Physiological and molecular adaptability of Notothenia rossii (Richardson, 1844) to osmotic stress: an integrated approach to climate change in Antarctica

• Grant number: 25/14395-4
• Support Opportunities: FAPESP Program for the South Atlantic and Antarctica (PROASA) - Regular Program Grants
• Start date: May 01, 2026
• End date: April 30, 2029
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Cleoni dos Santos Carvalho
• Grantee: Cleoni dos Santos Carvalho
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil
• City of the host institution: Sorocaba
• Associated researchers: Iolanda Cristina Silveira Duarte ; Lucelia Donatti

Abstract

Environmental salinity is an important parameter for aquatic organisms and can cause significant biochemical, immunological, morphological and physiological changes. The aim of this study was to evaluate the effect of low salinity on the biochemical, morphological, immunological and omic responses of the Antarctic fish, Notothenia rossii. Adult individuals of N. rossii were caught with hook and line in Admiralty Bay, near the Comandante Ferraz Antarctic Station (EACF) and the Henry Arctowski Polish Antarctic Station during the summer of 2025 in the XLIII Brazilian Antarctic Operation. After collection, the animals were transported to the EACF laboratory for acclimatization and subsequent exposure to different salinities. After the acclimatization period, the fish were randomly divided into four groups with six individuals each and subjected to salinities of 33 (control) and 20 for 12 h, 24 h and 168 h at a controlled temperature of 0-0.5 oC. At the end of each experimental period, the fish were anaesthetized with benzocaine (100 mg/L). Biometry was then carried out and blood samples were taken to obtain plasma and erythrocytes. The animals were then euthanized by spinal section for organ harvesting. The biological material for biochemical, immunological and omics analysis was frozen and stored in a -80 oC ultrafreezer, while the material for morphological analysis was preserved in specific fixatives. The samples remained in these conditions until they were transported to Brazil on board the Ary Rongel Oceanographic Support Ship (NApOc). In Brazil, the material for biochemical, immunological and omics analysis was transported on dry ice to the Biomarkers Laboratory (LaBioM) at the Federal University of São Carlos, where it remains stored in a -80 oC ultrafreezer. (AU)