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Harpagochromis sp. "orange rock hunter"
作者 Christophe de Medeiros, 2006.
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Harpagochromis sp. 'Orange Rock Hunter' male in the aquarium of Stan Kislyuk, Germany. Photo by Stan Kislyuk.
Species: Undescribed but resembles H. howesi
Common noun: Orange rock hunter
Distribution: Lake Victoria, specifically Gabalema Island
Trophic Group: Piscivorous predator
Habitat: Inhabits the crevices and faults In areas of large boulders
Size: 20 to 25 cm
Description: The male "orange rock hunter" is a relatively elongated fish. The height of the body from the girth of the pelvic region to the nape of the neck represent a little less than one quarter of the overall length. The length of the head is approximately 1/4 of the overall body length. The head has an straight oblique profile with a large split mandible that is typical of a piscivorous predator. The mouth begins at a straight line drawn directly down from the middle of the eye. The lips are of gray color. Small unicuspid teeth line the outer jaw rows. The snout is a grey coloration. The face and the nape of the neck sport a traditional haplochromine mask with traces of red on the external edge of the jaw, as well as the gill plates. A relatively large eye is crossed by a black bar on the pupil and most of the iris. The belly is gray-black merging to an orange-red on the abdomen. This coloration mixes with the blue-gray dorsally along the flanks. Gray scales are surrounded by a red margin. The back is grey-blue merging with a yellow-green or clear chestnut caudal peduncle. The area around the anus and anal fin is red. There are 6-8 vertical black bars on the body whose intensity varies according to mood. A horizontal black bar is visible when H. sp. "orange rock hunter" appears stressed.
The dorsal fin is sky-blue along the spinous rays with traces of red on the soft portion. A red border also runs the length of the dorsal fin. The pectoral fins are translucent. Pelvic fins are black along the first hard ray, red-orange on the remainder of the fin. These fins are longer on the male than the female. Adolescent individuals have the black pelvic fins but become red with growth and maturity. The anal fin is red with orange-yellow ocelli of relative significant size. These egg spots are laid out in a horizontal line on the last 2 rays. The caudal fin is truncated gray-blue and is approximately 1/5 th the length of fish. The female has the body similar to the male, except the belly which is slightly more rounded. It is green-gray or chestnut, with a white belly and the lower part of the body. The fins are colorless with a faint trace of pink in the soft portions of dorsal fins and anal area. The melanin dress consists of a broken black horizontal median band running the length of the body ending at the end of the caudal peduncle. The caudal fin is gray with very light traces of pink. Dominant or incubating females show more marked melanin bars.
Dimorphism: There is visible sexual dimorphism between male and female. The male has a more elongated body. Black and red pelvic fins are much longer and more pointed in the male. The soft portions of the anal and dorsal fins are red and the ocelli are more vibrant on the male. Male body coloration consists of red, green-yellow, blue-gray and the melanin black body bars are more intense. Females sport green-grey soft portions with the more rounded dorsal fins and anal fins. A median horizontal bar appears from time to time in accordance with mood.
Maintenance: Considering its large adult size, a significant aquarium volume of about 400 liters is the minimum suggested for a trio. One can maintain H. sp. "orange rock hunter" in a trio or quartet (only one male) setting or with two or three trios of compatibly sized and tempered species. One can maintain a group of three males for 6 to 8 females in a species only tank.
Food: Although a definite piscivorous, H. sp. "orange rock hunter" will also heartily devour pieces of shrimp, artemia, poached spinach, ground worms, krill, black mosquito larvae, etc. Suitable foods for fry include brine shrimp napulii, crushed pellets and crushed spirulina flake. When the young attain a length of 3 cm, pieces of chopped shrimp and adult artemia will provide suitable nutrition.
Behavior: Although not a fiercely aggressive fish, H. sp. "orange rock hunter" defends its territory with intimidation rather than violence. The males will share a cave which is their territory, with the female. Other species are aware of the male’s territory and know their limits; however this is not the case with aggressive species as the mbipi’s. With age, males may become very aggressive. A German aquarist (Ralf Paul) one day witnessed an older male violently attacking other males in a tank after a year of peaceful cohabitation.
Spawning: This species is a maternal mouth brooder with a gestation period of between 15 and 18 days. The female cares for the fry a further week to 10 days by defending the cave where her young were released. It is best to isolate her in a small tank during the sixth or seventh day of brooding so that she can complete the incubation without fear of harassment from others. Post release, one can observe the mother taking the fry into her mouth by cueing the young with slight body quiver. The fry all enter the mother’s oral cavity simultaneously and one can observe them through the membrane of her buccal area. I have never witnessed of swapping of incubation duties by the exchange of the larvae between males and females. The larvae grow at the rate as other species of haplochromines. A sex ratio of 1 male for 2 to 3 females usually persists.
Incompatibilities: It is necessary to avoid maintaining H. sp. "orange rock hunter" with robust territorial species such as the mbipi’s and certain sand dwelling species such as H. brownae and H. "thick skin". One can maintain it with paedophagous species such as H. sp. "Matumbi hunter", H. sp. "melanopterus", H. sp. "parvidens", certain species of molluscivorouss A. alluaudi, H. sp. "ishmaeli". It is also compatible with some of the other piscivores like H. orthostoma, H. "torpedo kribensis" or H. cf dentex. Avoid introducing small fish into the tank because anything that will fit into the mouth will eventually be eaten.
Observations: H. sp. "orange rock hunter" is a superb fish and of large stature. H. sp. "orange rock hunter" is a rather docile and reclusive species. It is not very widespread in the hobby or the aquatic trade, even by specialized aquarists. It is a rather shy fish which, in my tank, lives in a crevice and very seldom leaves its hiding-place. Maintained with an abundant rock decoration, it spends its time in the cave which is its territory. I rarely observe this species in the open except when it ventures out to obtain food or with the onset of breeding; Courting includes a parade in front of the female. The first specimens of this beautiful cichlid were captured by Yves Fermon in the 90's at Gabalema Island. The Present captive population is derived from three captured individuals. The Antwerp Zoo maintains this species as part of a captive breeding program. Since the Nineties, a HEST team of researchers from the University of Leiden have obtained several wild individuals and reproduced them on site. It is one of few surviving piscivorous species to endure the negative impact of the Nile perch in lake Victoria.
H. sp. "orange rock hunter", when hunting, has an unusual and particular posture. It positions itself at a 45° angle, 10 cm underneath its prey. The eyes fixate on the victim as it approaches the head. It arches its body then flexes as a spring and seizes the prey by the head. Its strong jaws chew and then crush the bones and swallow the prey head first. In the aquarium it is a very fast species and uses this speed to pursue its victim. Live food is held in place with spike-like unicuspid teeth (Personal observation). It could be well that H. sp. "orange rock hunter" is a specialized predator that pursues its prey inside the rock faults. It shows a great maneuverability within the rock decor.
Harpagochromis sp. 'Orange Rock Hunter' female in the aquarium of Christophe de Medeiros, France. Photo by Stan Kislyuk.
© Copyright 2006 Christophe de Medeiros, all rights reserved
de Medeiros, Christophe. (二月 10, 2006). "Harpagochromis sp. "orange rock hunter"". 慈鯛魚室同好網. 檢索 五月 24, 2013, 來自: http://www.cichlidae.com/section.php?id=129&lang=zh.