasitic trematode worm, Parahemiurus merus (Dyer et al. 1986).
Although there are no obligate associations documented between the red-ear sardine and other species, H. humeralis is commonly found alongside organisms from the various coastal marine and estuarine habitats in which it resides. For more extensive information on these ecosystems and their associated species found in and around the IRL, please visit Habitats of the IRL.
No information is available at this time
Dyer, WG, Williams Jr., EH & LB Williams. 1986. Some trematodes of marine fishes of southwestern and northwestern Puerto Rico. Trans. Illinois Acad. Sci. 79: 141-143.
Houde, ED, Richards, WJ & VP Saksena. 1974. Description of eggs and larvae of scaled sardine, Harengula jaguana. Fish. Bull. 72: 1106-1122.
Munroe, TA & MS Nizinski. 2002. Clupeidae. pp. 804-821. In: The living marine resources of the Western Central Atlantic. Volume 2: Bony fishes part 1 (Acipenseridae to Grammatidae). Carpenter KE (Ed.). FAO species identification guide for fishery purposes and American Society of Ichthyologists and Herpetologists special publication no. 5. FAO, Rome. pp. 601-1374.
Nagelkerken, I, van der Velde, G, Verberk, WCEP & M Dorenbosch. 2006. Segregation along multiple resource axes in a tropical seagrass fish community. Mar. Ecol. Prog. Ser. 308: 79-89.
Ortaz, M, Rocha, ME & JM Posada. 1996. Food habits of the sympatric fishes Harengula humeralis and H. clupeola (Clupeidae) in the Archipelago de Los Roques National Park, Venezuela. Carib. J. Sci. 32: 26-32.
Randall, JE. 1967. Food habits of reef fishes of the West Indies. Stud. Trop. Oceanogr. 5: 665-847.
Robins CR, Ray GC, and J Douglas. 1986. A Field Guide to Atlantic Coast Fishes. The Peterson Field Guide Series. Houghton Mifflin Co., Boston. 354 pp.
Report by: LH Sweat,
Smithsonian Marine Station at Fort Pierce
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Page last updated: 28 September 2010