Edit Nannostomus unifasciatus

You can suggest changes to this profile. A moderator will review each change.

Name

Scientific name

Nannostomus unifasciatus

Described by

Authority Steindachner, Year 1876

Family

Lebiasinidae

Common names

One-lined Pencilfish

Photograph credits

All 3 credited

Summary

The one-lined pencilfish, Nannostomus unifasciatus, occurs in the upper Amazon and upper Orinoco basins in Brazil, Bolivia, Colombia and Ve…

Size and aquarium

Maximum size

40mm, standard length

Aquarium size

Minimum length 75 cm, Minimum depth 30 cm

Water

Water conditions

Temperature 23–28°C, pH 4–7

Hardness

1–10dGH

Conductivity

Not recorded

Behaviour

Temperament

Peaceful

Community suitability

Community-safe

Where it lives

Countries, regions, rivers and lakes

Bolivia, Brazil, Colombia, Guyana, Trinidad and Tobago, Venezuela, Amazon, Negro, Orinoco

Writing

Etymology

Nannostomus: from the Latin nannus, meaning 'small', and Greek stoma, meaning 'mouth', in reference to the small mouthparts of member species. unifasciatus: fr…

Distribution

Type locality is given as 'near mouth of Rio Negro, Brazil', but this species is currently accepted to range throughout much of the upper Amazon basin in Brazi…

Habitat

Inhabits sluggish tributaries, small rivers, and swampy zones, especially in areas where aquatic vegetation grows densely or with submerged woody structures an…

Inhabits sluggish tributaries, small rivers, and swampy zones, especially in areas where aquatic vegetation grows densely or with submerged woody structures and leaf litter.

It's often found in areas of flooded forest and floodplain lakes in blackwater regions.

Caño La Guardia is a blackwater, floodplain morichal stream in the llanos of Apure state, southwestern Venezuela.

It has a forested riparian zone but open grassland dominates much of its drainage basin.

During the annual wet season (May to October) the riparian forest and adjacent savanna are flooded, and fish disperse throughout the floodplain.

The dry season is associated with falling water levels, forcing them back into the main channel and associated littoral habitats.

N. unifasciatus occurs here alongside numerous other fish species, particularly in flooded, vegetated habitats with slow current and largely covered by woody debris derived from morichito palms and other riparian vegetation, grass, and leaf litter.

Other fishes recorded in, and displaying a preference for, this habitat-type included the congener Nannostomus eques plus Brittanichthys sp., Charax condei, Gnathocharax steindachneri, Hemigrammus analis, H. barrigonae, H. elegans, H. rhodostomus, H. stictus, H. vorderwinkleri, Iguanodectes spilurus, Characidium sp., Elachocharax pulcher, Microcharacidium gnomus, Hoplias malabaricus, Hoplerythrinus unitaeniatus, Carnegiella marthae, Copella metae, C. nattereri, Pyrrhulina lugubris, Fluviphylax obscurus, Microsternarchus bilineatus, Acaronia vultuosa, Apistogramma hoignei, Apistogramma sp., Crenicichla aff. wallacii, Heros aff. severus, Mesonauta insignis, Mikrogeophagus ramirezi, Satanoperca mapiritensi, Corydoras sp., Amblydoras affinis, A. gonzalezi, Physopyxis ananas, Scorpiodoras heckelii, Panaque maccus, Parotocinclus sp., Microglanis iheringi, and Synbranchus marmoratus.

Editing needs JavaScript. This is the text as it was last saved.

Where does this come from?

My own experienceFor example, I've kept twelve in a planted 60 cm tank since March 2024.A website I sawFor example, an IUCN Red List assessment, a museum catalogue or a FishBase page.A paperFor example, Marshall et al. (2011), Water temperature differences in interfluvial palm swamp habitats of Paracheirodon axelrodi and P. simulans.A book, or something not onlineFor example, Tappin (2010), Rainbowfishes: their care and keeping in captivity.Something already on the pageFor example, the Behaviour and compatibility section already says this.

Web address

Paste the address of the page that says this. What counts as a source

DOI

Paste a DOI and we will look up the rest of the reference. A DOI looks like 10.11646/zootaxa.4694.4.1, and most papers print it on the first page.

Title

Enter the title of the paper, book or page. If you leave it empty, we will use the website's address.

Authors

Separate authors with semicolons, e.g. Tan, H.H.; Ng, P.K.L.

Year

Journal or publisher

Pages

Enter the page that says this, e.g. 218 or 218–221.

Anything worth adding

Describe what you saw, or which part of the source says this.

Aquarium size

Base dimensions of at least 75 ∗ 30 cm or equivalent are required.

Maintenance

Should ideally be kept in a heavily-planted set-up, preferably with a dark substrate and some patches of floating vegetation around which the fish will tend to…

Water conditions

Not written yet

Diet

A micropredator feeding on tiny invertebrates and other zooplankton in nature. In the aquarium it will accept dried foods of a suitable size but should also be…

Behaviour and compatibility

Very peaceful but does not make an ideal community fish due to its small size and rather timid nature. In a community it's best kept with similarly-sized, peac…

Sexual dimorphism

Adult males are more colourful and usually slimmer than females, and also possess an enlarged anal-fin.

Reproduction

Not thought to have been bred in captivity, with earlier reports all appearing to pertain to the congener N. eques which is known to deposit eggs on the unders…

Notes

This species has been referred to the genera Poecilobrycon and Nannobrycon in the past and in the aquarium hobby is also known as 'oneline' or 'red fin' pencil…

References

6 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