Gerridae
Sandpipers at the mating
The Sandpipers ( Gerridae - colloquially and regionally also tailor or water cutter ) are a family within the suborder of bugs (Heteroptera ). They occur in Europe with 16 species, of which 10 live species of the genus Gerris in Central Europe. The species are very difficult to distinguish from each other.
Features
Sandpipers are 8 to 10 millimeters long and are equipped with their physique the stream runners ( Veliidae ) are very similar. They have a very slender and elongated body that is completely covered with fine hairs that repel water. The hairs on their tarsi allow the animals to move quickly with the help of surface tension on the water surface without sinking it. The rear pair of legs, with which they control the direction and the middle pair of legs, which transmits the force of the movement, are very long, but the front legs are short and are only used for prey catching. Sandpipers have well-developed compound eyes and can see very well. The wings of various types are different well developed. Even within the same species there are all variations on the absence of wings over vestigial to well-formed wings ( Flügelpolymorphismus ); the formation is related to the intensity of the incident light together during the development of the larvae. Only animals with fully developed wings can fly.
Occurrence
The animals usually live in stagnant water and hold off on the water surface mostly in large groups. Some species, however, have specialized to live on flowing waters. The wingless species of the genus Halo Bates, the subfamily of the sea water striders ( Halobantinae ) belong to the year-round living on the coast. However, there are species that live on the high seas. They must lay their eggs on floating debris.
Way of life
Water striders live in moderately polluted water and require a water temperature of 11-15 ° C. They feed on prey on various insects that fall into the water. The survival rowing animals irritate the sensitive vibration sense organs in the legs, causing the prey can be located. The movement is done with even rowing the middle leg pairs, where the animals up to 1.5 m / s can be very fast. Similarly, 30 to 40 centimeters high and long jumps can be observed.
Development
The Sandpipers mate in spring to early summer. The females lay their eggs but distributed over several months available to plants near the water surface. The resulting hatching larvae go through five instars. In Europe, they overwinter as adult animals on land.
Twelve water runners at the collective consumption of a drowned bee
A sea water striders of the genus Halo Bates
Sandpipers at the mating
European Species
- Aquarius cinereus ( Puton, 1869)
- Aquarius najas ( De Geer, 1773)
- Aquarius paludum (Fabricius, 1794)
- Aquarius ventralis (fever, 1860)
- Gerris argentatus cheat, 1832
- Gerris Brasili Poisson, 1941
- Gerris gibbifer cheat, 1832
- Common Redshank ( Gerris lacustris ) (Linnaeus, 1758)
- Gerris maculatus Tamanini, 1946
- Gerris odontogaster ( Zetterstedt, 1828)
- Gerris sphagnetorum Gaunitz, 1947
- Gerris thoracic cheat, 1832
- Gerris asper (fever, 1860)
- Gerris lateralis cheat, 1832
- Limnoporus rufoscutellatus ( Latreille, 1807)
Non-European types (selection)
- Genus sea water striders ( Halo Bates )
- Type Potamobates Anchicayá (from Central America ( Panama ) to South America ( Ecuador) )
Fossil evidence
Sandpipers were identified from southwest France ( Charente- Maritime) in about 100 million years old Cretaceous amber. This is the oldest fossil representatives of this family at all. Other finds are known from the much younger Baltic amber and Dominican amber. The conservation wasserbewohnender organisms in amber requires exceptional circumstances and is therefore very rare.