Corydoras

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Corydoras
Corydoras semiaquilus

Corydoras semiaquilus

Systematics
Cohort : Otomorpha
Sub-cohort : Ostariophysi
Order : Catfish (Siluriformes)
Subordination : Loricarioidei
Family : Armored and calloused catfish (Callichthyidae)
Genre : Corydoras
Scientific name
Corydoras
Lacepède , 1803

Corydoras is a genus of fish from the family of armored and callous catfish (Callichthyidae). The genus belongs to the subfamily of armored catfish (Corydoradinae), which differs from the subfamily of calluses (Callichthyinae) by the lack of a row of bone plates between the dorsal and adipose fin and the smaller size. The animals, between 3 and 12 cm in size, are characterized by a characteristic body structure (double row of bone plates, overlapping like roof tiles from front to back: armor plates) and very variable coloration. An important distinguishing feature for species identification is (among other things) the expression and number of perforations ( odontodes ) on the pectoral spines. With a few exceptions, these catfish are bottom fish, which, as intestinal breathers , can swim to the surface of the water at regular intervals when there is insufficient oxygen in the water, where they can absorb atmospheric oxygen and breathe on the bottom. The phenomenon of intestinal respiration can also be observed under optimal housing conditions, albeit less often. The ability to breathe in the intestines does not indicate a greater tolerance to poor water quality.

The name Corydoras (German about "with helmet and spear") is derived from the Greek kory ("helmet") and dory ("lance", "spear") and probably refers to the bone plates armoring the body and the spiky first beam the pectoral fins .

ecology

The range of the genus includes the whole tropical and subtropical South America , the Amazon basin , the central Brazilian highlands, the northern pampas of Argentina and also z. B. the Caribbean island of Trinidad . In accordance with these geographical indications, the individual species are adapted to sometimes very different conditions. Corydoras come in white water (e.g. Marañón , Río Huallaga , Rio Branco , Río Napo , clay-colored, mineral-rich suspended matter), black water (e.g. Rio Negro , tar-brown to cola- colored, rich in humic substances, acidic) and clear water (central Brazil, Rio Guyana , slightly acidic). The Corydoras biotope descriptions cited in the specialist literature make it clear how different the temperature conditions can be. Thus Corydoras TYPES in the central Brazilian highlands at temperatures ranging from 8 to 10 degrees Celsius between the hottest and coldest months accustomed. In Guayanaschild encountered species, however, live at nearly constant temperatures between 25 and 27 degrees Celsius.

Social behavior

What most Corydoras species have in common is their sociable behavior. Almost only species of the Corydoras acutus group occur individually or in pairs . A species-appropriate aquarium keeping requires - with the exception mentioned - group keeping (at least 6 animals per species) and plants to which most species attach their eggs. Species of the Acutus group, on the other hand, can show a very pronounced territorial behavior and do not occur in nature in groups of their own species, but rather alone, in pairs or together with other mostly similarly colored short-snouted Corydoras species.

nutrition

Red mosquito larvae , tubifex , enchytrae (all: live) are popular. In aquarium conditions, high-quality dry food (in tablet form) is a good addition. The uptake of detritus (suspended and suspended matter of organic origin from parts of plant and animal tissue) from the substrate has been reported and frequently observed in the specialist literature . Mulm is therefore constantly rummaged through and eaten.

Systematics

There are now almost 160 valid species. Corydoras is a paraphyletic collective genus, i.e. This means that the genus does not include all descendants of the most recent common ancestral form. The species of the Brochis genus, which is no longer regarded as valid, are available for example. B. related within the genus Corydoras and, as a recent study shows, also the genera Aspidoras and Scleromystax . The authors of the study, which show cases of Müllerian mimicry between different Corydoras species, examined a total of over 400 described and undescribed Corydoras species and color forms, divided them into nine kin lines (including Aspidoras and Scleromystax ) and suggested new generic names for some.

Simplified cladogram of armored catfish according to Alexandrou et al.

  Corydoradinae  

 Corydoras acutus group ( Corydoras s. Str.)


   

 Aspidoras


   

 Scleromystax


   


 "Microcorydoras"


   

 "Gastrodermus" , Corydoras elegans group + Aspidoras pauciradiatus



   

 Corydoras paleatus group


   

 "Osteogaster" , Corydoras aeneus group


   

 sharp-snouted Panzerw. (incl.  "Brochis" )


   

 "Hoplisoma" , short-nosed armored catfish









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Corydoras acutus group ( Corydoras Sensu stricto )

Corydoras acutus
Corydoras septentrionalis
Corydoras hastatus

Free-swimming miniature armored catfish (" Microcorydoras ")

Corydoras elegans group ( "Gastrodermus" )

Corydoras elegans

Corydoras paleatus group

Corydoras paleatus

Corydoras aeneus group (" Osteogaster ")

Corydoras aeneus

Pointed-snouted armored catfish

Corydoras delphax
Corydoras multiradiatus
Corydoras pantanalensis
Corydoras splendens

Short- snouted armored catfish (" Hoplisoma ")

Corydoras duplicareus
Corydoras granti
Corydoras griseus
Corydoras habrosus
Corydoras loxozonus
Corydoras melini
Corydoras Schwartzi
Corydoras sterbai
Corydoras trilineatus

Not assigned

Corydoras sp. CW009, previously undescribed type.

swell

Individual evidence

  1. ^ Axel Zarske: Corydoras. 2004, p. 258.
  2. ↑ Corydoras on Fishbase.org (English)
  3. ^ A b Markos A. Alexandrou, Claudio Oliveira, Marjorie Maillard, Rona AR McGill, Jason Newton, Simon Creer & Martin I. Taylor: Competition and phylogeny determine community structure in Müllerian co-mimics. Nature 469, 84–88 (January 2011), doi : 10.1038 / nature09660 Supplementary Information (5.9M) (PDF; 6.2 MB)
  4. ↑ a b Markos A. Alexandrou & Martin I. Taylor: Evolution, ecology and taxonomy of the Corydoradinae revisited (PDF; 0.3 MB)
  5. ↑ Ingo Seidel: New findings about the relationships among armored catfish in Aquaristik Fachmagazin No. 223 February / March 2012, Tetra-Verlag GmbH, ISSN  1437-4854

literature

  • Hans-Georg Evers : Armored catfish: Aspidoras, Brochis, Corydoras . Ulmer Verlag. 1994 Stuttgart, ISBN 3-8001-7286-0 .
  • Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .
  • Axel Zarske: Corydoradinae , Corydoras , Corydoras […]. In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , pp. 257-277.

Web links

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