Red Drum (Red Fish)
Red Drum are found throughout Florida’s nearshore waters. Gold and Richardson (1991) identified weakly differentiated subpopulations occurring in the northeast Gulf of Mexico, Mosquito Lagoon, and along the coasts of North and South Carolina. Seyoum et al. (2000) also found genetic evidence for separate populations on Florida’s Gulf and Atlantic coasts but found no evidence of a separate population in Mosquito Lagoon. Red Drum along the Gulf of Mexico side of the Florida peninsula may be somewhat isolated from Red Drum in the northern and western Gulf. Rooker et al. (2010) assessed the degree of Red Drum population connectivity between early life and adult habitats in the northwestern GOM; results indicated the overall majority of sub-adult and adult Red Drum collected in estuaries had occupied the same region during their natal period. Newly hatched Red Drum spend about 20 days in the water column before becoming demersal (Rooker et al. 1999). Small juvenile Red Drum seek out and inhabit rivers, bays, canals, tidal creeks, boat basins, and passes within estuaries (Peters and McMichael 1987). Sub-adults are found in these habitats and in large aggregations on seagrass beds and over oyster bars, mud flats, or sand bottoms. Adult Red Drum are found mostly in nearshore shelf waters, except where they occur within the Mosquito-Indian River Lagoon complex on Florida’s Atlantic coast. Maximum age is about 40 years in Florida (Murphy and Taylor 1990), but there are reports of Red Drum as old as 60 years in North Carolina waters (Ross et al. 1995). Males mature when 1–3 years old, and females mature when 3–6 years old. Red Drum spawn during the late summer and early fall in inlets, within estuaries, or in nearshore shelf waters. Juvenile Red Drum feed primarily on copepods, mysid shrimp, and amphipods (Peters and McMichael 1987). Menhaden and anchovies were the most important prey for adult Red Drum in the winter and spring; crabs and shrimp were the most important prey in the summer and fall (Boothby and Avault 1971).
Black Drum inhabit Florida estuaries as juveniles and occasionally move into near shelf waters as adults. The species occurs in nearshore waters from Nova Scotia south to Argentina. Gold and Richardson (1991) suggested that there was little differentiation into subpopulations in U.S. waters; although, Gold and Richardson (1998b) emphasized a significant degree of clinal variation among Black Drum mtDNA haplotypes along the U.S. Gulf of Mexico coast. Growth is fairly slow; 11”–14" at age 1, 15”–17" at age 2, and 19”–21" at age 3 (Table 1; Murphy and Taylor 1989; Murphy and Muller 1995; Jones and Wells 1998). Black Drum, the largest members of the family Sciaenidae, can reach over 46" and 120 pounds. Long-lived fish, Black Drum can reach almost 60 years of age (Murphy et al. 1998; Jones and Wells 1998; Campana and Jones 1998). Black Drum spawn during the winter–early spring. Females mature at age 4–6 years and are prodigious, multiple spawners. An average-sized female (13.4 pounds) may spawn 32-million eggs each year (Fitzhugh et al. 1993). Black Drum are primarily bottom feeders. Young Black Drum feed on small fish and invertebrates, such as copepods, annelids, and amphipods (Pearson 1929; Thomas 1971). Larger Black Drum in Texas estuaries eat mostly mollusks, crabs, and shrimps (Miles 1949). As juveniles, Black Drum are prey to a wide range of estuarine piscivores, e.g., spotted seatrout, crevalle jack. Larger drum are probably subject to predation by sharks (Murphy and Muller 1995).
Spotted Seatrout are distributed throughout Florida’s bays and coastal waters. Studies indicate that Spotted Seatrout from various areas of Florida become more genetically isolated from one another as their geographic separation increases (Ramsey and Wakeman 1987, Gold et al. 1999). Recent results (e.g. Seyoum et al. 2014; 2018) from a re-analysis of genetic structure in Florida show the presence of three genetic stocks: 1) a western Gulf stock from South Padre Island, TX to Fort Walton, FL; 2) a Florida Gulf stock from Apalachicola Bay, FL to Biscayne Bay, FL; and 3) an Atlantic stock from Sebastian Inlet, FL to Morehead, NC. Each area may have localized groups of fish that do not intermix regularly with other groups and thus may only be affected by local fishing pressure. Growth is sex- and area-specific with male growth slower. Maximum ages reached in Florida are 9 years for males and 8 years for females. Spotted Seatrout first spawn between 0 and 2 years old and 11.8–15.7 inches total length (TL). Spawning occurs within estuaries and in nearshore waters during spring, summer, and fall. The diet of juvenile seatrout (<1.2 inches SL) includes amphipods, mysids, and carideans (Hettler 1989). Larger juveniles and adults feed primarily on shrimp and fish such as Bay Anchovy, Gulf Menhaden, shad, mullet, Sheepshead Minnow, Gulf Toadfish, pipefish, Pinfish, Pigfish, Silver Jenny, Atlantic Croaker, and Spotted Seatrout (Hettler 1989; McMichael and Peters 1989).
