Alosa killarnensis
| Alosa killarnensis | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Alosa killarnensis | ||||||||||||
| ( Regan , 1916) |
Alosa killarnensis (English and Irish common names : Goureen or Killarney Shad) is a rare species of fish from the genus Alosa within the herring family. Distribution is limited to Lough Leane in Killarney National Park ,Ireland. Charles Tate Regan described this form in 1916 as a subspecies of the feint ( Alosa fallax , synonym: Alosa finta ).
features
Alosa killarnensis reaches a standard length of 200 mm. The females grow larger than the males. There are 43 to 53 thin gill-trap rays on the anterior gill arch. The body height is 67 mm, the head length 50 mm. The number of dorsal rays is 17 to 19 and the anal rays 19 to 21. 55 to 60 scales are arranged in longitudinal and 17 to 19 scales in transverse rows. The number of abdominal shields, arranged in two rows, is 21 to 22 and 15 to 16. The belly is silvery, the back is purple. There is a dark spot on the shoulder. A lateral row of about seven vertically extended dark spots extends from behind the gill cover to the rear end of the anal fin .
Way of life
Alosa killarnensis reaches a maximum age of 5 years. The spawning season is between June and July. The eggs are laid on gravel banks and in the shallow water area covered with gravel along the large islands in Lough Leane. The diet consists mainly of zooplankton .
status
Alosa killarnensis is classified by the IUCN in the category “ critically endangered ” . The species has a very small distribution area of 19 km². The main threats are the eutrophication of Lough Leane and competition from neozoa such as the roach ( Rutilus rutilus ) and the bream ( Abramis brama ).
literature
- M. Kottelat and J. Freyhof (2007): Handbook of European Freshwater Fishes . Publications Kottelat, Cornol, Switzerland, p. 71, ISBN 978-2-8399-0298-4 .