Rainbowfish types: colour, threadfins and group requirements

Melanotaenia boesemani — adult male AI side-view illustration

Boesemani rainbowfish9 cm SLAdult males have a blue front and orange rear; an active group needs a long swimming run.

AI illustration of adult male Bedotia madagascariensis, left side, ordinary adult male

Madagascan rainbowfishTypical adult total length unknownAn elongated, reflective body with dark stripes; males have more colourful unpaired fins.

AI illustration of adult male Chilatherina alleni, left side, Wapoga illustrated form

Chilatherina alleniTypical adult total length unknownA dark lateral stripe above a pale or orange-yellow band; colour varies with locality.

AI illustration of adult male Chilatherina bleheri, complete left-facing side view

Chilatherina bleheriTypical adult total length unknownMales grade from a silvery front to an orange-red rear; females are paler and slimmer.

AI illustration of adult male Chilatherina fasciata, left side, Lake Wanam male, resting coloration

Chilatherina fasciata11 cm SLColoration varies widely by locality; one vivid color form cannot represent all fasciata.

AI illustration of adult male Chilatherina sentaniensis, left side, red aquarium population; wild locality unknown

Chilatherina sentaniensis10 cm SLWhen distinguishing it from the similar fasciata, its longer snout is more useful than how dark its colors are.

AI illustration of adult male Glossolepis dorityi, left side, adult male display coloration

Glossolepis dorityi11.5 cm SLMature males are deep-bodied, with striking orange-red stripes between scale rows.

AI illustration of adult male Glossolepis incisa, complete left-facing side view

Glossolepis incisaMales reported at 15 cm (length basis unknown)Mature males stand out for their rich red flanks; juveniles have not fully developed this color. Male and female appearances should be considered separately.

AI illustration of Glossolepis multisquamata, complete left-facing side view

Glossolepis multisquamata12 cm SLMales have red bars on silvery flanks; their mature fin shape is also worth observing.

AI illustration of adult male Glossolepis wanamensis, left side, adult male representative

Glossolepis wanamensis9 cm SLMales are deep green to nearly black, with a deep body and conspicuous anal fin. Females are smaller and paler.

Iriatherina werneri — adult male AI side-view illustration

Threadfin rainbowfishTypical adult TL unknownMales display a fan-shaped dorsal fin and trailing rays; their tiny mouths make feeding competition important.

AI illustration of adult male Marosatherina ladigesi, complete left-facing side view

Marosatherina ladigesiSource reports 5–6 cm (measurement basis unknown)Males have elongated dorsal and anal fins and a black area on the first dorsal fin. The proportion of black varies among individuals.

AI illustration of adult male Melanotaenia affinis, complete left-facing side view, Pagwi form

Melanotaenia affinis11.5 cm SLMales of Pagwi stock may show a blue to olive base color and red-orange stripes. Colors from other localities cannot be applied directly.

AI illustration of Melanotaenia ajamaruensis, complete left-facing side view

Melanotaenia ajamaruensis9.6 cm SLSimilar to boesemani in shape and color, but stripes along the middle and lower flanks are usually more prominent. An Ajamaru trade locality label alone does not establish this species' identity.

AI illustration of Melanotaenia australis, complete left-facing side view

Melanotaenia australis11 cm SLMales usually have a higher back and longer fins. Locality forms differ markedly in color; retain provenance when buying.

AI illustration of Melanotaenia eachamensis, complete left-facing side view

Melanotaenia eachamensis6.5 cm SLSilvery-blue flanks carry a dark midlateral stripe and fine lower-flank lines. Male fin colors intensify during breeding; locality populations still differ.

Melanotaenia exquisita, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia exquisita7.5 cm SLA smaller rainbowfish; the examined Sleisbeck stock comes from rocky upper streams. Populations differ in appearance, and a representative color pattern still awaits confirmation from reference images.

Melanotaenia fasinensis, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia fasinensis12 cm SLReddish flank stripes contrast with a blue upper body, with a patch visible behind the pectoral fin. Color changes with condition; body depth alone cannot determine sex.

Melanotaenia fluviatilis, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia fluviatilis11 cm SLRed gill-cover patches and red fin spots in breeding males offer identification clues. This catalogue treats it as a separate species.

AI illustration of Melanotaenia fredericki, complete left-facing side view

Melanotaenia fredericki9 cm SLA pale violet body with blue reflective scales above the midlateral band and a yellow area below it, more conspicuous in juveniles. Adult males are usually deeper-bodied and more strongly colored.

AI illustration of adult male Melanotaenia herbertaxelrodi, left side, natural adult male

Melanotaenia herbertaxelrodiAbout 10 cm reported (length basis unknown)A yellow to olive body with a blue-black lateral band and red fins. Females are paler and less deep-bodied.

AI illustration of Melanotaenia kamaka, complete left-facing side view

Melanotaenia kamaka6.1 cm SLThe male's silvery-blue back becomes silvery white during courtship. Females are more silvery gray and smaller-bodied.

