Navigation Links
Nothing fishy about swimming with same-sized mates

Have you ever wondered why, and how, shoals of fish are comprised of fish of the same size? According to new research by Ashley Ward, from the University of Sydney in Australia, and Suzanne Currie, from Mount Allison University in Canada, fish can use a variety of different sensory cues to locate shoal-mates, but they are able to use chemical cues to find other fish of the same size as themselves. Using these cues, they can form a group with strength in numbers. The work is published online in Springer's journal, Behavioral Ecology and Sociobiology.

Forming groups is beneficial for animals. One important benefit is the reduction of individual risk from predators. Indeed when animals are in groups, predators are confronted by a number of almost identical prey animals, making it more challenging to select a target.

Dr. Ward said, "Fish typically form shoals with fish of the same size. The key question that motivated our study is this: How on earth does a fish know how big it is? For humans this is trivial - we can stand on a flat surface and see whether we're taller or shorter than someone, or we can look in a mirror. These options don't exist for fish, so how do they choose to associate with fish of the same size?"

The scientists explored which of their senses fish use both to assess the size of other individuals, and to determine how big they are themselves. They studied two freshwater shoaling fish species: three-spined stickleback and banded killfish. In a series of experiments, they exposed the fish to a variety of chemical cues - either from fish of the same species of varying sizes or a control, so-called 'blank' cue. Chemical cues are formed as fish constantly emit molecules into their surroundings.

Ward continued, "We know the sense of smell is well developed in fish and that they are sensitive to tiny differences in the chemical signature given off by others. So could they smell how big they are themselves and use this as a template to assess the size of others? It seems they can."

Both species of shoaling fish preferred the chemical cues of same-sized fish than those of larger or smaller fish from their own species. This suggests that the fish were able to determine their own size relative to other fish of the same species, primarily through chemical self-referencing.

"Using chemical cues to locate similarly sized fish of the same species in the wild promotes the formation of shoals, which creates confusion for predators as well as more coordinated, and potentially efficient, patterns of behavior for both activity and nutrition," concluded Ward.


Contact: Joan Robinson

Related biology news :

1. Teaching about hearing can save young peoples ears
2. A birds song may teach us about human speech disorders
3. Fielding questions about climate change
4. New research about facial recognition turns common wisdom on its head
5. New discoveries about brain-hand connection sought to improve therapies, treatments, prosthetics
6. Expedition to undersea mountain yields new information about sub-seafloor structure
7. Consumers need simple, concise messages about benefits of phytonutrients
8. Whats in a surname? New study explores what the evolution of names reveals about China
9. Analysis raises atmospheric, ecologic and economic doubts about forest bioenergy
10. Fruit flies provide new knowledge about uninhibited cell growth
11. Study raises questions about use of anti-epilepsy drugs in newborns
Post Your Comments:
(Date:10/1/2015)... 2015  Biometrics includes diverse set of technologies ... such as fingerprints, eye retinas, facial patterns, voice ... technology has been constantly increasing in ... In addition to the most prominent popular method ... means of biometric authentication are rapidly gaining traction ...
(Date:9/30/2015)... PALM BEACH GARDENS, Fla. , Sept. 30, 2015 ... Circuit earlier this month issued another key ruling in ... Commission,s (ITC,s) determination that Korean fingerprint scanner company Suprema ... the Tariff Act of 1930, a trade provision that ... connection with import trade, by infringing two of Crossmatch,s ...
(Date:9/29/2015)... , Sept. 29, 2015 News ... productivity while also saving energy , Minimized design ... Low Power Active Mode and embedded Fujitsu PalmSecure authentication ... Fujitsu today shows that good things come ... refreshed models to its enterprise desktop and mobile portfolio. ...
Breaking Biology News(10 mins):
(Date:10/12/2015)... Oct. 12, 2015 This report covers the ... cell type, products, applications, end-user markets and geographic segmentation. ... The global cell expansion market generated revenue of ... reach revenues of $9.7 billion in 2015 and $22.0 ... (CAGR) of 17.8% from 2015 to 2020. This ...
(Date:10/12/2015)... cell surface marker detection market ... to a new report by Grand View Research, Inc. This ... of oncology diseases and other cell-associated disorders. --> ... USD 6.49 billion by 2022, according to a new report ... be attributed to rise in incidence of oncology diseases and ...
(Date:10/12/2015)... CITY , Oct. 12, 2015 /PRNewswire/ - Aeterna ... specialty biopharmaceutical company engaged in developing and commercializing novel ... the departure of Dennis Turpin , the Company,s ... decision to close its Quebec City ... Chairman, President and Chief Executive Officer of the Company ...
(Date:10/12/2015)... , October 12, 2015 LabStyle ... Diabetes Management Solution, today announced its Medical Director, Dr. ... study at MobiHealth,s 5th EAI International Conference on ... healthcare through innovations in mobile and wireless technologies," the ... from October 14 - 16, 2015. The ...
Breaking Biology Technology: