Abstract. In this paper we analyze the characteristics of an experimental otolith
identification system based on image contours described with Elliptical Fourier
Descriptors (EFD). Otoliths are found in the inner ear of fishes. They are formed
by calcium carbonate crystals and organic materials of proteic origin. Fish otolith
shape ...»»»»
Abstract. In this paper we analyze the characteristics of an experimental otolith
identification system based on image contours described with Elliptical Fourier
Descriptors (EFD). Otoliths are found in the inner ear of fishes. They are formed
by calcium carbonate crystals and organic materials of proteic origin. Fish otolith
shape analysis can be used for sex, age, population and species identification studies,
and can provide necessary and relevant information for ecological studies. The
system we propose has been tested for the identification of three different species,
Engraulis encrasicholus, Pomadasys incisus belonging to the different families
(Engroulidae and Haemolidae), and two populations of the species Merluccius
merluccius (from CAT and GAL) from the family Merlucciidae. The identification
of species from different families could be carried out quite easily with some
simple class identifiers -i.e based on Support Vector Machine (SVM) with linear
Kernel-; however, to identify these two populations that are characterized by a
high similarity in their global form; a more accurate, and detailed shape representation
of the otoliths are required, and at the same time the Otolith identifiers have
to deal with a bigger number of descriptors. That is the principal reason that
makes a challenging task both the design and the training of an otolith identification
system, with a good performance on both cases.^^^^
