Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Colour matters - Colourful guppy males have the highest number of offspring

24.01.2014
Guppies have been popular among aquarium hobbyists for a long time due to their beautiful colours.

These diversely coloured fish have also attracted the attention of biologists from the Max Planck Institute for Developmental Biology in Tübingen, Germany, and the Bioscience and Biotechnology Centre of Nagoya University in Japan.


Spots near the midline of a Cumaná guppy male.
Verena Kottler / Max Planck Institute for Developmental Biology

In their recent scientific work, the team around the Ph.D. student Verena Kottler, Professor Christine Dreyer and Professor Detlef Weigel focussed on the structure of the colourful pattern of male guppies. The Journal PLOS One is publishing the scientific article on Wednesday.

While guppy females are camouflaged by an inconspicuous reticulate pattern, guppy males are highly colourful, displaying iridescent, orange, and black spots and stripes. Many studies have investigated the animals’ behaviour and interactions with their environment. Previous studies found that guppy females prefer males with high amounts of orange and iridescent pigments.

The guppy (Poecilia reticulata) is a small live-bearing freshwater fish native to northeastern South America. “Nowadays, they can be found worldwide because they were released for mosquito control in many countries,” says Verena Kottler. Guppy populations have been studied most extensively on the Caribbean island of Trinidad, where guppy populations have adapted to different river habitats and vary tremendously in behaviour, life history, and male colouration. While the zebrafish (Danio rerio) is particularly suitable to investigate early development, guppies are considered an excellent example for natural variation since the 1920s, because every wild guppy male has an individual ornamental pattern.

In Trinidad, guppies live in habitats that differ in the amount and kind of predatory fish. If there are only a few predators, guppies become sexually mature later and give birth to fewer offspring. Moreover, guppy males are much more colourful because females are attracted by colourful males, which then have more offspring. If large predators are present, however, the guppy males are less colourful, as predators can spot conspicuously coloured males more easily, which hence have a lower survival rate. The guppy is therefore a species whose evolution can be directly observed in the wild.

Verena Kottler and her team asked how different pigment cell types are organised within the male ornaments, which makes it possible to further understand the genetics that underlies these colours. “We know a lot about the behaviour and ecology of the guppy, but the underlying genetic factors haven’t been investigated much so far,” states Kottler. The research team investigated the pigment cell distribution within the spots and fins of male wild-type guppies from three genetically divergent strains called Cumaná, Quare6, and Maculatus. Cumaná guppies are derived from a wild population in Venezuela. Quare6 guppies are descendants of fish from the Quare River on Trinidad, and Maculatus guppies have been bred in captivity by researchers and hobby breeders. The scientists focused on the central orange and central black spots near the gonopodium, as these two spots are present in all three strains despite their considerably different male ornaments.

The research team identified three different pigment cell types in the skin of male guppies and their experiments revealed that at least two of the three types of pigment cells contribute to each of the investigated ornamental traits. This suggests that complex interactions between different pigment cell types are necessary to form the ornamental pattern of guppy males. Also, the study demonstrated that two layers of pigment cell types, one in the dermis and the other in the hypodermis, are responsible for the colour pattern of the fish. Notably, the researchers found that the pigment cell distribution within the central orange and black spots of Cumaná, Quare6, and Maculatus males are very similar, despite Cumaná and Quare6 guppies being derived from geographically distant populations that may have been separated for almost a million years. This suggests that the pigment cell distribution within these spots is indeed conserved within the guppy and might be controlled by conserved genetic factors.

Nadja Winter | Max-Planck-Institut
Further information:
http://tuebingen.mpg.de

More articles from Life Sciences:

nachricht Protein Shake-Up
27.03.2015 | Oak Ridge National Laboratory

nachricht How did the chicken cross the sea?
27.03.2015 | Michigan State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

Two Most Destructive Termite Species Forming Superswarms in South Florida

27.03.2015 | Agricultural and Forestry Science

ORNL-Led Team Demonstrates Desalination with Nanoporous Graphene Membrane

27.03.2015 | Materials Sciences

Coorong Fish Hedge Their Bets for Survival

27.03.2015 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>