Navigation Links
Piddling fish face off threat of competition
Date:12/12/2007

Aggressive territorial male Mozambique tilapia fish (Oreochromis mossambicus) send chemical messages to rival males via their urine. They increase urination, have smellier urine and store more in their bladders than less aggressive males, according to research published in the open access journal BMC Biology. 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. Weve found that tilapia dominant males store more urine in their bladders than subordinates, actively urinate during times of confrontation and the urines 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 fishs aggressive capabilities for instance. This is also probably not unique to tilapia, so were touching the tip of the urinary pheromone iceberg! concluded Barata.


'/>"/>

Contact: Charlotte Webber
press@biomedcentral.com
44-020-763-19980
BioMed Central
Source:Eurekalert

Related biology news :

1. Freshwater supplies threatened in central Pacific
2. Homeland Security awards 2 grants to Rutgers for nuclear threat detection
3. Smithsonian scientists working to save microscopic threatened species
4. Research shows loggerhead sea turtles threatened by small-scale fishing operations
5. Life-threatening gene defect located by UT-Houston researchers
6. Indigenous water frogs under threat
7. Women with AIDS face cervical cancer threat
8. Rising food prices threaten worlds poor people
9. New, rare and threatened species discovered in Ghana
10. Food source threatened by carbon dioxide
11. Waterborne carbon increases threat of environmental mercury
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:11/14/2016)... CLARA, Calif. , Nov. 14, 2016 ... the biometric identification market, Frost & Sullivan ... Frost & Sullivan Award for Visionary Innovation ... player in the biometric identification market by ... multi-modal verification solution for instant, seamless, and ...
(Date:6/22/2016)... 2016  The American College of Medical Genetics and Genomics ... as one of the fastest-growing trade shows during the ... Bellagio in Las Vegas . ... growth in each of the following categories: net square feet ... of attendees. The 2015 ACMG Annual Meeting was ranked 23 ...
(Date:6/22/2016)... On Monday, the Department of Homeland Security ... solutions for the Biometric Exit Program. The Request for ... (CBP), explains that CBP intends to add biometrics to ... United States , in order to deter visa ... Logo - http://photos.prnewswire.com/prnh/20160622/382209LOGO ...
Breaking Biology News(10 mins):
(Date:12/4/2016)... and CAMBRIDGE, Mass. ... , Dec. 4, 2016 SystemOne, ... connected diagnostics software platforms for the developing world, ... "Anywhere. Care.™" a reality with its portable and ... entered into a development and license agreement to ...
(Date:12/2/2016)... Amgen (NASDAQ: AMGN ) and Allergan ... of a Marketing Authorization Application (MAA) to the European Medicines ... ® (bevacizumab). The companies believe this submission is the ... "The submission of ABP 215 to the EMA is ... portfolio," said Sean E. Harper , M.D., executive vice ...
(Date:12/2/2016)... ... December 01, 2016 , ... ... demonstrating the value of DNA microarray comparative genomic hybridization (array CGH) for ... Breast Cancer Symposium. Using molecular test results from tumors with previously documented ...
(Date:12/2/2016)... ... , ... DrugDev believes the only way to achieve real change ... three tenets were on display at the 2nd Annual DrugDev User Summit (hosted by ... and site organizations to discuss innovation and the future of clinical research. , ...
Breaking Biology Technology: