Sperm whale of the Society for Marine Mammalogy, the largest international association of marine mammal scientists in the world, officially uses "Physeter macrocephalus" when publishing their definitive list of marine mammal species. The sperm whale is the largest toothed whale, with adult males measuring up to long and weighing up to . By contrast, the second largest toothed whale (Baird's Beaked Whale) measures and weighs up to . The Nantucket Whaling Museum has a -long jawbone. The museum claims that this individual was long; the whale that sank the "Essex" (one of the incidents behind "Moby-Dick") was claimed to be . A
Blue whale penis immature categorized whale was and the smallest penis of a mature whale was . By comparison the average blue whale penis is nearly 3 times the size of that of a sei whale. Specimen measurements indicate that a blue whale measuring in length had a vestigial mammary slit of width and length, with a penis measurement of . In another specimen in which the length of the whale was and weighed 50.9 metric tons, the brain weighed only . The Icelandic Phallological Museum has a portion of a blue whale's penis measuring long and weighing , which "Iceland Review" has