Species Description: The scaled sardine, Harengula jaguana, has a fusiform and laterally compressed body that is relatively deep, typically 34% of standard length (SL) or more. The abdomen is markedly more curved than the dorsum and has 28-31 scutes that form the distinct keel that is a defining characteristic of members of the sardine family (Clupeidae). The lower limb of the first gill arch is lined with 30-40 fine gill rakers (Robbins et. al 1986, Carpenter 2002). The top and upper sides are blue-black with faint lateral streaks. The lower sides and abdomen are lighter in color and silvery. A dark 'shoulder' spot just posterior to the gill cover is present, although it may be faint in some individuals (Carpenter 2002). Hoese and Moore (1977) give a ray count for this species as: dorsal 17-19; anal 16-18; pectoral 13-17.
Potentially Misidentified Species: Harengula jaguana co-occurs with several clupeids throughout much of its range. The congeners Harengula clupeola and Harengula humeralis occur alongside H. jaguana in the IRL, as do the Spanish sardine (Sardinella aurita), and the Atlantic thread herring (Opisthonema oglinum). Another co-occurring clupeid group, the menhaden (Brevortia spp.), are considerably larger than scaled sardines, reaching a standard length of 25 cm. The body depth of the Spanish sardine is substantially less than that of any other Harengula species, and the long thread-like dorsal filament present on the thread herring is sufficient to allow differentiation. The presence of a small toothed hypomaxilla between the hind tip of the premaxilla and the expanded blade of the maxilla also distinguishes the genus Harengula from co-occurring clupeid genera (FAO 1985). The scales of H. jaguanaare less deciduous (shed less easily) than those of H. humeralis (FAO 1985), and the lack of a dark shoulder spot aids in discriminating H. humeralis and H. clupeola from H. jaguana. Scaled sardines also lack the diffuse reddish-orange 'ear spot' at the edge of the opercle that is typical of H. humeralis (Robbins et. al 1986).
Regional Occurrence: The genus Harengula is a New World clupeid group found on both the Atlantic and Pacific coasts. Harengula jaguana occurs in the western Atlantic from New Jersey and Bermuda southward throughout Florida and the Gulf of Mexico (abundant), in the Caribbean and down to southern Brazil (FAO 1985).
IRL Distribution: Scaled sardines can be found throughout the IRL system.
Age, Size, Lifespan: Carpenter (2002) notes a SL of 12 cm as typical for the species, with the largest specimens growing to 22 cm. Scaled sardines are a fast-growing, short-lived species (FMRI undated). Scale ring count analyses by Martinez and Houde (1975) suggested a lifespan of three years for the species. More refined analysis involving the enumeration of otolith daily rings by Pierce et al. (2001), however, indicated that scaled sardines on both coasts of Florida live for a maximum of just one year. The authors report rapid growth rates exceeding 0.5 mm/day.
Abundance: Harengula jaguana is abundant in nearshore estuaries and bays, particularly from spring through autumn (Carpenter 2002). Acoustic-geostatistical population assessments conducted by Paramo and Roa (2003) in the northern Colombian Caribbean revealed that H. jaguana were 80% more abundant as the Atlantic thread herring (Opisthonema oglinum). Interestingly, O. oglinum, was a species under commercial exploitation in the region while H. jaguana was not. Thayer et al. (1999) record that the sardines Harengula jaguana and Sardinella aurita were the 15th most numerous fish species collected in Florida Bay by trawl in 1984-1985, and the 6th most abundant species collected a decade later. In the 1994-1996 trawl survey, sardines were collected at a mean abundance of approximately 25 individuals per hectare.
Although its commercial importance in Florida is minimal (see below), a Gulf of Mexico survey of eggs and larvae conducted by Houde (1977) indicated a potential fishery yield of 41-92 million kg/year.
Reproduction: Most individuals are mature at age-1 (80-130 mm), and all by age 2 (Carpenter 2002). Garcia-Abad et al. (1999) estimated that females in the southern Gulf of Mexico reached maturity at around 117 mm. Scaled sardines spawn offshore, typically 5-20 km from shore (Higgs and Fuman 1998). Carpenter (2002) suggests spawning occurs at night from January to September, with peak activity occurring from April to August depending on location. Garcia-Abad et al. (1999) found that reproduction persisted somewhat longer in the southern Gulf of Mexico, from February through October and at depths of 18-36 m. Martinez and Houde (1975) published details suggesting a serial spawning behavior for this species. The authors found fish maturing at 78-85 mm SL as well as continuous ripening of oocytes during a protracted spawning season from February to August. Multiple spawning peaks have been noted by other authors as well (Modde and Ross 1981). Fecundity is estimated to range from 5,500 to more than 52,000 eggs per individual, representing a relative fecundity of 323 to 807 eggs/g body mass. Scaled sardine eggs are pelagic, transparent, and spherical, averaging 1.55-1.85 mm in diameter (Carpenter 2002).
