question: Is the way that fish school in water caused by the same biological instinct as how birds flock in flight, or is it different?
comment: It's very similar yes, not biological instinct per se, more like convergent evolution. Basically large groups act as a whole, but no one animal is in control. Any one fish or bird will pay attention to the nearest 4-7 animals. If two on the left go down and right then they will as well, until the "ripple" evens out, or until more movement is needed in a new direction. Also they try and maintain some distance from the others in the flock or school, sort of like how magnets can get close but then push away, which is where the bubbly/shifty look comes from as they all try to stay in the group and not splinter off.
passages: In 2009, building on recent advances in acoustic imaging, a group of MIT researchers observed for "the first time the formation and subsequent migration of a huge shoal of fish." The results provide the first field confirmation of general theories about how large groups behave, from locust swarms to bird flocks.
   Common bottlenose dolphins have been observed using another technique. One dolphin acts as a "driver" and herds a school of fish towards several other dolphins who form a barrier. The driver dolphin slaps its fluke which makes the fish leap into the air. As the fish leap, the driver dolphin moves with the barrier dolphins and catches the fish in the air. This type of cooperative role specialization seems to be more common in marine animals than in terrestrial animals, perhaps because the oceans have more variability in prey diversity, biomass, and predator mobility.
   Some predators, such as dolphins, hunt in groups of their own. One technique employed by many dolphin species is herding, where a pod will control a school of fish while individual members take turns ploughing through and feeding on the more tightly-packed school (a formation commonly known as a bait ball.) Corralling is a method where fish are chased to shallow water where they are more easily captured. In South Carolina, the Atlantic bottlenose dolphin takes this one step further with what has become known as strand feeding, where the fish are driven onto mud banks and retrieved from there.
   Fish social behaviour called ‘shoaling’ involves a group of fish swimming together. This behaviour is a defence mechanism in the sense that there is safety in large numbers, where chances of being eaten by predators are reduced. Shoaling also increases mating and foraging success. Schooling on the other hand, is a behaviour within the shoal where fish can be seen performing various manoeuvres in a synchronised manner. The parallel swimming is a form of ‘social copying’ where fish in the school replicate the direction and velocity of its neighbouring fishes.
   It would seem reasonable to think that the regular spacing and size uniformity of fish in schools would result in hydrodynamic efficiencies. However, experiments in the laboratory have failed to find any gains from the hydrodynamic lift created by the neighbours of a fish within a school, though it is still thought that efficiency gains do occur in the wild. Landa (1998) argues that the leader of a school constantly changes, because while being in the body of a school gives a hydrodynamic advantage, being the leader means you are the first to the food.
  
  Section::::Predator avoidance.
   It has also been proposed that swimming in groups enhances foraging success. This ability was demonstrated by Pitcher and others in their study of foraging behaviour in shoaling cyprinids. In this study, the time it took for groups of minnows and goldfish to find a patch of food was quantified. The number of fishes in the groups was varied, and a statistically significant decrease in the amount of time necessary for larger groups to find food was established. Further support for an enhanced foraging capability of schools is seen in the structure of schools of predatory fish. Partridge and others analysed the school structure of Atlantic bluefin tuna from aerial photographs and found that the school assumed a parabolic shape, a fact that was suggestive of cooperative hunting in this species.
   Fish can be obligate or facultative shoalers. Obligate shoalers, such as tunas, herrings and anchovy, spend all of their time shoaling or schooling, and become agitated if separated from the group. Facultative shoalers, such as Atlantic cod, saiths and some carangids, shoal only some of the time, perhaps for reproductive purposes.
  