AI illustration of adult male Melanotaenia lacustris, complete left-facing side view

Melanotaenia lacustrisSource maximum 12 cm (length basis unknown)The upper body often appears blue with a paler belly. During courtship, the stripe on top of the head differs from the usual coloration.

AI illustration of Melanotaenia maccullochi, complete left-facing side view

Melanotaenia maccullochi7 cm SLSilver-white to yellow flanks bear 6–8 fine reddish-brown longitudinal stripes. The older, broadly used name included sahulensis and wilsoni, which were subsequently separated.

Melanotaenia mairasi, female representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia mairasiTypical adult total length is unknownThe live female holotype in the original description has a brown back, white belly, dark stripe from eye to tail base, fine red lines between scale rows and orange scale edges. This female appearance must not be used as male coloration.

AI illustration of Melanotaenia misoolensis, complete left-facing side view

Melanotaenia misoolensis7.7 cm SLYellow flanks carry a blue-black midlateral band. Color changes from juvenile to adult, so juvenile coloration does not establish the final appearance.

AI illustration of adult male Melanotaenia nigrans, left side, breeding male with yellow caudal

Melanotaenia nigrans10 cm TLA slender blue-gray body has a dark midlateral band passing through the eye and a visible pink gill-cover patch. Breeding males may develop a bright yellow tail.

Melanotaenia ogilbyi Timika representative left-facing AI illustration, sex unspecified

Melanotaenia ogilbyi7 cm SLThe reviewed photograph of a live Timika fish shows red scale-row markings, a darker midlateral stripe, silvery-blue lower flanks and yellowish translucent dorsal and anal fins. Its sex was not stated.

AI illustration of Melanotaenia oktediensis, complete left-facing side view

Melanotaenia oktediensis10 cm SLThe original description used three female specimens. Their lower-positioned flank stripe extends less far forward, offering a combination to compare with vanheurni. Live coloration and male morphology remain unknown.

Melanotaenia papuae, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia papuae6.5 cm SLA yellow-olive base and silvery-white flanks bear black longitudinal markings and one or two orange-red stripes. Stripes alone cannot distinguish it from similar species.

AI illustration of adult male Melanotaenia parkinsoni, left side, ordinary yellow-orange form; no uncertain spotted trade morph

Melanotaenia parkinsoniSource maximum: 14 cm (measurement basis unknown)The original population commonly has yellow-orange fins with dark edges, and markings on the rear half of males may merge into broad patches. Retain provenance for traded red and spotted forms.

AI illustration of Melanotaenia parva, complete left-facing side view

Melanotaenia parva6.7 cm SLMales may be blue-violet with a dark midlateral band, or silver with red spots and fine orange-red lines. Both forms have reddish fins; young males develop stronger colors as they grow.

Melanotaenia picta, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia picta9.3 cm SLThe rainbowfish formerly sold as Aru II develops stronger color as it matures. It is hard to distinguish visually from kolaensis, senckenbergianus and wokamensis in the same group; provenance matters more than vivid trade coloration.

Melanotaenia praecox — adult male AI side-view illustration

Dwarf neon rainbowfish5 cm SLBlue iridescence and red-orange fins; small size does not remove the need for a group and swimming room.

AI illustration of adult male Melanotaenia pygmaea, left side, ordinary adult male

Melanotaenia pygmaea5.5 cm SLMales are metallic blue with a reddish-brown head and whitish fins. Females have smaller fins and lack the reddish-brown head coloration.

Melanotaenia rubrivittata male left-facing AI illustration

Melanotaenia rubrivittata4.9 cm SLRed horizontal flank stripes in males are an important visual clue. Distinguishing it from praecox requires body shape and several other features.

AI illustration of adult male Melanotaenia rubrostriata, left side, natural adult male; not Dekai trade identification

Melanotaenia rubrostriataMaximum recorded: 12.5 cm SLOrange-pink stripes follow scale rows on blue-green to whitish flanks. Dorsal- and anal-fin membranes are reddish; larger males have a deeper upper-body profile.

Melanotaenia splendida, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia splendida20 cm SLLocality forms differ markedly, and the original population of some trade-bred fish is unknown. Images and information must distinguish Mary River, Ellery Creek and unknown-origin stocks.

Melanotaenia susii male left-facing AI illustration

Melanotaenia susii12.3 cm SLConsider the red dorsal-fin margin, dark vertical bands on the front of the body and relatively long snout together. Band count alone cannot confirm identity.

AI illustration of Melanotaenia synergos, complete left-facing side view

Melanotaenia synergos6.7 cm SLLive fish have a blue back and pale lower body. A blue-black midlateral stripe extends from the upper preopercular edge to the caudal-fin base, with stronger stripe contrast in males.

Melanotaenia trifasciata, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia trifasciata13 cm SLCato stock is predominantly blue with slightly reddish fins, and male coloration changes with display state. This color pattern does not represent every river locality form.

