Neophocaena phocaenoides

Common Name: Finless Porpoise

Finless Porpoise

At Miyajima Public Aquarium, Japan Size comparison against an average human

Conservation Status

Vulnerable (IUCN 3.1)[1]

Scientific Classification

Kingdom Animalia Phylum Chordata Class Mammalia Subclass Eutheria Order Cetacea Suborder Odontoceti Family Phocoenidae Genus Neophocaena Species N. phocaenoides

Binomial Name

Neophocaena phocaenoides (G. Cuvier, 1829) Finless Porpoise range.

Source: Wikipedia

General Description: The Finless Porpoise, like the Irrawaddy Dolphin Orcaella brevirostris, is said to present the appearance of a small Beluga Delphinapterus leucas. It has a small head, with the blowhole on top. The melon is rounded, and there is no beak. The mouthline is curved upwards towards the eye. Behind the blowhole is a slight depression, like a neck crease. The animal enjoys flexibility of this neck, and the head can be rotated freely. Interestingly, this is a facility also enjoyed by the Beluga, which is classified in a different family.

The dorsal fin is completely absent, and an area of the skin behind where the fin should be, is dark and covered with small rounded projections. The Finless Porpoise’s flippers are relatively long with blunt tips. The colour is uniform grey, often with a bluish tinge. The lips and chin of this animal are lighter.

The name ‘Finless Black Porpoise’ was once widely used for this species. This is not very apt, as the porpoise turns black only after death.

Size: Finless Porpoises grow to a maximum length of about 1.9 m. They weigh 30 to 45 kg.

Appearance At Sea: Generally found in pairs, groups of up to 10 Finless Porpoises are sometimes seen. Young calves are said to travel clinging to their mothers' backs.The Finless Porpoise is said to make a chirping sound, this being one of the reasons for its Malayalam name Eleyan eedi.

While breathing they rise so that they just touch the surface with their blowholes. The lack of dorsal fin makes it look as though the back is submerged but it in fact reaches the surface enough to reveal the absence of the fin.

After 3-4 abrupt breaths the porpoises dive for 45-75 seconds, often surfacing around 100m away. They are quick and lively underwater, swimming just beneath the surface with sudden, darting or circling movements.

Finless Porpoises are often found in the company of Indo-Pacific Hump-backed Dolphins Sousa chinensis.

Found In: These porpoises inhabit inshore coastal waters and estuaries, and are said to frequent rivers. They feed mainly on crustaceans.

Records from India: There are many instances of this porpoise being washed ashore or being found in fishermen’s catches, or entangled in gill nets. These are generally single specimens, but up to 17 animals have been caught together. An account of a group of porpoises being driven into a lagoon and slaughtered in the Laccadive (now Lakshadweep) Islands in the 1930s is given by R. W. Burton in the Journal of the Bombay Natural History Society.

Date	Details	References
1827	Skulls, an incomplete skeleton and a mounted specimen collected by Dussumier from Malabar coast, in the Museum National d’Histoire Naturelle,Laboratoire d’Anatomie Comparee.	De Silva, 1987
1866 [?]	“Delphinapterus molagen” described by Owen from “Madras”.	De Silva, 1987
1908	Several specimens purchased at Trivandrum.	Pillay, 1926
[?]	Skull and foetus from the mouth of Bombay Harbour in the British Museum (Natural History).	De Silva, 1987
[?]	Three skulls from the Malabar coast in the Bombay Natural History Society.	De Silva, 1987
December 1935 [?]	Ten porpoises slaughtered in a lagoon in the Laccadives.	Burton, 1940
12 November 1959	Seventeen porpoises landed in a large shore seine and two more together at Malpe on the South Kanara coast. Four embryos recovered.	Dawson, 1959
12 February 1965	One female caught off Karwar.	Devaraj & Sam Bennett, 1974
10 February 1973	One young female specimen caught in gillnet off Calicut.	Balan, 1976
1976	Eight caught in gillnets off the Calicut coast.	Lal Mohan, 1985
20 February 1980	One caught near the mouth of the Zoari river off Vasco-da-Gama, one foetus recovered.	Hafeezullah, 1984
July 1983–December 1986	One male and two females landed at Cochin Fisheries Harbour.	Jayaprakash et al., 1995
January–March 1986	Two porpoises washed ashore at Gahirmatha, Orissa coast.	James et al., 1989
January–March 1987	Two porpoises washed ashore at Gahirmatha, Orissa coast.	James et al., 1989
8 July 1988	One 77 cm long female landed at Mandapam.	Nammalwar et al., 1994
11 August 1990	One 1.32 m long female landed at Pillaimadam, near Mandapam.	Nammalwar et al., 1994
16 November 1990	One 1.26 m female landed at Verkodu, Rameswaram.	Nammalwar et al., 1994
January 1992	Three specimens stranded or washed ashore near Thondi, Tamilnadu, in one week in a 5 km stretch of beach.	Ganapathy, 1992
29 January 1992	One immature male, 1.39 m long, collected from Porto Novo during an inshore gillnet operation.	Kumaran & Subramanian, 1993
25 October 1992	One 1.32 m long male landed at Agnitheertham, Rameswaram.	Nammalwar et al., 1994
1993 [?]	One male specimen entangled in gillnets off the Calicut coast.	Lal Mohan, 1995
14 September 1995	One young porpoise found washed ashore at Ullal, near Mangalore.	Muthiah, 1995

There seem to be few records from Sri Lanka, though a number of strandings have been noted in Pakistan.

World Distribution: The Finless Porpoise is found in coastal waters of the Indo-Pacific, from Pakistan and India to China, Korea and Japan, including South-East Asia and Indonesia. In China, it shares the habitat of the highly endangered Beiji Lipotes vexillifer, a river dolphin, in the Yangtze River.

Could Be Confused With: There is a possibility of confusion with the Irrawaddy Dolphin Orcaella brevirostris, which also occurs in the same area.

Species	Size	Colour	Fin
Finless Porpoise	Small	The shade is more blue than gray.	Dorsal fin absent
Irrawaddy Dolphin	Relatively large	The shade is more gray than blue.	Dorsal fin with rounded tip present

Diagnostic Features: At sea, Absence of dorsal fin, rounded melon, absence of beak.

Stranded specimens: There are 13 to 22 pairs of spade-shaped teeth in each jaw. The shape of the teeth, and the tubercles on the back where the dorsal fin should be make it easy to identify a dead Finless Porpoise.