Red Grouper, which occur from Massachusetts to Brazil, are especially abundant in the Gulf of Mexico and on the Yucatan peninsula shelf (Bullock and Smith 1991). No population-level genetic differences have been found between eastern Gulf of Mexico and southern Gulf of Mexico Red Grouper; this may be due to historic bottlenecks in population abundance that have helped maintain the most common genotypes (Richardson and Gold 1997). In southwest Florida, smaller Red Grouper reside on shallow water reefs (10–59 feet deep) and move to depths greater than 118 feet after they mature. Red Grouper are mature at about 15.7 inches standard length (SL) and age 5 (Bullock and Smith 1991). Peak spawning occurs in late spring, during March and May, but spawning may occur during the period January–June (Johnson et al. 1998). Recent evidence suggests that Red Grouper are indeterminate batch spawners (Johnson et a1. 1998; Collins et al. 2002). Red Grouper are monandric protogynous hermaphrodites; all fish begin life as females, mature at about 17—21 inches TL when ages 4—6, and then transition to males, between ages 7 and 14, after reaching at least 23 inches (Moe 1969; Brule et al. 1999). Maximum age has been indicated to be at least 20 years in the South Atlantic (McGovern et al. 2002). Red Grouper in the male stage are generally older and larger than Red Grouper in the female stage. A variety of shrimp and amphipods made up the diet of several juvenile Red Grouper (0.6–1.0 inches TL) collected from Tampa Bay (Bullock and Smith 1991). The diet of adult Red Grouper included many small fish species, crab, shrimp, octopus, squid, scyllarids, and panulirids (Moe 1969).
Red snapper are distributed throughout the Gulf of Mexico and up the U.S. Atlantic coast to North Carolina and, although rarely, to Massachusetts. Gold et al. (1997), Camper et al. (1993), and Heist and Gold (2000) provide genetic evidence that support the hypothesis of a single red snapper stock in the northern Gulf of Mexico. Spawning peaks in June and July over most of its range but occurs from April through January (Bradley and Bryan 1975). Red snapper appear to move away from reef structure when spawning. Wilson et al. (1994, cited by Goodyear 1995b) found that red snapper first matured between 10.2 inches and 13.8 inches total length (TL); of the fish in their sample, 50% matured by 11.8 inches. Goodyear (1995b) found little evidence for strong sexual dimorphism. Early growth of red snapper appears to be similar for both otolithdetermined ages and scale-determined ages. Sizes at age were about 5.7–6.9 inches TL at age 1, 10.5–11.7 inches at age 2, reaching about 27.0 inches by age 7 (Nelson and Manooch 1982). An analysis of otolith-section-based ages gave smaller sizes at age after age 2 in the U.S. South Atlantic waters (Manooch and Potts 1997c). Maximum ages for Gulf of Mexico red snapper differed substantially between the two aging techniques: scale-determined maximum ages were about 16 years; whereas, the maximum otolith-determined age was 54 years (Wilson and Nieland 1997). Similarly, a recent study in the south Atlantic found that otolith methods using both observed lengths with fractional age and backcalculated lengths to the last annulus resulted in a maximum age of 54 years (McInerny 2007). The types of prey that contributed the greatest percentage by volume to the diet of juvenile red snappers were squid, octopuses, and shrimp (Bradley and Bryan 1975). The following fish species were among those most often found in the red snapper diet: Gulf pipefish, shoal flounder, puffer family, striped mullet, sea robin family, rough scad, butterfish family, sand perch, and clupeids.
