The northern red snapper (Lutjanus campechanus) is a species of marine ray-finned fish, a snapper belonging to the family Lutjanidae. It is native to the western Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico, where it inhabits environments associated with reefs. This species is commercially important and is also sought-after as a game fish.
The northern red snapper's body is very similar in shape to other snappers, such as the mangrove snapper, mutton snapper, lane snapper, and dog snapper. All feature a sloped profile, medium-to-large scales, a spiny dorsal fin, and a laterally compressed body. Northern red snapper have short, sharp, needle-like teeth, but they lack the prominent upper canine teeth found on the mutton, dog, and mangrove snappers. They are rather large and are red in color.This snapper reaches maturity at a length of about 39 cm (15 in). The common adult length is 60 cm (24 in), but may reach 100 cm (39 in). The maximum published weight is 50 lb, 4 oz (22.79 kg) and the oldest reported age is 57+ years.Coloration of the northern red snapper is light red, with more intense pigment on the back. It has 10 dorsal spines, 14 soft dorsal rays, three anal spines and eight to 9 anal soft rays. Juvenile fish (shorter than 30–35 cm) can also have a dark spot on their sides, below the anterior soft dorsal rays, which fades with age.
The northern red snapper is found at a depth of 30 to 620 feet in the Gulf of Mexico, the Caribbean Sea, and the southeastern Atlantic coast of Mexico and the United States and much less commonly northward as far as Massachusetts. In Latin American Spanish, it is known as mero, huachinango, pargo, or chillo.
This species commonly inhabits waters from 9–60 m (30–200 ft), but can be caught as deep as 90 m (300 ft) on occasion. They stay relatively close to the bottom, and inhabit rocky bottoms, ledges, ridges, and artificial reefs, including offshore oil rigs and shipwrecks. Like most other snappers, northern red snapper are gregarious and form large schools around wrecks and reefs. These schools are usually made up of fish of very similar size.
The preferred habitat of this species changes as it grows and matures due to increased need for cover and changing food habits. Newly hatched red snapper spread out over large areas of open benthic habitat, then move to low-relief habitats, such as oyster beds. As they near one year of age, they move to intermediate-relief habitats as the previous year's fish move on to high-relief reefs with room for more individuals. Around artificial reefs such as oil platforms, smaller fish spend time in the upper part of the water column while more mature (and larger) adults live in deeper areas. These larger fish do not allow smaller individuals to share this territory. The largest red snapper spread out over open habitats, as well as reefs.
Diaz reported weight vs. length data for L. campechanus for the National Marine Fisheries Service (US). As northern red snapper grow longer, they increase in weight, but the relationship between length and weight is not linear. The relationship between total length (L, in inches) and total weight (W, in pounds) for nearly all species of fish can be expressed by an equation of the form:
Invariably, b is close to 3.0 for all species, and c is a constant that varies among species. Diaz reported that for red snapper, c=0.000010 and b=3.076. These values are for inputs of length in cm and result in weight in kg.
Szedlmayer et al. reported length vs. age data for L. campechanus in a primarily artificial reef environment off the coast of Alabama, US: TL(age) = 1,025 (1 – e^( -0.15 age)), N=409, R = 0.96. For the first five years, growth can be estimated as being approximately linear: TL(age) = 97.7 age + 67.6, N = 397, R = 0.87 (for each equation, age is in years and total length is in mm). Szedlmayer & Shipp 1994, Patterson 1999, Nelson and Manooch 1982, Patterson et al 2001, Wilson & Nieland 2001, and Fischer et al 2004 show L. campechanus growing most rapidly over its first 8–10 years.
Northern red snappers move to different types of habitats during their growth process. When they are newly spawned, red snapper settle over large areas of open benthic habitat(s). Below age 1, the red snapper move to low-relief habitats for food and cover. If available, oyster shell beds are preferred. The second stage is when these fish outgrow low-relief habitats and move to intermediate-relief habitats as age 1 snapper leave to move on to another growth stage. Next, at about age 2, snapper seek high-relief reefs having low densities of larger snapper. Next, at platforms, smaller snapper occupy the upper water column. Then, the larger, older snapper occupy the deeper areas of the platforms and large benthic reefs and they prevent smaller snapper and other fish from using these habitats. In spite of local habitat preferences, Szedlmayer reported that of 146 L. campechanus tagged, released and recaptured within about a year, 57% were still approximately at their respective release site, and 76% were recaptured within 2 km of their release site. The greatest movement by a single fish was 32 km.
A northern red snapper attains sexual maturity at two to five years old, and an adult snapper can live for more than 50 years. Research from 1999–2001 suggested the populations of red snapper off the coast of Texas reach maturity faster and at a smaller size than populations off of the Louisiana and Alabama coasts.
