This 2010 video from the USA is called Dr. Jonathan Balcombe on Individuality in Fish.
From Wildlife Extra:
Researcher finds that fish are intelligent and feel pain like humans
New research suggests that fish are, in fact, far more intelligent than many previously believed.
They have very good memories, live in complex social communities where they keep track of individuals, and can learn from one another. This helps to develop stable cultural traditions.
Fish even recognise themselves and others. They also cooperate with one another and show signs of Machiavellian intelligence, such as cooperation and reconciliation. They build complex structures, are capable of using tools, and use the same methods for keeping track of quantities as humans do.
For the most part the primary senses of fish are just as good, says Brown, and in many cases better than those of humans.
Their behaviour is very much the same as that of primates, except that fish do not have the ability to imitate.
The Australian researcher believes that most people rarely think about fish other than as food, or as pets.
However, they are second only to mice in terms of the numbers used in scientific research, and more than 32,000 known species of fish far outweigh the diversity of all other vertebrates combined.
Very little public concern – which is so important to inform policy – is ever noted about fish welfare issues.
Brown says this relates to incorrect perceptions about the intelligence of fish, and ultimately of whether they are conscious. Such attitudes are also influenced because humans rarely come into contact with fish in their natural environments.
Brown’s review focused especially on bony fish. The level of mental complexity they displayed he found to be on a par with most other vertebrates, and there is mounting evidence that they can feel pain in a manner similar to humans.
While the brains of fish differ from other vertebrates, they have many analogous structures that perform similar functions. Brown concludes that if any animals are sentient, fish must be considered to be so, too.
“Although scientists cannot provide a definitive answer on the level of consciousness for any non-human vertebrate, the extensive evidence of fish behavioural and cognitive sophistication and pain perception suggests that best practice would be to lend fish the same level of protection as any other vertebrate,” concludes Brown, who acknowledges that such a move has implications for the fishing industry, among others.
“We should therefore include fish in our ‘moral circle’ and afford them the protection they deserve.”
This video is called Orange-Dotted Tuskfish Uses Tool.
Cichlid fish memory lasts for days, not seconds: here.
A single gene called Angiopoietin-1 (Ang-1) drives brain size and intelligence in fish according to a new study by researchers at UCL, Stockholm University and University of Helsinki: here.