Gray Snapper (Mangrove)
Gray Snapper are tropical, marine reef fish that occur from the U.S. mid-Atlantic south to Rio de Janeiro, Brazil. Using the analysis of allele and genotype distributions at 13 microsatellites and mitochondrial (mt) DNA haplotype distributions, Gold et al. (2009) found three distinct genetic groups of Gray Snapper collected from U.S. waters: northwestern and northcentral/northeastern Gulf groups, and an east coast Florida group. Juveniles are common to inshore waters throughout Florida, and adults are found in areas of moderate to high relief on the continental shelf. Spawning occurs during summer (June–September) in offshore waters around reefs, wrecks, and other bottom structures (Stark 1971; Domeier et al. 1996). Maturity occurs at about 7.5" standard length (Koenig 1993), which is probably the size when some Gray Snapper reach age-1 or age-2 (Manooch and Matheson 1981). Gray Snapper reach about 3.7”–5.8” total length (TL) at age 1, can grow to about 30", and can live at least 25 years (Manooch and Matheson 1981; Johnson et al. 1994). Burton (2001) noted that growth rates for Gray Snapper in northeast and southeast Florida differed: fish from northeast Florida attained a greater maximum size and age than those from southeast Florida. Catch curves showing estimates of total annual mortality ranged from 0.35 in northeast Florida to 0.94 in southeast Florida (Burton 2001). Adult Gray Snapper are nocturnal predators that forage away from their reef habitats. Juveniles feed diurnally among seagrass beds (Bortone and Williams 1986) and feed primarily on penaeid shrimp and crabs (Rutherford et al.1989a). Adult Gray Snappers feed on fish (largely grunts), shrimp, and crabs. (Harrigan et al. 1989; Hettler 1989).
Several different species of grunt are caught in Florida waters. Inshore fishers typically encounter Pigfish, Orthopristis chrysoptera, while offshore fishers are more likely to encounter White Grunt, Haemulon plumierii, or to a lesser extent tomtate, H. aurolineatum. Numerous grunt species with more tropical affinities are also caught in Florida waters including black margate, Anisotremus surinamensis; porkfish, A. virginicus; margate, H. album; French grunt, H. flavolineatum; cottonwick, H. melanurum; sailors choice, H. parra; and striped grunt, H. striatum. Darcy (1983a, 1983b) summarized life histories of Pigfish, White Grunt, and tomtate. Most grunt are small- to medium-sized fishes that occur in areas of moderate relief or with seagrass beds. White Grunt reach about 21" total length (TL) and 9–12 years old; Pigfish reach 18" standard length (SL) and 3–4 years old. White Grunt mature at age 3 or 10.6" fork length (FL), and Pigfish mature at age 2 or 7.4" FL. Peak spawning activity for White Grunt and Pigfish occurs during spring; although, some year-round spawning may occur in offshore areas. Growth is rapid until maturity is reached. Findings from a study of White Grunt life history in the eastern Gulf of Mexico indicate that White Grunt get as old as 18 years (Murie and Parkyn 2005). Growth is rapid through ages 4 or 5 then reaches a plateau at about 275–325 mm total length (TL) and showed sex-specific and regional differences. An estimate of total annual mortality from catch curves was 0.30 for White Grunt sampled from the headboat fishery catch in the eastern Gulf of Mexico during 1998 (Murie and Parkyn 2002). Predators of Pigfish included spotted seatrout, sand seatrout, and sharks and rays (Darcy 1983b). Randall (1967) reported dog snappers as one of the major predators feeding on White Grunts.
Tarpon are large, migratory fish that occur in coastal and inshore waters of the western Atlantic Ocean. They are found seasonally in all of Florida’s coastal waters and occur in peninsular Florida waters year-round. While generally inhabiting marine or brackish waters, Tarpon are known to travel for considerable distances up freshwater rivers. Spawning seems to be restricted to offshore waters such as the east coast of Florida to Cape Hatteras, the Florida Straits, west central Florida, the southwestern Gulf of Mexico, and the outer continental shelf and slope of the eastern Gulf of Mexico, but the exact locations of spawning are unknown. Females grow more quickly than males and appear to reach older ages (Table 1, Crabtree et al. 1995). The maximum observed age for male Tarpon was 43 years, whereas the oldest reported female was 55 years. Females become sexually mature at about 50 inches fork length (FL) and 10 years of age. Spawning occurs during April–August; peak spawning activity occurs during June and July in south Florida waters (Crabtree 1995; Crabtree et al. 1997). Larvae and small juvenile (<5 inches standard length) Tarpon are primarily plankton feeders, preying on copepods and ostracods, mosquito larvae, and detritus (Wade 1962, Odum 1971; Robins 1978). Once Tarpon attain sizes of five inches or more they gradually switch from copepods to small fish such as killifish, mosquitofish, silversides, and mullet (Rickards 1968; Odum 1971). Adults feed both nocturnally and diurnally on a variety of fish species, such as mullet, marine catfishes, pinfish, sunfish, sardines, silversides, needlefish, and anchovies, and shrimp, and crabs (Babcock 1951; Wade 1962; Rickards 1968; Odum 1971). Predation of adults is limited to other large predators such as sharks. Young Tarpon fall prey to ladyfish, spotted seatrout, dolphins, alligators, other Tarpon, and piscivorous birds such as kingfishers, pelicans, and herons (Killam 1992).
