Cambaridae

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Cambaridae
Red American crayfish

Red American crayfish

Systematics
Class : Higher crabs (Malacostraca)
Order : Decapods (decapoda)
Subordination : Pleocyemata
Partial order : Large crayfish (Astacidea)
Superfamily : Crayfish (Astacoidea)
Family : Cambaridae
Scientific name
Cambaridae
Hobbs , 1942

The Cambaridae are the largest of the three families of the (northern hemisphere) crayfish (Astacoidea). It includes more than 460 species.

features

The species of the family Cambaridae are rather small compared to other large crustaceans , the genus of the dwarf crayfish ( Cambarellus ) rarely becomes longer than 3 to 4 centimeters, the length of the other genera reaches a maximum of 15 centimeters.

The body consists of a head and chest area, the cephalothorax and an articulated abdomen, the pleon. The front part of the body is covered by a thick armor, the carapace , which ends in a pointed extension, the rostrum. The carapace length is measured without the rostrum and is called the postorbital carapace length. Five pairs of legs (pereiopods) sit on the front body, the first pair of legs being transformed into large claws. The remaining four pairs of legs can also carry small scissors and serve as walking legs. The gills, which are used for breathing, hang from them. The rear end of the crabs is formed by the tail fan , which consists of the telson and the uropods . The eyes are complex eyes , with two pairs of antennae on the head.

The shape of the male gonopods, i.e. the extremities of the first abdominal segment, is also important for species differentiation .

distribution

The family is limited in its natural distribution to the North American continent, where a genus of the Astacidae family also lives. Most species are native to North America east of the North American continental divide .

Some North American species of the Cambaridae have been introduced to other continents, including the red marsh kebab ( Procambarus clarkii ) and the crayfish ( Orconectes limosus , or Faxonius limosus ). These invasive crabs are not only displacing autochthonous species by changing their biotope , they are also carriers of cancer plague . The North American species are immune to this fungal disease, but there is currently no cure for other species and ends with the death of the infected crabs. The crab plague has already led to major changes in the composition of the large crustacean fauna in Europe and on other continents, and many species of the native crabs are threatened with extinction.

Way of life

The cancers from the Cambaridae family are omnivorous , they feed on the aquatic plants and microorganisms that grow near the banks of the water or in ponds. Animal food includes snails, mosquitoes , caddis flies and mayfly larvae as well as amphibians . Larger aquatic plants are only used to nourish the crabs when there is a lack of other food; detritus and algae are preferred in plant-based foods .

Systematics

The family Cambaridae was established in 1942 by Horton H. Hobbs Jr. in order to summarize all species originally assigned to the genus Cambarus , which had been split up into many genera, on a higher systematic level.

The core of the family has been confirmed as a monophyletic unit in most genetic studies. However, the species-rich genera Cambarus and Procambarus turned out to be non-monophyletic in their current description; they will have to be split up in future taxonomic revisions. For a long time the position of the East Asian genus Cambaroides , which had long been included in its own subfamily in the Cambaridae, was problematic . In various studies, this did not make the family monophyletic. The relationships between Cambaroides differed greatly between different studies, but it is now considered more likely that it is more closely related to the Astacidae family. Cambaroides is therefore no longer included in the Cambaridae, but placed in a family of its own.

Genera

The genus Procambarus is the largest of the family with more than 167 species, the genus Cambarus includes 118 species. The genus Cambarellus is partially differentiated as the subfamily Cambarellinae from the other genera that were grouped together in the subfamily Cambarinae. However, based on the genetic data, this special position is not justified.

Genera, with species numbers and selected species:

Individual evidence

  1. ↑ James W. Fetzner Jr .: Family Cambaridae Hobbs, 1942. The Crayfish and Lobster Taxonomy Browser last update: January 8, 2019
  2. ↑ Horton H. Hobbs Jr .: A Generic Revision of the Crayfishes of the Subfamily Cambarinae (Decapoda, Astacidae) with the Description of a New Genus and Species. American Midland Naturalist, 28, 2, pp. 334-357, 1942
  3. ↑ a b Keith A. Crandall & Sammy De Grave (2017): An updated classification of the freshwater crayfishes (Decapoda: Astacidea) of the world, with a complete species list. Journal of Crustacean Biology 37 (5): 615-653. doi: 10.1093 / jcbiol / rux070
  4. ↑ Keith A. Crandall, James W. Fetzner Jr. and Horton H. Hobbs Jr .: Cambarinae at Tree of Life web project, 2001

literature

  • Horton H. Hobbs Jr .: A Generic Revision of the Crayfishes of the Subfamily Cambarinae (Decapoda, Astacidae) with the Description of a New Genus and Species. American Midland Naturalist, 28, 2, pp. 334-357, 1942
  • Sven Gehrmann: Small crayfish practice: crayfish in aquariums and garden ponds & keeping of lobsters. Lobby for a dying nature publishing house, 2009, pp. 54–63

Web links

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