Fish are common in most water bodies around the world. They are found in almost all aquatic environments from the deepest parts of the ocean to the streams of the high mountains. There are about 33,600 species of fish known today. Fish are an essential resource to humans across the world, particularly as food.
Fish have played a significant role in the culture of humans since time immemorial, and they have served as religious symbols, deities, and have been subjects of movies and books. The majority of fish are ectothermic which means they are cold blood and can vary their body temperatures with the change in temperature. Some of the world's giant fish like the white shark have a higher core temperature.
The World's Most Common Types of Fish
Grass Carp (Ctenopharyngodon idellus)
The grass carp has the largest aquaculture population in the world with a commercial catch of 5,028,661 tons annually. This fish species inhabits freshwater, and it is a herbivorous fish native to eastern parts of Asia and northern regions of Vietnam to the Amur River in the Siberia-China border. The fish is relatively large and was introduced to Europe and the US to control aquatic weeds. It can tolerate a broad range of temperatures and will reproduce and spawn in temperatures ranging between 68 and 86 degrees Fahrenheit. China is the leading producer of the Grass Carp, and the reason why it is widely preferred in aquaculture is because it grows quickly and requires relatively little dietary protein.
Peruvian anchoveta (Engraulis ringens)
The Peruvian anchoveta is a fish species that is native to the south-east Pacific Ocean. It is the second most frequently caught of any fish species in the world, having an annual harvest that varies from 4.2 to 8.3 million tons. The fish is one of the most exploited in the world with the highest catch occurring in 1971 that reached 13.1 million tons. However, its population has been declining over the years, mostly due to overfishing.
Silver carp (Hypophthalmichthys molitrix)
The silver carp fish is also widely cultivated. It is also known as the flying fish and is invasive in some countries. The origin of the fish is eastern Siberia and China, and it is one of the highly caught fish having commercial harvesting of 4.2 million tons annually. The fish can grow to an average length of 24 to 39 inches with a maximum length of 55 inches. It can weigh up to 110 pounds. The fish species is a filter feeder having a specialized feeding apparatus which can filter particles as small as 4 microns. The fish have no stomach, and they feed almost continuously primarily on phytoplankton. They also consume detritus and zooplankton.
Overfishing has been a significant problem for some time. In fact, if the current rates of fishing continue, the world could very well run out of fish in future. According to FAOSTAT, almost 90% of the world's fish stocks are either overfished or fully fished. FAO reports state that world consumption of fish per capita is at an all-time high level due to high demand and every person consumes an average of 44 pounds of fish every year this was in contrast to the 1960s when the average consumption was at 22 pounds per person.
In the Black and the Mediterranean Seas, 59% of all the fish stocks are fished at levels that are not sustainable. Additionally, there have been invasive fish species in the region because of climate change which has affected the native fish.