Nothing to see here

November 11, 2013 by Mick Kulikowski
Nothing to see here
Although one looks a bit more colorful than the other, these mosquitofish both live under threat of predation in Bahamas blue holes. Their colors have evolved to blend into their surroundings more than fish living without the threat of predators.

( —"Blend in" appears to be the mantra for male Bahamas mosquitofish that live near predators. After all, fish with brighter, more colorful fins or patches are more conspicuous – and standing out with predators around could be a death sentence. So these fish evolve duller colors under the threat of predation, to try and hide in the watery background.

Meanwhile, male Bahamas mosquitofish that live in water without glam it up to attract females or outcompete other males for access to females. Brighter fins and color patches provide greater contrast with water and cave walls, making these fish really stand out in the water.

Those are the results of a paper on the evolution of fish coloration published online in the journal Evolution.

The study examined Gambusia hubbsi fish in so-called "" in the Bahamas. These "water islands" provide remarkable natural laboratories for comparing living under the threat of predation with those living in the absence of any major predators, says study senior author Brian Langerhans, an assistant professor of biological sciences at NC State. The paper's corresponding author is Ryan Martin, a former postdoctoral researcher in the Langerhans lab who is now an assistant professor at Case Western Reserve University.

"Blending in makes sense when you're trying to avoid being eaten," Martin says. "Less is certainly more when predators are around."

The study examined a number of different environmental factors and individual traits to uncover variation in male colors.

"For example, we found that the background water color of individual blue holes mattered greatly – male mosquitofish evolved colors that stood out in the absence of predators, but tended to blend in with the background in the presence of predators," Langerhans said. "We also found that G. hubbsi males with brighter colors had smaller testes. We think this may reflect variation in male mating strategies, where dull-colored males invest heavily in fertilization success and spend much of their time attempting to copulate with unreceptive females, while colorful males invest instead in mating success and spend more time 'courting' females to gain cooperative copulations."

Langerhans and Ph.D. student Justa Heinen-Kay recently published other findings that showed differences correlated with predation that have evolved in the size and shape of the mosquitofish's penis, or gonopodium.

Explore further: Females choose sexier friends to avoid harassment

More information:

Related Stories

Females choose sexier friends to avoid harassment

December 7, 2011

( -- Scientists have observed a strategy for females to avoid unwanted male attention: choosing more attractive friends. Published today (7 December) in the journal Proceedings of the Royal Society B, the study ...

New fish species offers literal take on 'hooking up'

September 27, 2012

Fishing hooks aren't the only hooks found in east-central Mexican waters. A new species of freshwater fish described by a North Carolina State University researcher has several interesting – and perhaps cringe-inducing ...

Male guppies ensure successful mating with genital claws

July 24, 2013

Some males will go to great lengths to pursue a female and take extreme measures to hold on once they find one that interests them, even if that affection is unrequited. New research from evolutionary biologists at the University ...

Why guppies have genital claws

August 2, 2013

New research from evolutionary biologists at the University of Toronto shows that the male guppy grows claws on its genitals to make it more difficult for unreceptive females to get away during mating.

Green poison-dart frog varies mating call to suit situation

November 11, 2013

In the eyes of a female poison-dart frog, a red male isn't much brighter than a green one. This does not however mean that the mating behavior of the green and red variants of the same species of frog is exactly the same. ...

Recommended for you

A long look back at fishes' extendable jaws

October 8, 2015

When it comes to catching elusive prey, many fishes rely on a special trick: protruding jaws that quickly extend their reach to snap up that next meal. Now, researchers reporting in the Cell Press journal Current Biology ...

New protein cleanup factors found to control bacterial growth

October 8, 2015

Biochemists have long known that crucial cell processes depend on a highly regulated cleanup system known as proteolysis, where specialized proteins called proteases degrade damaged or no-longer-needed proteins. These proteases ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.