Embryology: Pierce et al. (2001) examined combined Florida commercial purse-seine and cast-net length-frequency data sets to find multiple juvenile recruitment peaks consistent with the serial spawning reported by Martinez and Houde (1975). Peaks occurred between June and November 1993 in Tampa Bay and between June and August 1992 off of West Palm Beach. The authors note that length frequency data suggests near-continuous, year-round spawning, particularly in Tampa Bay. They further suggest that the earliest recruits of the year could reach maturity to become spawners in the fall of the same year. Garcia-Abad et al. (1999) also noted two distinct recruitment periods in their study, one occurring March-June and a second occurring August-November. Whereas spawning occurs well offshore, most of the larval development stages take place in nearshore and inshore waters (Shaw and Drullinger 1990, Hettler and Barker 1993). Vasquez-Yeomans (2000) reports that H. jaguana eggs and larvae were present in samples collected from the (Bahia de la Ascension estuary) in the western Caribbean from April through October, and then again in December. Larvae occur offshore, but their distribution patterns over time suggest shoreward movement (Houde 1977, Ruple 1984, Vasquez-Yeomans 2000).
Temperature: Harengula jaguana is found from the tropics to warm temperate waters as far north as New Jersey. The northern distributional limit for the species is likely to be temperature-based.
Salinity: Harengula jaguana is a euryhaline species encountered in habitats ranging from coastal marine areas to mesohaline estuaries to hypersaline lagoons (Carpenter 2002). Paperno et al. (2000) found that in the upper IRL system H. jaguana was most prevalent in the vicinity of Ponce de Leon Inlet, occurring in substantially lesser abundance in less saline portions of the estuary. Other investigators have also indicated that among the clupeids, H. jaguana and Opisthonema oglinum are two species typically associated with higher salinities (Richards et al. 1974, Hoese and Moore 1977, Higgs and Fuiman 1998).
Dissolved Oxygen: LC50 tests conducted by Goodman and Campbell (2007) to determine lethal levels of hypoxia for seven Gulf of Mexico fish species and two crustacean species indicated that Harengula jaguana was the most hypoxia-sensitive of all the species tested. Oxygen concentrations of 2.17 mg/L were low enough to kill a substantial number of test animals in less than four hours.
No information is available at this time
Trophic Mode: Adult scaled sardines are planktivores, feeding on a variety of prey items including copepods, mysids, amphipods, isopods, ostracods, insect larvae, and small molluscs (FMRI undated).
Competitors: Likely competitors with adult scaled sardines include other planktivorous fish species (e.g., anchovies), but it is unlikely that dietary resources are often a limiting factor.
Predators: Harengula jaguana represent an important prey resource for a wide variety of piscivore predators, including mackerels, gag grouper, bluefish, crevalle jack, tunas, and sharks (FMRI undated, Hoffmayer and Parsons 2003). The species is also an important prey item for sea birds and wading birds, as well as bottlenose dolphin (Sogard et al. 1989, FMRI undated).
Habitats: Scaled sardines are marine (especially coastal) and estuarine schooling pelagic and demersal fish commonly found over sand and mud bottoms and on and around seagrass meadows (Carr and Adams 1973, Williams 1985, Sogard et al.1989, Carpenter 2002). In coastal areas, individuals typically remain within the 40-m isobath, but are rarely collected from as deep as 500 m (Pierce et al. 2001).
Activity Time: Although the species is often encountered by day, Sogard et al. (1989) listed Harengula jaguana among the nocturnally active fish species on seagrass-covered shallow banks in Florida Bay. Animals increased in abundance at dusk with high catch rates continuing for a few hours thereafter and then declining through the night. The authors note, however, that activity patterns were influenced by tidal patterns as well as diel cycles. In addition, the authors pointed out that nocturnal activity seen in this study may be related to vertical migration in crustacean prey that reside on the bottom by day but ascend into the water column at night.
Economic/Ecological Importance: Scaled sardines represent an important link in estuarine and coastal food webs (Garcia-Abad et al. 1999). They are abundant consumers of zooplankton as well as an important prey species for a variety of piscivorous fish, birds, and marine mammals (Carr and Adams 1973, Pierce et al. 2001). A small Harengula jaguana baitfish industry exists in south Florida, and the species is caught as part of the mixed-species 'trashfish' fishery as well. It is marketed fresh for human consumption primarily outside of the US and it is canned in Cuba and Venezuela. Total statewide landings in 1999 were nearly 140,000 kg, with 61% of the total taken from the Gulf Coast and almost all of the landings attributable to the commercial fishery. Annual landings are highly variable, dropping by as much as 60% in two years (FMRI undated). Such variability is typical of several 'trashfish' fishery species.
