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Gonorynchiformes (Milkfishes) >
Phractolaemidae (Hingemouths)
Etymology: Phractolaemus: Greek, phraktos = fence + Greek, laimos = throttle (Ref. 45335); ansorgii: Named for the presence of 1-3 spines on the scales of the lateral line on the caudal peduncle, and on the 2 scale rows above and below the lateral line series (Ref. 93266).
More on author: Boulenger.
Environment: milieu / climate zone / depth range / distribution range
Ecologie
; zoet water benthopelagisch; pH range: 6.0 - 8.0; dH range: ? - 25. Tropical; 25°C - 30°C (Ref. 13371)
Africa: in West Africa from Lake Nokoué (Ouémé River, Benin) (Ref. 81277) to Cross River (Cameroon) (Ref. 52397), including Ogun, Osse and Niger Delta (Ref. 81277). Also in the middle Congo River basin (Ref. 93183) in Republic of Congo and Democratic Republic of the Congo.
Grootte / Gewicht / Leeftijd
Maturity: Lm ? range ? - ? cm
Max length : 25.0 cm TL mannelijk / geslacht onbekend; (Ref. 93183)
Korte beschrijving
Determinatiesleutels | Morfologie | Morfometrie
Dorsale stekels (totaal) : 0; Dorsale zachte stralen (totaal) : 6; Anale stekels: 0; Anale zachte stralen: 6; Wervels: 34 - 38. Diagnosis: head depressed and strongly ossified; anterior nostril elongate, forming an oblique, forward-pointing tube; posterior nostril crescent-shaped, located just behind the narial tube (Ref. 2913, 81277). Mouth small, protrusible (Ref. 245, 31256, 81277), placed at tip of a proboscis and opening upwards between the narial tubes (Ref. 2913, 81277), on upper surface of snout (Ref. 245, 31256). Narrow gill opening, but opercles very well developed, covering also the underside of the head where they overlap (Ref. 2913, 81277, 93183).
Facultative or obligate air-breathing (Ref. 126274); Lives in forest pools and swamps (Ref. 41580). Microphagous (Ref. 4910, 41580, 45483), especially phytophagous (epiphytes), and detritiphagous (Ref. 41580). Swim bladder entirely alveolar, functioning like a lung; this adaptation to aerial breathing allows the fish to survive under poor oxygenation conditions (Ref. 2913, 81277); recorded from nearly deoxygenated lungfish nest in Pool Malebo, Congo DR (Ref. 41585). Gonads, which are largely fused, are situated ventrally, not dorsally, in abdominal cavity (Ref. 41580). Mouth can be projected as a small trunk (Ref. 2913). Eggs transparent, yellow-greenish, 1.5-1.7mm diameter; large females may have several thousands of eggs (Ref. 41580). Particular blood system, with dark coloured and an abundant amouth of blood (Ref. 4910).
Levenscyclus en paargedrag
Maturities | Voortplanting | Spawnings | Egg(s) | Fecundities | Larven
Males and females have lateral tubercles on their body which probably aid in maintaining contact during spawning (Ref. 38266).
Lévêque, C., 1990. Phractolaemidae. p. 189-191. In C. Lévêque, D. Paugy and G.G. Teugels (eds.) Faune des poissons d'eaux douces et saumâtres d'Afrique de l'Ouest. Tome I. Coll. Faune Tropicale n° XXVIII. Musée Royal de l'Afrique Centrale, Tervuren, and O.R.S.T.O.M.,Paris, 384 p. (Ref. 2913)
Status op de Rode Lijst van het IUCN (Ref. 130435)
Gevaar voor de mens
Harmless
Gebruik door de mens
Tools
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Estimates based on models
Fylogenetische diversiteitsindex (Ref.
82804): PD
50 = 1.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00437 (0.00168 - 0.01131), b=3.13 (2.90 - 3.36), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trofisch niveau (Ref.
69278): 2.3 ±0.1 se; based on diet studies.
Fishing Vulnerability (Ref.
59153): Low vulnerability (15 of 100).
