Blues suit muddy waters

July 19, 2024 Staff reporters

The young progeny of a species of African fish have the visual edge on their parents when it comes to adaptation in murky waters, a recent study found.

 

Published in the Journal of Experimental Biology, the study, led by Jai Tiarks, a PhD candidate working in sensory and conservation physiological ecology at Ohio State University, showed that the blue lips cichlid, a species native to the swamps and lakes of Uganda, overshadowed their parents in visual evolution. Researchers raised a brood of fish in two water tanks – one half-clear, the other cloudy. When the eye and pupil diameters of both young and adult cichlids were measured, younger fish had developed larger eye structures in response to turbid waters. “When the cichlids were young, they had this huge plasticity and were able to alter their physiology to cope with the turbid environmental conditions,” said Tiarks. “But when we looked at the older fish, they didn’t have that same flexibility.”

 

Cichlids are known for filling a huge diversity of ecological niches and being able to adapt to changes in their environment, he said. “That has driven a lot of interest, from an evolutionary standpoint, especially for the timescale that this adaptation occurs.”

 

Deforestation in Africa is the major cause of habitat destruction, but this study suggests that as humans impact vital ecosystems, some creatures, rather than having to move on or die out, may hang on to their spot in the food chain, said the study’s authors.