In the wild, creatures of all sorts have a plethora of options for shelter, breeding, nesting, etc. Some build their own, and others simply take advantage of what’s around them. Fish are no different.
However, your tank is not “the wild.” What is available to your cichlids is what you provide. They can’t move off to another area in search of something different or better. You force them to choose from what you give them. So if provided multiple options, what would your cichlids choose and/or use?
While perusing one of the FB cichlid groups the other day, I came across an interesting post about a recently published research paper. Titled “Structural manipulations of a shelter resource reveal underlying preference functions in a shell-dwelling cichlid fish,” the research sought to identify what shell characteristics are preferred by the small Tanganyikan shell dweller, Neoamprologus multifasciatus.
The research team used adult males and female offspring from wild caught specimens at Chikonde Bay, Zambia. The team also used 113 randomly selected Neothauma tanganyicense snail shells, also taken from Chikonde Bay. These shells are endemic to the lake and favored by the N. multifasciatus. After taking multiple measurements of all 113 shells, the team chose a characteristic, full intact shell based on these measurements, then created a 3D model of that shell. Using the model and a 3D printer, the team manipulated each measured characteristic to produce multiple modified shells for use in the experiment.
The results? The experimental fish chose shell replicas with exaggerated measurements above and beyond the “characteristic” 3D model shell. This is some really fascinating stuff. You can download the paper here.
A word of caution on the results. The outcomes of experimental manipulation are often not a direct substitute for what might be observed in the wild. In other words, the results of the experiment don’t mean that similar fish in the wild would make the exact same selection in the wild if presented with the same options.
A shout out to FB user Jeremy Mallicoat who posted a link to this short article about the research.
A. P. H. Bose, J. Windorfer, et al., “Structural manipulations of a shelter resource reveal underlying preference functions in a shell-dwelling cichlid fish.” Proc. R. Soc. B. 287. 2020.