Mimagoniates microlepis

Mimagoniates microlepis
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Characiformes
Family:	Characidae
Genus:	Mimagoniates
Species:	M. microlepis
Binomial name
Mimagoniates microlepis Steindachner, 1876

Mimagoniates microlepis, also known as the Blue Tetra (a common name shared with Tyttocharax madeirae, Knodus borki, and possibly other Characidae as well),^[1] the Croaking Tetra (a name also applied to Mimagoniates inequalis^[2] and Mimagoniates lateralis),^[3] the Small-Scaled Tetra, is a species of tetra in the genus Mimagoniates. First identified by Franz Steindachner in 1876 and named Coelurichthys microlepis, it has also been identified as Coelurichthys iporangae (Miranda-Ribeiro, 1908), Coelurichthys lateralis, and Mimagoniates iporangae (McAllister, 1990) besides its current taxonomic classification. There is evidence of a variety called M. microlepis 'Joinville' which might be synonymous with Paragoniates microlepis.^[1][4]

Habitat

A freshwater tropical fish native to South America, the range of M. microlepis includes Venezuela and the region of Brazil between northern Rio Grande do Sul and southern Bahia. M. microlepis is benthopelagic and favors small to and medium-sized streams and rivers, especially clear coastal streams. It prefers temperatures of 18–23 °C (64–73 °F).^[5][6]

Anatomy

M. microlepis reaches about 6.1 centimetres (2.4 in) in length. Genetic diversity with the species is evidenced by its variable phenotype. For example, in this wild caught specimen ([1]), a brownish-black stripe runs along either side of its body from head to tail. Directly above this and touching it is stripe of similar size but of a lighter brown-beige color. It has a sort of blueish-purplish sheen all over. Except for this sheen, their two stripes, and their internal organs it is mostly transparent similar to the so-called "X-ray Tetra", Pristella maxillaris. By comparison, this aquarium-bred specimen ([2]) is mostly opaque and has much less prominent markings and this specimen ([3]) caught near Ubatuba has an appearance somewhat between that of the two previously described. According to a 2008 report, "phylogeographic studies based on molecular data indicate significant differences among the isolated populations of M. microlepis."^[7]

Males have a modified breathing organ (described in the next section) with which they make sound during courtship. They also have a modified caudal gland used to release pheromones, a characteristic they share with all members of the Glandulocaudinae subfamily.^[8]

Sound

Main article: Croaking Tetra

Like related species sometimes referred to as "Croaking Tetra" or "Chirping Tetra", M. microlepis has a supplementary breathing organ located above its gills which makes a faint chirping sound when it comes to the surface to gulp air.^[9] This noise also plays a role in courtship as the male chases and hovers near the female while taking gulps of air and expelling it to make a rhythmic sound.^[10] Croaking behavior may have evolved from a behavior called "nipping surface", a feeding behavior that occurs when the fish is searching for food; the fish often will gulp air when doing this. This gulping of air has no useful respiratory function.^[11]

Cultivation

M. microlepis is cultivated by aquarists and is appropriate for inclusion in a tank with other species of non-aggressive fish. They accept frozen and dry food but live food is especially recommended.^[12]

According to one enthusiast:

This peaceful fish likes to swim and you can keep him in a small school in the community aquarium. The aquarium should be planted on the sides and background. In the middle you should leave a lot of free swimming space. A dark substrate and a dimmed light by using floating plants bring out the colours of the fish.^[12]

Another expert says "they are an attractive fish that is worth shopping around for" but are not often for sale.^[13]

Breeding them is not difficult and a spawning mop (a sort of synthetic plant resembling the head of an old-fashioned mop) may be used as a substrate upon which they can lay and fertilize their eggs. The parents should then be removed so that they do not cannibalize their eggs or young. The fry emerge from their eggs in two or three days. Newborn M. microlepis may be feed firstly paramecia and rotifers. After increasing their size somewhat brine shrimp may be offered.^[12]

Bibliography

• Dufech, Ana Paula S.; Marco A. Azevedoand Clarice B. Fialho (2003). "Comparative dietary analysis of two populations of Mimagoniates rheocharis (Characidae: Glandulocaudinae) from two streams of Southern Brazil" (^{[dead link]} – ^{Scholar search}). Neotropical Ichthyology (Sociedade Brasileira de Ictiologia) 1 (1): 67–74. doi:10.1590/S1679-62252003000100008. http://www.ufrgs.br/ni/vol1num1%5Cartigo08.pdf. Retrieved 2008-07-15. ^{[dead link]}

References

1. ^ ^{a b} Master Index of Freshwater Fishes
2. ^ Fishbase -Mimagoniates inequalis
3. ^ Mimagoniates lateralis
4. ^ Characidoidea
5. ^ Fishbase
6. ^ Fish from Venezuela Foundation
7. ^ "Biogeography of Glandulocaudinae (Teleostei: Characiformes: Characidae) revisited: phylogenetic patterns, historical geology and genetic connectivity". http://www.mapress.com/zootaxa/2008/f/z01726p048f.pdf. 
8. ^ Bushmann, Paul J.; Burns, John R.; Weitzman, Stanley J. (2005). "Gill-Derived Glands in Glandulocaudine Fishes (Teleostei: Characidae: Glandulocaudinae)" (PDF). Journal of Morphology: 187–195. http://www3.interscience.wiley.com/cgi-bin/fulltext/93521003/PDFSTART?CRETRY=1&SRETRY=0. 
9. ^ "Encarta". Archived from the original on 2009-11-01. http://www.webcitation.org/query?id=1257052908304483. 
10. ^ Axelrod, Herbert, R. (1996). Exotic Tropical Fishes. T.F.H. Publications. ISBN 0-87666-543-1. 
11. ^ Nelson, Keith (1964). "The Evolution of a Pattern of Sound Production Associated with Courtship in the Characid Fish, Glandulocauda inequalis". Evolution (Evolution, Vol. 18, No. 4) 18 (4): 526–540. doi:10.2307/2406207. JSTOR 2406207.  Note: This paper precedes the reclassification of G. inequalis under Mimagoniates
12. ^ ^{a b c} Aquariumfish
13. ^ What Fish Species are Coldwater?