Aq11a11c Mammals 1993. 19.1. 13- 19

Information on the biology of Commerson's ( Cephalorhynchus commersonil)

1 2 3 R. A. Kastelein , J. McBain and B. Neurohr

1Hardeni·ijk .\larme .\/ammo/ POTk. Strandbou/e1·artl·oost I , 3841 AB Harden•·i;k. J/ullaml 2Sea World of Califomia. 1720 South Shores Rom/. San Diego. CA 91109 99110, USA lzoo . Muelheimerstrasse ~73. 4100 D11ish11rg.

Key words: Ceplralorlry11clrus co11u11erso11ii. food recorded the time when the red dye was passed in passage lime. metabolism. reproductioa. lactatioa. the faeces. Tests were conducted on 3 male animals. swimnung bahaviour. twice in September and once in October 1991. At Duisburg . 2 gelatine capsules with methylene blue dye were given to each of :? male Introduction Commerson 's dolphins wi1h lhe fish fed during Very lilllc is known about the Commerson's presentations (200 g Mackerel. Smmher srnmhruf. ( Ceplwlorlry11c/111s commerso11i1) due to its 250 g Herring. Clupea lrarengm. and 250 g Squid. remote distribution area around southern Chile. l/le'I: spp) The 2 capsules were frJ logether bu1 at a southern Argentina. the Falkland Islands and the different time each test day. and never at night. A Kcrguden Islands (Angot. 1954: Brownell. 1974: researcher watched the animal constantly on lest Aguayo. 1975). The small. black and while days. and n.>corded lhe time when the faeces were cetacean was first kept in human care in 1978 blue. Thi~ study was done m ovember and (Spolle er al.. 1979: Gewalt. 1990). This paper December 1991. presents some anecdotal information on passage The passage timi:s of ~•irmine red dye in 3 1imi: of food through the digestive lract, mc1abolic animals at Sea World arc shown in Table I. The rate. reproduction. suckling. weaning and swim· average passage ume was 143 min. The 2 results ming behaviour of Commerson's dolphins in from S5M in September 1991 were c:..cluded from /.oolog1cal parks. Some of lhese anecdotes may this calculation. With this small sample size. no ~timulate researchers to conduct more eluborale temporal varialion in passage times could be scientific studies. Details on the biology of the dctec1cd during the 8 hour period in which the Commerson's dolphins may provide infom1a1ion anunals were obscrveJ. The p:issage times of rcqum:d for the management of this dolphin and methylene blue Ill 2 animals al Duisburg Zoo are other ~mall loothe