Haplochromis vanheusdeni

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Haplochromis vanheusdeni
Systematics
Order : Cichliformes
Family : Cichlids (Cichlidae)
Subfamily : Pseudocrenilabrinae
Tribe : Haplochromini
Genre : Haplochromis
Type : Haplochromis vanheusdeni
Scientific name
Haplochromis vanheusdeni
Schedel , Friel & Schliewen , 2014

Haplochromis vanheusdeni is a species of cichlid known from three streams (Sonjo, Idete, and Kihansi) and one arm of the Ruaha in southern Tanzania . All four bodies of water arise from the eastern flank of the Udzungwa Mountains .

features

The fish species can reach a standard length of about 8 cm and a total length of 10 cm. It is elongated and resembles the species of the genus Orthochromis , but differs from the Orthochromis in the morphology of the caudal skeleton and, in contrast to these, shows egg spots in the anal fin. The tail stalk is longer than it is high.

The basic color of Haplochromis vanheusdeni is light brown to gray, the sides of the body, tail stalk, breast and belly are beige to yellowish. There is a black spot in the upper area of ​​the gill cover. A dark longitudinal band extends from this spot to the scaled part of the caudal fin. It crosses 6 to 7 gray, sometimes Y-shaped horizontal stripes. The dorsal fin is orange, whitish and blackish. The anal fin is yellowish green and becomes yellowish towards the edge. In the males it shows up to 10 orange egg spots that are bordered in white. Females have a maximum of two egg spots. The caudal fin base is orange, the rest is gray-yellow. The paired fins are gray to brownish. Young fish are gray with a silvery chest and belly. The longitudinal ligament is still not very pronounced. The fins are colorless and transparent. Only on the dorsal fin there are some orange spots.

habitat

Haplochromis vanheusdeni lives in waters with strong currents on the ground. The bottom of the water is sandy and interspersed with stones. At the Terra typica the water is about 4.5 meters wide and half a meter deep. The water had a temperature of 22 ° C, the pH was 8.1. In the Sonjo, the accompanying fish fauna consists of undetermined species from the genera Parakneria , Amphilius ( Amphiliidae ), Chiloglanis , Enteromius or Labeobarbus , Labeo , Lacustricola ( light-eye fish ) and another haplochromine cichlid ( Haplochromis cf. bloyeti ). The latter is missing in the Kihansi. Underwater observations showed that Haplochromis vanheusdeni snaps for edible particles and also scours the sand for food. Like all Haplochromis species, Haplochromis vanheusdeni is an ovophilic mouthbrooder in which the female takes care of the brood. Males and large females are territory-forming. The center of their territory is often an eroded stone. In the case of animals kept in aquariums, a clutch consisted of 20 to 40 eggs with a diameter of about 2 mm.

Systematics

Haplochromis vanheusdeni was described in 2014 by two German ichthyologists and an American colleague and named in honor of the Dutch ichthyologist Hans van Heusden, who made underwater recordings and videos of this species for the first time. Haplochromis vanheusdeni shows seven of the ten diagnostic features of the genus Orthochromis . In contrast to Orthochromis , however , Haplochromis vanheusdeni has a rather straight and less rounded head profile, in the caudal fin skeleton the hypuralia 1 and 2, as well as 2 and 4 are not grown together, but are completely or separated from one another by a recognizable suture and the fish have clear, bordered egg spots, as in the genus Haplochromis . Molecular biological data show that the genus Orthochromis in its current composition is not monophyletic . Haplochromis vanheusdeni differs genetically from the Orthochromis species of Malagarasi , where Orthochromis malagaraziensis is the type species of the genus. The authors of the first description therefore placed the new species in the genus Haplochromis ( sensu lato ), which they consider here as a collective genus, the internal system of which requires further research. Two of the authors of the first description, together with a colleague, published a study on the phylogeny of the East African cichlids in April 2019, in which Haplochromis vanheusdeni was identified as a sister group of the Tropheini .

supporting documents

  1. ↑ a b c d e f Frederic DB Schedel, John P. Friel & Ulrich K. Schliewen (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.
  2. ↑ Frederic DB Schedel, Zuzana Musilova and Ulrich Kurt Schliewen (2019): East African cichlid lineages (Teleostei: Cichlidae) might be older than their ancient host lakes: new divergence estimates for the east African cichlid radiation. BMC Evolutionary Biology, 19:94. Doi: 10.1186 / s12862-019-1417-0

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