Red Snapper (fish) - Reproduction and Growth

Reproduction and Growth

Diaz reported weight vs. length data for L. campechanus for the National Marine Fisheries Service (US). As red snapper grow longer, they increase in weight. 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, a=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, USA: 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).

Red snapper 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, 76% were recaptured within 2 km of their release site. The greatest movement by a single fish was 32 km.

A 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.