Aquarist Atlas
↑ Collection form of Lethrinops microdon

Lethrinops microdon "South East Arm"

South East Arm — SOWTH EEST ARM (approx.)

The fish

How this cichlid is built, and everything about how it lives, eats and breeds, is shared with the species — this page doesn't repeat it.

Read the full Lethrinops microdon account →

Specific to South East Arm

  • Collection locality & coordinates
  • Local coloration — best judged from the living-fish photo
  • Kept as a single-provenance line, never crossed with other collection points

Care facts below are the species' — shared with Lethrinops microdon.

IUCNDATA DEFICIENT · 2018
DDnot on the EX–LC scale
CARESNOT LISTED
Scientific size5.2 in13.1 cm standard length
Temperature75–82 °F24–28 °C
pH7.7–8.6alkaline
Depth115–328 ft35–100 m
DietBenthic diatom feeder and invertivore (sediment sifter)
BreedingMaternal mouthbrooder (polygynous, lek-spawning)not published for this species; estimated several dozen to ~50-80 eggs based on body size and congeners — FLAGGED as unconfirmed
Sexual dimorphismYesMales in breeding dress bear 7 dark vertical bars below dorsal fin and lack a midlateral spot; females smaller, plainer, cryptically countershaded. Males grow larger (~20 cm TL vs smaller females).
PhotographsSee photosGoogle Images →

The South East Arm population

Lethrinops microdon "South East Arm" is the South East Arm population of Lethrinops microdon, a geographic colour form from the Malawi coast of Lake Malawi in the southern part of the lake. It is the same species as Lethrinops microdon, distinguished by its collection locality and local coloration; aquarists keep and breed it as a discrete, provenance-labelled line.

Colour reference: living South East Arm fish at malawi.si →

About the species

Lethrinops microdon, the small-toothed sand cichlid, is one of the deepest-living and least-seen haplochromines in Lake Malawi — a stocky, heavily barred fish that haunts sedimentary mud bottoms at depths of 35 to 100 metres in the lake's southern SE Arm. It was once extraordinarily abundant there: in the 1970s and 1980s it constituted up to 44 percent of the cichlid catch in experimental trawls between 60 and 80 metres and nearly a third of the commercial demersal trawl catch. The same trawling that recorded those numbers then stripped them; recent surveys from the SE Arm have turned up no individuals at all, and the species may persist wild only near Karonga in the far north, where comparable deep mud habitat exists. Its diagnostic signature — an exceptionally high lower gill-raker count of 24 to 29, the largest of any deep-water Lethrinops — marks it as a specialist filter-feeder of benthic diatoms, a life built entirely below the sunlit zone.

Full Lethrinops microdon account →

Sources

  1. malawi.si — Lethrinops microdon "South East Arm"
  2. Eschmeyer's Catalog of Fishes — Lethrinops microdon (species record; holotype BMNH 1977.1.11.413; updated May 2026)
  3. FishBase — Lethrinops microdon (Eccles & Lewis, 1977)
  4. GBIF — Lethrinops microdon Eccles & Lewis, 1977 (species key 2372725)
  5. Turner, G. F. — 'A new species of deep-water Lethrinops (Cichlidae) from Lake Malawi' (Journal of Fish Biology, 2023; doi:10.1111/jfb.15208; uses L. microdon as key comparator)
  6. Eccles, D. H. & Lewis, D. S. C. — 'A taxonomic study of the genus Lethrinops Regan (Pisces: Cichlidae) from Lake Malawi. Part 1.' (Ichthyological Bulletin of the J. L. B. Smith Institute of Ichthyology, No. 36, 1977; original description)