The unique dorsal fin of Burmeister’s porpoise rises at a very shallow angle from behind the midpoint of the back, and the trailing edge is straight to convex. Additionally, there are tubercles along the leading edge of the fin (this characteristic gave the species its scientific name). Other than this, the species has a rather typical phocoenid body form, with a blunt, nearly beakless head and broad-based flippers with rounded tips.
Coloration is dark charcoal to gray, with lighter gray streaks on the chin and belly. Burmeister’s porpoises have dark eye patches, dark lips, and dark chin-to-flipper stripes (well-defined by lighter areas above and below). These flipper stripes are asymmetrical; they are narrower and extend further forward on the right side. Teeth number 10-23 in each upper tooth row and 14-23 in each lower row. As in other phocoenids, the teeth are spatulate.
Most adults are up to 1.85 m in length, although animals from Uruguay up to 2.0 m have been recorded. Newborns are 0.8-0.9 m. Maximum weight is about 85 kg.
Can be Confused With
Burmeister’s porpoises can be confused with South American fur seals and southern sea lions, which often stick their fins in the air (these can look like Burmeister’s porpoise dorsal fins). They can also be confused with Chilean dolphins off the east coast of South America. Dorsal fin shape will be the best cue to distinguish them. Differences in coloration, dorsal fin shape, and swimming style should allow Burmeister’s porpoises to be distinguished easily from Commerson’s dolphins and spectacled porpoises, and head shape will be the best characteristic to allow distinction from franciscana.
Burmeister’s porpoises are distributed in coastal waters of South America, from southern Brazil, south to Cape Horn in Tierra del Fuego, and north to northern Peru.
Ecology and Behavior
Very little is known about the natural history of this species. Most sightings are of less than six individuals, but aggregations of up to 70 have been reported. Behavior of this species is inconspicuous; they surface with little surface disturbance.
There appears to be a protracted summer birth peak; most births in Peru apparently occur in late summer to fall.
Feeding and Prey
Feeding is on demersal and pelagic fish species, such as anchovies and hake, as well as squid and shrimps.
Threats and Status
Burmeister’s porpoises are taken incidentally in fishing nets, especially gillnets throughout their range. In southern Chile, porpoises may be killed directly by harpooning. Most of the these kills are not known to be large, but in Peru, up to 2,000 per year are taken, and the meat may be used for human consumption. Currently, they are listed as ‘Data Deficient’ (IUCN) and ‘Not Listed’ (ESA).
Brownell, Jr., R.L. and P.J. Clapham. 1999. Burmeister’s porpoise Phocoena spinipinnis Burmeister, 1865. pp. 393-410 in S.H. Ridgway and R. Harrison, eds. Handbook of marine mammals, Vol. 6: The second book of dolphins and the porpoises. Academic Press.
Goodall, R.N.P., K.S. Norris, G. Harris, J.A. Oporto and H.P. Castello. 1995. Notes on the biology of the Burmeister’s porpoise, Phocoena spinipinnis, off southern South America. Reports of the International Whaling Commission Special Issue 16:317-348.
Goodall, R.N.P., B. Würsig , M. Würsig, G. Harris and K.S. Norris. 1995. Sightings of Burmeister’s porpoise, Phocoena spinipinnis, off southern South America. Reports of the International Whaling Commission Special Issue 16:297-316.
Reyes, J.C., 2002. Burmeister’s porpoise Phocoena spinipinnis. pp. 177-179 in W.F. Perrin, B. Würsig and J.G.M. Thewissen, eds. Encyclopedia of marine mammals. Academic Press.
Reyes, J.C. and K. Van Waerebeek. 1995. Aspects of the biology of Burmeister’s porpoise from Peru. Reports of the International Whaling Commission Special Issue 16:349-364.