New Zealand grayling
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| New Zealand grayling | ||||||||||||||||
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| Prototroctes oxyrhynchus Günther, 1870 |
The New Zealand grayling, Prototroctes oxyrhynchus, is an extinct smelt of the genus Prototroctes, which was found only in lowland rivers and streams of New Zealand. Their length was between 20 and 40 cm.
The New Zealand grayling was a pelagic, shoaling species like the common smelt. It was widespread and common in lowland rivers and streams during summer, autumn, and winter in the early 1800s. The life cycle was probably similar to that of the whitebait species and common smelt, with the fish growing and spawning in fresh water, and the newly hatched larvae being washed out to sea to live for several months.
New Zealand grayling numbers began to reduce soon after Europeans arrived in New Zealand, and as early as the 1870s biologists were expressing concern about their decline. In 1923 the Maori medical officer Te Rangi Hiroa caught some specimens of the New Zealand grayling in the Waiapu River in the east of the North Island. (Day, D., 1981). In 1930 the British Museum acquired a specimen of unknown date and origin, which is probably the last one. The introduction of trout and widespread forest clearance that rapidly followed European settlement are thought to have contributed to their demise.
A closely related grayling species, Prototroctes maraena, still lives in Australia and studies on this grayling have provided some insight into the life of the New Zealand grayling.
[edit] References
- World Conservation Monitoring Centre (1996). Prototroctes oxyrhynchus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes a brief justification of why this species is listed as extinct
- "Prototroctes oxyrhynchus". FishBase. Ed. Ranier Froese and Daniel Pauly. March 2006 version. N.p.: FishBase, 2006.
- NIWA June 2006
- David Day (1981): The Doomsday Book of Animals.
