Editing Cardinal tetra (section)

==Ecology and behavior==
===Diet===
The cardinal tetra forages in areas of slow-moving, shallow water. It is predominantly predatory, feeding on tiny animals found on underwater plants, roots, and [[leaf litter]]. Creatures commonly eaten include the larvae of [[Chironomidae|chironomid]] midges and microcrustaceans such as water fleas ([[Cladocera]]) of the families [[Moinidae]], [[Macrotrichidae]], and [[Daphniidae]], and [[copepod]]s of the family [[Harpacticidae]]. Other organisms eaten include other fly larvae, insect eggs, [[rotifer]]s, and [[testate amoebae]].<ref name=walker2004>{{cite journal|last=Walker|first=Ilse|date=2004|title=The food spectrum of the cardinal - tetra (''Paracheirodon axelrodi'', Characidae) in its natural habitat|journal=Acta Amazonica|volume=34|issue=1|pages=69–73|doi=10.1590/S0044-59672004000100009|doi-access=free}}</ref>

===Reproduction===
In the wild, the cardinal tetra swims upstream in large numbers to parts of its native river habitat completely enclosed above by [[rainforest]] [[Rainforest#Layers|canopy]]. Such waters are subject to heavy shading by the rainforest trees, and virtually no sunlight reaches them. Here, the fishes spawn in large aggregations. If the fishes are ready to spawn, the male pursues the female into fine-leaved plants; her fuller outline, which usually indicates the presence of ripe eggs within her reproductive tract, should be readily apparent at this point. If the female is ready, she allows the male to swim alongside her, and together, the pair release eggs and sperm.

===Lifespan===
The fish might also be effectively an annual species with a lifespan of just a single year in nature. It lives for several years in captivity. For those seeking to breed them in the aquarium, the best way to do so is by mimicking the same natural setup. A study conducted in Manaus, Brazil, subjected cardinal tetras to adverse water conditions for 96 hours. The fish perished at a low temperature of {{cvt|19.6|C|F}} and a high of {{cvt|33.7|C|F}}, and [[pH]] below 2.9 or above 8.8.<ref>{{cite journal|author=Sarah Ragonha de Oliveira|author2=Rondon Tatsuta Yamane Baptista de SouzaI|author3=Érica da Silva Santiago NunesI|author4=Cristiane Suely Melo de CarvalhoI|author5=Glauber Cruz de MenezesI|author6=Jaydione Luíz MarconII|author7=Rodrigo Roubach|author8=Eduardo Akifumi OnoI|author9=Elizabeth Gusmão Affonso|date=2008|title=Tolerance to temperature, pH, ammonia and nitrite in cardinal tetra, ''Paracheirodon axelrodi'', an amazonian ornamental fish|journal=Acta Amazonica|volume=38|issue=4|pages=773–779| doi=10.1590/S0044-59672008000400023|doi-access=free}}</ref>