Nematobrycon palmeri
The Emperor tetra (Nematobrycon palmeri) is found the streams and rivers of western Colombia including the Rio Atrata and the Rio San Juan.
In the aquarium
The Emperor tetra is a placid aquarium fish and will be disturbed by more boisterous species. It grows to 7.5 cm. It prefers a pH of 6.5, a hardness of 50–100 mg/l and a temperature of 23-27 C. It does not school as readily as most tetras, and a single fish, or a pair appears happier than with most tetras.
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| Nematobrycon palmeri |
image source: http://commons.wikimedia.org/w/index.php?title=User:Sitron&action=edit&redlink=1
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| Nematobrycon palmeri |
image source: http://commons.wikimedia.org/wiki/User:Lascorz
Foods and Feeding
The Emperor Tetra is an omnivore, eating both animal and vegetable food. Any good flake or pelleted fish food is a good basis for its diet. It will benefit from live food like Daphnia and wrigglers (Mosquito larvae) as well as frozen fish food including frozen bloodworms.
Gender
Emperor Tetras are highly sexually dimorphic and thus males and females are quite easily distinguished from each other. There are several ways to tell a male and female apart, the most reliable method is to observe the eye color. Males will have metallic blue eyes while females possess metallic green eyes. Also, the male has a three pronged tail with the medial black stripe usually extending beyond the rest of the tail while in the females this median black stripe will typically only reach as far as the clear part of the tail. However, this is not always the best indicator as the third prong in males can sometimes be nipped off in competitions with tank mates and more dominant females may sometimes grow this extension of the tail as well.
Breeding
In a large well planted aquarium a single pair of Emperor tetras will often breed without any extra stimulation. If there are no other fish, some of the babies may survive especially if the parents are well fed. In a large, well planted aquarium the babies will find some useful natural food in the form of protozoa, algae, etc. Screened Daphnia will provide them with more nourishment as they grow, and dry fry food can be used.
Appearance
The purple hue of these tetras will be more apparent in an aquarium with floating plants on the surface and relatively subdued lighting. If the aquarium is too bright, the yellow coloration will dominate.