Hostname: page-component-848d4c4894-p2v8j Total loading time: 0.001 Render date: 2024-05-21T02:25:08.924Z Has data issue: false hasContentIssue false

Identification of stomach contents from a Shepherd's beaked whale Tasmacetus shepherdi stranded on Tristan da Cunha, South Atlantic

Published online by Cambridge University Press:  21 November 2012

P.B. Best*
Affiliation:
Mammal Research Institute, University of Pretoria, c/o Iziko South African Museum, PO Box 61, Cape Town, 8000, South Africa
M.J. Smale
Affiliation:
Port Elizabeth Museum at Bayworld, Bayworld Centre for Research and Education, PO Box 13147, Humewood, 6013 South Africa, and Department of Zoology, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031, South Africa
J. Glass
Affiliation:
Director of Fisheries, Fisheries Department, Tristan da Cunha Government, South Atlantic Ocean
K. Herian
Affiliation:
Royal Society for the Protection of Birds Project Officer, Conservation Department, Tristan da Cunha, South Atlantic Ocean
S. Von Der Heyden
Affiliation:
Evolutionary Genomics Group, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland, 7602South Africa
*
Correspondence should be addressed to: P.B. Best, Mammal Research Institute, University of Pretoria, c/o Iziko South African Museum, PO Box 61, Cape Town, 8000, South Africa email: pbest@iziko.org.za

