Cetaceans

Last modified: Wednesday December 6th, 2000

Classification of whales

order Cetacea
The cetacean suborders
A note on the taxonomy of whales and dolphins
Classification of the sperm whales
Sources for the names in different languages

order Cetacea
Mysticeti		Baleen Whales
		Baardwalvissen
		Bartenwale
		Bardehvaler
		Hetulavalaat
		Bardvalar
		Bardehvaler
		Mysticètes
		Misticeti
		Ballenas de barbas
Odontoceti		Toothed Whales
		Tandwalvissen
		Zahnwale
		Tannhvaler
		Hammasvalaat
		Tandvalar
		Tandhvaler
		Odontocètes
		Odontoceti
		Ballenas dentadas

The cetacean suborders

The modern cetaceans, the order Cetacea, are represented by two suborders: the baleen whales or Mysticeti and the toothed whales or Odontoceti. The third suborder, the Archeoceti is now extinct. The main differences between the two groups are:

Mysticeti	Odontoceti
No teeth. Instead they have keratin baleen plates, suspended from the roof of the mouth	All species have teeth. There number of teeth varies from 2 in some beaked whales to more than 250 in some dolphin species.
Two nasal openings (or blowholes)	Single nasal opening (or blowhole)
The skull is symmetrical	The skull is asymmetrical
The melon is present only in the fetal stage and absent or poorly developed in adults. They have no echolocation capabilities.	The melon is well developed. It plays a major role in echolocation.

Mysticete skeleton (right whale)

Odontocete skeleton (killer whale)

A note on the taxonomy of whales and dolphins

The taxonomy of cetaceans is still subject to change. Recent developments in the fields of paleontology, molecular biology (especially DNA sequencing) and phylogeny have led to new insights into this area. In a recent publication, Rice (1998) proposed a number of new cetaceans families and a species status for some varieties that may or may not have been accepted as subspecies before. In addition, some species names have been altered.

In the following pages, I have used the more traditional list of species and families, but where there are differences between this list and the one proposed by Rice, I have added the new names (and inserted family names) marked with ^‡.

Reference

Rice, D.W. (1998): Marine mammals of the world - Systematics and distribution
Society of Marine Mammalogy Special Publication Number 4, 231 pp.

Classification of the sperm whales

The sperm whales are currently classified as toothed whales, but there is a growing body of evidence that they are actually closer to the baleen whales than to the toothed whales. This is based on the following data:

Examination of mitochondrial ribosomal DNA sequences
The embryonal development of the nasal structures in sperm whales resembles that of the baleen whales.
Sperm whales have 2 air ducts ending leading to a single blowhole, so although the sperm whale has only one external blowhole (an odontocete feature), the internal air ducts suggests a double air passage, much like that in mysticetes (baleen whales).
Baleen whales currently have no echolocation, but have most likely had that capability in the past. In baleen whales fetuses, evidence of a vestigial melon has been found. The melon is the "acoustical lens" needed for echolocation in toothed whales. So the baleen whales may have had echolocation, but lost it later.

Based on this the relationships between the cetacean groups may be as follows. Note that especially the placement of the beaked whales (Ziphiidae) and the river dolphins (Platanistidae) is still unclear.

For more information see:

Evans, P.G.H (1987): The natural history of whales and dolphins. Christopher Helm, London
Klima, M. (1995): Cetacean phylogeny and systematics based on the morphogenesis of the nasal skull. Aquatic Mammals 21(2):79-89
Milinkovitch, M.C., Orti, G. and Meyer, A. (1993): Revised phylogeny of whales by mitochondrial ribosomal DNA sequences. Nature 361: 346-348

Sources for the names in different languages:

Note: There are no set rules for non-scientific animal names. The lists of common names provided in the following pages is by no means exhaustive and there can be any number of different regional names for a certain species within any language. Some species may not have a common name in certain languages. The lists of common names are based on the sources listed below. Corrections and/or additions are welcome. If you wish to provide a list of common names in a language not yet listed on this site, you can download a species list here. This is a Word document. Return it by e-mail to jaap@rosmarus.com

	M. Klinowksa (1991) Dolphins, Porpoises and Whales of the World. The IUCN Red Data Book IUCN, Gland, Switzerland and Cambridge, U.K.
	M. Camm and B. Stonehouse (1983) (Translation: M.A. IJsseling & A. Scheyground) Zeezoogdieren. Thieme, Zutphen, the Netherlands
	A. Collet (1999) (Translation: Jutta Koch) Tanz mit den Walen. Econ & List Taschenbuch Verlag, München, Germany
	D. W. MacDonald (ed.) (1985) (Translation: Ragnar Frislid) Verdens dyr - Havets pattedyr. J.W. Cappelens Forlag A-S, Oslo, Norway
	Finnish names kindly provided by University of Helsinki and Tampereen Särkänniemi OY.
	B. Stonehouse and M. Camm (1983) (Translation: Lennart Stenberg) Haverts däggdjur. Wahlström & Widstrand, Stockholm, Sweden.
	M. Carwardine (1997) (Translation: Carl Kinze) Hvaler og delfiner i farver. Politikens Forlag A/S, Copenhagen, Denmark
	French names kindly provided by Anne Collet
	Italian names kindly provided by Alessandro Bortolotto (Zoönomia)
	T.A. Jefferson, S. Leatherwood and M.A. Webber (1996) Marine mammals of the world. ETI World Biodiversity Database CD-ROM series. Expert Center for Taxonomic Identification, Amsterdam, The Netherlands Additional Spanish names kindly provided by Alfred Boeren
	Portugese names kindly provided by Pedro Martins (Projecto Delfim)