THE WORLD'S MOST POPULAR PETS Not dogs or cats but freshwater fishes It's the same picture from the United States to the United Kingdom and beyond: freshwater fish consistently top the polls when it comes to pet numbers. Keeping a home aquarium is a truly global hobby - and one that is also good for our health. Having a fish tank (or visiting an aquarium) has been found to reduce stress, anxiety and blood pressure, and even help us to sleep50. Another study found that reduced heart rate and increased feelings of wellbeing correlated with greater fish diversity in aquaria51. It's certainly not a coincidence that many doctors' and dentists' waiting rooms have an aquarium! The World's Forgotten Fishes page 30