Perch

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Perch
Nandus nandus, copper engraving for the first description by Francis Hamilton in 1822

Nandus nandus ,
copper engraving for the first description by
Francis Hamilton in 1822

Systematics
Spinefish (Acanthopterygii)
Perch relatives (Percomorphaceae)
Order : Climbing fish species (Anabantiformes)
Subordination : Nandoidei
Family : Nandidae
Genre : Perch
Scientific name of the  family
Nandidae
Günther , 1861
Scientific name of the  genus
Rhea
Valenciennes , 1831

The Nanderbarsche ( Nandus ) are a genus of perch-related freshwater fish and today the only genus of the monotypical family Nandidae. They are common in South and Southeast Asia.

features

The most noticeable common features are the relatively large head with large eyes and the wide, flexible mouth with the deeply cut mouth. The body of all species is irregularly spotted in different earth and gray tones, this coloration and patterning imitates dead leaves ( mimesis ), whereby they are camouflaged as predators and at the same time protected from predators. This irregularity is reinforced by the typical enormous color changing capacity, with which the appearance can be completely changed within a few moments. However , there are always three dark bands that run from the eye towards the tip of the snout, the attachment of the dorsal fin and the lower edge of the gill cover . This, as well as the unmistakable snout profile, distinguishes the perch from all other perch-like freshwater fish in Asia. Clearly developed spines in the hard-nosed part of the dorsal fin are another characteristic of the family. The total lengths are between eight and fifteen centimeters.

ecology

Nander perch populate the catchment areas of large rivers on the Indian subcontinent and the Southeast Asian mainland , with the Mekong system representing the eastern limit of distribution. The spread to the south is proven by evidence on the Malay Peninsula and on the two large Sunda Islands Borneo and Sumatra .

All sea perches live solitary. In bank areas, between vegetation or dead wood, but also slowly flowing or stagnant water over stony ground, they lurk almost motionless for prey, which consists mostly of fish, but also small crustaceans , molluscs and large insect larvae . In contrast to the Polycentridae , they also track their prey. By suddenly opening the mouth, the prey is attracted as a result of the resulting negative pressure.

Reproduction

Nander perch do not care for broods. Males and females spawn after violent courtship and while twisting around the body, several thousand 0.7 to 0.8 millimeter small eggs , which adhere to various substrates in the immediate vicinity of the spawning site with their animal pole. The larvae are three to five millimeters in size and hatch after about a day and a half. They are equipped with a relatively large supply of yolk and an oil ball that allows them to float freely in the water. In addition, they have the ability to attach themselves to various surfaces with their belly side through adhesive cells on the yolk sac.

Systematics

The genus Nandus was established by Achille Valenciennes in 1831 . The genus type is the Nandus nandus from the Ganges Delta in India, described by Francis Hamilton in 1822 as Coius nandus .

The family was first described by Albert Günther in 1861 . In the course of time, numerous perch species were assigned to the Nandidae family, which are now in their own fish families : blue perch ( Badidae), sawscale perch (Pristolepididae) and multi-spined fish (Polycentridae). The definition of the Nandidae that is valid today was made in 2002 by Ralf Britz and Sven O. Kullander .

species

Individual evidence

  1. ^ R. Britz: Egg surface structure and larval cement glands in nandid and badid fishes (Teleostei, Percomorpha), with remarks on phylogeny and zoogeography . American Museum Novitates, 3195 pp. 1-17, 1977
  2. ↑ R. Britz & R. Rucksack: On the reproductive biology of the nander and blue perch . The Aqu. u. Terr. Zeitschrift ( DATZ ), 53, 5, pp. 18-21 & 53, 6, pp. 10-14, 1997
  3. ^ A. Valenciennes in G. Cuvier and A. Valenciennes (1831): Histoire naturelle des poissons . Tome septième. Livre septième. Of the Squamipennes. Livre huitième. Des poissons à pharyngiens labyrinthiformes. Historie naturelle des poissons. Tome Sixième. 7: i-xxix + 1-531, Pls. 170-208.
  4. ^ F. Hamilton (formerly Buchanan) (1822): An account of the fishes found in the river Ganges and its branches . Edinburgh & London.
  5. ^ Albert Günther: Catalog of the fishes in the British Museum. Catalog of the acanthopterygian fishes in the collection of the British Museum. , Vol. 3, pp. 362, 1861, online
  6. ^ Franz Hermann Troschel: Report on the achievements in ichthyology during the year 1861. In: Archive for Natural History, 28: 2, 1862, p. 202, online
  7. ^ SO Kullander & R. Britz (2002): Revision of the family Badidae (Teleostei: Perciformes), with description of a new genus and ten new species . Ichthyological Exploration of Freshwaters 13 (no. 4): 295-372.
  8. ^ JE Gray (1830-35): Illustrations of Indian zoology; chiefly selected from the collection of Major-General Hardwicke, FRS , 20 parts in 2 vols.
  9. ↑ HH Ng, C. Vidthayanon & PKL Ng (1996): Nandus oxyrhynchus, a new species of leaf fish (Teleostei: Nandidae) from the Mekong Basin . The Raffles Bulletin of Zoology 44 (no.1): 11-19.
  10. ↑ P. Chakrabarty, RG Oldfield & HH Ng: Nandus prolixus, a new species of leaf fish from northeastern Borneo (Teleostei: Perciformes: Nandidae) . Zootaxa 1328, pp. 51-61, 2006
  11. ↑ HH Ng & Z. Jaafar (2008): A new species of leaf fish, Nandus andrewi (Teleostei: Perciformes: Nandidae) from northeastern India . Zootaxa 1731: 24-32.
  12. ↑ HH Ng: Nandus mercatus (Teleostei: Perciformes: Nandidae), an new leaf fish from Sumatra . Zootaxa, 1963, pp. 43-53, 2008

Web links

Commons : Nandus  - collection of images, videos and audio files