New Zealand trout pike
| New Zealand trout pike | ||||||||||||
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New Zealand trout pike ( Prototroctes oxyrhynchus ) |
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| Scientific name | ||||||||||||
| Prototroctes oxyrhynchus | ||||||||||||
| Günther , 1870 |
The New Zealand trout pike ( Prototroctes oxyrhynchus ), called upokororo in the Māori language , is an extinct New Zealand fish species from the genus of trout pike within the New Zealand salmon family (Retropinnidae). Its only living relative is the Australian trout pike ( Prototroctes maraena ), which is native to Australia and Tasmania .
features
The New Zealand trout pike reached a length of 50 centimeters and a weight of over 1.4 kilograms. It was also characterized by a high dorsal fin . Its exact color is not known. Specimens caught on their way upstream from the sea were silvery with a slate-blue back. A few months later, however, specimens were often found that had a reddish-brown, gray-speckled back and a golden tint on the belly.
Way of life
His way of life has not been researched and therefore information about him is mostly speculative or based on comparisons with the Australian trout pike. Occasionally the Māori reported “large schools of mature fish migrating upstream”. It has seldom been seen further than 50 km from the salt water. He preferred fast flowing waters and the stone beds of streams and rivers . Although it has often been caught with bait hooks, its teeth and gastrointestinal tract indicate that it was primarily an algae eater. According to contemporary reports, he went looking for food at night. The New Zealand trout pike presumably lived an amphidromic way of life, that is, they spawned in fresh water and the hatched larvae were washed into the sea by the current. They developed in the plankton and returned to the spawning grounds as sexually mature animals.
die out
Until the 1860s, it was considered common on both the North Island and the South Island . However, British anglers introduced brown trout and rainbow trout to New Zealand from 1870 onwards . The trout spread quickly in New Zealand's river systems, displacing the New Zealand trout pike from their habitat. In addition, the deforestation of the shade-giving trees along the water resulted in a stronger exposure to the sun on the water surface and thus in an increase in the water temperature. In 1874 the population of the Waikato River became extinct. When a specimen was caught in 1904 and exhibited in a hotel, it was considered a great rarity. In March 1923, the Māori Te Rangi Hīroa (also known as Sir Peter Buck) caught a few specimens in the Waiapu River in northeast New Zealand. In 1930 the British Museum acquired a specimen of unknown date and origin.
literature
- Lawrence James Paul: Grayling . In: Alexander Hare McLintock (Ed.): An Encyclopaedia of New Zealand . Wellington 1966 ( online [accessed December 15, 2015]).
- David Day: The Doomsday Book of Animals . Ebury Press, London 1981, ISBN 0-670-27987-0 .
- Walton Beacham: World Wildlife Fund Guide to Extinct Species of Modern Times . 1997, ISBN 0-933833-40-7 .
Web links
- New Zealand trout pike on Fishbase.org (English)
- Prototroctes oxyrhynchus in the Red List of Threatened Species of the IUCN 2006. Posted by: World Conservation Monitoring Center, 1996. Retrieved on 28 May of 2007.
- Grayling - Prototroctes oxyrhynchus Günther, 1870. National Institute of Water and Atmospheric Research , accessed on January 6, 2016 .
- First fossils of extinct native fish identified. National Institute of Water and Atmospheric Research, November 22, 2005, accessed January 6, 2016 .