Edit Megalamphodus eques

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Name

Scientific name

Megalamphodus eques

Described by

Authority Steindachner, Year 1882, Bracketed

Family

Characidae

Common names

Serpae Tetra

Photograph credits

All 16 credited

Summary

The serpae tetra, Megalamphodus eques, is a characid with an enormous range through much of the Amazon drainage and the Río Paraguay. Very …

Size and aquarium

Maximum size

40mm, standard length

Aquarium size

Minimum length 80 cm, Minimum depth 30 cm

Water

Water conditions

Temperature 20–28°C, pH 5–7.5

Hardness

1–15dGH

Conductivity

Not recorded

Behaviour

Temperament

Territorial

Community suitability

Community-safe

Where it lives

Countries, regions, rivers and lakes

Argentina, Bolivia, Brazil, Paraguay, Peru, Amazon, Apa, Guaporé, Jauru, Juruena, Paraguay, Paraná

Writing

Etymology

Megalamphodus: from the Ancient Greek μεγαλάμφοδος (megalamphodos), meaning 'with spacious ways'. Eigenmann did not explain the name, but it probably refers to…

Distribution

As currently understood (see below) H. eques has an enormous distribution throughout much of the Amazon drainage in Brazil, Peru and Bolivia plus the Río Parag…

Habitat

Most typically inhabits still and sluggish tributaries and backwaters, including ponds and small lakes, where it forms aggregations around patches of marginal …

Aquarium size

An aquarium with base dimensions of 80 ∗ 30 cm or equivalent should be the absolute minimum considered.

Maintenance

Choice of decor is not especially critical although it tends to show better colouration when maintained in a well-furnished set-up with live plants and a dark …

Water conditions

Temperature: 20 – 28 °C pH: The farm-raised fish available in stores are fairly adaptable where water chemistry is concerned and should be happy within the ran…

Diet

Likely to be omnivorous feeding on small invertebrates, crustacea, filamentous algae, fallen fruit and suchlike in nature. In aquaria it may survive on a diet …

Behaviour and compatibility

H. eques is notorious as an aggressive community inhabitant with a reputation for nipping the fins of tankmates although this behaviour tends to be most pronou…

Sexual dimorphism

Sexually mature females are noticeably rounder-bodied and a little larger than males.

Reproduction

An egg-scattering free spawner exhibiting no parental care. When in good condition adults will spawn often and in a mature aquarium it's possible that small nu…

Notes

This species is very common in the aquarium trade and is also referred to as 'jewel', 'red minor', 'blood', or 'callistus' tetra. A number of selectively-bred …

This species is very common in the aquarium trade and is also referred to as 'jewel', 'red minor', 'blood', or 'callistus' tetra.

A number of selectively-bred ornamental strains have been developed, including 'metallic', 'long-finned', 'balloon' and 'fairy-fin'.

Characiformes is among the most diverse orders of freshwater fishes currently including close to 2000 valid species distributed among 19 families.

This tremendous taxonomical and morphological diversity has historically impaired the ability of researchers to resolve their genetic relationships with many taxa remaining incertae sedis.

A further limiting factor has been that in many cases exhaustive study of these on an individual basis is the only way to resolve such problems.

Modern phylogenetic techniques have allowed some headway, though, and a molecular investigation of characiform relationships by Calcagnotto et al. published in 2005 revealed some interesting hypotheses.

Their results suggest that Hyphessobrycon is a member of a clade also containing the genera Astyanax, Astyanacinus, Moenkhausia, Inpaichthys, and Hemigrammus, of which all species possess five or more teeth in the inner series of the premaxilla.

A more extensive analysis by Oliveira et al. (2011) placed Hyphessobrycon in a much larger clade containing 29 genera including all those listed above.

This clade was one of three large clades, plus the genus Spintherobolus which was recovered as sister to all other characids, that formed the authors' revised Characidae family.

Hyphessobrycon was raised by Durbin in Eigenmann (1908) as a subgenus of Hemigrammus, differing from the latter by the absence of scales on the caudal-fin.

The grouping was revised by Eigenmann (1918, 1921) while Géry (1977) created artificial groups of species based on pigmentation patterns, and these definitions are still widely used today, e.g., the H. aghula group, the H. heterorhabdus group, etc.

Weitzman & Palmer (1997) hypothesised the existence of a monophyletic assemblage within the genus based on colour pattern and male fin morphology that they termed the ‘rosy tetra clade’.

They did not offer any hypotheses regarding relationships between the remaining species although Hyphessobrycon has long been recognised as a polyphyletic lineage and thus is likely to be split into several genera in the future.

De Carvalho (2011) redescribed H. compressus, type species of the genus, and conducted a molecular phylogeny incuding 227 taxa.

He concluded that Hyphessobrycon sensu stricto should be restricted to a monophyletic group of 24 species which share the unambiguous synapomorphy of the Weberian apparatus being orientated dorso-horizontally though the dorsal margin of the operculum with other defining characters comprising a black spot in the dorsal-fin and lack of visible lateral-line except in some specimens of H. pulchripinnis.

This group contains H. compressus, H. pulchripinnis, H. hasemani, H. haraldschultzi, H. troemneri, H. cf. troemneri, H. copelandi, H. takesei, H. minor, H. micropterus, H. rosaceus, H. megalopterus, H. bentosi, H. eques, H. sweglesi, H. werneri, H. epicharis, H. socolofi, H. pyrrhonotus, H. erythrostigma, H. khardinae, H. georgetta, H. roseus and H. simulans.

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References

5 on this profile

Name

Scientific name

Described by

Family

Common names

Photograph credits

Summary

Size and aquarium

Maximum size

Aquarium size

Water

Water conditions

Hardness

Conductivity

Behaviour

Temperament

Social needs

Community suitability

Where it lives

Countries, regions, rivers and lakes

Writing

Etymology

Distribution

Habitat

Aquarium size

Maintenance

Water conditions

Diet

Behaviour and compatibility

Sexual dimorphism

Reproduction

Notes

References

References