Melanotaenia wilsoni, natural-form representative in left-facing lateral AI illustration; not a photograph.

Melanotaenia wilsoni3.3 cm SLSimilar to maccullochi but smaller and more timid. Keepers report a strong tendency to group and a preference for vegetation cover; older guidance for maccullochi in its broad sense cannot be applied directly.

AI illustration of Pseudomugil connieae, complete left-facing side view

Pseudomugil connieae5 cm SLMale dorsal and anal fins have broad white to yellow margins and a dark central band. Females have smaller fins. It was historically confused with furcatus.

Pseudomugil furcatus — adult male AI side-view illustration

Forktailed blue-eye5 cm SLBlue eyes, yellow fins and a deep forked tail; a small but fast swimmer.

Pseudomugil gertrudae — adult male AI side-view illustration

Spotted blue-eye3.8 cm SLBlue eyes and spotted fins, with colours that vary between populations.

Pseudomugil ivantsoffi, natural-form representative in left-facing lateral AI illustration; not a photograph.

Pseudomugil ivantsoffi2.8 cm SLA small blue-eye from around Timika, with males slightly larger than females. Formerly confused with reticulatus; identification requires checking provenance rather than carrying forward old labels.

AI illustration of adult male Pseudomugil luminatus, complete left-facing side view

Pseudomugil luminatusSource maximum for males: 3.5 cm (measurement basis unknown)Adult males range from yellow-orange to red, with a neon-blue line along the upper back and scattered black fin spots. Females are paler and usually lack fin spots.

Full left-facing side-view AI illustration of Pseudomugil paludicola.

Pseudomugil paludicola3.5 cm TLA translucent body with a silvery head and belly and yellowish pelvic fins. The dorsal fins sit far back, and males have longer dorsal fins than females.

Pseudomugil pellucidus, natural-form representative in left-facing lateral AI illustration; not a photograph.

Pseudomugil pellucidus3.1 cm SLThe anal-fin band may vary from yellow to red. The colors in one retailer’s photograph do not represent every individual.

AI illustration of Pseudomugil reticulatus, complete left-facing side view

Pseudomugil reticulatus2.8 cm SLThe account reviewed describes a translucent blue-green body, silver belly and red fin areas, with similar female coloration. Verify Ajamaru stock origin to avoid confusion with ivantsoffi.

Pseudomugil signifer, natural-form representative in left-facing lateral AI illustration; not a photograph.

Pseudomugil signifer7 cm SLResembles a miniature Celebes rainbowfish. Males display frequently and compete with each other. Single-male arrangements in small tanks or breeding setups do not mean the species must always be kept with only one male.

Pseudomugil tenellus, natural-form representative in left-facing lateral AI illustration; not a photograph.

Pseudomugil tenellus5.5 cm SLPearl-like scale spots on the flanks and relatively short dorsal and anal fins. Fish labeled Daly may look coppery; retain provenance and note their color condition.

Rhadinocentrus ornatus, natural-form representative in left-facing lateral AI illustration; not a photograph.

Rhadinocentrus ornatus6 cm SLEspecially slender; keepers report nervous behavior and stronger colors in the early morning in densely planted surroundings. Locality forms are recorded separately.

Rainbowfish types: colour, threadfins and group requirements

Start with outline before colour

This entrance includes rainbowfish and blue-eyes, not one interchangeable species. Melanotaenia boesemani and Iriatherina werneri offer contrasting starting points: adult body shape and colour in the former, extended male fins in the latter. Match unfamiliar trade names to scientific identities before comparing.

Boesemani juveniles do not show the final appearance

Juveniles are often less colourful than adults, and mature males become brighter and deeper-bodied than females. An adult male photograph is not the expected appearance of every young fish. This species needs a group and swimming room; its activity can disturb smaller or slower tankmates despite a peaceful reputation.

Threadfins need food that fits their tiny mouths

Male Iriatherina werneri develop extended fins. Their tiny mouths demand suitably small food, and competition can prevent them eating enough. Some tankmates also nip the fins. Mature, stable planted conditions and gentle water movement matter alongside the display. Observe actual feeding rather than assuming food entering the tank reaches every fish.

Turn an appearance preference into useful questions

Explore Melanotaenia boesemani for adult colour and body depth, or Iriatherina werneri for threadfin displays. Assess each group arrangement with its own space and environment; these examples do not establish one stocking number for the gallery. For blue-eyes and other members, repeat the same checks: identity, sex and stage, adult space, food and tankmates.

Sources

melanotaenia boesemani — Seriously Fish

iriatherina werneri — Seriously Fish

Rainbowfish and blue-eyes

Rainbowfish types: colour, threadfins and group requirements

Start with outline before colour

Boesemani juveniles do not show the final appearance

Threadfins need food that fits their tiny mouths

Turn an appearance preference into useful questions