Finless porpoise

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Finless porpoise
Neophocaena phocaenoides -Miyajima Aquarium -Japan-8a.jpg
Neophocaena sunameri at Miyajima Public Aquarium
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Suborder: Whippomorpha
Infraorder: Cetacea
Family: Phocoenidae
Genus: Neophocaena
Palmer, 1899
Type species
Delphinus phocaenoides [1]
Cuvier, 1829
Species

Neophocaena asiaeorientalis
Neophocaena phocaenoides
Neophocaena sunameri

Jiang Tun De Fen Bu .svg
For all three finless porpoise species

Neophocaena is a genus of porpoise native to the Indian and Pacific oceans, as well as the freshwater habitats of the Yangtze River basin in China. They are commonly known as finless porpoises. Genetic studies indicate that Neophocaena is the most basal living member of the porpoise family. [2]

There are three species in this genus: [3] [4]

ImageScientific nameCommon nameDistribution
Yangtze finless porpoise, 12 February 2008a.jpg Neophocaena asiaeorientalis Yangtze finless porpoise Yangtze River basin in China
Stamps of Indonesia, 040-05.jpg Neophocaena phocaenoides Indo-Pacific finless porpoise Persian Gulf east to the Taiwan Strait, south to Indonesia
Neophocaena phocaenoides DSC 03.jpg Neophocaena sunameri East Asian finless porpoise Taiwan Strait north to the Yellow Sea, east to the east coast of Japan

Description

The finless porpoises are the only porpoises to lack a true dorsal fin. Instead there is a low ridge covered in thick skin bearing several lines of tiny tubercles. In addition, the forehead is unusually steep compared with those of other porpoises. With fifteen to twenty-one teeth in each jaw, they also have, on average, fewer teeth than other porpoises, although there is some overlap, and this is a not a reliable means of distinguishing them. [5] Finless porpoises in Ariake Sound-Tachibana Bay showed ontogenctic and seasonal variations in diet. The mean length at weaning was estimated to be 101 cm, corresponding to approximately 6 months of age. Calves fed on small-sized demersal fish and cephalopods. [6]

References

  1. Wilson, D. E.; Reeder, D. M., eds. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. ISBN   978-0-8018-8221-0. OCLC   62265494.
  2. Rosel, P. E.; et al. (1995). "Phylogenetic relationships among the true porpoises (Cetacea: Phocoenidae)". Molecular Phylogenetics and Evolution. 4 (4): 463–474. Bibcode:1995MolPE...4..463R. doi:10.1006/mpev.1995.1043. PMID   8747302.
  3. Mammal Diversity Database (2021-08-10), Mammal Diversity Database, doi:10.5281/zenodo.5175993 , retrieved 2021-08-28
  4. "Finless Porpoises: Neophocaena phocaenoides, N. asiaeorientalis". Encyclopedia of Marine Mammals . 2018-01-01. pp. 372–375. doi:10.1016/B978-0-12-804327-1.00129-1. ISBN   978-0-12-804327-1.
  5. Jefferson, T. A.; Hung, S. K. (2004). "Neophocaena phocaenoides". Mammalian Species. 746: 1–12. doi: 10.1644/746 . S2CID   198125391.
  6. Shirakihara, Miki; Seki, Kenji; Takemura, Akira; Shirakihara, Kunio; Yoshida, Hideyoshi; Yamazaki, Takeshi (2008-10-01). "Food Habits of Finless Porpoises Neophocaena phocaenoides in Western Kyushu, Japan". Journal of Mammalogy. 89 (5): 1248–1256. doi: 10.1644/07-MAMM-A-264.1 . ISSN   0022-2372.