Animal behaviourists have known for some time that the urine of freshwater fish is a vehicle for reproductive hormones that act in the water as pheromones, affecting the behaviour and physiology of members of the opposite sex. Now, this research sheds light on the role of urine in influencing members of the same sex.
“Few studies have looked at the roles of pheromones in urine during competition between individuals of the same sex. We’ve found that tilapia dominant males store more urine in their bladders than subordinates, actively urinate during times of confrontation and the urine’s olfactory potency or smell strength is even greater,” explained Eduardo Barata, who led the Portuguese research.
As a lekking species – where males group together in the same area to breed, never leaving their nest, not even to feed – social hierarchy is important for the cichlid fish from Africa. Males actively advertise their dominant status through urinary odorants, which are thought to control aggression in rival males and so maintain social stability within the area, or lek. By measuring male urination frequency during competition, Barata et al. found that dominant or ‘resident’ males increased urination frequency in the presence of ‘intruder’ males from once every ten minutes to once every minute. Dominant males stopped urination when their opponent gave up, indicating a close link between aggression and urination rate. By also collecting urine and measuring the volume over five days and evaluating olfactory potency using an electro-olfactogram, it was seen that subordinate males also stored less urine and the urine was less smelly than that of dominant males.
“We know pheromones are involved in reproductive and non-reproductive behaviours of fish, for example during migration, mating and schooling,” explained Barata. “While we do not yet know what these chemicals are, it is clear they play a major role in many aspects of tilapia social behaviour by providing information about the fish’s aggressive capabilities for instance. This is also probably not unique to tilapia, so we’re touching the tip of the urinary pheromone iceberg!” concluded Barata.
Charlotte Webber | alfa
When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie
WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences