Life through rose-coloured glasses

Over thousands of years some animals have specialised to live in environments where the sun never shines: giant squid with eyes the size of volleyballs see even in the darkest depths while others, like cave-dwelling olms, have lost the functionality of their eyes completely. But for animals that do not live in these extremes, how do species manage a world that suddenly becomes dark? Lakes that become turbid from algal blooms, agricultural run-off, or other environmental pollutants represent common examples of environmental disturbances that can impact the visual scene that aquatic animals must navigate to survive.

Over thousands of years some animals have specialised to live in environments where the sun never shines: giant squid with eyes the size of volleyballs see even in the darkest depths while others, like cave-dwelling olms, have lost the functionality of their eyes completely. But for animals that do not live in these extremes, how do species manage a world that suddenly becomes dark? Lakes that become turbid from algal blooms, agricultural run-off, or other environmental pollutants represent common examples of environmental disturbances that can impact the visual scene that aquatic animals must navigate to survive.

Metamorphic animals provide a unique opportunity to explore the effects of environmental turbidity throughout development

Researchers from the University of Jyväskylä, Finland,  turned to a peculiar species to explore the effects of long-lasting turbidity on animal behaviour: Neotropical poison frogs. While poison frogs may not be the first animal that comes to mind to understand the impact of disturbance on vision in aquatic animals, the unique life history of these frogs makes them the perfect candidates to study the effects of turbidity throughout development. Poison frog tadpoles grow in small pools of water formed by vegetation (such as a leaf axil of a bromeliad) that serve as nurseries where individuals are confined until metamorphosis.

– These small pools of water can readily serve as natural “simulations” of larger environments, such as lakes, as their small size makes them easy to measure and these pools vary significantly in their turbidity, explains Chloe Fouilloux from The Department of Biological and Environmental Science at the University of Jyväskylä.

Naturally, the water in pools can range from being as clear as drinking water to as dark as wine. As such, these environments can serve arenas to test how rearing conditions affect an animal’s response to risk.

 

Visibility makes a difference

Unexpectedly, the world within a leaf axil can be teeming with life from invertebrates to amphibian tadpoles. The goal of this multi-species comparison was to measure how turbidity affects an individual’s response to the visual cues of predators in novel conditions. Researchers found that poison frog tadpoles that develop in clear environments are able to visually discriminate between different types of predators and respond accordingly. In contrast, those that have developed in darker environments exhibit weaker responses to the visual cues of predators.

– The responses from tadpoles illustrate how predator-prey interactions may shift in dynamic light environments and have important implications for the visual plasticity of animals in response to environmental change, clarifies Bibiana Rojas, the project leader currently based at the Konrad Lorenz Institute of Ethology, Vienna.

Researchers believe their findings may serve as a useful model to understand animal responses to habitat disturbance and how communities may shift when visually-guided animals are challenged.

Researchers at Sandia, Northeastern develop method to study critical HIV protein

ALBUQUERQUE, N.M. – More than 36 million people worldwide, including 1.2 million in the U.S., are living with an HIV infection. Today's anti-retroviral cocktails...

First-in-kind study reveals genetic markers of type 2 diabetes in East Asians

An international team of researchers conducted the largest-ever genome-wide study of people from across East Asia to uncover the genetic roots of type 2...

SNMMI publishes appropriate use criteria for V/Q imaging in pulmonary embolism

Reston, Va. — The Society of Nuclear Medicine and Molecular Imaging (SNMMI) has published appropriate use criteria for ventilation/perfusion (V/Q) imaging in pulmonary embolism...

Disrupting crystalline order to restore superfluidity

When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called...

NSF selects Penn State to establish, lead Center for Trustworthy Machine Learning

Patrick McDaniel, Distinguished Professor of Computer Science and Engineering and the William L. Weiss Chair in Information and Communications Technology, Penn State College of...

Supermassive black holes control star formation in large galaxies

Young galaxies blaze with bright new stars forming at a rapid rate, but star formation eventually shuts down as a galaxy evolves. A new...

Coming soon to Montreal: The infrastructure cost of climate change

It's sunny in downtown Montreal and pouring rain at the airport. Such events will be more likely in the future.The climate of the city...

FEFU scientists obtained new compounds with potential antitumor effect from sea sponge

Chemists from Far Eastern Federal University’s School of Natural Sciences (SNS FEFU) developed a new method to synthesize biologically active derivatives of fascaplysin —...

Rare dinosaur embryo exquisitely preserved inside the egg suggests bird-like pre-hatching posture

Over the last 100 years, many fossilized dinosaur eggs and nests have been found, but finding one with a well-preserved embryo inside is exceedingly...