Abstract

Shepherd's beaked whale Tasmacetus shepherdi is one of the most poorly known cetaceans, whose diet has created some speculation given that its dentition differs greatly from that of most other beaked whales that are primarily teuthophagous. The few stomachs examined previously have given seemingly conflicting dietary information. In this paper the stomach contents of a freshly stranded adult female on Tristan da Cunha have been examined through identification of trace elements and genetic analysis of soft parts. At least 13 cephalopod and 8 fish species were identified from beaks and otoliths respectively, but only undigested fish remains were present in the stomach and identified genetically as Beryx splendens. Reconstituted masses totaled 8809 g for cephalopods and 17,554 g for fish, with four species (Histioteuthis atlantica, Taningia danae, Ommastrephes bartrami and Pholidoteuthis ‘A’) comprising 78.6% of the cephalopods and one species (B. splendens) comprising 87.4% of the fish eaten. It is concluded that Tasmacetus may alternately exploit fish and cephalopods, depending on the time of day and access to seamount or continental slope areas.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 2012 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Andrew, T.G., Hecht, T., Heemstra, P.C. and Lutjeharms, J.R.E. (1995) Fishes of the Tristan da Cunha group and Gough Island, South Atlantic Ocean. Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology 63, 143.Google Scholar
Bowen, W.D. (2000) Reconstruction of pinniped diets: accounting for complete digestion of otoliths and cephalopod beaks. Canadian Journal of Fisheries and Aquatic Sciences 57, 898905.CrossRefGoogle Scholar
Bulman, C.M. and Koslow, J.A. (1992) Diet and food consumption of a deep-sea fish, orange roughy Hoplostethus atlanticus (Pisces: Trachichthyidae), off south-eastern Australia. Marine Ecology Progress Series 82, 115129.CrossRefGoogle Scholar
Clarke, M.R. (1986) A handbook for the identification of cephalopod beaks. Oxford: Clarendon Press.Google Scholar
Clarke, M. (2007) Seamounts and cephalopods. In Pitcher, T.J., Morato, T., Hart, P.J.B., Clarke, M.R., Haggan, N. and Santos, R.S. (eds) Seamounts: ecology, conservation and management. Fish and Aquatic Resources Series. Oxford: Blackwell, pp. 207229.CrossRefGoogle Scholar
Dürr, J. and González, J.A. (2002) Feeding habits of Beryx splendens and Beryx decadactylus (Berycidae) off the Canary Islands. Fisheries Research 54, 363374.CrossRefGoogle Scholar
Goodall, R.N.P., Dellabianca, N., Boy, C.C., Benegas, L.G., Pimper, L.E. and Ricciadelli, L. (2008) Review of small cetaceans stranded or incidentally captured on the coasts of Tierra del Fuego, Argentina, over 33 years. Paper SC/60/SM21 submitted to the Scientific Committee of the International Whaling Commission, Santiago, Chile, June 2008.Google Scholar
Ivanova, N.V., Zemlak, T.S., Hanner, R.H. and Hebert, P.D.N. (2007) Universal primer cocktails for fish DNA barcoding. Molecular Ecology Notes 7, 544548.CrossRefGoogle Scholar
Kubodera, T., Koyama, Y. and Mori, K. (2007) Observations of wild hunting behaviour and bioluminescence of a large, deep-sea, eight-armed squid, Taningia danae. Proceedings of the Royal Society, B 274, 10291034.CrossRefGoogle ScholarPubMed
MacLeod, C.D., Santos, M.B., Lopez, A. and Pierce, G.J. (2006) Relative prey size consumption in toothed whales: implications for prey selection and level of specialisation. Marine Ecology Progress Series 326, 295307.CrossRefGoogle Scholar
Mead, J.G. (1989) Shepherd's beaked whale—Tasmacetus shepherdi Oliver, 1937. In Ridgway, S.H. and Harrison, R. (eds) Handbook of marine mammals. Volume 4. River dolphins and the larger toothed whales. London: Academic Press, pp. 309320.Google Scholar
Mead, J.G. (2009) Shepherd's beaked whale Tasmacetus shepherdi. In Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (eds) Encyclopedia of marine mammals. 2nd edition. Amsterdam, Boston, Heidelberg, London, New York, Oxford, Paris, San Diego, San Francisco, Singapore, Sydney and Tokyo: Academic Press, pp. 10111014.CrossRefGoogle Scholar
Mead, J.G. and Payne, R.S. (1975) A specimen of the Tasman beaked whale, Tasmacetus shepherdi, from Argentina. Journal of Mammalogy 56, 213218.CrossRefGoogle Scholar
Moiseev, S.I. (1991) Observation of the vertical distribution and behavior of nektonic squids using manned submersibles. Bulletin of Marine Science 49, 446456.Google Scholar
Paxton, J.R. (1999) Berycidae. Alfonsinos. In Carpenter, K.E. and Niem, V.H. (eds) FAO species identification guide for fishery purposes. The living marine resources of the western central Pacific. Volume 4. Bony fishes. Part 2 (Mugilidae to Carangidae). Rome: FAO, pp. 22182220.Google Scholar
Pitman, R.L., Van Helden, A., Best, P.B. and Pym, A. (2006) Shepherd's beaked whale (Tasmacetus shepherdi): information on appearance and biology based on strandings and at-sea observations. Marine Mammal Science 22, 744755.CrossRefGoogle Scholar
Sekiguchi, K. and Best, P.B. (1997) In vitro digestibility of some prey species of dolphins. Fishery Bulletin, US. 95, 386393.Google Scholar
Smale, M.J., Watson, G. and Hecht, T. (1995) Otolith atlas of southern African marine fishes. Ichthyological Monographs 1. Grahamstown, South Africa: J.L.B. Smith Institute of Ichthyology, 253 pp.CrossRefGoogle Scholar
Tuset, V.M., Lombarte, A. and Assis, C.A. (2008) Otolith atlas for the western Mediterranean, north and central eastern Atlantic. Barcelona: Scientia Marina, 72S1, 203 pp.Google Scholar
Young, R.E. (1978) Vertical distribution and photosensitive vesicles of pelagic cephalopods from Hawaiian waters. Fishery Bulletin, US 76, 583615.Google Scholar
Xavier, J.C. and Cherel, Y. (2009) Cephalopod beak guide for the Southern Ocean. Cambridge: British Antarctic Survey, 129 pp.Google Scholar