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:4/28/2016)... First quarter 2016:   , Revenues amounted to ... of 2015 The gross margin was 49% (27) ... operating margin was 40% (-13) Earnings per share rose ... was SEK 249.9 M (21.2) , Outlook   ... The operating margin for 2016 is estimated to exceed ...
(Date:4/15/2016)... -- A new partnership announced today will help life ... a fraction of the time it takes today, ... insurance policies to consumers without requiring inconvenient and ... rapid testing (A1C, Cotinine and HIV) and higi,s ... pulse, BMI, and activity data) available at local ...
(Date:3/31/2016)... 31, 2016   ... the "Company") LegacyXChange is excited to release ... soon to be launched online site for trading 100% ... ) will also provide potential shareholders a sense of ... to an industry that is notorious for fraud. The ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... - FACIT has announced the creation of a ... Propellon Therapeutics Inc. ("Propellon" or "the Company"), to ... of first-in-class WDR5 inhibitors for the treatment of ... an exciting class of therapies, possessing the potential ... patients. Substantial advances have been achieved with the ...
(Date:6/23/2016)... Prostate Cancer Foundation (PCF) is pleased to announce 24 new Young Investigator ... Members of the Class of 2016 were selected from a pool of 128 ... About the Class of 2016 PCF Young Investigators ... ... ...
(Date:6/23/2016)... ... , ... STACS DNA Inc., the sample tracking software company, today announced that ... joined STACS DNA as a Field Application Specialist. , “I am thrilled that ... of STACS DNA. “In further expanding our capacity as a scientific integrator, Hays brings ...
(Date:6/23/2016)... , June 23, 2016 ... Hematology Review, 2016;12(1):22-8 http://doi.org/10.17925/OHR.2016.12.01.22 ... , the peer-reviewed journal from touchONCOLOGY, Andrew ... escalating cost of cancer care is placing an ... result of expensive biologic therapies. With the patents ...
Breaking Biology Technology: