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:1/20/2016)...   MedNet Solutions , an innovative SaaS-based eClinical ... research, is pleased to announce the attainment of record-setting ... result of the company,s laser focus on (and growing ... it,s comprehensive, easy-to-use and highly affordable cloud-based technology platform. ... MedNet growth achievements in 2015 include: , ...
(Date:1/18/2016)... SAN JOSE, Calif. , Jan. 18, 2016 ... storage security software that simplifies the use and ... a technology and go-to-market partnership with American Cyber.  ... "American Cyber brings extensive experience leading transformational C4ISR ... missions implementing and integrating the latest proven technology ...
(Date:1/13/2016)... January 13, 2016 --> ... a new market report titled - Biometric Sensors Market - ... 2015 - 2023. According to the report, the global biometric sensors ... anticipated to reach US$1,625.8 mn by 2023, expanding at ... terms of volume, the biometric sensors market is expected ...
Breaking Biology News(10 mins):
(Date:2/3/2016)... ... February 03, 2016 , ... Aerocom, a ... dedicated to the North American healthcare market. , Aerocom Healthcare, LLC will be ... The company will provide new pneumatic tube systems or expand existing systems within ...
(Date:2/3/2016)... ... February 03, 2016 , ... ... and Unix visualization solutions today announced the addition of a powerful “Session Preview” ... to see the current state of the remote Linux desktop or other applications ...
(Date:2/3/2016)... 2016  Silk Therapeutics, Inc., today announced the closing of ... now raised a total of $10.25 million in Series A ... Series A2 round was led by existing investor The Kraft ... from new investors Lear Corporation and Highland Consumer Partners, as ... ; Richard Sackler , MD, with Summer Road, LLC; ...
(Date:2/3/2016)... ... 03, 2016 , ... ZeptoMetrix™ Corporation (ZMC), announced today the ... quality control of molecular assays targeting the Zika Virus. , “Our level of ... President and CEO of ZeptoMetrix, relayed to his Executive Team. “We need to ...
Breaking Biology Technology: