Shoaling
Many aquarium fish are shoaling fish and the term is applied to fish that prefer to be kept in groups. In the wild, shoaling has several advantages, which include finding food and confusing predators, and for small fish it is usually much safer to stay in groups.
In the aquarium if shoaling fish are kept in small numbers or as individuals they may show signs of distress, ill health, and behavioural changes.
Whilst 'shoaling' relates to fish staying in groups 'schooling' relates to fish which swim in large numbers, keeping an equal and accurate position within the group.

