Turban Eye

from Wikipedia, the free encyclopedia
Turban eye of the mayfly Ephemera spec.

The turban eye ( English turbinate eye ) represents the upper ( dorsal ) half of the eye of the male imago of many mayflies (Ephemeroptera). It got its name because of its turban-like appearance.

Layout and function

The turban eye has two unusual properties: its sensitivity only in the UV range and the five-armed candelabra-like shape of its rhabdomen . It is surrounded by yellow pigment, which gives the turban eye a yellow-brown color. The turban eye of Baetis notos (from the family Baetidae) is creamy white and yellowish in color.

From the structure it can be concluded that the dark yellow turban eye cannot display sharp superimposed images (like other complex eyes), but rather produces one UV pixel per ommatidium .

Since the turban eye is a noticeable part of sexual dimorphism , it should play a functional role in swarm formation or in recognizing females.

Male mayflies (not members of the families Caenidae and Tricorythidae) perform a swarm dance ( English nuptial flight ), where they often jostle in the air. Only a few females go into the swarm to mate at the same time , the others stay apart. Pairs in the swarm are not hindered by the other males. Warmth and light intensity are the most important impulses of swarm formation, their time of day is species-dependent, in warm areas mainly during the twilight period.

The upward pointing turban eyes are optimized for twilight vision in order to recognize females in the swarm (from below). But even with non-swarming species or asynchronous appearances, females can be seen from below by males with these eyes.

development

The development of the turban eye (described in Cloeon dipterum ) can be recognized in male larvae from about 4 mm, probably corresponding to the 19th larval stage, as a slight elevation, the cuticle of which later takes on a yellowish or light brownish color and thus differs greatly from neighboring areas. When the larvae molt to the already winged subimago, the system of the turban eye can be seen as a darker and clearer elevation. 24 hours later, the final moult to the imago takes place, whereby the turban eyes rise again and assume a cylindrical shape.

Occur

Fossils are turban eyes made from Burmese amber since the Lower Cretaceous .

Turban eyes have male adults of the Baetidae family and some of the Leptophlebiidae. In others like the Caenidae, Leptohyphidae or Polymitarcyidae, both sexes have similar complex eyes. The only known genus of the mayflies without turban eyes within the Baetidae is typically called Aturbina .

Individual evidence

  1. ↑ a b c G. A. Horridge, Miriam McLean: The Dorsal Eye of the Mayfly Atalophlebia (Ephemeroptera). In: Proceedings of the Royal Society of London. Series B, Biological Sciences. Volume 200, No. 1139, February 23, 1978, pp. 137-150.
  2. ^ A b Hermann Priesner: On the history of the development of the turban eyes of Cloeon dipterum L. (PDF) In: Zoologische Jahrbücher Volume 39, No. 3, 1916.
  3. ^ Richard S. Durfee, BC Kondratieff: Description of adults of Baetis notos (Ephemeroptera: Baetidae). (PDF) In: Entomological News 106, 1995, pp. 71-74.
  4. ↑ a b c K. G. Sivaramakrishnan, К. Venkataraman: Behavioral strategies of emergence, swarming, mating and imposition in mayflies. (PDF) In: Proc. Indian Acad. Sci. Volume 94. No. 3, June 1985, 351-357.
  5. ↑ Janet E. Harker: Swarm behavior and mate competition in mayflies (Ephemeroptera). In: Journal of Zoology 228, No. 4, 1992, pp. 571-587, doi: 10.1111 / j.1469-7998.1992.tb04456.x .
  6. ^ A b Eduardo Domínguez: Ephemeroptera de América del Sur . Volume 2. Aquatic biodiversity in Latin America . Pensoft Publishers, 2006, ISBN 9546422592 , ISBN 9789546422590 , p. 23.
  7. ^ W. La Baume: About the metamorphosis of the Epherimeriden. In: SB. Ges. Naturf. Frde. Berlin , No. 3, 1909, pp. 137-153.
  8. ↑ George Poinar Jr: Vetuformosa buckleyi n. Gen., N. Sp. (Ephemeroptera: Baetidae; Vetuformosinae n. Subfam.), A new subfamily of mayflies in Early Cretaceous Burmese amber. In: Historical Biology 23, No. 4, 2011, pp. 369-374, doi: 10.1080 / 08912963.2011.559084 .
  9. ↑ Eduardo Domínguez: Ephemeroptera de América del Sur . Volume 2. Aquatic biodiversity in Latin America . Pensoft Publishers, 2006, ISBN 9546422592 , ISBN 9789546422590 , p. 20.
  10. ↑ CR Lugo-Ortiz, WP McCafferty: Aturbina georgei gen. Et sp. n .: A Small Minnow mayfly (Ephemeroptera: Baetidae) without turbinate eyes. In: Aquatic Insects: International Journal of Freshwater Entomology Volume 18, No. 3, 1996, 175-183, doi: 10.1080 / 01650429609361619 .

Web links