External morphology, postcranial and appendicular osteology of three southwestern Atlantic flatfishes ( Paralichthys , Paralichthyidae), and comparisons with other congeneric species

Juan M Díaz De Astarloa,Thomas A Munroe,Philippe Béarez,Damián L Castellini,Mariano Gonzalez-Castro

doi:10.1590/1982-0224-20170164

Juan M Díaz De Astarloa, Thomas A Munroe + Show 3 more

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https://doi.org/10.1590/1982-0224-20170164

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Abstract

ABSTRACT Comparisons of the external morphology and analysis of osteological features of the postcranial and appendicular skeletons of three southwestern Atlantic flatfish species of the genus Paralichthys (P. isosceles, P. orbignyanus and P. patagonicus) were carried out. Bones are described, and detailed morphological, morphometric and meristic characteristics of these flounders are given in order to provide information about the external and internal morphology of three species of Paralichthys occurring in the south-west Atlantic waters that add new information and will help regarding within the framework of a phylogenetic study of the group. Interspecific differences were found in the number of vertebrae and intermuscular bones, as well as in the morphology and morphometry of vertebrae, caudal skeletons, pectoral and pelvic girdle bones. Relationships between bones are discussed and bone characteristics compared with those found in other species of Paralichthys and in other pleuronectiform species. The position of Paralichthys isosceles within Paralichthys is discussed, along with other congeners such as P. triocellatus and P. oblongus.

Highlights

Paralichthys Girard, 1858 is a genus of the Paralichthyidae, a non-monophyletic family (Hensley, Ahlstrom, 1984; Chapleau, 1993; Munroe, 2015a) of sinistral flatfishes
Some species of Paralichthys inhabit a variety of different substrata on the continental shelf, with some [P. isosceles Jordan, 1891; P. oblongus (Mitchill, 1815); P. triocellatus Miranda Ribeiro, 1903] found on deep-water substrata located on the outer continental shelf
Seven nominal species have long been reported from coastal seas of the Southwest Atlantic (Ginsburg, 1952), including P. bicyclophorus Miranda Ribeiro, 1915, P. brasiliensis (Ranzani, 1842), P. isosceles, P. orbignyanus (Valenciennes, 1839), P. patagonicus Jordan, 1889, P. triocellatus, and P. tropicus Ginsburg, 1933

Summary

Introduction

Paralichthys Girard, 1858 is a genus of the Paralichthyidae, a non-monophyletic family (Hensley, Ahlstrom, 1984; Chapleau, 1993; Munroe, 2015a) of sinistral (usually) flatfishes. Members of Paralichthys are medium- to large-sized flatfishes (Norman, 1934; Ginsburg, 1952; Hensley, 1995; Munroe, 2003). Throughout the southwest Atlantic region, species of Paralichthys occur in diverse habitats including coastal shallow-waters in areas containing muddy and silty substrata such as turbid estuaries, and on sandy substrata in moderate depths on the continental shelf. Seven nominal species have long been reported from coastal seas of the Southwest Atlantic (Ginsburg, 1952), including P. bicyclophorus Miranda Ribeiro, 1915, P. brasiliensis (Ranzani, 1842), P. isosceles, P. orbignyanus (Valenciennes, 1839), P. patagonicus Jordan, 1889, P. triocellatus, and P. tropicus Ginsburg, 1933. Paralichthys bicyclophorus was later synonimized with P. patagonicus, in Jordan, Goss (1889) by Díaz de Astarloa (1996)

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