Thermal optima in the hypoxia tolerance of marine ectotherms: Physiological causes and biogeographic consequences
Fig 5
Biogeography and state-space habitats of species with thermal optima in hypoxia tolerance.
Global occurrence data for 2 species, (A) the midwater shrimp Oplophorus spinosus and (B) the flounder Platichthys stellatus, from the Ocean Biodiversity Information System are mapped on the climatological temperature (lines) and pO2 (color field), from the World Ocean Atlas, averaged from the surface to the 95th percentile depth of reported species occurrences. The location (latitude, longitude, and depth) and month of each reported occurrence are matched to the climatological T and pO2, whose joint histogram is shown in the state-space habitat diagrams for each species. (C) In Oplophorus spinosus, measured Pcrit values (red dots) as well as the curve fit based on the Metabolic Index (dashed red line) align with the lowest inhabited pO2 across the temperature range [10]. (D) In the flounder Platichthys stellatus, the Pcrit curve (dashed red line) predicted from the Metabolic Index framework and physiological rates also exhibits a thermal optimum consistent with the occurrence data. The data underlying this figure can be found in https://doi.org/10.6084/m9.figshare.24547270. The code underlying this figure can be found in https://doi.org/10.6084/m9.figshare.24547255.