Otopharynx sp. "Decorus Featherfin"

CARESNOT LISTED
Scientific size7 in18 cm total length
Temperature75–79 °F24–26 °C
pH7.5–8.5alkaline
Hardness (GH)very hardup to 446 ppm
Depth20–66 ft6–20 m
DietPresumed visual sand-sifting insectivore, scanning sand with large eyes then biting for hidden invertebrates, following O. decorus; not directly documented for this population.
Breedingmaternal mouthbroodernot documented for this form; genus-typical, a few dozen eggs
Sexual dimorphismYesBreeding males reported with elongated "featherfin" dorsal and anal rays; the precise colour pattern of this form is not documented.
PhotographsSee photosGoogle Images →
For the aquarist

Replicate this biotopei

Target water

Temperature75.2–78.8 °F
pH7.5–8.5alkaline
Hardnessvery hardup to 446 ppm

Recommended tank

Standard aquarium125-gallon72 × 18 × 23 in · 125 gal (473 L)

Aquascape & setup

Hard, alkaline, well-buffered water of the kind that defines Lake Malawi — stability matters more than chasing a single number.

Build the hardscape first: stacked rock with caves, crevices and sight-lines breaks up territories the way a rocky shoreline does in the wild. Open swimming room, bright light and strong, well-oxygenated flow round it out. A fine sand bed reads as natural and is kind to digging mouths.

Biotope tankmates

Other fish recorded from Lake Malawi, of broadly compatible size — a starting shortlist, not a stocking plan. Always check temperament and territory before mixing.

Hybridization watchi

Otopharynx sp. "Decorus Featherfin" is an undescribed cichlid recorded at Kande Island, in the northern part of Lake Malawi. Its trade name links it to Otopharynx decorus, a described sand-dwelling relative already notable for an unusually high dorsal-fin ray count, and to "featherfin," suggesting further elongated, trailing extensions to the dorsal and anal fins in this population's breeding males.

What's in the name

Otopharynx sp. "Decorus Featherfin"oh-toh-FAIR-inks, form "DEK-or-us FETH-er-fin"

Descriptive nameA descriptive epithet — neither an eponym nor a place name.
Otopharynx
  • otosGreekear
  • pharynxGreekthroat — together referring to features of the pharyngeal (throat) bones used in the genus's original description
"Decorus Featherfin"
  • decorusLatincomely, elegant — from the described relative O. decorus
  • Featherfininformal (English)a descriptive trade term for elongated, feather-like dorsal and anal fin rays reported in breeding males. As an undescribed form it has no formal species name.

Taxonomy & naming

Otopharynx sp. "Decorus Featherfin" has no describing author, no publication date, and no entry under a validated name in Eschmeyer's Catalog of Fishes. The trade name follows the standard convention for an undescribed form allied to a known species: the genus, a reference to the described relative Otopharynx decorus (Trewavas, 1935) — Latin for "comely" or "elegant" — and "Featherfin," a descriptor for elongated, feather-like fin rays. Otopharynx decorus is itself distinguished within its genus partly by an unusually high dorsal-fin ray count (13 or 14 soft rays, versus fewer than 12 in most relatives), and its generic placement is debated, with some authors considering it better assigned to the closely related genus Mylochromis. Whether the Kande Island population represents a genuinely distinct, more extravagantly finned form, or simply well-developed individuals of ordinary O. decorus, has not been settled by any published study. It should be treated as an unresolved, undescribed entity.

Morphology

As its trade name suggests, breeding males of this form are reported to carry noticeably elongated dorsal and anal fin rays — a "featherfin" trait layered onto a species, Otopharynx decorus, already known for an unusually high dorsal ray count among Otopharynx. Otopharynx decorus itself reaches about 7 in total length, has a notably small mouth for a sand-dwelling haplochromine of its size, and carries the genus's three-spot melanic pattern, though the blotches are often faint and hard to see in the subdued light of its deeper habitat. That size figure is used here only as a genus/species-typical reference rather than a direct measurement of the Kande Island population. No formal morphometric study specific to this form has been published, and the extent of its finnage beyond the general "featherfin" description is undocumented.

