Glass Walls, Dumb Calls! 🐟 Guppies were put to the test in a recent study to uncover how inbreeding and warmer water temperatures affect their cognition and boldness. When raised in either normal water or water slightly above their comfort zone, the guppies faced a puzzle: navigate around a clear barrier to reach their reward. While it might sound straightforward, inbred guppies raised in warmer water struggled significantly more to solve the task, spending extra time trying to swim straight through the barrier instead of detouring around it. Males, in particular, had a harder time in hotter water, with their performance in the cognitive test taking a bigger hit than that of females. Inbred guppies weren’t just slower thinkers—they were also less bold, showing a reluctance to explore their surroundings. Interestingly, while the fish as a group improved over repeated trials, proving they could learn, the combination of inbreeding and high temperatures left certain groups starting much further behind. These findings highlight how rising temperatures, combined with shrinking habitats and increased inbreeding, could leave fish populations less equipped to tackle everyday challenges in the wild. Read more: royalsocietypublishing.org/d… @IvanVin_ @Md_MahmudHasan @chenke_zang @megabugface @Mikejennions

Eggs Who Sniff Out Danger! 🐟 Can fish learn before they hatch? According to this study on fathead minnow embryos, the answer is YES! Researchers exposed some eggs to predator water (a mix of predator scent and alarm cues), while others received plain water. They tracked the embryos' movements over several days and found that by day 4, embryos exposed to predator water moved less when they smelled it again, showing they had learned to associate the scent with danger. In contrast, embryos raised in plain water didn’t show this response, and some even became more active when exposed to the unfamiliar predator smell. The researchers also looked at whether social factors, like group size and whether eggs were touching or spaced apart, influenced behavior. Eggs in larger groups tended to move more overall, while those in physical contact with neighbors moved less. However, these social factors didn’t affect when predator learning appeared. This study shows that fathead minnow embryos can learn about predators before they even hatch, giving them an early survival advantage right from the start! Read more: sciencedirect.com/science/ar…