The lamena is a vulnerable

Vulnerable species

On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...

 species of cichlid

Cichlid

Cichlids are fishes from the family Cichlidae in the order Perciformes. Cichlids are members of a group known as the Labroidei along with the wrasses , damselfish , and surfperches . This family is both large and diverse. At least 1,300 species have been scientifically described, making it one of...

 fish from the vicinity of the confluence of the Amboaboa and Mangarahara Rivers near Mandritsara

Mandritsara

Mandritsara is a city and commune in northern Madagascar. It belongs to the district of Mandritsara, which is a part of Sofia Region. The population of the commune was estimated to be approximately 17,000 in 2001 commune census....

 in northern Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

. This relatively elongate Paretroplus

Paretroplus

Paretroplus is a genus of fishes in the cichlid family, all of which are endemic to lakes and rivers of Madagascar. The vast majority are threatened and restricted to the northwestern part of the island. Only P. polyactis is found in the southern half of Madagascar and only P. polyactis and P....

reaches about 16 centimetres (6.3 in) in length, and is closely related to P. lamenabe and P.tsimoly

Paretroplus tsimoly

Paretroplus tsimoly is a species of cichlid fish from the Betsiboka River basin in northwestern Madagascar. Like other members of the lamena group, it is a rheophile . This relatively elongate Paretroplus reaches about in length, and is closely related to P. lamenabe and P. nourissati....

. P. nourissati is threatened by habitat loss and invasive species

Invasive species

"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

.

Like other members of the lamena group, it is a rheophile

Rheophile

A rheophile is an organism that prefers to live in fast moving water.-Insects:*Many aquatic insects living in riffles require current to survive.*Epeorus sylvicola, a rheophilic mayfly species .-Fish:...

 (although less so than Oxylapia polli

Oxylapia polli

Oxylapia polli, known locally as the songatana, is a critically endangered species of fish in the cichlid family, and the only member of its genus. It is endemic to the Marolambo Rapids in the Nosivolo River in east-central Madagascar. It is threatened by habitat loss and sedimentation caused by...

), and typically found in river sections that are shallow, clear and fast-flowing. P. gymnopreopercularis is found in the same region, but it appears to be restricted to deeper pools in the river. A member of another cichlid genus, Ptychochromis insolitus

Ptychochromis insolitus

Ptychochromis insolitus is a critically endangered species of fish in the Cichlidae family. It is endemic to the Amboaboa and Mangarahara Rivers near Mandritsara in northern Madagascar. Prior to its official description, it was sometimes known as Ptychochromis sp. nov. "Joba mena" or Ptychochromis...

, is also restricted to the region.