Spanish Mackerel is an epipelagic neritic species that inhabits coastal waters of the western Atlantic Ocean from the Gulf of Maine to Yucatan, Mexico. Depending on water temperature, Spanish Mackerel migrate seasonally along the coastline (Collette and Nauen 1983). In the eastern Gulf, these fish move northward during late winter and spring, appearing off the central west coast of Florida about April 1 (Moe 1972, Sutherland and Fable 1980). Movement continues westward and terminates along the northern Gulf coast. During fall, Spanish Mackerel migrate back southward to the wintering grounds in south Florida waters (Moe 1972, Sutherland and Fable 1980). Based on observed patterns of movement and spawning, it appears that one Atlantic and one or more Gulf groups of Spanish Mackerel occur in Florida waters. Spawning occurs from May through August. Larval and early juvenile Spanish Mackerel grow about 1.9 mm d-1 for their first 23 days. Growth then increases to nearly 5 mm d-1 until about 40 days of age, when growth slows to 2.1 mm d-1 (Peters and Schmidt 1997). Ninety-five percent of females along the Atlantic coast are mature by age-1 and 14.1” fork length (FL). All males are mature at age-1 and 13.3” FL (Schmidt et al. 1993). Females can get older and grow to larger sizes than males. On the Atlantic coast, the oldest females reach about age-11 and 29.1” FL, and the oldest males reach about age-6 and 18.3” FL (Schmidt et al. 1993). In South Florida and the Gulf of Mexico, maximum observed ages were 9 years (28.8” FL) for females and 7 years (26.4” FL) for males (Fable et al. 1987). Spanish Mackerel are primarily piscivorous, preying heavily on small schooling fishes in the families Clupeidae, Carangidae, and Engraulidae (Saloman and Naughton 1983b).
Nearly all flounders landed by anglers in Florida are one of three species in the genus Paralichthys: Gulf Flounder P. albigutta; Southern Flounder, P. lethostigma; or Summer Flounder, P. dentatus. Gulf Flounder are the only species to range along the entire Florida coast. Summer Flounder are only a minor component of the flounder landings in northeast Florida; their center of distribution is off the U.S. Mid-Atlantic Bight. Southern Flounder are generally only found north of the Loxahatchee River on the Atlantic coast and north of the Caloosahatchee River on the Gulf coast. Southern Flounder are found on silt and mud, and Gulf Flounder are found mostly on sand. Studies have shown that female Southern Flounder reach about 28" and 7 years of age while female Gulf Flounder reach only about 18" and 3 years of age (Wenner et al. 1990; Stokes 1977). More recently, Fitzhugh et al. (1999) reported that Gulf Flounder attain older ages than previously thought: the oldest Gulf Flounder found in offshore waters off northwest Florida was age 11. While estuarine samples of Southern Flounder show maximum ages of about 4 years (Stunz et al. 2000; Fitzhugh et al. 1999), older fish probably occur in shelf waters. Males of both species do not get as large as females. Female Southern Flounder mature at age 3 or 4 (Wenner et al. 1990), and female Gulf Flounder mature at age 1 (Fitzhugh et al. 1999). Both species spawn in offshore waters during late fall–winter (65 ft–200 ft). Gulf Flounders are benthic carnivores. Large juveniles feed primarily on small fish and crustaceans (shrimp and crabs). Adults feed on schooling fish such as menhaden, bay anchovy, pinfish, grunts, pigfish, Atlantic croaker, and mullets (Springer and Woodburn 1960; Topp and Hoff 1972; Benson 1982).