H. odoe is the only characid in its range that displays nest building reproductive behavior (Merron, Holden, & Bruton, 1990).
H. odoe avoids open water where its biggest predator is found. It uses weeds and vegetation along with its coloring to avoid detection (Jackson, 1961).
Known Predators:
Hepsetus odoe bears a striking resemblance to the European pike. It is, however, the only member of its genus and a characiform, only distantly related to the European pike. Kafue pike are torpedo-shaped, predatory fish. The body form is elongate with a pronounced snout. The dorsal surface is usually dark brown or green while the ventral surface is silvery. The face is often light green or brown with prominent dark brown or black stripes radiating from the eye. The coloration of the adults is relatively uniform but coloration of young is extremely variable (Jubb, 1961).
The scales of the Kafue pike are rough to the touch and number 49-58 along its lateral line. The dorsal fin has 9 rays total, with 2 unbranched and 7 branched. The dorsal fin origin is set far back on the body, behind the anal fin origin. The adipose fin, with its red or orange base and black tip, lies midway between dorsal and caudal fins. The anal fin has a total of 11 rays with 2 unbranched and 9 branched. The unpaired fins often have fine black spots between the rays (Jubb, 1967).
The most striking feature of H. odoe is its dentition. Both upper and lower jaws are filled with sharp pointed teeth, but the lower jaw has two rows while the upper only has one. There are also two large canines in each jaw. Two pairs of dermal flaps can be found on the upper and lower jaws (Barnard, 1971). The folds on the upper jaw are smaller than those on the lower jaw. They were once thought to be sensory organs but are now thought to be used in building nests for breeding (Merron et al., 1990).
Average mass: 1.2 kg.
Range length: 37-47 (high) cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Average mass: 2200 g.
Hepsetus odoe are known to live 4-5 years in the wild (Montambault, 2000).
Average lifespan
Status: wild: 4.5 years.
Average lifespan
Status: captivity: 5 years.
Hepsetus odoe is usually found near the banks of rivers in heavy vegetation, but also can be found in swampy environments, lagoons and backwaters. In areas where one of its major predators is absent (Hydrocynus forskahlii), Kafue pike will venture into more open waters (Jackson, 1961).
Habitat Regions: tropical ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams
Wetlands: swamp
Hepsetus odoe is widespread in the tropical regions west and central Africa. It is found in most rivers in West Africa from the Senegal southwards to Botswana. The southern limit of its distribution is the Okavango Delta in Northern Botswana (Merron et al., 1990).
Biogeographic Regions: ethiopian (Native )
H. odoe is piscivorous, feeding on several species of smaller fish. They are primarily diurnal ambush predators, hiding out in dense vegetation and lunging suddenly to seize prey (Winemiller, 1993). Their diet consists primarily of cichlids and mormyrids. Although smaller specimens have been found to eat mochokid catfishes in greater amounts than cichlids or mormyrids (Winemiller, 1993).
Animal Foods: fish
Primary Diet: carnivore (Piscivore )
Very little is known about the ecosystem role of this species, other than it is a high level predator in freshwater systems (Winemiller, 1993).
H. odoe is a prized game fish in Africa. Anglers from all around the world come to fish for it. Despite its small size, the Kafue pike is considered a better sport fish than H. forskahlii (Sepupa, 1997).
Positive Impacts: food
Very little is known about the development of H. odoe. However, it is suspected that the species undergoes direct development due to a very short larval period (Merron et al., 1990). When the young hatch, they wiggle their way through the nest to the water. Upon submersion the larvae attach themselves to the bottom edge of the nest using a special cement gland on the top of their heads. They hang there, suspended tail down for four days. As they develop, they begin to move away from the nest, often attaching to nearby vegetation. As they become more developed, the fry rely less on their cement gland and eventually, in just a week or so, become free swimming.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Perception Channels: tactile ; chemical
The onset of the spawning season varies depending upon the region, but the method is consistant across Hepsetus odoe populations. Spawning season usually begins after the flood season has begun; it is suspected that flood waters may actually stimulate the gonads of H. odoe. However, water temperatures play a critical role as well, and it is not until August that the water temperatures are likely to reach optimal levels for the eggs and developing embryos.
