A new study by the Leibniz-Institute of freshwater ecology and inland fisheries (IGB) shows how groups work and why it is sometimes better to leave the group and join a new.
Many animal species live in groups, because it search about for food, defence, or the choice of a partner is advantageous. In animals, the aggressiveness can rise to each other however, if the individuals a long time in the unchanged groups. The ITUC study shows in the journal Animal Behaviour, the IGB researchers Amazon toothcarps studied a species of fish reproduces through cloning and genetic identical individuals.
Familiarity is not the same as user related
So far has been neglected in the behavioural ecology of the factor “familiarity” often, since familiarity is often associated with kinship and to consider is therefore difficult to individually, according to the study.
The Amazon killifish (Poecilia formosa) is different, because these animals, as clones have identical genetic relationships.
Also in the case of the elephant, some animals leave the group and join new associations
IGB researcher Carolina Doran and her colleagues, David Bierbach and Kate Laskowski took three groups of these fish under the magnifying glass, which had a different long lived together in the same aquarium – a day, seven days and three weeks. In the case of the first two groups has been replaced after a day or a week, a part of the fish according to the random principle, the individuals of the third group stayed together.
At the reporting date, IGB Team gave each a defendable food source in the basin and analyzed the behavior of the animals in the three groups, respectively, before and after.
Familiar fish afford more aggressiveness
“We were surprised that the fish knew best, communicated on the most aggressive to each other,” explains David Bierbach. He and his Co-authors were assumed to be the opposite: “live together Amazon toothcarps for a while, are established hierarchies of Domination, and the fish have less reason to fight with each other,” explains the IGB researchers.
In the investigation, the Amazon toothcarps, who knew each other the longest-behaved, however, both before and after the feed of the addition, particularly aggressive, for example, by chasing each other through the pelvis.
The researchers explain the unexpected behavior: “The fish, which know the longest, are stressed for this reason, the least, and can afford to, in a sense, to be more aggressive,” said David Bierbach.
If from a playful fight is Serious, switch hyenas of the group
Recommended change in other groups
The increased aggressiveness has its advantages, groups, longer, cope better in new environments, because they are not too careful. You know, however, is so good that the degrees of aggressiveness too much, leave some animals in the group, and join new associations.
Thus, Fission-Fusion societies”, in which animals change the associations in which they live”. Such dynamic conditions are common in other vertebrate species: dolphins, elephants, hyenas, bison, or baboons also live in Fission-Fusion societies.
Natural clones as the ideal model organisms
The IGB researchers argue in favour of intensified studies involving vertebrate animals, the way plants are, of course, by cloning, such as the Amazon killifish. In contrast to artificial clonal animals, such as the cloned sheep “Dolly” – have made natural clones already in nature, their ability to Survive and, therefore, are better to explain biological processes.