Complete Care Guide for Glass Bloodfin Tetras

Optimal Tank Conditions for Glass Bloodfin Tetras

Glass Bloodfin Tetras are native to South America, specifically found in the Amazon River and its tributary, the Madeira. These tetras thrive in a tropical freshwater environment. For the best results, aim to replicate a South American Blackwater Stream biotope in their aquarium. Although they are not particularly difficult to care for, they require stable water conditions to remain healthy. The ideal water hardness should be around 10° dGH, and the water should be slightly alkaline, with a pH level between 7.1 and 7.2. It is crucial to avoid acidic water, as it can cause the tetras to turn white and lead to their gradual decline.

These tetras are adaptable to a range of temperatures, comfortably living in water temperatures from 22°C to 28°C (72°F to 82°F). When setting up their tank, ensure that there are both hiding places and open swimming spaces. Glass Bloodfin Tetras enjoy swimming and chasing each other, but they also need areas to rest. If housed with aggressive tank mates, they may seek refuge more frequently, so providing a balanced environment is essential.

Social creatures by nature, Glass Bloodfin Tetras prefer to be in groups. A 100-liter (26-gallon) tank can comfortably accommodate around 50 of these fish without overcrowding. It is not advisable to keep just one or two tetras, as they tend to be shy and will spend most of their time hiding. Ideally, keep at least six tetras, though having 10 to 20 will provide the best display of their natural behavior. While individual tetras do not require much space, they need ample room to swim. A 40-liter (10-gallon) tank is too small, and the minimum recommended size is an 80-liter (21-gallon) tank to ensure their well-being.

Creating a Safe and Comfortable Environment for Glass Bloodfin Tetras

These tetras are not aggressive, but they do chase each other for fun. So, make sure the tank has open areas without sharp decorations that could hurt them. Also, keep the aquarium covered because these fish are great jumpers. Their strong bodies let them swim fast and jump out of the tank if they get scared. This can happen during tank cleaning or if you put your hands in the water. To help them feel safe, grow live plants in the tank. This gives them places to hide and reduces their fear.

Always keep Glass Bloodfin Tetras in groups because they are shy and nervous on their own. It’s also a good idea to place the aquarium where people are often around. If they get used to seeing movement, they will be less likely to get scared by it. But if they are in a quiet place, they might become too fearful. This can lead to them trying to jump out of the tank or hiding in places where they could get stuck.

It’s important to avoid scaring these fish. Stress can make them act in unnatural ways and is bad for their health. Handle them and their tank with care to prevent panic and keep them happy.

Sexing and Body Characteristics

Glass Bloodfins grow to about 5 to 6 cm (roughly 2 inches) when fully mature. Their see-through bodies and red tail fins make them a stunning addition to any aquarium, whether it's a community tank or a dedicated setup. These fish have a unique half-centimeter spot on their gills, which is fascinating because it reflects light, creating a shimmering effect. However, if you keep just one Glass Bloodfin, its colors may appear pale due to the absence of a shoal. These tetras thrive in groups, and their beauty truly shines when they swim together, with their red tails creating a striking visual. Although they might not be as brightly colored as some Malawi cichlids, their charm lies in their subtle elegance. The presence of plants and a well-chosen background can further enhance their colors.

In terms of sexing, the male Glass Bloodfin is smaller and slimmer compared to the female. Females are larger, rounder, and may have a slightly bigger first anal fin with white beams. This difference is because females carry eggs, making them naturally larger and rounder.

Feeding

Glass Bloodfins will readily accept all types of food, whether it’s live, frozen, or dried. We often feed them flakes, which they enjoy eating from the surface along with Black Skirt Tetras. They can appear quite voracious, almost like little piranhas during feeding time. This behavior isn't due to a lack of food but rather because they are naturally very hungry. Their small stomachs mean it's best to feed them twice a day in small amounts. If you've just introduced new Glass Bloodfins to your tank, they might be shy at feeding times for the first few days or weeks until they settle into their new environment. As mentioned earlier, they will also eagerly eat granules, pellets, bloodworms, insects, or worms.

Breeding

Glass Bloodfins prefer to breed in the morning, especially when the aquarium is naturally lit by sunlight and they are in a shoal rather than in pairs. The breeding tank shouldn’t be too small - dimensions of about 30x30x80 cm (approximately 12x12x32 inches) are optimal. Spawning usually takes place underwater, above or among soft aquarium plants like Java moss, or even between silk plants. During a single spawn, they can lay anywhere from 200 to 350 eggs. The eggs are clear and not very sticky, so only a few will remain attached to the spawning site, while most will fall to the substrate.

The eggs are about 0.90 mm long and, at a temperature of 27°C (80.6°F), they hatch quickly - usually within 14 to 15 hours. The fry are about 2.25 mm long at hatching. They have a sticky secretion on their heads that allows them to cling to the walls of the aquarium or to plants in shaded areas. Sometimes they even stick to the water surface. After 84 to 85 hours, the fry begin to swim freely, and at this stage, they need to be fed live natural foods like newly hatched brine shrimp (Artemia salina).

The breeding behavior of Glass Bloodfins is similar to that of Aphyocharax anisitsi and Rathbuni species. The fry tend to cling to plants, aquarium glass, or equipment with their bellies facing up. However, Glass Bloodfins grow faster than Anisitsi and Rathbuni. By the time they are 7 to 8 weeks old, they start to swim in shoals throughout the entire aquarium, just like their parents. At this age, they can be fed crushed TetraMin or similar foods. With a good diet, they will reach full size within 4 to 8 months. If their diet is less rich, they may take 8 to 10 months to fully mature. It's important to maintain crystal-clear water, low in nitrogenous compounds, and to keep the pH between 7 and 7.8 while they are juveniles.

Glass Bloodfins thrive best in a species-specific shoal, but they also enjoy the company of Black Skirt Tetras (Gymnocorymbus ternetzi) or Flame Tetras (Hyphessobrycon flammeus). Be cautious if keeping them with Neon Tetras, as Glass Bloodfins may not do well. It’s believed that Neon Tetras release a secretion that is slightly acidic, which Glass Bloodfins dislike. In contrast, Black and Flame Tetras, which prefer harder water, make better companions. Glass Bloodfins can also be housed with some semi-aggressive fish, as long as their tankmates have smaller mouths. Gouramis or Paradise Fish are good options. Lastly, be aware that Glass Bloodfins are very fast swimmers, making them difficult to catch, especially in a large, heavily planted aquarium.

Video

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Some of the information presented is sourced from an article by Stanislav Frank in the 1982/1 issue of Akvarium Terarium magazine.