Fishes of southern South America: a story driven by temperature

• Published in: Fish physiology and biochemistry Vol. 35; no. 1; pp. 29 - 42
• Main Authors: Cussac, V. E, Fernández, D. A, Gómez, S. E, López, H. L
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.03.2009; Springer Netherlands; Springer Nature B.V
• Subjects: anatomy & histology; Animal Anatomy; Animal Biochemistry; Animal Physiology; Animals; Argentina; Biodiversity; biogeography; Biomedical and Life Sciences; Climate change; Fish; Fishes; Fishes - anatomy & histology; Fishes - physiology; Fresh Water; Freshwater; Freshwater & Marine Ecology; Freshwater fish; Greenhouse Effect; Habitat utilization; habitats; Histology; indigenous species; Life history; Life Sciences; Low temperature; Marine fish; Morphology; oceans; physiology; Pisces; South America; Streams; Temperature; Temperature gradients; temperature profiles; Time Factors; Water temperature; Zoology; South America; Argentina; ASW, South America; Marine; Neotropical region; Thermal biology; Austral subregion; Biodiversity; Ecophysiology; Autoecology; Freshwater
• ISSN: 0920-1742; 1573-5168; 1573-5168
• DOI: 10.1007/s10695-008-9217-2

The latitudinal extension of southern South America imposes a thermal gradient that affects the structure of marine and freshwater fish assemblages and the biology of the species through direct exposure to the temperature gradients or by means of a web of historical and ecological relationships. We have reviewed biological and ecological data of marine and freshwater fishes from the southern Neotropics, including Patagonia, and report several examples of dependence on temperature, from glacial times to today's climate change. We were able to identify historic and present effects on the diversity of fish assemblages, isolation, southern limits for the distribution of species, and morphological variation among populations. There is a wide range of characteristics that exemplify an adaptation to low temperatures, including biochemical peculiarities, physiological adjustments, and alternative life history patterns, and these appear in both freshwater and marine, and native and exotic fishes. The consequences of stable temperature regimes in both the ocean and thermal streams deserve special mention as these shape specialists under conditions of low selective pressure. At present, habitat use and interactions among species are being subject to changes as consequences of water temperature, and some of these are already evident in the northern and southern hemispheres.