A formal introduction

With plenty of little-known and newly discovered cetacean species roaming our oceans, here is just a handful that you may not have heard of…

1 ANTARCTIC MINKE WHALE

Balaenoptera bonaerensis

Declared a new species in 1998, when it was formally split from the slightly smaller common minke whale (though we now know that the two species diverged sometime around 4.7–7.5 million years ago).

2 DERANIYAGALA’S BEAKED WHALE

Mesoplodon hotaula

Currently known from only 11 confirmed specimens and a handful of tentative sightings at sea, this poorly known beaked whale was originally described in 1963 but wasn’t formally accepted as a separate species until 2014.

3 NORTH PACIFIC RIGHT WHALE

Eubalaena japonica

4 NORTH ATLANTIC RIGHT WHALE

Eubalaena glacialis

The so-called northern right whale was split in 2000 into the North Atlantic right whale and the North Pacific right whale, due to genetic differences between both the whales and their lice.

5 DWARF BAIRD’S BEAKED WHALE OR KARASU

Berardius sp

The existence of a new species of Baird’s beaked whale has been speculated for decades. Just eight dead specimens have been found – from the Sea of Okhotsk and Alaska.

6 INDO-PACIFIC FINLESS PORPOISE

Neophocaena phocaenoides

7 NARROW-RIDGED FINLESS PORPOISE

Neophocaena asiaeorientalis

In 2009 it was officially agreed that, instead of one species of finless porpoise, there are actually two, which are reproductively isolated and can be told apart in the wild.

8 AUSTRALIAN SNUBFIN DOLPHIN

Orcaellaheinsohni

Until recently, the Australian snubfin dolphin was regarded as a form of Irrawaddy dolphin, but was declared a separate species in 2005.

9 SPADE-TOOTHED WHALE

Mesoplodontraversii

Everything we know about the spadetoothed whale is from two strandings (a mother-and-calf pair, and one adult male), two weathered skulls and a single jawbone with teeth.

10 PERRIN’S BEAKED WHALE

Mesoplodonperrini

Officially named in 2002, this is one of the least-known of all large mammals. All information is based on a handful of stranded specimens in southern California.

11 GUIANA DOLPHIN

Sotaliaguianensis

At first glance, the Guiana dolphin resembles a small bottlenose dolphin. But it is most closely related to the tucuxi. The two species were separated in 2007.

12 INDIAN OCEAN HUMPBACK DOLPHIN

Sousaplumbea

Recent work now describes four species of humpback dolphins (instead of two): Indian Ocean, Into-Pacific, Australian and Atlantic.

13 PERUVIAN BEAKED WHALE

Mesoplodonperuvianus

There is evidence that this is the previously unnamed species known for years merely as ‘ Mesoplodon species A’. Recently, it has become the most frequently sighted Mesoplodon beaked whale in the sub-tropical and tropical eastern Pacific Ocean (although, of course, this is relative).

14 OMURA’S WHALE

Balaenopteraomurai

Named in 2003 (making it the most recently described living species of baleen whale), Omura’s whale was originally believed to be a small member of the ‘Bryde’s whale complex’.