Claw tails

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Claw tails
Daphnia spec.

Daphnia spec.

without rank: Primordial mouths (protostomia)
Over trunk : Molting animals (Ecdysozoa)
Trunk : Arthropod (arthropoda)
Sub-stem : Crustaceans (Crustacea)
Class : Gill pods (Branchiopoda)
Order : Claw tails
Scientific name
Eriksson , 1934

The claw tails or water fleas in the broader sense (Onychura) represent a summary of the following leaf pods : Spinicaudata , Laevicaudata , Ctenopoda , Anomopoda , Onychopoda and Haplopoda .

The way of life and construction of the individual subgroups differ greatly and can therefore be found in the articles on the subgroups.

The following diagnostic (recognition) features of the claw tails are to be mentioned:

  1. Growing strips on the shell ( carapace ), as the outer walls of the shell are not shed during the moult
  2. a strongly developed 2nd antenna that serves as a swimming leg
  3. Breeding space in the shell behind the back of the female, the eggs and embryos are attached via thread-like leg appendages
  4. short abdomen ( pleon ) drawn into the shell
  5. backward-facing claws on the abdomen fork ( furca ) for cleaning the inside of the shell
  6. long bristles on the last segment ( telson )
  7. strong approach of the complex eyes in the middle of the head
  8. Clamp hooks in males on the 1st pair of trunk legs for attachment during copulation

Autapomorphies , which speak as arguments for a monophyly of the claw tails ( onychura ), are the secondary body-enveloping carapace , the reduction of the primary carapace to a head shield and the claw nature of the tail fork (furka).

The claw tails are classically divided into the mussel shells ("Conchostraca") and the water fleas ("Cladocera"), both groups probably not forming natural groups. Today it is assumed that the Spinicaudata and Laevicaudata, formerly combined as mussel shells, represent original forms of the claw tails from which the Ctenopoda, Anomopoda and Haplopoda, formerly combined as water fleas, have developed in various subgroups (Fryer (1987), Walossek (1993), Make up (1997)). Ax (1999) considers at least the group of water fleas (Cladocera) to be a natural group.

The exact phylogenetic relationships between the individual subgroups are currently under discussion.


  • Ax P (1999): "The system of the Metazoa II. A textbook of phylogenetic systematics"; Gustav Fischer Verlag.
  • Flößner (1972): "Crustaceans, Crustacea. Gill and leaf feet, Branchiopoda. Fish lice, Branchiura."; Die Tierwelt Deutschlands 60, 1-501, Gustav Fischer Verlag
  • Gruner HE (1993): "Class Crustacea"; in Gruner HE (Ed.): "Textbook of Special Zoology, Volume I, Part 4: Arthropoda (without Insecta)"; Gustav Fischer Verlag
  • Schminke HK (1997): "Crustacea, Krebse"; in Westheide, Rieger (Ed.): "Special Zoology Part 1: Protozoa and Invertebrates"; Gustav Fischer Verlag