physalus

Physalus is an historical genus name that has appeared in cetacean taxonomy. In contemporary classification the fin whale is placed in the genus Balaenoptera, with the species name Balaenoptera physalus. As a result, Physalus is generally treated as a synonym or deprecated genus rather than a valid current taxon. The fin whale, Balaenoptera physalus, is one of the largest baleen whales, with adults commonly reaching up to 20–27 meters in length and weighing many tens of tons.

Distribution and habitat form a cosmopolitan pattern. Fin whales inhabit all major oceans, from subpolar to tropical waters, though they concentrate in high-latitude feeding areas during the productive seasons and migrate to warmer regions for breeding. They are typically surface-oriented swimmers and frequent deep, long-duration dives while foraging.

Feeding behavior centers on filter feeding using baleen plates. They primarily consume small schooling fish, squid, and occasionally krill, taking in large volumes of water and prey while expelling water through their baleen. Their streamlined bodies and powerful tails enable relatively fast travel for a baleen whale species.

Reproduction and population dynamics involve lengthy intervals between calves. Gestation is about 11–12 months, and calves are typically weaned after several months. Calving intervals are commonly on the order of 2–3 years, with regional variation influenced by food availability and environmental conditions.

Conservation and management have been shaped by historical whaling, which greatly reduced early populations. Today, fin whales are protected under international agreements and various national laws; main contemporary threats include bycatch, ship strikes, entanglement in gear, and climate-related changes to prey distribution.