Sato's beaked whale

Sato's beaked whale Temporal range: Middle Miocene to present, 11.5–0  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Illustration of Berardius minimus (black scale bar is 1 metre [3.3 ft])
Size compared to an average human
Conservation status
Near Threatened  (IUCN 3.1) [1]
CITES Appendix I (CITES) [2]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Suborder:	Whippomorpha
Infraorder:	Cetacea
Family:	Ziphiidae
Genus:	Berardius
Species:	B. minimus
Binomial name
Berardius minimus Yamada, Kitamura & Matsuishi, 2019

Sato's beaked whale (Berardius minimus; Japanese: Kurotsuchi-kujira) is a little-known species of four-toothed whale, a type of beaked whale. ^[3]

Description

Sato's beaked whale is one of the poorly distinguished species in the genus Berardius . It was distinguished from Arnoux's and Baird's beaked whale in 2019 on the basis of mtDNA differences. ^{[4] [5]} It generally has a short beak (~4% body length). While other four-toothed whales are generally grey with long linear scars, kurotsuchi-kujira usually have few linear scars, so that the dark, smooth skin contrasts highly with round, white scars of about 5 cm diameter, most likely from cookiecutter shark bites. ^[5] The common name for Berardius minimus is in recognition of Hal Sato, a Hokkaido-based researcher whose photographs of the whales helped to distinguish this species from other beaked whales (note the image credit in Figure 1 and Figure 2 from the Yamada et. al. paper ^[5] ). ^{[6] [7]}

Distribution

The species' distribution, based on genetic samples from strandings only, is believed to include the southern Sea of Okhotsk north of Hokkaido, the Commander Islands, and the southeastern Bering Sea. ^[5]

Diet

Sato’s beaked whale is an elusive deep diving whale. ^[8] Despite this, there is a basic understanding of their behavior and diet. Similar to the other deep diving beaked whales of the genus Berardius , Sato’s beaked whale feeds primarily on deep dwelling fish and squid living in the benthic or mesopelagic zones. ^[9] Like Biard’s and Arnoux’s beaked whales, this species is thought to feed through suction feeding, resulting in a significant reduction in the number of functional teeth. ^[9]

Reproduction

This species of beaked whale travels in small, mixed groups with both females and males traveling together in pods. ^[9] Unlike other species of beaked whales, both male and female Sato’s beaked whales have been seen with scarring. ^[9] This scarring is believed to stem from teeth raking caused by competition and males' access to females. ^[9]

Conservation

Although very little is known about the ecology and populations of Sato's beaked whale, the IUCN has assigned the species a classification of Near threatened based on its estimated low population numbers. ^[1]

References

1. Brownell Jr., R.L. (2020). "Berardius minimus". IUCN Red List of Threatened Species . 2020: e.T178756893A178756918. doi: 10.2305/IUCN.UK.2020-3.RLTS.T178756893A178756918.en . Retrieved 4 December 2023.
2. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
3. "Berardius minimus Yamada, Kitamura & Matsuishi in Yamada, Kitamura, Abe, Tajima, Matsuda, Mead & Matsuishi, 2019". Catalogue of Life . Species 2000: Leiden, the Netherlands. Retrieved 17 July 2021.
4. Morin, P. A.; Scott Baker, C.; Brewer, R. S.; Burdin, A. M.; Dalebout, M. L.; Dines, J. P.; Fedutin, I.; Filatova, O.; Hoyt, E.; Jung, J.-L.; Lauf, M.; Potter, C. W.; Richard, G.; Ridgway, M.; Robertson, K. M.; Wade, P. R. (2016). "Genetic structure of the beaked whale genus Berardius in the North Pacific, with genetic evidence for a new species". Marine Mammal Science. 33: 96–111. doi:10.1111/mms.12345. S2CID   88899974.
5. Yamada, T.K.; Kitamura, S.; Abe, S.; Tajima, Y.; Matsuda, A.; Mead, J.G.; Matsuishi, T.F. (2019). "Description of a new species of beaked whale (Berardius) found in the North Pacific". Scientific Reports. 9 (1): 12723. Bibcode:2019NatSR...912723Y. doi: 10.1038/s41598-019-46703-w . PMC   6717206 . PMID   31471538.
6. Bidal, Devon. "Scientists Had Never Seen This Elusive Whale Alive—Until Now". Hakai Magazine. Retrieved 2023-01-06.
7. Hathaway, Rozi. "An Illustrated Tribute to the Sato's Beaked Whale". Hakai Magazine. Retrieved 2023-01-06.
8. Brownell Jr., Robert L.; Kasuya, Toshio. "Sato's beaked whale: A new cetacean species discovered around Japan". Marine Mammal Science. 37 (2) – via National Oceanic and Atmosphere Administration.
9. Alves, Filipe; Mesnick, Sarah L.; Rosso, Massimiliano; Pitman, Robert L. (2023), Würsig, Bernd; Orbach, Dara N. (eds.), "Beaked Whale Sexual Dimorphism, Mating Strategies, and Diversification" , Sex in Cetaceans: Morphology, Behavior, and the Evolution of Sexual Strategies, Cham: Springer International Publishing, pp. 385–413, doi:10.1007/978-3-031-35651-3_17, ISBN   978-3-031-35651-3 , retrieved 2025-04-21