Banca de DEFESA: SILVIA YASMIN LUSTOSA COSTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : SILVIA YASMIN LUSTOSA COSTA
DATE: 20/05/2020
TIME: 08:30
LOCAL: Por videoconferência
TITLE:

Integrative taxonomy and biogeography of armored catfish of the genus Hypostomus Lacépède, 1803 (Siluriformes: Loricariidae) in the drainages in northeastern Brazil

KEY WORDS:

Hypostominae, Maranhão-Piauí ecoregion, headwaters capture, Caatinga fish.

PAGES: 176
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUBÁREA: Taxonomia dos Grupos Recentes
SUMMARY:

The Northeast of Brazil comprises four biomes (Caatinga, Cerrado, Atlantic Forest and the Amazon) and five continental hydrographic ecoregions: Mid-East Northeast (NEMO), Maranhão-Piauí (MAPI), São Francisco (SAFR), Northeast Atlantic Forest (MANE), and Estuary of the Amazon basin and coastal drainages (EADC). In the last few decades, several species of fish have been described from these ecoregions, including some of the armored catfish of the genus Hypostomus, the richest genus in the Loricariidae family and one of the most widely distributed throughout the Neotropical region. In two of the five ecoregions
mentioned above (NEMO and MAPI), nine nominal species of Hypostomus are known: seven from NEMO, and two from MAPI. However, many of these species, described in the mid-twentieth century, present problems with the definition of type locality, insufficient specimens making up the type series, undetailed descriptions, and diagnosis based on few external morphological characters. These factors have hindered estimations of richness and distribution of species of the genus in these ecoregions,
which causes problems when assessing their conservation status. The aim of the present study was to carry out a systematic review of Hypostomus in the NEMO and MAPI ecoregions using integrative taxonomy, and to discuss the diversification of the genus in drainages in the northeast semiarid. Based on our results, Hypostomus carvalhoi, H. jaguribensis, H. nudiventris, H. papariae and H. salgadae are junior synonyms of H. pusarum. The geographical distribution of H. pusarum was expanded
to MAPI, and two new species of the genus were revealed for this ecoregion and were described here. We provided data on the distribution of species of the genus in the studied ecoregions, and recorded the occurrence of a total of six species of Hypostomus (H. johnii, H. pusarum and H. vaillanti, two described in this study and another possible new species) in the MAPI ecoregion. The results indicate that the species richness of the genus in NEMO is overestimated, while in MAPI it is underestimated. We verified phylogenetic relationships between a group of NEMO and MAPI species with species from the Amazon and Guyana regions, as well as past relationships between these ecoregions with the SAFR, as well as the latter with the tributaries of the La Plata system, in addition as concluding that the color pattern of the species is not very informative about the phylogenetic relationships. Our biogeographic inferences suggest that there were at least two invasions in MAPI and NEMO, and at least three in SAFR, and the processes that acted in the diversification of the majority of Hypostomus species in the northeast semiarid region were the headland capture events. According to our results, the species diversified between the late Miocene and the Pliocene, which coincides with the period of lowest temperatures on the globe, a condition that possibly led to the expansion of the semiarid areas of the region.

BANKING MEMBERS:
Externo à Instituição - CLAUDIO HENRIQUE ZAWADZKI - UEM
Externa à Instituição - LÚCIA HELENA RAPP PYDANIEL - INPA
Externo à Instituição - PEDRO HOLLANDA CARVALHO - UFRJ
Presidente - 1865104 - SERGIO MAIA QUEIROZ LIMA
Externo à Instituição - UEDSON PEREIRA JACOBINA - UFAL