Description & Behavior
Finless porpoises, Neophocaena phocaenoides (G. Cuvier, 1829), aka black porpoises, black finless porpoises, Jiangzhu, Shushuk, and Limbur, are distinguished and named for their lack of a dorsal fin. Instead, their back has a small ridge that begins just behind the blowhole and extends to the tail flukes; the ridge is covered in small circular bumps known as tubercles.They have a small, curving mouth and unfused neck vertebrae, which allows unrestricted head movement. About 50% o finless porpoises have pink eyes. The streamlined body is blue-gray in color (in Japan and northern China, the adults are a light gray), which darkens to black after death. They reach a maximum of 1.9 m in length and these small cetaceans weigh just 30-45 kg.
There are three subspecies of finless porpoises, Neophocaena phocaenoides:
- Finless porpoise (Indian Ocean), N. phocaenoides phocaenoides
- Finless porpoise (West Pacific), N. phocaenoides sunameri
- Finless porpoise (Yangtze), N. phocaenoides asiaeorientalis
Their lifespan thought to be between 10-20 years.
World Range & Habitat
Finless porpoises, Neophocaena phocaenoides, are found in warm, shallow coastal waters and all major rivers of the Indian and western Pacific Oceans. They have been observed in groups of between 1-4 individuals, though aggregations of 20-50 are not uncommon. They are known to “spy hop”, a behavior where they raise their head vertically from the water until the eyes are exposed then they lower their head back into the water. There are reports of mothers carrying their calves upon their backs.
Feeding Behavior (Ecology)
Finless porpoises, Neophocaena phocaenoides, feed upon fish, shrimp, prawns, and octopuses.
Finless porpoises, Neophocaena phocaenoides, are apparently about 0.75-0.85 m at birth. Reproduction has been studied in Japanese and Chinese waters, which has shown that sexual maturity occurs between 3-6 years of age and calving occurs at different times of the year in different regions.
Conservation Status & Comments
Pakistan operates a small directed fishery of finless porpoises. In China they are under legal protection, though they are declining due to habitat destruction. Some are caught accidentally in fishing gear as bycatch around Sri Lanka and Japan.
References & Further Research
OBIS-SEAMAP – Species Profiles
Jefferson, T.A., S. Leatherwood, and M.A. Webber, FAO species identification guide, Marine mammals of the world, Rome, FAO. 1993. 320 p. 587 figs.
AMANO, M. 2002. Finless porpoise Neophocaena phocaenoides sinus. Pp. 432-435 in W. F. Perrin, B. Wursig and J. G. M. Thewissen, eds. Encyclopedia of marine mammals. Academic Press.
Research Neophocaena phocaenoides @
Barcode of Life ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History Ichthyology Department ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species Database ~ WoRMS