ScienceDaily (Apr. 6, 2007) — With the unappealing prospect of being eaten, one might imagine that during a predator attack it is a case that all fish escape at once in the desperate hurry to escape as quickly as possible. However, new research indicates that this is not the case, and in fact fish in schools escape using a relatively fixed chronological order.

Scientists mimicked an aerial predator attack by mechanical stimulation and used a high speed camera to record responses in schools of ten grey mullet each. Individuals within a school were then ranked according to the timing of their escape. The experiment was performed ten times at 10 minute intervals on a total of seven separate schools of grey mullet. Interestingly, results suggested that there is a trend for individual fish to maintain a given rank, indicating that the chronological order of escape responses within a school is maintained in successive startle events.

Head of the research group Dr Paolo Domenici stated, "Our work is the first to show that fish maintained under the same conditions, with no differential treatment, show a tendency for keeping a relatively fixed chronological order of escape. This implies that in a given school certain individuals may have a greater influence on the escape strategies of the whole school."

Researchers are keen to explore whether the tendency to keep a fixed chronological order of escape corresponds to a leadership maintained over a relatively long period of time.

This research was carried out at the International Marine Centre (IMC) in Sardinia, Italy, and was presented at the Annual Meeting of the Society for Experimental Biology in Glasgow (31st March -- 4th April).

Related Stories

How Cockroaches Keep Their Predators 'Guessing' (Nov. 19, 2008) — When cockroaches flee their predators, they choose, seemingly at random, amongst one of a handful of preferred escape routes, according to a new ...  > read more

Why Do Subordinates In Many Animal Species Accept Social Position Without A Fight? (June 29, 2009) — In many animal species stable hierarchies are routinely formed in which some individuals seem to slip naturally into their dominant role whereas others resign themselves to play the part of lowly ...  > read more

Keeping Fish in Home Aquariums: Two Is Not Company, As Far As Fish Are Concerned (July 2, 2009) — New research has shown that fish kept alone or in small groups are more aggressive and exhibit fewer natural behaviors such as ...  > read more

Risk Assessments Urged For Fish Escaping From Net-pen Aquaculture (May 3, 2005) — The substantial risk to salmon stocks posed by salmon that escape from net-pen farms argues for risk assessments of all types of marine fish farming, according to an article published in BioScience. ...  > read more

Search ScienceDaily

Safety-Proofing Plastic