Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


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

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:

More articles from Life Sciences:

nachricht Soil crusts emit nitrogen oxides and nitrous acid
01.12.2015 | Max-Planck-Institut für Chemie

nachricht Discovery of an embryonic switch for cancer stem cell generation
01.12.2015 | University of California - San Diego

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How do Landslides control the weathering of rocks?

Chemical weathering in mountains depends on the process of erosion.

Chemical weathering of rocks over geological time scales is an important control on the stability of the climate. This weathering is, in turn, highly dependent...

Im Focus: How Cells in the Developing Ear ‘Practice’ Hearing

Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular chain of events that enables the cells to make “sounds” on their own, essentially “practicing” their ability to process sounds in the world around them.

The researchers, who describe their experiments in the Dec. 3 edition of the journal Cell, show how hair cells in the inner ear can be activated in the absence...

Im Focus: Climate study finds evidence of global shift in the 1980s

Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.

Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...

Im Focus: Innovative Photovoltaics – from the Lab to the Façade

Fraunhofer ISE Demonstrates New Cell and Module Technologies on its Outer Building Façade

The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

All Focus news of the innovation-report >>>



Event News

Urbanisation and migration from rural areas challenging agriculture in Eastern Europe

30.11.2015 | Event News

Fraunhofer’s Urban Futures Conference: 2 days in the city of the future

25.11.2015 | Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Latest News

UofL scientists identify critical pathway to improve muscle repair

01.12.2015 | Health and Medicine

IU chemists craft molecule that self-assembles into flower-shaped crystalline patterns

01.12.2015 | Life Sciences

Simulation shows key to building powerful magnetic fields

01.12.2015 | Physics and Astronomy

More VideoLinks >>>