Musculoskeletal evolution of Flatfishes and their intrarelationships (Teleostei: Percomorphacea: Pleuronectiformes)

• Grant number: 20/02232-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2021
• End date: November 30, 2024
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Aléssio Datovo da Silva
• Grantee: Paulo Presti Migliavacca
• Host Institution: Museu de Zoologia (MZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 22/11956-7 - Branchial musculature of flatfishes, BE.EP.DR

Abstract

Pleuronectiformes is a fish order with about 800 globally distributed species, arranged in 123 genera and 14 families. Flatfishes, the representatives of the order, present one of the most intriguing known morphological transformations: the migration of one eye towards the opposite side of the body. Although the monophyletism of the order has sometimes been contested, more recent molecular and morphological studies corroborate Pleuronectiformes as a natural group. However, the internal relationships of pleuronectiforms are far from a satisfactory and consensual resolution. So far, only two morphological cladistic analyses have been carried out with the order. Besides the highly conflicting hypotheses presented by those studies, both have serious limitations in character and taxon sampling. There are also several conflicts among the different molecular hypotheses and among them and those based on morphological data. Most of the previous morphological studies have only addressed the skeleton, whereas the musculature of the pleuronectiforms remains largely unknown. Symptomatic of this situation is the fact that one of the three synapomorphies proposed for the order, the presence of the recessus orbitalis, supposedly involves muscles that have never been illustrated and described in detail. The homologies and distribution of these supposed muscles within the order also remain unknown. This project proposes to develop a comparative study of the musculoskeletal system, with an emphasis on myology, of all Flatfish families. These data will serve as basis for the assembling of a morphological matrix that will be concatenated with molecular data to produce the most extensive phylogenetic review ever made for pleuronectiforms. (AU)