Pjotter
male Pacific walrus (O. r. divergens)
wild caught in 1978
deceased in 1984
Ancestors and Descendants
None.
Transfer History
capture 1978 on Wrangel Island, Russia
transfer 1978 to Dolfinarium Harderwijk
death 1984 at Dolfinarium Harderwijk
Physical Data
The dates listed here generally represent the time at which the measurements were published, not necessarily the date on which they were taken.
Weight
1978: 60 kg · 132 lb
1984: 750 kg · 1,653 lb
Diet
"The animals were fed 3 to 6 times per day on an average diet of 35% herring (Clupea harengus; approx. 8880 kJ/kg), 26% mackerel (Scomber scombrus; approx. 9550 kJ/kg), 9% sprat (Sprattus sprattus; approx. 10.400 kJ/kg), 2% whiting (Merlangius merlangus; approx. 4750 kJ/kg), and 28% squid (Illex spp.; approx. 1000 kJ/kg) by weight. Vitamins (Seavit>, 1 tablet per 2.5 kg of food) were added to this thawed diet." (R. A. Kastelein et al, 2000)
1980: 5,500 kg · 12,125 lb annually
1982: 6,000 kg · 13,227 lb annually
Image Gallery
No images available at this time.
Identifiers
Local
OrZH005 (Dolfinarium Harderwijk)
Notes and Information
This walrus died of a tusk infection at 6 years of age.
Pjotter was estimated to have been born in June of 1978, and arrived at Harderwijk when he was 2 months old, placing his date of transfer around August.
Pjotter's skull is held in the collection of the University of Utrecht's Veterinary Faculty.
References
1984-Jul-28. Leidsch Dagblad. Dolfinarium Harderwijk. Retrieved from Erfgoed Leiden.
1990-Jan. R. A. Kastelein and N. M. Gerrits. The anatomy of the Walrus head (Odobenus rosmarus). Part 1: The skull. Retrieved from the Aquatic Mammals Journal.
2000-Jan. R. A. Kastelein et al. Food consumption and body weight of captive Pacific walruses (Odobenus rosmarus divergens). Retrieved from researchgate.net [archive]