Habitat

Otopharynx sp. "Decorus Featherfin" is recorded from Kande Island, a small island in the northern part of Lake Malawi long popular with Malawi cichlid collectors and exporters. Otopharynx decorus, the described relative this form is named after, forages over open sand at depths reported to reach around 66 ft in subdued light, typically in small groups of up to about six fish, and the Kande Island population is presumed to occupy broadly similar sandy, moderate-depth habitat. The surrounding water follows the general Lake Malawi profile — warm, hard and strongly alkaline.

Feeding

Otopharynx decorus feeds as a visual sand-sifting insectivore: it uses its large eyes to scan the substrate closely, then bites into the sand once it locates hidden prey, taking mainly invertebrates buried within the substrate rather than picking food from the surface. Otopharynx sp. "Decorus Featherfin" is presumed to feed similarly, though no dedicated feeding study has been published for this Kande Island population specifically.

Mating

No courtship behaviour has been documented specifically for this form. Field surveys of Otopharynx decorus itself have not found clearly territorial, breeding-dressed males defending a spawning site; occasional individuals within foraging groups show partial nuptial colour, but behave as foragers rather than territory holders, and it remains speculative whether the species moves onto rocky substrate to breed. If the Kande Island form follows the reproductive pattern universal to Lake Malawi's haplochromines, mating would still be maternal mouthbrooding with polygynous, lek-style spawning, but the courtship sequence and spawning site have not been directly observed for either the described species or this population.

Breeding

As with all Lake Malawi haplochromines, reproduction is presumed to be by maternal mouthbrooding: the female would incubate the fertilised eggs in her buccal cavity for roughly three weeks, fasting throughout, before releasing free-swimming fry, which she may continue to shelter in her mouth when threatened. Clutch sizes in haps of this size are typically modest, on the order of a few dozen eggs, but no figures have been recorded specifically for this population. Even for the described relative, Otopharynx decorus, breeding has never been directly observed in the field, so the reproductive details given here are inferred from the wider Malawi haplochromine flock rather than measured.

In the aquarium

Otopharynx sp. "Decorus Featherfin" reaches the hobby occasionally through specialist Malawi cichlid importers working the northern lake's export points, including Kande Island. A tank for it should provide a sand substrate with moderate rockwork, reflecting the sand-and-intermediate habitat of its described relative, and open swimming space appropriate to a fish that may reach a respectable size. Water chemistry should follow the Lake Malawi standard — hard and alkaline, pH roughly 7.5 to 8.5, temperature in the mid-20s Celsius. A varied invertivore diet of quality pellets and meaty frozen foods such as bloodworm and mysis suits it, avoiding rich mammalian-based feeds. Given the population's reported elongated finnage, keepers should expect fin damage from boisterous tankmates to be a particular risk, and calm, similarly sized companions are advisable.

Conservation

Otopharynx sp. "Decorus Featherfin" has not been evaluated by the IUCN and, as an undescribed form, has no Red List status of any kind. Its described relative, Otopharynx decorus, is assessed as Least Concern based on its comparatively wide, lake-spanning distribution, but that status does not extend to the Kande Island population specifically. No population-specific data exist to assess whether this form is affected by ornamental collection or other localised pressure at Kande Island. The honest statement is that it is unassessed.

Sources

  1. malawi.si — Otopharynx (Konings-based species database; Malawi genus overview)
  2. Konings, A. — Malawi Cichlids in their Natural Habitat (Cichlid Press; foremost Malawi field authority)
  3. Cichlid Room Companion — Otopharynx (genus profile)

Last reviewed 2026-07-23.

How to cite

Aquarist Atlas (2026). Otopharynx sp. "Decorus Featherfin". Aquarist Atlas. https://www.aquaristatlas.com/species/otopharynx-sp-decorus-featherfin/

Where it has been recorded

1 georeferenced records (GBIF). Each point is a field observation or museum specimen — pan and zoom to explore where this species turns up. The coordinates come straight from GBIF and are often rounded or tied to the nearest town or river landing, so a dot can sit just beside the actual water rather than in it; the fish aren't on dry land.

Literature occurrence: 1
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