Ninespine stickleback
Nine-spined stickleback
The nine -spined stickleback ( Pungitius pungitius ), even small stickleback, dwarf stickleback or Stechelstange, is a predominantly live in small bodies of water fish.
As well as most other stickleback species and the nine -spined stickleback has virtually no economic importance. The remarkable thing about him, however, is its insensitivity to poor water conditions.
Distribution and habitat
The nine -spined stickleback usually lives in small inland waters, such as ditches and ponds but also in quiet parts of streams and rivers. In brackish and salt water, it is also to be found. Preference is flat, plant -covered areas. This Stichlingsart is quite insensitive to widely fluctuating water quality, as is typical for small bodies of water.
The distribution area is not yet fully investigated, but it is clear that it is very similar to the three-spined stickleback, but not so far extends to the south. In Northern Germany appreciable populations, especially in the catchment areas of the rivers Elbe and Eider and the Baltic Sea can be found. In southern Germany, the nine -spined stickleback lives isolated in tributaries of the River Main. This southern occurrences are, however, possibly due to stocking by aquarists.
Overall, the species is much less common than the three-spined stickleback and missing in the Mediterranean, Norway and Scotland completely.
The live in salt and brackish water populations migrate to the spawning period in freshwater.
Features
As already hint at some of the common names, nine -spined stickleback remains quite small with a length of five to seven centimeters. His body is slender and laterally compressed. The eyes are relatively large. The lower jaw of the small and slightly above permanent mouth before jumping, forming the tip of the head. In older males the jaw edges are thickened beaded. Before the soft-rayed dorsal fin located between eight and eleven, but usually only nine to ten, retractable spikes. The pelvic fins also each carry a powerful sting. The spines are almost always smooth edges.
The top of the nine -spined stickleback is gray-green to brown, the sides lighter and silvery shimmering. Animals from the seagrass beds of the Baltic Sea or waters with high iron content can show an intense shiny brass. There are often irregularly distributed dark spots or transverse bands on the flanks. The spawning season Hull, Iris and fin rays take the male specimens of a matte, more or little intense black. A striking contrast in breeding plumage form then glaring white pectoral spines. Immediately before spawning also takes the genital papilla of the male in this white coloring. In terms of color during the spawning period, there are also different observations, such as greenish shades on the belly and reddish tones on the head.
The family- typical signs of the sides of the body is dependent population less pronounced. In the nominate form is reduced to a weakly keeled scutes on the caudal peduncle. Only one subspecies is fully signposted, a subspecies is completely naked. The nine -spined stickleback has ten to 14 Kiemenreusenzähnchen.
Fins formula:
- Dorsal 1 IX -X (VIII- XI)
- Dorsal 2 10-12
- Anal I/9-11
- Pectoral 9-10
- Ventral II / 1
- Caudal 12
Behavior
The nine -spined stickleback feeds mostly on invertebrates, where he thereof almost everything eats what he can overpower.
The reproductive behavior of nine -spined stickleback is related to its larger cousins , the three-spined stickleback. However, the tons nest is generally not built on the ground, but usually suspended between plants.
Outside the breeding season of nine -spined stickleback lives mainly solitary and is remarkably shy. In imminent danger he tried to hide in the mud or in the vegetation. During the run, he also attempts to kick up mud by groundings and " darken " so the attacker to view.
Males are usually only 3 years old, the females can reach 5 years.
Subspecies
Intraspecific the nine -spined stickleback is once again differentiated into several subspecies, these differ mainly in terms of distribution area and signage. However, the taxonomic problems here are significant, so the outline is subject to frequent changes.
- P. pungitius pungitius
- P. sinensis pungitius
- P. laevis pungitius
- P. occidentalis pungitius
- Sakhalin- spined stickleback ( P. pungitius tymensis )
(after Keivany & Nelson)