Reproductive biology, development and evolutionary history of organic fall specialists under the influence of south hemisphere high latitudes

• Grant number: 24/22259-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2025
• End date: July 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Paulo Yukio Gomes Sumida
• Grantee: Gilberto Bergamo Neto
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/12551-8 - Benthic connections of high Southern Latitudes: BECOOL, AP.PFPMCG.TEM

Abstract

Whale carcasses on the ocean floor have acted as sources of evolutionary innovation and adaptive radiation since whales began their diversification about 40 million years ago. Recent evidence suggests that these "organic islands" may have served as ecological or evolutionary stepping-stones for organisms adapted to chemosynthetic environments. This is corroborated by the typical co-occurrence of many species in cognate habitats, such as hydrothermal vents and cold seeps. Currently, one of the biggest challenges in deep-sea ecology is the elucidation of the biological processes that allow connectivity between these spatially isolated populations. The ephemeral nature of these environments favors species with rapid colonization, maturation, population growth, and greater dispersal capacity. Most of these species produce lecithotrophic larvae capable of dispersing for thousands of kilometers, while other species produce a large quantity of planktotrophic larvae, capable of capturing bacteria and detritus and/or even absorbing dissolved organic matter directly from the water column. This high variability of reproductive modes highlights the need for more studies on the biology and development of the species involved, since the reproductive strategies employed by specialist organisms, as well as their development, would be directly related to evolutionary success and dispersal power in such unpredictable and ephemeral environments. Despite the great importance of these ecosystems, studies are still scarce, and therefore, the global and regional patterns of biodiversity, and the biogeographic relationships in the biotas of organic islands and cognate habitats remain largely unexplored. In this context, the present proposal is inserted, whose focus is to understand aspects of the reproductive biology and development of the target organisms of the main proposal, in order to try to understand their biogeographic relationships, connectivity and adaptive success in the deep sea. To assess these questions, we will use the fauna of organic substrates as a case study through the implantation of autonomous experimental structures with the implantation of whale bones and wood plots in shallow waters (~70 m) and deep sea (~1500 m) in the cold waters of Antarctica. The oceanographic conditions of the experimental site and the logistical support of the bases in the Southern Hemisphere will enable studies on the reproductive biology and development of organisms, including the study of living organisms. This is a highly innovative scientific project in Brazil and has high-level national and international scientific partnerships, presenting a pioneering and low-cost study methodology in deep ecosystems, which are environments that are difficult to access with the resources available so far by Brazilian institutions.