Ammersee ruff
| Ammersee ruff | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Gymnocephalus ambriaelacus | ||||||||||||
| Geiger & Schliewen , 2010 |
The Ammersee ruff ( Gymnocephalus ambriaelacus ) is a real bony fish from the family of real perch . It lives endemically in the Ammersee and was only described as a separate species in 2010 .
features
In 2005, the student Matthias Geiger noticed that ruffle from the Ammersee have larger eyes, a different pattern and different proportions than the nominate form of the genus Gymnocephalus , the (common) ruff ( Gymnocephalus cernua ). Genetic examinations then also corroborated the opinion, published in 2010 and now accepted by experts, that it was a separate species.
The Ammersee ruff reaches almost 12 cm in length. The color is silvery light gray. The partly yellowish fins show a series of spots. It differs from the (common) ruff in its higher back, statistically a slightly longer dorsal fin (D1 15 instead of 14), larger eyes and only small dark spots without a pattern. It differs from the Danube rump ( Gymnocephalus baloni ) in that it has slightly larger eyes, a slightly lower tail stalk, more P-fin rays (15 instead of 13) and a steeper head profile.
The Ammersee ruff has 37 lateral scales (two less than oblique rows). As with all rudders, the lateral lines of the head do not run in bone tubes, but in grooves that are only covered by thin skin on the outside - so the fish can track down food from the bottom even at night, without sight.
Fin formula : D1 XII – XV, D2 I / 10–12, A II / 5–6.
habitat
This species has only been found in the Ammersee so far. It developed for about 12,000 years after the end of the Pleistocene in this glacial rim lake, isolated from other populations. Rufffish are rarely found in lakes in the foothills of the Alps . The Ammersee ruff is most closely related to the Danube ruff. This and the common ruff are currently found in the Isar as the closest body of water, but not in the Amper , the feeder from the Ammersee.
In Middle Latin , the Ammersee was called Ambriae lacus . The selection of the species epithetons ambriaelacus was based on this term.
Probably recently introduced by carefree anglers, the common ruff Gymnocephalus cernua is now also found in the Ammersee.
Way of life
The fish spawns near the shore (at a depth of approx. 3 - 5 m) in May. The eggs float or sink to the sandy bottom. But they hardly stick to the ground.
Individual evidence
- ↑ Michal Jakubowski: A method for the manifestation of lateral-line canals and their neuromasts in fishes. Copeia, pp. 234-235, 1967
literature
- Matthias F. Geiger and Ulrich K. Schliewen: Gymnocephalus ambriaelacus, a new species of ruffe from Lake Ammersee, southern Germany (Teleostei, Perciformes, Percidae). Spixiana, 33, pp. 119-137, 2010
Web links
- Ammersee ruff on Fishbase.org (English)
- Gymnocephalus ambriaelacus in the endangered Red List species the IUCN 2012. Posted by: Freyhof, J., Kottelat, M., Smith, K., 2011. Accessed April 2, 2012th