Glass Bloodfin Tetra Care Guide: Tank Setup, Diet, Tank Mates & More

Table of Contents

• Key Takeaways
• Species Overview
• Classification
• Origin & Natural Habitat
• Appearance & Identification
• Average Size & Lifespan
• Care Guide
• Tank Mates
• Food & Diet
• Breeding & Reproduction
• Common Health Issues
• Common Mistakes to Avoid
• Where to Buy
• Frequently Asked Questions
• Closing Thoughts
• Recommended Video
• References

The glass bloodfin tetra is basically a living piece of glass with a paintbrush dipped in red at the tail. That’s the simplest way to describe it, and honestly, it’s pretty accurate. The body is so transparent you can see the internal organs, the spine, and even the swim bladder through the skin. Then right at the caudal fin, there’s this striking splash of deep red that gives the fish its name.

What a lot of people don’t realize about glass bloodfins is just how long-lived and hardy they are. We’re talking about a tetra that can live up to 10 years with good care. That’s exceptional for a small schooling fish. Add in the fact that they’re peaceful, active, and tolerant of a wide range of water conditions, and you’ve got an underappreciated gem that deserves more attention than it gets.

Key Takeaways

• Strikingly transparent body with a vivid red caudal fin that creates an eye-catching contrast
• Exceptionally long-lived for a tetra – can reach 10 years with proper care, far outlasting most similar species
• Hardy and beginner-friendly – tolerates a wide range of water conditions and is very forgiving of minor mistakes
• Active upper-level swimmer – needs a tight-fitting lid because they are known jumpers
• Keep in groups of 8+ for the best schooling behavior and to see their natural social dynamics

Species Overview

Field	Details
Scientific Name	Prionobrama filigera
Common Names	Glass Bloodfin Tetra, Glass Bloodfin, Translucent Bloodfin
Family	Characidae
Origin	Amazon River basin (Brazil, Peru, Bolivia, Colombia, Ecuador)
Care Level	Easy
Temperament	Peaceful
Diet	Omnivore
Tank Level	Mid to Top
Maximum Size	2.5 inches (6 cm)
Minimum Tank Size	20 gallons (75 liters)
Temperature	72-82°F (22-28°C)
pH	6.0-7.5
Hardness	2-12 dGH
Lifespan	5-10 years in captivity
Breeding	Egg scatterer
Breeding Difficulty	Moderate
Compatibility	Community
OK for Planted Tanks?	Yes

Classification

Rank	Name
Kingdom	Animalia
Phylum	Chordata
Class	Actinopterygii
Order	Characiformes
Family	Characidae
Subfamily	Aphyocharacinae
Genus	Prionobrama
Species	P. filigera

Prionobrama filigera was described by Cope in 1870. The genus name comes from the Greek “prion” (saw) and “brama” (referring to a bream-like shape), while “filigera” means “thread-bearing,” likely referring to the elongated rays of the anal fin. The species belongs to the subfamily Aphyocharacinae within Characidae, which it shares with the regular bloodfin tetra (Aphyocharax anisitsi). Following the 2024 phylogenomic revision by Melo et al., Aphyocharacinae remains within the family Characidae.

Origin & Natural Habitat

Glass bloodfin tetras have one of the widest distributions of any small tetra. They’re found across the Amazon River basin in Brazil, Peru, Bolivia, Colombia, and Ecuador. Unlike many tetras that are confined to specific tributary systems, glass bloodfins turn up in rivers and streams throughout the broader Amazon drainage.

In the wild, they avoid the main river channels and prefer smaller creeks, tributaries, and flooded forest areas where the current is gentler. The water tends to be warm, soft, and slightly acidic, often stained with tannins from decaying vegetation. They’re typically found in the upper water layers, often near the surface among floating plants and overhanging vegetation. This surface-dwelling tendency is important to understand when setting up their aquarium.

Appearance & Identification

The glass bloodfin tetra’s defining feature is its remarkable transparency. The body is elongated and laterally compressed, with skin so translucent that you can clearly see the skeleton, swim bladder, and internal organs. Under the right lighting, the scales pick up a subtle silvery-blue iridescence that shimmers as the fish moves, but the overall impression is of a fish made from living glass.

The caudal fin is where the color is. Both lobes of the tail carry a deep red pigment that stands out dramatically against the clear body. This red coloration extends slightly onto the caudal peduncle. The anal fin is also noteworthy, being quite long and extending much further back than in most tetras. In males, the front edge of the anal fin develops a hooked appearance, which is one of the easiest ways to sex the fish.

Males are typically slimmer than females and often display a dark marking on the anal fin. Females have a fuller body, especially when carrying eggs, and lack the hooked anal fin edge. Both sexes show the same transparent body and red tail coloration.

Average Size & Lifespan

Glass bloodfin tetras reach about 2.5 inches (6 cm) at full maturity, making them slightly larger than many popular community tetras. They’re longer and more slender than neons or cardinals, with a streamlined body built for active swimming.