Carr WES, and CA Adams. 1973. Food habits of juvenile marine fishes occupying sea-grass beds in the estuarine zone near Crystal River, Florida. Transactions of the American Fisheries Society 102:511-540.
Carpenter KE (ed.). 2002. The living marine resources of the Western Central Atlantic. Volume 2: Bony fishes part 1 (Acipenseridae to Grammatidae). FAO Species Identification Guide for Fishery Purposes and American Society of Ichthyologists and Herpetologists Special Publication No. 5. pp. 601-1374.
Florida Marine Research Institute. Undated. Scaled Sardines (Harengula jaguana). Species account for scaled sardines in Florida. FMRI Stock Assessment Group. 3 p.
Garcia-Abad MC, Tapia-Garcia M, Yanez-Arancibia, and P. Sanchez-Gil. 1999. Distribucion, abundancia y reproduccion de Harengula jaguana Goode y Bean, 1879, en la platform continental del sur del Golfo de mexico (Pisces: Clupeidae). Biotropica 31:494-501.
Goodman LR and JG Campbell. 2007. Lethal levels of hypoxia for gulf coast estuarine animals Marine Biology 152:37-42. Hettler WF and DL Barker. 1993. Distribution and abundance of larval fishes at two North Carolina inlets. Estuarine and Coastal Shelf Science 37:161-179.
Higgs DM and LA Fuiman. 1998. Associations between sensory development and ecology in three species of clupeoid fish. Copeia 1998:133-144. Hoese HD and RH Moore. 1977. Fishes of the Gulf of Mexico. Texas, Louisiana, and Adjacent Waters. Texas A&M University Press, College Station TX. 327 p.
Hoffmayer ER and GR Parsons. 2003. Food Habits of Three Shark Species from the Mississippi Sound in the Northern Gulf of Mexico. Southeastern Naturalist 2:271-280.
Houde ED. 1977. Abundance and potential yield of the scaled sardine, Harengula jaguana, and aspects of its early life history in the eastern Gulf of Mexico. Fishery Bulletin 75:613-628.
Martinez S, and ED Houde. 1975. Fecundity, sexual maturation, and spawning of scaled sardine (Harengula jaguana Poey). Bulletin of Marine Science 25:35-45.
Modde T and ST Ross. 1981. Seasonality of fishes occupying a surf zone habitat in the northern Gulf of Mexico. Fisheries Bulletin 78:911-922.
Paperno R, Milleand KJ, and E Kadison. 2001. Patterns in species composition of fish and selected invertebrate assemblages in estuarine subregions near Ponce de Leon Inlet, Florida. Estuarine and Coastal Shelf Science 52:117-130.
Paramo J and R Roa. 2003. Acoustic-geostatistical assessment and habitat-abundance relations of small pelagic fish from the Colombian Caribbean. Fisheries Research 60:309-319.
Pierce DJ, Mahmoudi B, and RR Wilson, Jr. 2001. Age and growth of the scaled herring, Harengula jaguana, from Florida waters, as indicated by microstructure of the sagittae. Fishery Bulletin 99:202-209.
Richards WJ, Miller RV, and ED Houde. 1974 Egg and larval development of the Atlantic threadfin herring, Opisthonema oglinum. Fishery Bulletin 72:1123-1136.
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 p.
Ruple DL. 1984. Occurrence of larval fishes in the surf zone of a northern Gulf of Mexico barrier island. Estuarine, Coastal and Shelf Science 18:191-208.
Shaw RF and DL Drullinger. 1990. Early life history profiles, seasonal abundance, and distribution of four species of clupeid larvae from the northern Gulf of Mexico, 1982 and 1983. NOAA Technical Report NMFS 88.
Sogard SM, Powell GVN, and JG Holmquist.1989. Utilization by fishes of shallow, seagrass-covered banks in Florida Bay: 2. Diel and tidal patterns. Environmental Biology of Fishes 24:81-92.
Thayer GW, Powell AB, and DE Hoss. 1999. Composition of Larval, Juvenile, and Small Adult Fishes Relative to Changes in Environmental Conditions in Florida Bay. Estuaries 22:518-533.
Vasquez-Yeomans L. 2000. Seasonal variation of ichthyoplankton in a western Caribbean bay system. Environmental Biology of Fishes 58: 379-392.
Whitehead PJP. 1985. Clupeoid fishes of the world. An annotated and illustrated catalogue of the herrings, sardines, pilchards, sprats, anchovies and wolf-herrings. Part 1 - Chirocentridae, Clupeidae and Pristigasteridae. FAO Fisheries Synopsis No. 125, Volume 7. 303 p.