  Shoaling fish can shift into a disciplined and coordinated school, then shift back to an amorphous shoal within seconds. Such shifts are triggered by changes of activity from feeding, resting, travelling or avoiding predators.
   These sometimes immense gatherings fuel the ocean food web. Most forage fish are pelagic fish, which means they form their schools in open water, and not on or near the bottom (demersal fish). Forage fish are short-lived, and go mostly unnoticed by humans. The predators are keenly focused on the shoals, acutely aware of their numbers and whereabouts, and make migrations themselves, often in schools of their own, that can span thousands of miles to connect with, or stay connected with them.
   Support for the social and genetic function of aggregations, especially those formed by fish, can be seen in several aspects of their behavior. For instance, experiments have shown that individual fish removed from a school will have a higher respiratory rate than those found in the school. This effect has been partly attributed to stress, although hydrodynamic factors were considered more important in this particular study. The calming effect of being with conspecifics may thus provide a social motivation for remaining in an aggregation. Herring, for instance, will become very agitated if they are isolated from conspecifics. Fish schools have also been proposed to serve a reproductive function since they provide increased access to potential mates.
   In the Malili Lakes of Sulawesi, Indonesia, one species of sailfin silverside ("Telmatherina sarasinorum") is an egg predator. They often follow courting pairs of the closely related species "T. antoniae". When those pairs lay eggs, "T. sarasinorum" darts in and eats the eggs. On four different occasions in the field (out of 136 observation bouts in total), a male "T. sarasinorum" who was following a pair of courting "T. antoniae" eventually chased off the male "T. antoniae" and took his place, courting the heterospecific female. That female released eggs, at which point the male darted to the eggs and ate them.
   Many species of large predatory fish also school, including many highly migratory fish, such as tuna and some oceangoing sharks. Cetaceans such as dolphins, porpoises and whales, operate in organised social groups called "pods".
   Section::::Leadership and decision-making.
  
  Fish schools are faced with decisions they must make if they are to remain together. For example, a decision might be which direction to swim when confronted by a predator, which areas to stop and forage, or when and where to migrate.
   Subsets of bottlenose dolphin populations in Mauritania are known to engage in interspecific cooperative fishing with human fishermen. The dolphins drive a school of fish towards the shore where humans await with their nets. In the confusion of casting nets, the dolphins catch a large number of fish as well. Intraspecific cooperative foraging techniques have also been observed, and some propose that these behaviours are transmitted through cultural means. Rendell & Whitehead have proposed a structure for the study of culture in cetaceans,
   BULLET::::- Wootton, RJ (1998) "Ecology of Teleost Fishes" Springer.
  
  Section::::External links.
  
  BULLET::::- Collective Animal Behavior website organized around David Sumpter's book (2008) by the same name
  
  BULLET::::- STARFLAG project: Description of starling flocking project
  
  BULLET::::- Center for Biologically Inspired Design at Georgia Tech
  
  BULLET::::- David Sumpter's research website
  
  BULLET::::- Iain Couzin's research website
  
  BULLET::::- Website of Julia Parrish, an animal aggregation researcher
  
  BULLET::::- Pelagic Fisheries Research Program (2002) "Current status and new directions for studying schooling and aggregation behavior of pelagic fish"
  
  BULLET::::- Clover, Charles (2008) "Fish can count to four – but no higher" Telegraph Media Group.
   Some shoals engage in mobbing behaviour. For example, bluegills form large nesting colonies and sometimes attack snapping turtles. This may function to advertise their presence, drive the predator from the area, or aid in cultural transmission of predator recognition.
   The observational approach is complemented by the mathematical modelling of schools. The most common mathematical models of schools instruct the individual animals to follow three rules:
  
  BULLET::::1. Move in the same direction as your neighbour
  
  BULLET::::2. Remain close to your neighbours
  
  BULLET::::3. Avoid collisions with your neighbours
  
  An example of such a simulation is the boids program created by Craig Reynolds in 1986. Another is the self-propelled particle model introduced by Vicsek "et al." in 1995 Many current models use variations on these rules. For instance, many models implement these three rules through layered zones around each fish.
   Section::::Biological swarming.:Marine life.
  
  Section::::Biological swarming.:Marine life.:Fish.
  
  The term "shoal" can be used to describe any group of fish, including mixed-species groups, while "school" is used for more closely knit groups of the same species swimming in a highly synchronised and polarised manner.
  
