Doctor of Philosophy (PhD)
Oceanography and Coastal Sciences
An extensive search for data on life-history and ecological variables was conducted for a representative number of the species within the family Lutjanidae. After creating different databases and standardizing all data, these variables were examined in statistical, correlation and graphic analyses. Additionally, a series of Principal Component Analyses were used to examine patterns among variables. Life-history variables included age at length zero, asymptotic length, maximum length, longevity, asymptotic weight, length at maturity, age at maturity, reproductive life span, growth rate and mortality rate. Ecological variables included latitudinal and vertical distribution, habitat selection (represented by substrate type), and spawning seasons. The feeding habits of snappers were examined after determining the most common items reported in the literature and summarizing them in ten categories. Results indicated that life-history variables related to the size of the species were highly correlated, supporting the findings of other studies that length at maturity is dependent on asymptotic length. Longevity and reproductive life span were also highly correlated, while longevity and age at maturity had a low correlation, indicating that maturity among snappers is independent of life span and with relatively low variation among species. A review of the geographic and vertical distribution of snappers suggests that pre-settlement larvae in several species may exhibit strong nursery habitat selection, and that adult snappers have distinctive vertical distributions. Finally, based on the variability of prey items found in snapper diets, two basic feeding strategies were evident, species in the subfamily Lutjaninae feed mainly on benthic organisms, mainly crustaceans; while species in the subfamily Etelinae feed in the water column on a variety of pelagic fishes and invertebrates.
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Martinez-Andrade, Fernando, "A comparison of life histories and ecological aspects among snappers (Pisces: Lutjanidae)" (2003). LSU Doctoral Dissertations. 2271.
Donald M. Baltz