A review of the taxonomic status of Gadiculus argenteus thori Schmidt, 1914 (Gadidae)

A review of the taxonomic status of Gadiculus argenteus thori Schmidt, 1914 (Gadidae). This study provides a first approach to clarify the taxonomic status of Gadiculus argentus thori. A total of 69 specimens of G. a. argenteus Guichenot, 1850 and 6 specimens of G. a. thori Schmidt, 1914 with a size range of 52.1-133.2 mm TL were examined. According to Schmidt (1914) and Svetovidov (1986), the total number of vertebrae, the meristics of D3 and A2 fins and the interorbital distance / head length proportion are the main characters distinguishing both two small gadids. Fourteen morphometric measurements and 7 meristic counts were used to assess the degree of differentiation among the three studied populations: Mediterranean G. a. argenteus (G1, n = 48)), Atlantic G. a. argenteus (G2, n = 21), and G. a. thori (G3, n = 6). A morphometric discriminant analysis, based on four variables related to the eyes and both anal fins, provided two canonical functions able to correctly classify 91.7 and 70% of the G1 and G2 specimens, respectively, but 50% of G3 samples were mixed with the G1 population. Moreover, the square Mahalanobis distances showed that the Atlantic G. a. argenteus (G2) group had closer affinities with G. a. thori (G3) than with the Mediterranean G. a. argenteus (G1). The Kruskal-Wallis test indicated that there were not significant differences, in meristic counts, between the three groups. Further investigations remain to be done but our results indicate that the differences between the two subspecies are not significant. We conclude that G. argenteus thori is a synonym of G. argenteus argenteus.Original Abstract: Cette etude tente de clarifier le statut taxinomique de Gadiculus argentus thori. Au total, 69 specimens de G. a. argenteus Guichenot, 1850 et 6 specimens de G. a. thori Schmidt, 1914 de longueur totale (LT) comprise entre 52,1 mm et 133,2 mm ont ete examines. D'apres Schmidt (1914) et Svetovidov (1986), le nombre de vertebres, la formule radiaire des nageoires D3 et A2 et la proportion entre la distance interorbitaire et la longueur cephalique sont les principaux caracteres qui permettent de separer ces deux petits Gadides. Nous avons utilise 14 donnees morphometriques et 7 donnees meristiques afin d'eclaircir le degre de differenciation entre les trois populations etudiees : G. a. argenteus mediterraneens (G1, n = 48), G. a. argenteus atlantiques (G2, n = 21) et G. a. thori (G3, n = 6). L'analyse discriminante des donnees morphometriques,