Altolamprologus fasciatus is a 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...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 in the subfamily Pseudocrenilabrinae

Pseudocrenilabrinae

The Pseudocrenilabrinae is a subfamily in the cichlid family of fishes to which, according to a study from 2004, includes all the Middle Eastern and African cichlids with the exception of the unusual Heterochromis multidens and the Malagasy species. Previous authors recognized additional African...

. It is endemic to Lake Tanganyika

Lake Tanganyika

Lake Tanganyika is an African Great Lake. It is estimated to be the second largest freshwater lake in the world by volume, and the second deepest, after Lake Baikal in Siberia; it is also the world's longest freshwater lake...

, where it is found in the waters of Burundi

Burundi

Burundi , officially the Republic of Burundi , is a landlocked country in the Great Lakes region of Eastern Africa bordered by Rwanda to the north, Tanzania to the east and south, and the Democratic Republic of the Congo to the west. Its capital is Bujumbura...

, the Democratic Republic of the Congo

Democratic Republic of the Congo

The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...

, Tanzania

Tanzania

The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

, and Zambia

Zambia

Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....

.

This species is often placed in Neolamprologus

Neolamprologus

Neolamprologus is a genus of cichlid fishes endemic to eastern Africa with all but one species occurring in Lake Tanganyika. It is the largest genus of cichlids in Lake Tanganyika and also the largest genus in the tribe Lamprologini, which includes Altolamprologus, Chalinochromis, Julidochromis, ...

. With its torpedo

Torpedo

The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

-like shape, is more similar to these than to the high-backed Altolamprologus

Altolamprologus

Altolamprologus is a small genus of pseudocrenilabrine cichlids endemic to Lake Tanganyika in eastern Africa. They inhabit areas of the lake with large amounts of rock, most frequently in water two to ten metres in depth. Two formally described species comprise this genus, with perhaps one dwarf A....

. But in other respects it is a fairly typical Altolamprologus, and like the other two species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of that genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 a ferocious (for its size) carnivore

Carnivore

A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...

 preying on smaller fish such as juvenile cichlids. Analysis of mtDNA NADH dehydrogenase

NADH dehydrogenase

NADH dehydrogenase is an enzyme located in the inner mitochondrial membrane that catalyzes the transfer of electrons from NADH to coenzyme Q...

 subunit

Protein subunit

In structural biology, a protein subunit or subunit protein is a single protein molecule that assembles with other protein molecules to form a protein complex: a multimeric or oligomeric protein. Many naturally occurring proteins and enzymes are multimeric...

 2 sequence

DNA sequence

The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...

 data confirms that it is closer to Altolamprologus than to Neolamprologus, but still represents a lineage well distinct from the other Altolamprologus.

The reason for these unclear relationships may be that the origin of A. fasciatus lies in hybridization of a female of the original Altolamprologus and a male of some other lineage of Lamprologini

Lamprologini

Lamprologini is a tribe of African cichlid fishes. It contains seven genera and nearly 100 species. Over half of the species in this tribe are in the large genus Neolamprologus. Most genera in the tribe are endemic to Lake Tanganyika, but one species of Neolamprologus Lamprologini is a tribe of...

. Such an event would have happened long ago enough to arguably place A. fasciatus in a monotypic

Monotypic

In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 genus, though such inconvenient arrangements are generally avoided in taxonomy

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

.

Alternatively, A. fasciatus could be an offshoot of its genus that has adapted

Adaptation

An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....

 to mimic Neolamprologus or similar cichlids which hunt invertebrate

Invertebrate

An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s. Such fishes are not considered a threat by the prey of A. fasciatus, and thus the predator may be able to catch its prey unawares. But it not known whether A. fasciatus indeed represents a case of cryptic or other aggressive mimicry

Aggressive mimicry

Aggressive mimicry is a form of mimicry where predators, parasites or parasitoids share similar signals with a harmless model, allowing them to avoid being correctly identified by their prey or host...

. Lepidiolamprologus mimicus – the only lamprologine for which aggressive mimicry has been confirmed as of mid-2008 – is a Batesian-Wallacian aggressive mimic; it appears similar to females of Paracyprichromis brieni

Paracyprichromis brieni

Paracyprichromis brieni is a species of fish in the Cichlidae family. It is endemic to the Democratic Republic of the Congo. Its natural habitat is freshwater lakes.-References:* Bigirimana, C. 2005. . Downloaded on 4 August 2007....

and joins swarms of that species to feed on their young.

Given the basal position of A. fasciatus in its genus, it may also be that there is really nothing unusual about this species: it might simply represent a missing link

Missing Link

Missing link is a nonscientific term for any transitional fossil, especially one connected with human evolution; see Transitional fossil - Missing links and List of transitonal fossils - Human evolution.Missing Link may refer to:...

 between the "typical" Altolamprologus and other lamprologines, retaining the shape of the latter while already possessing several other apomorphies of the former, and successful enough to persist for a long time in its ecological niche

Ecological niche

In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...

. Detailed studies of its anatomy

Anatomy

Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

, genetics

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

, and behavior

Behavior

Behavior or behaviour refers to the actions and mannerisms made by organisms, systems, or artificial entities in conjunction with its environment, which includes the other systems or organisms around as well as the physical environment...

will probably be necessary to decide what the underlying reasons for this species' unusual appearance are.