Comparative behavioural assessment of an established and a new tigerfishHydrocynus vittatuspopulation in two man-made lakes in the Limpopo River catchment, southern Africa

Abstract

With the continued establishment of man-made lakes within the natural distribution range of tigerfish in southern Africa, many artificial tigerfish populations now exist in the region. Very little of the behavioural ecology of these artificial but ecologically important populations is known. Letsibogo and Schroda man-made lakes are two such systems in the Limpopo River catchment. Currently, an established population of tigerfish occurs in Schroda, which is proposed to be used to establish another population in Letsibogo. This study evaluates the suitability of Letsibogo for tigerfish and the behavioural ecology implications associated with an artificial population in the lake. The behaviour of a small population of tigerfish relocated from Schroda to Letsibogo was monitored and compared with the behaviour of the established Schroda population. In Letsibogo the tigerfish established behavioural patterns suggesting that it is suitable to maintain a tigerfish population. To conserve the locally threatened tigerfish in the Limpopo catchment, the establishment of populations in man-made lakes such as Letsibogo is recommended. The effect of tigerfish on indigenous fishes in Letsibogo is unknown and should be considered.

Implications of the movement behaviour of African tigerfishHydrocynus vittatusfor the design of freshwater protected areas

“…() from a boat between 21 June and 22 October 2016 (Table ). On capture, each fish was guided into a soft weighing sling before being lifted and placed in a 50 l aerated water‐filled container into which 2‐phenoxy‐ethanol, 0.3 ml l −1 , had been added as anaesthetic (O'Brien et al ., ). Once the fish was anaesthetised, it was moved into another 50 l aerated water container with circulating freshwater from the river to start the recovery process.…”

Surgical implantation of radio tags in three eel species (Anguilla spp.) in South Africa

“…Fewer than 40 papers are available for African inland fish telemetry studies. Most recapture attempts were unsuccessful (Baras et al ., ; OʼBrien et al ., ). Mlewa et al .…”

“…Fewer than 40 papers are available for African inland fish telemetry studies. Most recapture attempts were unsuccessfulOʼBrien et al, 2012) Mlewa et al (2005). were the only researchers to observe live recapture of fishes (Lungfish, Protopterus spp.)…”

First observation of African tigerfish Hydrocynus vittatus predating on barn swallows Hirundo rustica in flight

“…Recently, O'Brien et al () characterized the feeding behaviour of the H. vittatus population in Schroda Dam and found that they demonstrated routine crepuscular, piscivorous feeding patterns. Active roaming movements in deep open water adjacent to well‐vegetated areas, or areas with structure in the limnetic zone along the periphery of Schroda, were associated with this feeding behaviour (O'Brien et al , ). During the day (0800 to 1600 hours) H. vittatus characteristically occupied deep sheltered areas where their activity decreased (O'Brien et al , ).…”

“…Active roaming movements in deep open water adjacent to well‐vegetated areas, or areas with structure in the limnetic zone along the periphery of Schroda, were associated with this feeding behaviour (O'Brien et al , ). During the day (0800 to 1600 hours) H. vittatus characteristically occupied deep sheltered areas where their activity decreased (O'Brien et al , ). During a summer (February 2011) survey at least five radio‐tagged H. vittatus individuals displayed daily uncharacteristic increases in mid‐morning activity (0800 to 1200 hours).…”