<Li> The strict biological definition of a fish, above, is sometimes called a true fish . True fish are also referred to as finfish or fin fish to distinguish them from other aquatic life harvested in fisheries or aquaculture . </Li> <P> A random assemblage of fish merely using some localised resource such as food or nesting sites is known simply as an aggregation . When fish come together in an interactive, social grouping, then they may be forming either a shoal or a school depending on the degree of organisation . A shoal is a loosely organised group where each fish swims and forages independently but is attracted to other members of the group and adjusts its behaviour, such as swimming speed, so that it remains close to the other members of the group . Schools of fish are much more tightly organised, synchronising their swimming so that all fish move at the same speed and in the same direction . Shoaling and schooling behaviour is believed to provide a variety of advantages . </P> <Ul> <Li> Cichlids congregating at lekking sites form an aggregation . </Li> <Li> Many minnows and characins form shoals . </Li> <Li> Anchovies, herrings and silversides are classic examples of schooling fish . </Li> </Ul> <Li> Cichlids congregating at lekking sites form an aggregation . </Li>

What is the name of a female fish