Haplochromis

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Haplochromis
Haplochromis thereuterion.jpg
Haplochromis thereuterion
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cichliformes
Family: Cichlidae
Tribe: Haplochromini
Genus: Haplochromis
Hilgendorf, 1888
Type species
Chromis obliquidens
Hilgendorf, 1888
Synonyms

Many, see text

Haplochromis is a ray-finned fish genus in the family Cichlidae. It has been used as the default "wastebin taxon" for Pseudocrenilabrinae cichlids of the East African Rift, and as such became the "largest" fish "genus". Many of these cichlids are popular aquarium fishes; like similar Haplochromini they are known as "haplos", "happies" or "haps" among aquarium enthusiasts. [1]

Contents

The genus was established by F.M. Hilgendorf in 1888. It was originally conceived as a subgenus of A.C.L.G. Günther's "Chromis", at that time an even larger "wastebin genus" for Pseudocrenilabrinae cichlids. The type species of Hilgendorf was H. obliquidens . "Chromis" of Günther turned out to be a junior homonym of G. Cuvier's ocean fish genus Chromis , already established in 1814, and was abolished. As the years went by, other genera of (mostly) Haplochromini were lumped with and split again from Haplochromis, and the final delimitation of the clade around H. obliquidens is not yet done.

Extinction crisis in Lake Victoria

The introduction of Nile perch (Lates niloticus) to Lake Victoria after 1954 severely upset the lake's ecosystem. By the late 1970s, the perch's population was approaching carrying capacity, and the smaller cichlids were fair game for the huge carnivorous Lates. The Nile tilapia (Oreochromis niloticus), an adaptable generalist, was also introduced and competed with the often specialized endemic cichlids of the lake for food and other resources. When the Nile perch stocks finally declined again in the late 1980s, an estimated 200 Haplochromini species (mostly Haplochromis) may have become extinct  – many of these had only been scientifically described a few years before their demise, and additional ones were only known or suspected to exist, but never properly studied or described. [2]

While the stocks of those species that survived are in many cases recovering, the lake ecosystem has changed irrevocably. The entire trophic web has been observed to be upset. But still, evolution runs its course: those Lake Victoria Haplochromis species that still exist are in many cases adapting to new food sources, and in time, speciation is likely to set in and produce a new adaptive radiation of these fishes. Until then, however, the ecological balance of the lake is still on the brink, and many of the cichlids that survived the peak population of Lates are still critically endangered and close to extinction. [3]

Systematics and taxonomy

Haplochromis is the type genus of the tribe Haplochromini. Most of the tribe's members were at one time or another included in the present genus, but in many cases this was only temporary. Around the year 1900, as well 100 years later, the trend was to split up the genus; especially in the mid-20th century, on the other hand, most authors lumped any and all Haplochromini that were not conspicuously distinct in the type genus. [4]

While a number of African Rift Valley cichlids are certainly very close relatives of H. obliquidens , the type species of the present genus, it is not very clear where to draw the boundary of Haplochromis with regard to its relatives. Still, several genera are now recognized as distinct by many authors and scientific databases, such as FishBase (see below); in particular the Haplochromini from Lake Tanganyika and Lake Malawi are usually removed from Haplochromis. The genus delimitation in the entire tribe remains badly resolved, however, and further changes in taxonomy are likely in the future. In particular, between Haplochromis, Astatotilapia and Thoracochromis , species have been moved to and from over the years. The habit of Pseudocrenilabrinae to hybridize is hampering molecular phylogenetic studies based on mtDNA alone, while trophic morphs of a single species may appear to be distinct "species" if they are not phylogenetically studied. Several proposed genera are again included in Haplochromis at present, but it cannot be ruled out that some of these will eventually be recognized as valid again. [5]

Species

There are currently 229 recognized species in this genus:

Undescribed species

These populations are typically referred to by the names they have in the aquarium fish trade. A number of them are likely to represent undescribed distinct species; others might just be subspecies or color morphs. Whether they all belong in Haplochromis is, of course, doubtful. Some of these populations are:

Formerly in Haplochromis

Adult male Golden Mbuna (Melanochromis auratus) Melanochromis auratus (male).jpg
Adult male Golden Mbuna (Melanochromis auratus)
Giraffe Hap (Nimbochromis venustus) Nimbochromis venustus.JPG
Giraffe Hap (Nimbochromis venustus)
Adult male Sciaenochromis fryeri Fryeri2.jpg
Adult male Sciaenochromis fryeri

Among other genera of Haplochromini that were formerly included here, many are small or monotypic. The distinctness of these is highly doubtful, as they may just be distinct lineages of Haplochromis or other haplochromines. That nonwithstanding, Haplochromini genera to which some former "Haplochromis" have been removed are in particular: [9]

Some other Pseudocrenilabrinae were also – mainly by early authors – included in Haplochromis, though they are not members of its tribe. These are: [4]

Synonyms of Haplochromis

With all the taxonomic and systematic confusion affecting Haplochromis and its allies, it is hardly surprising that the genus has a large number of junior synonyms. Most referred to small or monotypic genera that were once considered distinct, but are now included in Haplochromis again, if only to wait for a major review of their status. Synonyms are:

  • AllochromisGreenwood, 1980
  • CleptochromisGreenwood, 1980
  • EnterochromisGreenwood, 1980
  • GaurochromisGreenwood, 1980
  • HarpagochromisGreenwood, 1980
  • LabrochromisRegan, 1920
  • LipochromisRegan, 1920
  • PlatytaeniodusBoulenger, 1906
  • PrognathochromisGreenwood, 1980
  • PtyochromisGreenwood, 1980
  • PsammochromisGreenwood, 1980
  • TridontochromisGreenwood, 1980
  • XystichromisGreenwood, 1980
  • YssichromisGreenwood, 1980

Sometimes other genera listed above are also synonymized.

Footnotes

  1. Linke & Staeck (1994)
  2. Linke & Staeck (1994), Kishe-Machumu et al. (2008), IUCN (2009)
  3. Kishe-Machumu et al. (2008), IUCN (2009)
  4. 1 2 FishBase [2009b]
  5. Nagl et al. (2001), FishBase [2009b]
  6. 1 2 3 4 5 6 7 de Zeeuw; Mietes; Niemantsverdriet; ter Huurne; Witte (2010). "Seven new species of detritivorous and phytoplanktivorous haplochromines from Lake Victoria". Zoologische Mededelingen. 84: 201–250.
  7. Wamuini Lunkayilakio; Vreven (2010). "'Haplochromis' snoeksi, a new species from the Inkisi River basin, Lower Congo (Perciformes: Cichlidae)" (PDF). Ichthyological Exploration of Freshwaters . 21 (3): 279–287.
  8. Schedel, F. D. B., Friel, J. P. & Schliewen, U. K. (2014): Haplochromis vanheusdeni, a new haplochromine cichlid species from the Great Ruaha River drainage, Rufiji basin, Tanzania (Teleostei, Perciformes, Cichlidae). Spixiana, 37 (1): 135-149.
  9. Linke & Staeck (1994), FishBase [2009b]

Related Research Articles

<i>Oreochromis</i> Genus of fishes

Oreochromis is a large genus of oreochromine cichlids, fishes endemic to Africa and the Middle East. A few species from this genus have been introduced far outside their native range and are important in aquaculture. Many others have very small ranges; some are seriously threatened, and O. ismailiaensis and O. lidole possibly are extinct. Although Oreochromis primarily are freshwater fish of rivers, lakes and similar habitats, several species can also thrive in brackish waters and some even survive in hypersaline conditions with a salinity that far surpasses that of seawater. In addition to overfishing and habitat loss, some of the more localized species are threatened by the introduction of other, more widespread Oreochromis species into their ranges. This is because they—in addition to competing for the local resources—often are able to hybridize.

<i>Sarotherodon</i> Genus of fishes

Sarotherodon is a genus of oreochromine cichlids that are native to the northern half of Africa, with a single species, S. galilaeus, also ranging into the Levant. A couple of species from this genus have been introduced far outside their native range, and are important in aquaculture. Most other species have small ranges and some are seriously threatened. They mainly inhabit fresh and brackish water, but a few can live in salt water. Species in this genus, as well as those in several other oreochromine and tilapiine genera, share the common name "tilapia" and historically they were included in the genus Tilapia.

Ethelwynn Trewavas was an ichthyologist at the British Museum of Natural History. She was known for her work on the families Cichlidae and Sciaenidae. She worked with Charles Tate Regan, another ichthyologist and taxonomist.

<i>Protomelas</i> Genus of fishes

Protomelas is a genus of haplochromine cichlids endemic to Lake Malawi in East Africa. The genus is part of the haplochromine tribe and have maternal mouthbrooding and sexual dimorphism typical of this group. Popular in the aquarium hobby, Protomelas species are sold under a variety of trade names.

<i>Thoracochromis</i> Genus of fishes

Thoracochromis is a fish genus of haplochromine cichlids that are endemic to Africa. Most species are from rivers in Angola and Namibia, or the Congo River Basin in Central Africa, but T. wingatii is from the Nile system. Additionally, there are a few apparently undescribed species from the Nile system, which appear to be close relatives of T. wingatii or Haplochromis loati. Many species have been moved between this genus and Haplochromis, and while some consensus has been reached in recent years, their mutual delimitation is still far from settled.

<i>Otopharynx</i> Genus of fishes

Otopharynx is a genus of haplochromine cichlids endemic to Lake Malawi in Eastern Africa.

<span class="mw-page-title-main">Haplochromine</span> Tribe of fishes

The haplochromine cichlids are a tribe of cichlids in subfamily Pseudocrenilabrinae called Haplochromini. This group includes the type genus (Haplochromis) plus a number of closely related genera such as Aulonocara, Astatotilapia, and Chilotilapia. They are endemic to eastern, southern and northern Africa, except for Astatotilapia flaviijosephi in the Middle East. A common name in a scientific context is East African cichlids – while they are not restricted to that region, they are the dominant Cichlidae there. This tribe was extensively studied by Ethelwynn Trewavas, who made major reviews in 1935 and 1989, at the beginning and at the end of her career in ichthyology. Even today, numerous new species are being described each year.

<i>Synodontis</i> Genus of fishes

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<i>Lethrinops</i> Genus of fishes

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<i>Mylochromis</i> Genus of fishes

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<i>Neochromis</i> Genus of fishes

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<i>Haplochromis argens</i> Species of fish

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<span class="mw-page-title-main">Chromidotilapiini</span> Tribe of fishes

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<i>Enteromius</i> Genus of cyprinid fishes

Enteromius is a genus of small to medium-sized cyprinid fish native to tropical Africa. Most species were placed in the genus Barbus.

References