Females are repeat spawners and produce about 6,440 eggs in a season. These eggs vary in size from 2.5-2.9 mm in diameter. As with many other species of fish, H. odoe must reach a certain length before being able to breed. Males mature at 140 mm while females do not mature until they reach 160 mm. Prior to spawning, the adults stake out a territory and begin defending it from rivals. They also begin to build a portion of a nest out of foam bubbles. The nest is irregularly dome-shaped with an average diameter of 17 cm and an average height of 9 cm. This nest will hold the fertilized eggs and will be guarded by the adults until after the eggs hatch. The fertilized eggs are inserted in the nest during spawning and actually rest above the surface of the water, often as much as 3 cm. The nest is built around strands of vegetation, which gives it extra stability and protection from wind induced wave action. The nest building is thought to give this species a few advantages in an area where actual flood levels and times fluctuate from year to year. 1) acts as a deterrent to predators due to both its placement in highly vegetation areas, as well as providing a hiding place for developing embryos and newly hatched larvae. 2) places the eggs out of the water and the embryos at the air/water interphase, the young are provided with an oxygen rich environment during a seasonal time of low oxygen concentration. 3) floats on the surface of the water, which keeps the nest at the optimal oxygen level when water levels fluctuate. 4) provides an anchor for the young to attach themselves to. This prevents the small fry from being swept away by the current into areas where they could be preyed upon or where there is insufficient oxygen for their development (Merron et al., 1990).
Breeding season: Spawning usually begins in August and continues until January. Although in some locations there is an extended spawning season which lasts until May.
Average number of offspring: 6,440.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization (External ); viviparous
The adults guard the foam bubble nests until the young have hatched and attached themselves to the bottom edge. During this time, it is believed that the adults actively protect and rebuild the nest, applying foam where needed. After the young have attached themselves to the bottom edge of the nest, the adults abandon it and their young. The nest breaks up about four days afterwards (Merron et al., 1990).
Parental Investment: male parental care ; female parental care
Hepsetus odoe, the African pike characin, is a predatory freshwater characin belonging to the family Hepsetidae. It was formerly considered that there was a single species of Hepsetus pike characin but recent studies have led to the species being split and Hepsetus odoe sensu stricto is the west African representative of the group.
It is an elongated fish with a pike-like body, however this species is a characin and the pike resemblance is due to convergent evolution. This species can reach up to about 28 cm (11 in) in length.[2] The back is normally dark brown or green while the belly is silver. The head is normally light green or brown with distinct dark brown or black stripes radiating out from the eye. The colour and pattern of adult fish is relatively stable but juveniles are more variable.[3]
Hepsetus odoe is found in western sub-Saharan Africa, from the Sassandra River in the Cote d'Ivoire in the west to the Shari River in the Central African Republic in the east, and southwards up to the Kienke River in Cameroon.[2]
The species prefers quiet and deep water, and may only live about five years. Spawning normally begins in August and continues until January. Although in some locations there is an extended spawning season which lasts until May. The eggs are laid in a bubble nest, which they then guard until the young have attached themselves to the bottom of the nest, at which stage the adults abandon the nest and their young. The nest breaks up about four days afterwards and the juveniles disperse to live in well-vegetated marginal habitats.[3]
Hepsetus odoe is piscivorous and preys on a variety of smaller fish. It is mainly diurnal and is an ambush predator, waiting among dense submerged or emergent vegetation until prey comes within range and the fish can lunge at it. The diet of Hepsetus odoe consists predominantly of cichlids and mormyrids; although smaller individuals have been recorded eating mochokid catfishes more than cichlids or mormyrids.[3] Hepsetus odoe prefers the upper courses of small rivers where the elongate tigerfish (Hydrocynus forskahlii) is absent or less abundant.[1] It uses weeds and vegetation along with its coloring to avoid detection.[3]
Hepsetus odoe is fished as game[4] and for human consumption and for the aquarium trade.[1]
It was formerly believed to the only species in the genus and widespread in sub-Saharan Africa, but studies in 2011-2013 have found that there are several species, and the true H. odoe is restricted to West and Central Africa from the Sassandra River, Ivory Coast, to the Kienké River, Cameroon (species elsewhere are now recognized as separate; H. cuvieri, H. kingsleyae, H. lineata and H. occidentalis).[5][6][7][8]
Hepsetus odoe, the African pike characin, is a predatory freshwater characin belonging to the family Hepsetidae. It was formerly considered that there was a single species of Hepsetus pike characin but recent studies have led to the species being split and Hepsetus odoe sensu stricto is the west African representative of the group.