The lifespan is where this species really stands out. Under good conditions, glass bloodfins regularly live 5 to 8 years, with some reports of individuals reaching 10 years. That’s remarkable for a small tetra and means you’re making a longer commitment than with many comparable species. Consistent water quality and a varied diet are the biggest contributors to longevity.

Care Guide

Tank Size

A 20-gallon tank is the minimum for a school of glass bloodfin tetras. These are active, fast-swimming fish that use horizontal space extensively, so a longer tank is preferred over a taller one. A 30 or 40-gallon long tank gives a group of 8-12 plenty of room to cruise and display their natural schooling behavior.

Water Parameters

• Temperature: 72-82°F (22-28°C)
• pH: 6.0-7.5
• General Hardness (GH): 2-12 dGH
• Carbonate Hardness (KH): 1-8 dKH

Glass bloodfins are notably adaptable when it comes to water chemistry. They handle a wider range of parameters than many tetras, which is part of what makes them so beginner-friendly. While they prefer soft, slightly acidic water, tank-bred specimens adapt well to moderate hardness and neutral pH. The broad temperature tolerance is also a plus, making them suitable for both heated tropical tanks and cooler room-temperature setups in warmer climates.

Tank Setup

The most important thing with glass bloodfins is a tight-fitting lid. These fish jump. It’s not a maybe, it’s a when. Any gap large enough for them to fit through becomes an escape route, especially during the first few days in a new tank or if they get startled. Make sure every opening is covered, including gaps around filter intakes and airline tubing.

For the tank itself, provide plenty of open swimming space in the upper and middle areas. Plant the background and sides with tall-growing species, and add some floating plants for partial shade. A dark substrate helps showcase their transparent bodies. Driftwood and leaf litter on the bottom add natural aesthetics and release beneficial tannins. The overall setup should balance open water for swimming with planted areas for security.

Filtration & Maintenance

A sponge filter or HOB filter with adjustable flow works well. Glass bloodfins prefer gentle to moderate water movement. Strong currents make them uncomfortable since their natural habitat consists of calm tributaries and creeks. Weekly water changes of 20-25% will keep conditions stable. While they’re hardy, they still respond poorly to ammonia and nitrite, so make sure the tank is fully cycled before adding them.

Tank Mates

Glass bloodfin tetras are genuinely peaceful community fish. They don’t nip fins, they don’t bully, and they mind their own business in the upper water layers. This makes them compatible with a wide range of tank mates, including some surprisingly large ones.

Good Tank Mates

• Other peaceful tetras – cardinal tetras, neon tetras, ember tetras, rummy nose tetras
• Corydoras catfish – perfect bottom-dwelling companions that stay out of the way
• Otocinclus – peaceful algae eaters that share similar water preferences
• Dwarf cichlids – Apistogramma, rams, and similar species
• Discus and angelfish – in suitably large tanks, glass bloodfins coexist well with these larger cichlids
• Hatchetfish – fellow surface dwellers that share the upper water column peacefully
• Small peaceful barbs – cherry barbs, gold barbs
• Dwarf gouramis – calm mid-level companions

Tank Mates to Avoid

• Aggressive cichlids – anything territorial or predatory will stress them
• Large predatory fish – their transparent bodies don’t offer much intimidation factor
• Very nippy species – their elongated anal fin can be a target for fin nippers

Food & Diet

Glass bloodfin tetras are easy to feed and not picky at all. A quality flake or micro pellet as the daily staple works perfectly. Supplement regularly with frozen or live foods like brine shrimp, daphnia, bloodworms, and white mosquito larvae. These protein-rich additions help maintain the red coloration in the tail and keep the fish in top condition.

They feed primarily in the upper and middle water levels. Their mouths are upturned slightly, which makes them well-suited to taking food from the surface. Feed small amounts two to three times daily. Being active swimmers, they burn through calories quickly and benefit from frequent feedings over single large ones.

Breeding & Reproduction

Breeding glass bloodfin tetras is achievable but requires some preparation. Set up a dedicated spawning tank (10-15 gallons) with very soft, acidic water (pH 6.0-6.5, GH 1-5) at a temperature around 80-84°F. Keep the lighting dim and add fine-leaved plants or spawning mops for egg deposition. A bare bottom or a layer of marbles helps protect eggs from being eaten.

Condition breeding pairs with plenty of live and frozen foods for a week or two. When ready to spawn, the female scatters eggs among the plants while the male fertilizes them. Remove the adults immediately after spawning to prevent egg predation. The eggs are light-sensitive, so keep the breeding tank dark or heavily shaded.

Eggs typically hatch within 24-36 hours, and the fry become free-swimming around day 3-4. Feed infusoria or liquid fry food initially, graduating to baby brine shrimp as the fry grow. The young fish develop their transparent body relatively early, though the red tail coloration fills in gradually over the first few months.

