Abstract

In the southern Gulf of Mexico, at Campeche Bank, hogfish Lachnolaimus maximus represents a great economic interest for Yucatan. This study focuses on shape analysis of 89 hogfish´s left sagittae taking into account collection areas, ontogenic stages and sizes. After the digitization of otoliths using an SEM, the use of morphometric variables and otolith shape data revealed significant differences in the morphology of otoliths between individuals. Seventeen morphometric variables, eight shape indexes and contour descriptors by discrete wavelet transform (WLT4) from the anterior and posterior otolith zones, were extracted from the images, using Image-Pro Plus® 7.0 and Age & Shape programs. Principal components (PCA) and linear discriminant analyses (LDA) were performed with standardized and normalized data in a Euclidean distance matrix. PCA ordination revealed that 9 morphometric and indexes variables (rectangularity, fractal dimension, diameter max, exuda area, antipostrostrum width and length, postrostrum length, postexude area and otolith area) accounted for 50% of the variability of the data. Results from the LDA displayed consistent differences in otolith shape due to: ontogenic stages (juveniles: 100% classification success; females; 96.77%; males: 100%), individual sizes within each collection area: Celestún (86.52%); Dzilam de Bravo (100%) and Río Lagartos (100%) and within each collection area: Celestún (94.44%); Dzilam de Bravo (94.12%) and Río Lagartos (100%). WLT4 anterior zone also discriminate groups for ontogenic stages (95.51%); sizes (100%) and collection area (97.75%). This work validates the interest of the use of otoliths in ichthyological studies and brings new data on the hogfish population of Campeche Bank

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