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Siluriformes (Catfishes) >
Bagridae (Bagrid catfishes)
Etymology: Bagrus: Mozarabic, bagre, taken from Greek, pagros = a fish (Dentex sp.) (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Οικολογία
; Γλυκού νερού βενθικό(ς); ποταμόδρομος (Ref. 51243); εύρος βάθους ? - 60 m (Ref. 43507). Tropical; 22°C - 28°C (Ref. 12468)
Africa: Nile River, Lake Chad, Niger and Senegal rivers, lakes Mobutu [=Lake Albert] and Turkana (Ref. 3236). Reported from Sanaga River basin (Ref. 27691).
Length at first maturity / Μέγεθος / Βάρος / Age
Maturity: Lm 37.4, range 29 - 34 cm
Max length : 112 cm FL αρσενικό/απροσδιόριστο; (Ref. 43434); common length : 50.0 cm TL αρσενικό/απροσδιόριστο; (Ref. 13851); μεγ. δημοσιευμένο βάρος: 12.5 kg (Ref. 43434); μεγ. αναφερόμενη ηλικία: 8 έτη (Ref. 51644)
Ραχιαίες άκανθες (συνολικά) : 1; Μαλακές ραχιαίες ακτίνες (συνολικά) : 8 - 12; Εδρικές άκανθες: 0; Μαλακές εδρικές ακτίνες: 13 - 15; Σπόνδυλοι: 48 - 53. Diagnosis: head much depressed, often ridged (Ref. 4903), roundly pointed when viewed from above (Ref. 28714). Head width 1.6-2.2 times in head length (Ref. 28714, 57125) or 47.5-63% HL (Ref. 81641). Body rather elongate, 5-6 times longer than deep (Ref. 7324, 57125). Premaxillary tooth plate 6-7 times as long as broad, a little shorter than the vomerine tooth plate (Ref. 43434). Occipital process 4-6 times longer than broad (Ref. 57125). 9-11 branched dorsal-fin rays (Ref. 57125), the first prolonged into short filaments (Ref. 13851, 31256, 57125). Longest filament comprised 3-4 times in standard length (Ref. 7324, 57125). Predorsal length 2.4-2.6 times in standard length (Ref. 57125). Adipose fin long, its origin well in front of the anal fin (Ref. 28714), narrowly separated from dorsal fin (Ref. 43434). Width of premaxillary tooth plate 2.5-2.8 times in head length (Ref. 57125). Lobes of caudal fin often with short filaments (Ref. 7324, 13851, 57125). Upper caudal-fin lobe comprised 2-3 times in standard length (Ref. 57125).
Found in lakes, swamps and rivers (Ref. 31256). Avoids salt water (Ref. 31439). Spends nearly the whole of the daylight hours in crevices of rocks and is therefor seldom seen (Ref. 51850). Lives and feeds on or near the bottom (Ref. 3034). Adults exclusively piscivorous (Ref. 31256). Preys on small fish, particularly Alestes spp. (Ref. 13851), or Chrysichthys auratus as in Lake Kainji (Ref. 3034), but also feeds on insects, crustaceans and molluscs (some debris and vegetable matter may also be ingested) (Ref. 28714). Efficiency of catching prey catfish is maximised by face to face attack, avoiding damage by dorsal and pectoral spines of the prey (Ref. 33614). There is some indication that the species comes to shallower water to breed (Ref. 43507). Spawning season extends from April to July (Ref. 51850). Parents build and guard the nest, which is like a flat disc with a central hole where the eggs are dropped; size of the nest and the central hole depend on the fish size (Ref. 51638). Males become up to 7 years old, females 8 years (Ref. 51644). Mean sizes and weight of males are less than those of females from the same age (Ref. 51644, 51645). An important food fish. Flesh is good eating and of economic importance (Ref. 36900), commonly sold as food (Ref. 43521). Reputed to reach 100,000 g.
Reproduction takes place during high water (Ref. 2756). There is some indication that the species comes to shallower water to breed (Ref. 43507). From 4 breeding fish taken, 3 were from inshore waters and 1 from 40m depth in the open water (Ref. 49805). The nest is a relatively large depression with the shape of a flat dish and proportions relative to the size of the fish (Ref. 51638). A single well formed hole of about 10-15cm in diameter and 10-15cm depth is present nearly in the middle (Ref. 51638). Eggs are laid inside this hole (Ref. 51638). Eggs are white, having a diameter of little more than 1 millimeter (Ref. 45962). Larvae stay in the hole a couple of days after hatching (Ref. 51638). They swim above the nest when disturbed and return to hole after disturbance has stopped (Ref. 51638).
Risch, L.M., 1986. Bagridae. p. 2-35. In J. Daget, J.-P. Gosse and D.F.E. Thys van den Audenaerde (eds.) Check-list of the freshwater fishes of Africa (CLOFFA). ISNB, Brussels; MRAC, Tervuren; and ORSTOM, Paris. Vol. 2. (Ref. 3236)
IUCN Red List Status (Ref. 130435)
CITES (Ref. 128078)
Not Evaluated
Threat to humans
Harmless
Human uses
αλιεία: Εμπορικό(ά); αλιεία αναψυχής: ναί
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Διαδικτυακές πηγές
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5005 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00955 (0.00766 - 0.01191), b=3.00 (2.94 - 3.06), in cm Total Length, based on LWR estimates for this species (Ref.
93245).
Τροφικό Επίπεδο (Ref.
69278): 4.0 ±0.2 se; based on diet studies.
Ελαστικότητα (Ref.
120179): Χαμηλό, ελάχιστος χρόνος για διπλασιασμό πληθυσμού 4,5 - 14 έτη (tm=4-5; tmax=8; K=0.07-0.18; Fec=18,630-47,920).
Fishing Vulnerability (Ref.
59153): Moderate to high vulnerability (52 of 100).
