Human capacity to sense and respond to the suffering of non-Human animals is key to animal care and welfare. Intuitively these modes of relating seem best suited to interactions between humans and warm-blooded mammals who share Human-like facial features and characteristics. Animal geographers and those working in animal welfare have noted the challenges that humans face in learning to care about fishes, and how this leads to welfare guidelines and regulations which are poorly suited to aquatic species. This paper draws on interviews with laboratory aquarists and biomedical researchers to explore how they have learnt to sense and respond to the needs of fishes in the laboratory. We offer two key observations. Firstly, despite significant bodily differences, humans find ways to empathise with fishes. Secondly, whilst observations of bodies and behaviours predominate in laboratory mammal welfare assessments, when working with fishes water quality serves as an important proxy for species health. We conclude that the laboratory aquarium signifies methodological and conceptual limits in contemporary animal geographies. We further argue that these barriers should be understood as cultural, and - as we demonstrate - that there is consequently scope and capacity to reach beyond them by engaging in amphibious ethics and speculative immersions.
