Like the larger blue whale, fins are baleen whales. They filter feed on small organisms such as crustaceans, squid and small fish by taking in large quantities of water into their mouths, and then forcing the water back out again through their baleen. The baleen are long, vertical plates made out of keratin and suspended in the whale’s mouth analogous to teeth. Unlike teeth however, they are fibrous, and capture food by acting like a strainer. Water is able to filter past, but organisms remain trapped by the baleen. A single fin whale can ingest 1,800 Kg of food each day, which means that the whales typically need to spend around 3 hours each day foraging for food. When hunting for small schooling fish, they often use their speed to corral their prey into a tight ball which they then consume and filter back through their baleen.