Banca de QUALIFICAÇÃO: THIAGO ALMEIDA SANTORO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : THIAGO ALMEIDA SANTORO
DATE: 19/11/2025
TIME: 09:00
LOCAL: Sala da Pós graduação do PPGBIOEF
TITLE:

Evaluation of the Tympano-Periotic Complex in Antillean Manatees (Trichechus manatus manatus, Linnaeus, 1758).

KEY WORDS:

morphometrics; tympanic bulla; anatomy; sirenia.

PAGES: 56
BIG AREA: Ciências Biológicas
AREA: Morfologia
SUMMARY:

The West Indian manatee (Trichechus manatus manatus) is an aquatic mammal inhabiting frequently turbid coastal and estuarine environments, where hearing is a primary sense for communication and environmental perception. The tympano-periotic complex (TPC), which houses the middle and inner ear structures, is the anatomical basis for this capability. Literature indicates that the sirenian TPC is notably large and well-developed at birth, suggesting critical functional importance from the earliest life stages. Despite this, the morphology of this structure in T. manatus manatus remains poorly studied.The main limitation for this analysis is methodological: the manatee TPC is firmly integrated with the bones of the cranial base, particularly the squamosal bone, and no standardized protocol exists for the complex extraction that preserves its integrity for subsequent osteological analyses. The present study aimed to fill this gap through a two-stage approach. The first was to develop, validate, and describe a novel osteological protocol for the extraction of the TPC from skulls of T. manatus manatus obtained from stranded dead animals. The second was to apply this protocol to conduct the first detailed morphometric analysis of the tympanic bulla in this subspecies, investigating morphological variation related to ontogeny and sexual dimorphism. Samples were collected through necropsy of four (04) individuals - two calves and two adults - recorded by the Projeto Cetáceos da Costa Branca of the Universidade do Estado do Rio Grande do Norte. The methodology was developed by adapting the "bone window" concept from existing protocols for brain removal. The protocol exploits anatomical points of fragility in the manatee skull, identified from ossification literature. The method involves creating two access windows: a "dorsum-lateral window," achieved by the controlled fracture of the parieto-squamosal suture and further removal of portions of the squamosal bone; and a "caudal window," achieved by removing the exoccipital bone via the supraoccipital-exoccipital synchondrosis. This dual-access approach permitted the bilateral extraction of the whole TPC while preserving the main cranial architecture.Given this, this work presents as a partial result a validated osteological protocol that allows for the removal of the CTP from sirenians, maximizing the use of rare biological specimens by preserving the skull. It also presents the first quantitative morphometric characterization of the tympanic bulla in T. manatus manatus, providing unprecedented data on its growth trajectory and morphological variation. These results offer new insights into the ontogenetic development of the auditory system and the sensory ecology of this threatened species.

COMMITTEE MEMBERS:
Presidente - 1672446 - SIMONE ALMEIDA GAVILAN
Interno - 1076490 - FERNANDO VAGNER LOBO LADD
Externa ao Programa - 3291543 - RENATA SWANY SOARES DO NASCIMENTO - UFRN