Skip to content
Know your inhabitants. Start with their needs.
aquariumwebshop
Care guide · Freshwater · fish

Celebes rainbowfish

Marosatherina ladigesi

Celebes rainbowfish (Marosatherina ladigesi)
Photo: Shigella dysenteriae, CC BY-SA 3.0; resized and compressed. Photo: Shigella dysenteriae · Source · CC BY-SA 3.0Resized and compressed; no cropping or colour changes.

The Celebes rainbowfish (Marosatherina ladigesi) is a slender, shimmering shoaling fish known only from Sulawesi. It is peaceful but can be skittish and responds poorly to abrupt changes. Keep at least six in a mature, sufficiently long aquarium with open swimming lanes and planted margins. It needs clean, mineral-rich, mildly alkaline water. The species is listed as Vulnerable, so choose traceable captive-bred stock where possible. Its limited natural range and sensitivity to rapid water changes call for a calm, well-prepared approach. Check water conditions before purchase and plan maintenance around the established aquarium.

Plan your aquarium →

At a glance

Temperature
22–28 °C
pH
7.0–8.0
GH
10–25 °dGH
Aquarium length
At least 76 cm
Minimum aquarium volume
At least 68 L
Adult size
Up to 8 cm
Group size
At least 6 individuals
Temperament
Peaceful

About this species

The accepted name is Marosatherina ladigesi (Ahl, 1936), family Telmatherinidae; Telmatherina ladigesi is the original combination. It is currently the only living species in its genus. The slender silvery fish has a blue lateral line. Males are more colourful and develop extensions to the second dorsal and anal fins. References report up to about 8 cm standard length, measured to the tail base.

Natural habitat

The fish is endemic to Sulawesi, Indonesia. Its restricted range and habitat pressure contribute to its Vulnerable status. In aquaria, clean, stable, mineral-rich water matters more than reproducing one exact locality. It tolerates mildly brackish conditions, but adding salt is unnecessary. Ask about source and breeding history and never release aquarium animals outdoors.

Aquarium and layout

Seriously Fish recommends considering about a 76 × 30 cm footprint and 68 L gross as a minimum. A long tank gives the shoal swimming room and lets males display without constant crowding. Keep at least six, preferably more; a female-biased group can reduce courtship pressure. Plant the margins, optionally add floating plants and leave open lanes. Mature filtration, regular partial water changes and gradual acclimation matter because this fish reacts poorly to rapid changes.

Water conditions

The specialist aquarium profile recommends 22–28 °C, pH 7.0–8.0 and GH 10–25 dGH. It does poorly in acidic water. Keep mineral content and alkalinity stable. Although mildly brackish water is tolerated, a freshwater aquarium does not need added salt. The reviewed sources do not establish a separate KH target.

Behaviour and group size

This peaceful shoaling fish can be skittish if the group is too small or it is startled. Conspecifics encourage natural behaviour. Choose companions that tolerate warm, neutral-to-alkaline, moderately hard water and match its size and feeding style. Avoid predators, aggressive fish and fin-nippers. Consider swimming zone, food competition and tank length; water values alone do not prove compatibility.

Feeding

It accepts dried, frozen and live foods. Offer complete flakes or small granules it can swallow, alternating with small prey such as Artemia and Daphnia. Variety supports condition and colour. Feed portions the shoal can finish and remove leftovers; clean water is essential.

Breeding

This egg-scatterer attaches adhesive eggs to fine plants or a spawning mop over several days. Adults often eat them. Inspect the plants or mop regularly and move eggs to a separate container with water from the spawning aquarium. Seriously Fish reports hatching in roughly 5–10 days depending on temperature. Tiny fry first need infusoria-sized food and later larger prey such as Artemia nauplii. Keep rearing water clean and stable.

Sources & review

This care guide draws on several specialist sources and was last checked on .

View the sources