Rivulus caudomarginatus

Rivulus caudomarginatus, scientific name Kryptolebias caudomarginatus, belongs to the family Rivulidae (Rivulaceae). The fish is native to South America. Wild populations are found along the coast of Brazil between the cities of Rio de Janeiro, Santa Catarina and Sao Paulo. Fish live in swamps and reservoirs with stagnant brackish and sea water.

Description

Adults reach a length of about 6 cm. The fish has an elongated body with short fins. The color is gray with a blue tint. Belly silvery. The body pattern consists of black numerous black strokes and two distinct spots located behind the head and at the base of the tail.

Males differ from females in a brighter contrasting body pattern and colored fins. In females, the fins and tail are translucent.

Behavior and Compatibility

It is considered a peaceful and slightly shy species. Prefers to be in a group of relatives. It is acceptable to keep together with fish of comparable size, mainly from among the species living in brackish waters.

Brief information:

• The volume of the aquarium is from 60–80 liters.
• Temperature – 20-30°C
• Value pH — 7.0–8.5
• Water hardness – medium hardness or hard (15–30 GH)
• Substrate type – dark soft
• Lighting – moderate or bright
• Brackish water – recommended at a concentration of 10-15 grams per 1 liter
• Water movement – little or no
• The size of the fish is about 6 cm.
• Food – live or frozen food
• Temperament – peaceful
• Small group content
• Life expectancy about 3 years

Keeping in an aquarium

The optimal size of the aquarium for a group of 3-4 fish starts from 60-80 liters. In the design, it is recommended to provide a lot of shelters from thickets of plants. Any dark soil with a layer of foliage, snags.

Rivulus caudomarginatus can live in fresh water. However, it will feel most comfortable in a brackish environment with a salt concentration of 10-15 grams. per 1 liter. The main parameters of the water must be maintained at medium to high levels of hardness with pH values ​​above 7.0.

Food

The basis of the daily diet should be live, frozen or fresh food with a high protein content. A good choice would be brine shrimp, daphnia, bloodworms.

Features of reproduction

The fish reach sexual maturity by 5-7 months. They spawn regularly, laying eggs in soft silted ground. The size of the eggs is quite large for such miniature fish – about 2 mm. Despite such dimensions, there can be several dozen eggs in one clutch. The incubation period lasts 2-3 weeks.

Sources: FishBase, ItrainsFishes