  Fish derive many benefits from shoaling behaviour including defence against predators (through better predator detection and by diluting the chance of capture), enhanced foraging success, and higher success in finding a mate. It is also likely that fish benefit from shoal membership through increased hydrodynamic efficiency.
   Fish can learn how to perform a behavior simply by watching other individuals in action. This is variously called observational learning, cultural transmission, or social learning. For example, fish can learn a particular route after following an experienced leader a few times. One study trained guppies to swim through a hole marked in red while ignoring another one marked in green in order to get food on the other side of a partition; when these experienced fish (“demonstrators”) were joined by a naive one (an “observer”), the observer followed the demonstrators through the red hole, and kept the habit once the demonstrators were removed, even when the green hole now allowed food access. In the wild, juvenile French grunt follow traditional migration routes, up to 1 km long, between their daytime resting sites and their nighttime foraging areas on coral reefs; if groups of 10-20 individuals are marked and then transplanted to new populations, they follow the residents along what is for them – the transplants – a new migration route, and if the residents are then removed two days later, the transplanted grunts continue to use the new route, as well as the resting and foraging sites at both ends.
   Individual role specialization has also been observed in bottlenose dolphins. The bottlenose dolphins form groups of three to six. One dolphin acts as the “driver” and herds the fish in circles towards the “barrier dolphins” who are tightly grouped together to form a barrier. The driver performs fluke-slaps to cause the fish to leap into the air. As the fish begin to leap, the driver moves next to the barrier dolphins, who all catch the fish in the air with their mouths open. Stefanie Gazda and colleagues predict that this role specialization is more common in marine than terrestrial animals due to a higher variability in prey diversity, biomass, and predator mobility in the ocean. One specific type of cooperative feeding behavior is mud ring feeding.
   Section::::Shoaling and schooling.
  
  Many teleosts form shoals, which serve multiple purposes in different species. Schooling is sometimes an antipredator adaptation, offering improved vigilance against predators. It is often more efficient to gather food by working as a group, and individual fish optimise their strategies by choosing to join or leave a shoal. When a predator has been noticed, prey fish respond defensively, resulting in collective shoal behaviours such as synchronised movements. Responses do not consist only of attempting to hide or flee; antipredator tactics include for example scattering and reassembling. Fish also aggregate in shoals to spawn.
  
  Section::::Relationship with humans.
   Inangas could be taught to seek food in one half of their aquarium in the morning and in the other half in the afternoon, even on test days when food was withheld. However, they could not be taught to avoid one half in the morning and the other half in the afternoon in response to simulated attacks by a heron.
   One potential method by which fish schools might thwart predators is the "predator confusion effect" proposed and demonstrated by Milinski and Heller (1978). This theory is based on the idea that it becomes difficult for predators to pick out individual prey from groups because the many moving targets create a sensory overload of the predator's visual channel. Milinski and Heller's findings have been corroborated both in experiment and computer simulations. "Shoaling fish are the same size and silvery, so it is difficult for a visually oriented predator to pick an individual out of a mass of twisting, flashing fish and then have enough time to grab its prey before it disappears into the shoal."
   "The reason for this is the presence of many eyes searching for the food. Fish in shoals "share" information by monitoring each other's behaviour closely. Feeding behaviour in one fish quickly stimulates food-searching behaviour in others.
   Food stocking can be viewed potentially as an animal planning for the future. One example of short-term stocking involves climbing perch ("Anabas testudineus"). Individuals were kept singly in aquaria and fed with pellets dropped at the surface. When the pellets were dropped one after the other at 1-s intervals, the fish took them as they reached the surface and stocked them inside the mouth. On average, the fish placed 7 pellets in their mouth before moving away to consume them. When starved for 24-h before the feeding test, they doubled the number of pellets stocked (14 on average); the underside of their heads bulged under the load. The behaviour may be an indication that competition for food is normally severe in this species and that any adaptation to secure food would be beneficial.
   In a school of Pacific blue-eyes that is threatened, a few individuals accelerate and change direction, which initiates an "escape wave" that spreads through the whole cohort. Animals are known to dart in random directions and speeds as an escape response when threatened. Pacific blue-eyes on their own dart in this manner for up to ten seconds after being faced with a threat at close range. This period is briefer when faced with more distant threats or for fish in schools.
  
  Section::::Breeding.
  
raw_presuppositions: Birds flock and fish school because of biological instinct.
raw_corrections: Birds flock and fish school because of convergent evolution.