Banca de DEFESA: RENATA LILIAN DANTAS CAVALCANTE

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RENATA LILIAN DANTAS CAVALCANTE
DATE: 11/08/2025
TIME: 09:00
LOCAL: https://meet.google.com/ovj-birq-frb
TITLE:

The mitogenome of Brachyplatystoma filamentosum and the macroevolution of body size in catfishes (Siluriformes)

KEY WORDS:

Mitogenome; Siluriformes; Brachyplatystoma filamentosum; Body size evolution; Amazon Basin.

PAGES: 66
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

The order Siluriformes, commonly known as catfishes, represents one of the largest and most diverse groups of fishes in the world. This group exhibits remarkable variation in body size across its species, ranging from just a few centimeters to giants exceeding 4 meters in length. This morphological diversity makes Siluriformes a valuable model for investigating evolutionary processes related to body size dynamics in aquatic vertebrates. Within this context, Brachyplatystoma filamentosum, known as Piraíba or Filhote, stands out as the largest catfish in the Amazon Basin and one of the largest representatives of the order. In this study, the complete mitochondrial genome (mitogenome) of B. filamentosum was sequenced and analyzed for the first time, providing novel genomic data for Amazonian ichthyofauna. The mitogenome of B. filamentosum comprises 16,566 base pairs, with a GC content of 42.21% and a D-loop region of 911 base pairs. The mitochondrial sequences encoding proteins, tRNAs, and rRNAs were incorporated into a comprehensive phylogenetic analysis including 137 additional species of Siluriformes and 10 outgroup species. Phylogenetic trees, constructed using maximum likelihood and calibrated over time, estimated the origin of the Siluriformes order at approximately 118.4 million years ago. The analyses indicated that the suborder Loricarioidei was the first to diversify, followed by Diplomystoidei and subsequently Siluroidei, which underwent a rapid evolutionary radiation around 94.1 million years ago. The reconstruction of body size evolution revealed 16 directional increases and 11 decreases in body size across the order, with no overall global trend. However, B. filamentosum exhibited a significant increase in size over 40.8 million years, with an estimated 5.65-fold growth rate, standing out as a remarkable case of gigantism within the order. The publication of the first complete mitogenome of B. filamentosum represents a significant advancement in the genetic and evolutionary knowledge of Amazonian species, especially considering the scarcity of molecular data for  many taxa in the region. This gap is particularly concerning given the ecological, economic, and conservation importance of Amazonian fishes. By integrating genomic data with phylogenetic analyses, this study contributes not only to the understanding of the evolutionary history of Siluriformes but also to the broader knowledge of an iconic species from the largest river basin on the planet.

 

 

COMMITTEE MEMBERS:
Presidente - 3063244 - TETSU SAKAMOTO
Interno - 1513597 - JOAO PAULO MATOS SANTOS LIMA
Interno - 2170415 - Jorge Estefano de Santana Souza
Externo à Instituição - LUCIANO FOGACA DE ASSIS MONTAG - UFPA
Externo à Instituição - SIDNEY EMANUEL BATISTA DOS SANTOS - UFPA