Common Health Issues

Glass bloodfin tetras are among the hardier tetras, but they’re not immune to common freshwater diseases. Ich is the most frequent issue, usually appearing after temperature drops or stressful events. The transparent body actually makes disease diagnosis easier than in many fish since you can often see internal problems that would be hidden in opaque species.

Bacterial infections and fin rot can occur in tanks with poor water quality. The elongated anal fin is particularly susceptible to fin rot, so watch for any fraying or discoloration at the edges. Internal parasites can sometimes be spotted through the transparent body wall, appearing as unusual dark masses or stringy white feces.

Prevention through good water quality, quarantine of new fish, and varied nutrition covers most health concerns. Their hardiness and longevity mean that a healthy glass bloodfin maintained in clean water rarely develops problems.

Common Mistakes to Avoid

• No lid on the tank. Glass bloodfins are jumpers. This is the number one cause of lost fish. A tight-fitting lid with no gaps is essential.
• Strong water current. They come from calm tributaries and dislike strong flow. Dial back the filter output or use a spray bar to diffuse it.
• Keeping too few. A group of 3-4 won’t school properly and will seem nervous and skittish. Start with at least 8 for confident, natural behavior.
• Bright lighting without cover. While they’re not as light-sensitive as some tetras, they do look better and act more confidently with some floating plant cover.
• Underestimating their lifespan. These fish can live a decade. Make sure you’re ready for the commitment before purchasing.

Where to Buy

Glass bloodfin tetras are moderately available in the hobby. They’re not as common as neon or cardinal tetras, but specialty shops and online retailers usually stock them. Try Flip Aquatics or Dan’s Fish for tank-bred specimens. Prices typically range from $3-5 per fish, often with discounts for larger groups.

When buying, look for active fish that are swimming confidently in the upper levels of the tank. The body should be clear and transparent (cloudiness can indicate disease), and the red caudal fin should be vivid. Avoid any fish from tanks with sick-looking inhabitants.

Frequently Asked Questions

What’s the difference between a glass bloodfin tetra and a regular bloodfin tetra?

They’re related but different species. The regular bloodfin tetra (Aphyocharax anisitsi) has a more opaque, silvery body with red on the fins. The glass bloodfin (Prionobrama filigera) is much more transparent with red concentrated primarily on the caudal fin. Glass bloodfins also have a notably longer anal fin and tend to be slightly larger.

Do glass bloodfin tetras jump?

Yes, frequently. They are one of the more jump-prone tetra species. A tight-fitting lid is absolutely essential. They’re especially likely to jump when first introduced to a new tank, during water changes, or if startled by sudden movements or sounds.

How long do glass bloodfin tetras live?

With proper care, they commonly live 5-8 years, with some reaching 10 years. This is significantly longer than most small tetras like neons (3-5 years) or cardinals (4-5 years). Consistent water quality and varied nutrition are the biggest factors in achieving a long lifespan.

Can you see the organs inside a glass bloodfin tetra?

Yes, that’s one of their most distinctive features. Their body is so transparent that you can clearly see the spine, swim bladder, and digestive organs. This transparency actually serves as a health indicator too, since internal problems (like parasites) are often visible through the body wall before external symptoms appear.

Are glass bloodfin tetras good for beginners?

Yes, they’re excellent beginner fish. They’re hardy, tolerate a wide range of water conditions, are peaceful, and easy to feed. The only caveat is that they need a secure lid because of their jumping tendency. Beyond that, they’re one of the more forgiving tetras available.

Closing Thoughts

The glass bloodfin tetra is one of those fish that gets better the longer you keep it. Not just because it can live a decade, but because a settled, confident school in a well-designed tank is genuinely captivating. The transparency creates an almost ethereal quality, and watching a group of 10+ cruise through the upper water column with those red tails flashing is a sight that never gets old. They’re hardy, peaceful, and stunning in a way that few other tetras can match. If you’re looking for something a little different from the usual tetra lineup, the glass bloodfin deserves serious consideration.

Recommended Video

Check out our Tetra Tier List video where we rank different tetra species and discuss their pros and cons for the home aquarium.

References

• Cope, E.D. (1870). Contribution to the ichthyology of the Marañon. Proceedings of the American Philosophical Society, 11, 559-570.
• Melo, B.F., Ota, R.P., et al. (2024). Phylogenomics of Characidae, a hyper-diverse Neotropical freshwater fish lineage, with a phylogenetic classification including four families. Zoological Journal of the Linnean Society, 202(1).
• Froese, R. and D. Pauly, Editors. (2024). Prionobrama filigera. FishBase. fishbase.se
• Seriously Fish. Prionobrama filigera – Glass Bloodfin Tetra. seriouslyfish.com

Explore More Tetras

The glass bloodfin tetra is just one of over 90 tetra species we cover. Visit our complete Tetras A-Z directory to explore care guides for every species in the hobby.