A key evolutionary step determining osmoregulatory ability for freshwater colonisation in early life stages of fish

Colonisation of freshwater habitats by marine animals is a remarkable evolutionary event that has enriched biodiversity in freshwater ecosystems. The acquisition of tolerance to hypotonic stress during early life stages is presumed to be essential for their successful freshwater colonisation, but very little empirical evidence has been obtained to support this idea. This study aimed to comprehend the evolutionary changes in osmoregulatory mechanisms that enhance larval freshwater tolerance in amphidromous fishes, which typically spend their larval period in marine (ancestral) habitats and the rest of their life history stages in freshwater (derived) habitats. We compared the life history patterns and changes in larval survivorship and gene expression depending on salinity among three congeneric marine-originated amphidromous goby species (Gymnogobius), which had been suggested to differ in their larval dependence on freshwater habitats. An otolith microchemical analysis and laborator..., A) Person-Period data for survival analysis.xlsxThis dataset was used for a survival time analysis to evaluate larval tolerance to freshwater in the three Gymnogobius species, one of which has freshwater resident populations. In this analysis, to compare the survivorship between the freshwater and seawater groups, Cox proportional hazard models were established for each species using the coxph function in the survival R package version 3.2-13. In addition, to directly illustrate interspecific variations in the freshwater tolerance and test whether freshwater tolerant species also exhibit high survival in seawater (i.e. exhibit physiological plasticity), the survival in each salinity group was compared among the species by establishing the Cox proportional hazard models with the explanatory variable being species.
B) Data for osmoregulatory gene expression analysis.xlsxThis dataset was used to compare the magnitude of expression changes of important osmoregulatory genes in larval fish be..., , This README file was generated on 2023-10-24 by Yumeki Oto.

GENERAL INFORMATION

1. Title of Dataset: A key evolutionary step determining osmoregulatory ability for freshwater colonisation in early life stages of fish
2. Author Information
A. Principal Investigator Contact Information
Name: Yumeki Oto
Institution: National Fisheries University
Address: Shimonoseki City, Yamaguchi Prefecture, Japan
Email: angler\[e-mail]

B. Associate or Co-investigator Contact Information
Name: Katsutoshi Watanabe
Institution: Kyoto University
Address: Kyoto City, Kyoto Prefecture, Japan
Email: [e-mail]
3. Date of data collection (single date, range, approximate date): 2018-2021
4. Geographic location of data collection: Hokkaido, Niigata, Tokyo, Fukui, Shiga, Mie, and Kyoto Prefectures, Japan
5. Information about funding sources that supported the collection of the data:
Japan Society for the Promotion of Science, Award: ...