Tropheus Polli care guide
Tropheus Polli (Tropheus polli) — minimum tank 450 L, temperature 24-27 °C, pH 8.5-9.2.
Compiled by Aquairi from published sources · Published · Updated
Overview
Tropheus polli is the largest member of the genus, reaching about 18 cm, endemic to the deeper rocky habitats of central Lake Tanganyika. The body is silvery-grey with darker vertical bars and a robust, less compressed shape than other Tropheus.
Taxonomy
- Family: Cichlidae
- Genus: Tropheus
- Scientific name: Tropheus polli
- Common synonyms: Bulu Point Cichlid
Habitat
Endemic to Lake Tanganyika, where it inhabits the wave-washed upper rocky littoral. Tanganyika water is exceptionally hard and alkaline — pH 8.5-9.2, KH 12-20 — with stable warm temperatures and very high dissolved oxygen. Each colour morph corresponds to a discrete stretch of shoreline.
Tank requirements
- Minimum tank volume: 450 L (118.9 US gal)
- Adult size: 14-18 cm
- Temperature: 24-27 °C (75-81 °F)
- pH: 8.5-9.2
- GH: 12-25 °dGH
- Water flow: medium
- Lifespan: 8-12 years
- School size: ≥10 individuals
Diet
In the wild a strict aufwuchs grazer that takes algae filaments, biofilm and associated micro-invertebrates from the rocks. In aquaria the diet must be predominantly plant-based — spirulina-rich pellets, blanched vegetables and only occasional small frozen brine shrimp or cyclops. High-protein or fatty foods cause severe and often fatal "bloat".
Compatibility
Aggressive within the genus; the recommended approach is a single-species colony of 10-15+ individuals so that aggression is spread across many targets. Avoid mixing different Tropheus colour morphs in one tank (they hybridise and fight) and avoid other aggressive rock-dwelling Tanganyikans in the same volume.
Breeding
A polygamous maternal mouthbrooder producing relatively few but large eggs (typically 5-20). The female holds the brood for around four weeks. Captive breeding is straightforward in established colonies and most aquarium stock is now tank-raised.
Conservation status
IUCN Red List: see species page. Several Tropheus species and locality forms are assessed and most are categorised Least Concern, but Lake Tanganyika export is regulated by the riparian countries and some morphs have restricted ranges.
Tropheus polli Breeding Guide
Overview
Tropheus polli is a larger, more elongate Tropheus endemic to Lake Tanganyika, known from the central eastern coast in areas with rocky substrates and reaching a total length of about 16.5 cm (Wikipedia). It is considered by some authorities to be a synonym of Tropheus annectens. As a genus member it is an algal grazer and a maternal mouthbrooder; detailed species spawning data is limited, so the genus pattern is used below.
Sexing
Sexes are hard to distinguish in Tropheus, which differ little in colour; venting (pointed papilla in males, rounded in females) or watching spawning roles in the colony is the practical method. The record notes a grey body with vertical bars and yellow blotches developing in males.
Conditioning
Provide a strictly herbivorous diet based on spirulina flakes and blanched greens, avoiding animal protein as advised for the genus. Recorded parameters are a temperature of 24-27 C, pH 8.5-9.2 and GH 12-25 dGH; stable hard, alkaline water supports conditioning.
Breeding Setup
Keep as a colony to disperse aggression; the record indicates a minimum school size of about 10 and a minimum tank of 450 L, larger than smaller Tropheus owing to this species' greater adult size. Rockwork over sand reproduces the natural biotope.
Spawning Behavior & Trigger
As a maternal mouthbrooder the female collects the eggs into her mouth, where the male fertilises them in the typical Tropheus sequence. A stable, well-fed colony in hard alkaline water is the main spawning trigger.
Egg & Fry Care
In keeping with the genus, broods are small and the fry comparatively large; the female holds them orally for several weeks before releasing free-swimming young that accept brine shrimp nauplii and powdered foods. Isolating a holding female protects the limited brood.
Common Challenges
Susceptibility to 'bloat' on incorrect feeding makes the herbivorous diet and clean water non-negotiable, and the aggressive temperament noted in the record means a large colony and ample tank are needed to breed this species reliably.