Redfin Notho 'Mbezi' (Nothobranchius rubripinnis) Pair

Common Name

Mbezi River Nothobranchius

Origin and Habitat

Nothobranchius rubripinnis occurs in coastal Tanzania. The Mbezi River population comes from seasonal rain pools, grassy marsh edges, and shallow ditches connected to the Mbezi catchment near Dar es Salaam. These pools fill quickly with the rains, turn turbid with fine mud and decaying grass, then dry completely in the long dry season. Water is shallow, warm, and rich in tiny aquatic life. Substrate is soft silt with mats of roots and fallen stems. Flow is minimal, and cover is provided by emergent grasses and leaf litter.

Temperature and Water Conditions

Preferred temperature is 72 to 78 F, which is 22 to 26 C. Wild sites for Nothobranchius often read near neutral, sometimes a little acidic or a little alkaline depending on season and soil. Stable parameters are far more important than chasing a single value. Keep the water very clean, gently filtered, and well oxygenated. Match the water your fish were raised in for everyday keeping, and adjust only for specific breeding goals.

Appearance and Size

A classic annual Notho with males that glow. Mature males show a bronze to green base with a vivid red net pattern across the body, bright red in the fins, and a clean contrasting edge on the caudal. Females are tan with fine speckling and a clear or faintly tinted fin set. Adult size is about 5 to 6 cm for males and a little smaller for females, roughly 2.0 to 2.4 inches and 1.6 to 2.0 inches. Good light and a dark background bring out the reticulation beautifully.

Diet in the Wild

A quick growing micro predator of seasonal waters. It feeds on mosquito larvae, small chironomids, tiny crustaceans, and other micro invertebrates that bloom after the first rains.

Feeding in Captivity

Offer small live and frozen foods such as newly hatched brine shrimp, daphnia, cyclops, mosquito larvae, and finely chopped bloodworms. Many strains take a high quality micro pellet once they learn it, use pellets as a supplement rather than a base. Juveniles grow best on several small meals each day. Adults color and condition quickly on a rich, varied menu.

Behavior and Tank Setup

Peaceful with similar sized fish, though males posture and display. For breeding and best color, keep a dedicated setup as pairs or trios, or keep a small group so attention is spread out. A 10 to 15 gallon tank works well. Use a bare bottom or a thin layer of fine sand for easy cleaning. Add a removable container of rinsed peat moss or coco fiber for spawning, plus floating plants for shade and security. Gentle sponge filtration keeps water clear without disturbing eggs. A tight lid is important since Notho jump when startled.

Breeding

Conditioning: Condition a trio or small group with heavy live and frozen foods so females fill with eggs and males show strong color. Keep water clean and stable near neutral and in the low to mid seventies Fahrenheit.

Spawning method: Provide a plastic container of peat or coco fiber deep enough to allow a shallow depression. Fish dive into the medium and deposit eggs. Collect the medium weekly.

Egg handling: Gently squeeze the medium until just damp, then store it in a labeled bag or cup at room temperature. Aim for peat that clumps when pressed but does not drip. Too wet starves eggs of oxygen, too dry desiccates them. Check progress by opening a small sample every few weeks and inspecting with a magnifier. Many Mbezi River keepers report that storage around 22 to 24 C produces eyed eggs in roughly eight to twelve weeks.

Raising fry: When sampled eggs are fully eyed, wet a test portion in soft, clean water at the target rearing temperature and provide gentle aeration. Hatch usually occurs within a day. Start fry on newly hatched brine shrimp from the first feeding. Keep the rearing tank shallow for the first week and perform small daily water changes. At one to two weeks, add fine powdered foods along with nauplii. Separate the fastest growers if needed to prevent crowding. Most fry sex out at four to six weeks at warm temperatures.

Quick Facts

• Scientific name: Nothobranchius rubripinnis, Mbezi River population
• Common name: Mbezi River Notho
• Origin: coastal Tanzania, seasonal pools and ditches within the Mbezi River catchment
• Adult size: males about 5 to 6 cm, females a little smaller
• Temperature: 72 to 78 F preferred
• Wild pH: often near neutral with seasonal swings
• Temperament: peaceful small predator, males display to each other
• Diet: live and frozen micro invertebrates, accepts quality micro pellets
• Breeding type: annual bottom spawner into peat or coco fiber, eggs stored damp through diapause, fry take brine shrimp at first feeding
• Notes: stable conditions matter more than exact numbers, gentle sponge filtration and frequent small water changes support fast growth

Tropical Fish Co. Notes

This is a rewarding project fish that lets you experience the full annual cycle. The color on mature Mbezi River males is vivid and the contrast lines on the fins look painted on. Success comes from routine. Feed rich, collect peat on a schedule, label and date every batch, sample a few eggs at intervals, and wet when you are ready to raise a cohort. Keep rearing water sparkling clean and shallow at first, then grow them on with daily care.