Paretroplus:Cichlid Genus

Introduction

Paretroplus is a genus of fish in the subfamily “Etroplinae”, family Cichlidae.
These are endemic to Lakes and rivers of Madagascar, Africa and is the sister genus to Etroplus which are endemic to southern India and Sri Lanka.
Together these two genera comprise the subfamily Etroplinae.

Taxonomy

The Genus Paretroplus was described by Bleeker in 1868.
The genus name Paretroplus comes from the Greek 'para' meaning 'on the side of'.
In taxonomy it is commonly used in generic names to express similarity or relatedness.
Hence the genus name literally means 'next to Etroplus' and signifies the close relationship these two genus have.

Description

Paretroplus are medium-sized to large cichlid fishes.
They are found in a variety of habitats, including rivers, shallow floodplain lakes, brackish and marshy coastal environments throughout northwestern and eastern coastal Madagascar.

All members of the genus are highly threatened (with the possible exception of P. polyactis) due to habitat destruction, overfishing, and competition from a number of exotic species, primarily tilapiine cichlids and the Asian snakehead.

Until very recently, when a small isolated population was discovered, one species, Paretroplus menarambo, was presumed extinct.

A remarkable features of this family, is the development of the front part of the gas bladder and corresponding changes to the posterior of the neurocranium(back part of the skull that houses the brain.
This creates a direct connection between the gas bladder and inner ear, and it is not seen in any other Cichlid families.
This allows fish of this genus to have remarkable hearing power.

Relationship with sister genus Etroplus

The sister-group relationship between Etroplus and Paretroplus represents a well-corroborated transoceanic link within Cichlidae, a pattern congruent with the Mesozoic fragmentation of Gondwana.
Although separated by the Indian Ocean, due to striking similarities in external morphology Etroplus and Paretroplus have been hypothesized to have a sister-group relationship since the original description of Paretroplus by Bleeker.

This trans–Indian Ocean relationship has been widely accepted by subsequent workers including Regan (1920), Cichocki (1976), and Stiassny (1991).

Distribution & Habitat

Paretroplus are endemic to Madagascar(Africa).
Their greatest diversity is concentrated in the northwestern part of the island,
where 11 species occur. The eatern side of island is inhabitated by only Paretruplus polyactis

Paretroplus are absent from Central western, Central highland, and South-western parts of Madagascar.
Generally, species of Paretroplus show very distinct distributions, the only exception is Paretroplus kieneri, which exhibits a relatively wide distribution, and is usually found with another member of the genus, Paretroplus polyactis.

Paretroplus damii is the only member of the genus that occurs in both eastern and western basins. Most species of Paretroplus live in freshwater however some species like P. polyactis and P. maromandia exhibit tolerance to brackish or saline environments and may be found, temporarily at least, in full seawater.

Species

Paretroplus comprises 13 species.
There are three morphologically distinct groups.

Group 1

First group consist of comparatively elongated fish which primarily live in rivers and swift flowing waters .

Species Name	Common Name	Image
Paretroplus damii	damii
Paretroplus nourissati	lamena
Paretroplus tsimoly	Tsimoly
Paretroplus lamenabe
Paretroplus loisellei

Group 2

Second group consists of deep-bodied fish which are primarily lake dewelling.

Species Name	Common Name	Image
Paretroplus polyactis	Masovoatoaka
Paretroplus petiti
Paretroplus maculatus
Paretroplus menarambo
Paretroplus mariomandia
Paretroplus dambabe

Group 3

The third clade comprises of species which are shallow-bodied and highly mottled.
These species which are found in both rivers and lakes.

Species Name	Common Name	Image
Paretroplus gymnopreopercularis
Paretroplus kieneri