although the neuweltlichen tremor and knife-eels the old-terrestrial knife-fish Z. T. sees extremely similarly, they are not nearer relative with these. they rather represent an American side-branch of the carp-fish.
System One distinguishes 4 families today: the tremor-eels or electric eels (Electrophoridae), the real knife-eels (Gymnotidae), the American knife-fish (Rhamphichthidae) and the tail flukes*-knife-eels (Apteronotidae). they are called also American knife-fish.
Characteristics While the electric eels in the look remind something of our native river-eels, the other tremor-eels have one extremely leveled off, knife-sound-similar body-form. This odd fish-shape is created through displacement of the Leibeshöhle forward, with simultaneous strong extension of the tail-section. The anus-fin turns into a long hem (up to 500 fin-rays of a type), that extends from the gill-region to the tail-top. Is back and tail fluke more or less receded on the other hand, and the stomach-fin is missing completely.
The long anus-fin is used for the locomotion of these fish. Through undulating fin-hit, it is able to urge on the animals even with completely stiff body just as well onward like backwards. This way, the predatory tremor-eels can creep up quite very well on loot-animals without recognizable body-movements. All tremor-eels have only very small eyes; they are usually night-active.
Real knife-eels (family Gymnotidae)) The most known representative of this species-poor family is the Gebänderte knife-fish widespread in South America, striped knife-eel or Carapo (Gymnotus carapo, until 60 cm). In the tail-region, this fish like all tremor-eels carries an admittedly only weak electric organ, with whose help the fish generates an electric field in its surroundings and can get the bearings well also at night so. Disturbances of the electric field through other fish or smaller loot-animals are registered by sensitive Sinneszellen. The formation of such electric bearings-organs reminds of the African Nile-pikes, to whom however, no nearer relationship exists. The frequency of the electric jolts fluctuates from type to type and depends also on the arousal-condition of the animals. With growing arousal, also the hit-frequency increases. The striped knife-eel normally generates electric signals with a frequency of 30-60 Hz. Comparative measurements at other tremor-eels resulted in values of 2-1000 Hz.
American knife-fish (family Rhamphichthidae)) From this family, the long-beak-knife-fish (Rhamphichthys rostratus) also reminds something of the African Nile-pikes through its trunk-nicely moved out mouth externally. This knife-fish long until 1,5 m is mainly widespread in the Amazon-basin and is regarded as valuable food-fish. Also the sand-knife-fish (Gymnorhamphichthys hypostomus), who occurs in the same area, carries a similar muzzle-formation. Both types scour sandy underground after loot-animals with its "trunk." they are placed (Rhamphichthyinae) because of its deviant food-acquisition and the adaptation interconnected with it into an independent subfamily.
All other types of the family are kurzschnauzige robbery-fish as well as. Small animal-hunters (subfamily Sternopyginae). The most known glass-knife-fish (type Eigenmannia) is the Greens party knife-fish (Eigenmannia virescens) long until 45 cm, who lives in the northern South America. it carries a long, lash-good fort-sentence on the tail-end instead of a tail fluke.
Tail flukes*-knife-eels (family Apteronotidae)) These tremor-eels owe its name of the usually very small tail fluke, that is clearly taken off the remaining body at a short, thin tail-stalk. they differ from the other bare-eels also in the form of the back-fin. This is changed to a thread-good fort-sentence, whose meaning is unknown until now. Under the numerous types, we also find forms, that resemble African Nile-pikes in conspicuous manner, like Z. B. the trunk or tapir-knife-eels (type Sternarchorhynchus) or the pointed-beak-knife-eels (type Sternarchorhamphus). The muzzle-formations equipped with feels and taste-cells also serve here the tracking down of small animals in mud. Other types from this family carry big mouths and are fish and cancer-hunters.
Actual tremor - or electric eels (family Electrophoridae)) The single type of the family, the tremor-eel (Electrophorus electricus) takes a special-position in some sense one, that justifies it, to place it into an independent family. it yields, as mentions, with its cylindrical shape very much from the other bare-eels from. As well, it also becomes significantly bigger than its relatives up to 2,30 m of length. it spreads, rounded and leveled off head carries a mighty mouth and marks this fish as robbers from the start. it hunts freshwater-shrimps and fish in the youth.
Electric organs However, its sophisticated electric organs are protruding characteristic of the Zitteraales. Beside weak electric bearings-fields, that the tremor-eel like all other bare-eels also generates, it is able to distribute essentially stronger electric hits. These electric jolts even deaden standing mammals big in the water. The strong electric impulses become from 2 massive ones, generates lain organs, that take up four fifth of the length, at the rear end of the body on both sides of the spinal column. they were created from muscles and consist of thousand of column-shaped one on the other-standing Elektroblasten. Beside these organs, there are even further, smaller organs, that serve the production of the weak bearings-impulses. The main-organ generates tension-pushes of over 550 volts with a maximum amperage of barely 2 amperes and achieves up to 1 kilowatts consequently. However, the discharge lasts only 2-3 thousandth of seconds. A powerful, full-grown tremor-eel can hand over until 150 discharges in the hour. Primarily, the mighty electric organ probably serves defense-purposes. However, one knows that the tremor-eel with its discharges deadened also other fish and amphibians and then consumed.
Scientific name: