Nicaraguan cichlid

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Nicaraguan cichlid
Nicaraguan cichlids, on the left an older male with a hump on the forehead, on the right a female.

Nicaraguan cichlids, on the left an older male with a hump on the forehead, on the right a female.

Systematics
Order : Cichliformes
Family : Cichlids (Cichlidae)
Subfamily : Cichlinae
Tribe : Heroini
Genre : Hypsophrys
Type : Nicaraguan cichlid
Scientific name of the  genus
Hypsophrys
Agassiz , 1859
Scientific name of the  species
Hypsophrys nicaraguensis
( Günther , 1864)

The Nicaragua cichlid ( hypsophrys nicaraguensis ) is a freshwater fish from the family of cichlids , which in Nicaragua in Managua , in Nicaragua , in Xiloásee , in the Río San Juan and in Costa Rica in rivers that flow into the Caribbean, occurs.

features

Nicaraguan cichlids have an oval, laterally strongly flattened body and a strongly curved head profile with the mouth in the lower half of the head. Males can reach a length of 25 cm, females stay a little smaller. The color of the fish is very variable, specimens from Nicaragua should have a bronze-colored head and back, those from Costa Rica a blue-green to green-yellow. The basic color is dark yellow to light brown. The head, chest and sometimes the front half of the body are light blue to greenish. The scales have a golden sheen and dark edges, especially on the back of the body. Depending on the mood, the fish show a central, dark longitudinal band that begins directly behind the eye and extends to the tail stalk. One dark spot each lies on the middle of the body and on the tail stalk. Older males often develop a forehead hump and show neither the longitudinal ligament nor the dark spots. Females are more contrasty in color and show longitudinal ligament and the dark spots in most cases even with age. The unpaired fins are yellowish to light brown and in the males they are patterned with darker points and lines. Those of the females are without pattern. Young fish show 6 or 7 only indistinctly pronounced vertical bands.

Way of life

Nicaraguan cichlids live in deep (Lake Xiloá approx. 90 meters) and shallow lakes (Lake Managua 8 meters, Lake Nicaragua ⌀ 12.5 meters) and in moderately to strong flowing rivers with a sandy bottom in the lakes and stony soil in the rivers. The rivers are mostly clear, the lakes clouded by rich phytoplankton stocks. The fish species feed on snails and other mollusks, mosquito larvae, detritus and parts of plants. Young fish eat aquatic insects.

In Lake Nicaragua, the Nicaraguan cichlids tend to live in deeper open water (10-13 meters) above sandy soils, while the lemon cichlid ( Amphilophus citrinellus ) , which also occurs there, prefers shallower water around 3 meters deep. In Lake Xiloa, too, the Nicaraguan cichlids prefer the open water, but they go to the rocky coasts to reproduce. This is in April in the dry season. The fish thus avoid territorial competition with the aggressive cichlid species Amatitlania nigrofasciata and Neetroplus nematopus , which spawn beforehand. Spawning takes place in self-dug hollows in the bottom of the water, but also in caves and crevices, preferably in those with sloping walls. A clutch consists in most cases of 200 to 400, in rare cases of up to 1500 eggs. The eggs do not stick to each other, a feature that is normally only found among the Neotropical cichlids in the South American genus Geophagus , which also lives on sandy water bottoms . Often three to four females guard their eggs and their fry together.

Parachromis dovii

In Lake Xiloá, it was observed that male Nicaraguan cichlids helped the large fish-eating cichlid Parachromis dovii protect their juveniles. The brood of Parachromis dovii is threatened by Amatitlania nigrofasciata and Neetroplus nematopus , later, when they are larger, by the large, fish-eating goby Gobiomorus dormitor . If the brood is protected by a Nicaraguan cichlid in addition to the parents, a successful rearing of young fish is more likely than with a Parachromis dovii pair that is cared for alone. Parachromis dovii is piscivorous and prey for the small cichlids Amatitlania nigrofasciata and Neetroplus nematopus , adult Nicaraguan cichlids are too big. The benefit for the Nicaraguan cichlids is that it is easier for them to occupy safe spawning grounds in the rocky zone of Lake Xiloá when the stocks of the aggressive cichlid species decline.

Systematics

The Nicaraguan cichlid was described by the German zoologist Albert Günther in 1864 and received the scientific name Heros nicaraguensis . The genus Hypsophrys was introduced in 1859 by the American naturalist Louis Agassiz together with the description of Hypsophrys unimaculatus . The Mexican ichthyologist Juan J. Schmitter-Soto assigned the Nicaraguan cichlid to the genus Hypsophrys in 2007 and made Hypsophrys unimaculatus a synonym for Hypsophrys nicaraguensis . The priority rule of biological nomenclature, according to which older names have priority over younger (later published) names, was not violated, since the description of Hypsophrys unimaculatus is insufficient and the name is therefore considered a noun nudum . In the same year the species was Neetroplus with hypsophrys synonymised and hypsophrys received with hypsophrys nematopus a second type. In April 2016 this was reversed and Neetroplus to a separate genus although it is recognized again, the hypsophrys nicaraguensis and Neetroplus nematopus sister species are. However, the two species differ significantly in their skull and tooth morphology, in their diet, their ecological niche, in their brood color and the assignment of the two species to two genera is therefore more in line with the principles of the classification of the other Central American cichlids. Other synonym names of the species are Cichlasoma nicaraguensis , Cichlasoma spilotum , Copora nicaraguensis and Heros baalteatus .

Individual evidence

  1. ↑ a b c d e Rainer Stawikowski and Uwe Werner: Die Buntbarsche Amerikas, Vol. 1 Verlag Eugen Ulmer, 1998, ISBN 978-3-8001-7270-2 , pages 422-425.
  2. ↑ a b c Günther Sterba : Freshwater fish of the world. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 , p. 712.
  3. ↑ a b Říčan, O., Piálek, L., Dragová, K. & Novák, J. (2016): Diversity and evolution of the Middle American cichlid fishes (Teleostei: Cichlidae) with revised classification . Vertebrate Zoology, 66 (1): 1-102.
  4. ↑ Juan J. Schmitter-Soto (2007): A systematic revision of the genus Archocentrus (Perciformes: Cichlidae), with the description of two new genera and six new species. Zootaxa No. 1603: 1-76.
  5. ↑ Chakrabarty, P. and JS Sparks 2007 Relationships of the New World cichlid genus Hypsophrys Agassiz 1859 (Teleostei: Cichlidae), with diagnoses for the genus and its species. Zootaxa No. 1523: 59-64.

Web links

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