Description & Behavior
Stejneger’s beaked whales, Mesoplodon stejnegeri (True, 1885), aka saber-toothed beaked whales, Bering Sea beaked whales, and North Pacific beaked whales, range in length from 3-7 m, usually averaging more than 5.3 m. Females are typically longer than males with larger heads. Adults of both sexes are dark gray to black and females usually have paler coloring on their ventral (under) sides. M. stejnegeri is distinguished from other Mesoplodon species by the shape and position of their 2 tusk-like teeth located on their lower jaw, which are larger in males. The bodies of the males are often scarred from the tusks, which are used during competitions for females during mating seasons.
Beaked Whales (Family Ziphiidae)
These medium-sized to moderately large whales have a single pair of grooves on their throats. They have a distinct snout, and often the few teeth present are visible only in adult males. They have a single nostril or blowhole. Beaked whales are generally slender with small dorsal fins toward the rear on their backs. The rear edge of their flukes (tails) usually lack a well-defined notch. These whales are deep divers and are rarely seen. Many species are known only from a few specimens, and little is known about the life history and biology of the group. All members of this family, except Blainville’s beaked whales, are difficult to distinguish from each other, and study by museum experts is usually necessary for identification.
World Range & Habitat
Stejneger’s beaked whales, Mesoplodon stejnegeri, are found from the Bering Sea to the coasts of California and Japan in deep, temperate waters of the Northern Pacific Ocean far from shore.
M. stejnegeri has been observed co-existing with Mesoplodon carlhubbsi where their ranges overlap off the coast of northern Japan to Oregon and British Columbia.
Feeding Behavior (Ecology)
Very little data exist about the reproduction of Stejneger’s beaked whales. It is thought that, like other beaked whale species, females give birth to one calf in spring or summer.
Conservation Status & Comments
Commercial fisheries, primarily in Japan, catch a small number of Stejneger’s beaked whales yearly.
References & Further Research
Research Mesoplodon stejnegeri @
Barcode of Life ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History Ichthyology Department ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species Database ~ WoRMS