Depth-Specific Adaptations: The Evolutionary Morphology of Stomiiformes

• Grant number: 24/17778-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2025
• End date: October 31, 2028
• 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

Abstract

Stomiiformes, an order of marine fishes inhabiting deep-sea environments, is notable for its diversity, comprising five families, 52 genera, and 463 species. These animals are striking examples of how morphology can adapt to different evolutionary pressures. Loaded with photophores throughout their body and head, some species have the unique ability among vertebrates to emit light and see within the far-red spectrum. Many Stomiiformes species exhibit distinct specializations to maximize their efficiency in prey capture, such as the persistence of a notochord space between the skull and vertebrae, well-developed movable teeth, and elongated maxillae. These adaptations allow these fishes to capture prey that can reach up to half of their body size. Despite the anatomical complexity of these animals, there is a lack of detailed studies on their morphology, with most research focusing on osteological aspects. The scarcity of myological studies in Stomiiformes underscores the importance of the present project, which aims to fill these gaps in knowledge about the anatomy of these fishes. Through a comparative and evolutionary analysis of the main muscle groups, the project seeks to map the myological evolution of the order. Additionally, an Anatomical Network Analysis will be conducted, an innovative tool to assess and understand the complex relationships between morphological structures of organisms. This analysis will provide valuable insights into the organization and function of biological systems in Stomiiformes, allowing the examination of macroevolutionary patterns of the different groups within the order in a phylogeny. (AU)