Balaenoptera physalus

Common Name: Fin Whale

Fin Whale*
Fin Whalethumb

A Fin Whale surfaces in the Kenai Fjords, Alaska

Fin whale size.svg

Size comparison against an average human

Conservation Status
fin Status iucn3.1 EN.svg

Endangered (IUCN 3.1)

Scientific Classification
Kingdom Animalia
Phylum Chordata
Class Mammalia
Subclass Eutheria
Order Cetacea
Suborder Mysticeti
Family Balaenopteridae
Genus Balaenoptera
Species B. physalus
Binomial Name
Balaenoptera physalus
(Linnaeus, 1758)

finwhale Cetacea range map

Fin Whale range.

Source: Wikipedia

General Description: A large and sleek whale, the Fin Whale has a narrow, V-shaped snout. The top of the head is flat, with a prominent median ridge. The back, from the dorsal fin to the flukes, is distinctly ridged (‘razorback’). The ventral grooves, numbering 56 to 100, extend to the navel or beyond.

The falcate dorsal fin is up to and more than 60 cm tall. It is located about one-third the body length forward from the fluke notch.

The colouration is dark grey to brownish black on the back and sides. The head has asymmetric pigmentation, with the right lower jaw white, and the left, dark. Below, the animal is white, including the undersides of the flukes and flippers.

finwhale

Size: Adults, Males are up to 21 m long, and females, 26 m. The weight is about 80 tons. The Fin Whale is the second largest of the great whales after the Blue Whale B. musculus.Calves at birth, 6.5m long.

Appearance At Sea: At is reported that Fin Whales may be easily approached very close in a small inflatable boat. The whales are quite aware of the human presence, and exercise great caution to avoid overturning the boat.

TheThe dorsal fin, in travelling whales, appears on the surface shortly after the blow. The blow is tall (4 to 6 m high), and shaped like an inverted cone.

finwhale1

Fin Whales are known to make loud low-frequency sounds that may be heard hundreds of kilometres away under the sea. The sounds they make may be a way of keeping in contact with others, so that each Fin Whale or pair may be part of a very large herd scattered across the ocean. The throbbing of ships’ engines may interrupt such communications.

Fin Whales have more and coarser baleen plates than Blue Whales. They filter out the larger planktonic animals and small fish that travel in shoals. Fins, the only known asymmetrically coloured cetacean species, have been reported using their white right side to confuse and concentrate schools of fish. This is believed to allow them to get more fish in one gulp. Fin Whales are reported to frequently hunt in pairs.

finwhale2

Found In: Generally found in the open ocean, Fin Whales may also be seen near the coast.

Records from India: There are a number of instances of Fin Whale strandings and of live animals being caught in fishing nets in India. Strandings are also known from Pakistan and Sri Lanka. Many rorquals recorded in India have not been identified. Some of these may be Fin Whales.

Date Details Reference
[?] Five vertebrae of “Balaenoptera blythi” in the Medical College, Calcutta. De Silva, 1987
6 August 1965 One 14.10m long specimen stranded at Virar near Bombay. Grubh & Pereira, 1965
9 October 1965 One 15.10m long specimen washed ashore off Nepean Sea Road, Bombay. Grubh & Pereira, 1965;
Karbhari et al., 1966
April 1970 A 13.50m long specimen found at Candolim, north of Panaji. Dhawan, 1970
13 August 1971 Carcass of 14.05m long whale found off Magdalla near Surat,
about 8 km upstream in the river Tapti.
Karbhari, 1973
22 January 1983 Young Fin Whale washed ashore at Akkamadam, Rameswaram Island. Nammalwar et al., 1983
15 June 1988 Female 4.69m long landed at Pudumanaikuppam, Madras. Subramani, 1989;
Anonymous, 1988a
15 March 1989 A 14.02m long female specimen stranded at Ullal, South Kanara. Kulkarni et al., 1989
14 April 1991 Carcass about 10m long at Kodi Kanyana (Kota), Karnataka. Purandhara & Vaman Naik,
1992
20 November 1995 A 6.8m specimen stranded on rocks at Kanyakumari. Joel et al., 1996

World Distribution: The Fin Whale has a wide distribution, being found in all waters, but is less common in the tropics.

Could Be Confused With: There is a possibility of confusion with the Sei Whale Balaenoptera borealis and Bryde’s Whale Balaenoptera edeni. They can be distinguished as follows:

Species Fin Back Scarring Ridges Diving
Fin Whale Angle of 50° from back; visible long after blow. Dark back Seldom scarred One ridge on head Longest dives 5–15 minutes
Sei Whale Angle of 30°; visible simultaneously with blow. Shiny back Often scarred One ridge on head Short dives of 3–6 minutes
Bryde's Whale Angle of 70°; visible son after blow. Dark back Sometimes scarred Three ridges on head Fairly long dives of 4–10 minutes

Diagnostic Features: At sea, Small dorsal fin placed well back on the body; flat head.

Stranded Specimens: There are 260 to 480 baleen plates on each side, reaching a maximum length of 72 cm and width of 30 cm. The front baleen plates on the right side are white or yellowish white. The remainder of the baleen plates on the right side, and all those on the left side, are striped with alternate bands of yellowish white and bluish grey. The fringes of the plates are brownish grey to greyish white.

Note: A species of baleen whale Balaenoptera omurai has been described recently. This species is reported to be similar to but smaller in size than the Fin Whale, B. physalus. Further, the occurrence in the northern Indian Ocean has been questioned recently. The species in the region needs or need to be confirmed.

* According to the current understanding of distribution, these species are not present in the Northern Indian ocean.