The parasite fauna of characids’ (Osteichthyes: Characidae) Anambra River, Nigeria

Abstract

Baseline information on the parasites of frequently caught species of the characids namely Hydrocynus vittatus, Alestes baremoze, Brycinus macrolepidotus and Brycinus leuciscus was investigated in Anambra River from August 2004 to July 2005. The parasites recovered were the Myxosporid, Myxobolus sp (Protozoa), Polyopistocotylids, Diplozoon ghanense and Neodipolzoon polycotyleus (Monogeneans), the Caryophyllid Caryophylleus sp (Cestoda) and Rhabdochona sp (Nematoda). The prevalence of Caryophylleus sp in B. macrolepidotus (14.2%) and A. baremoze (8.1%) as well as Rhabdochon sp and Myxobolus sp in H. vittatus (9.6% and 7.8% respectively) was relatively high (>7.0%); while the other parasite species Myxobolus sp in B. leuciscus (2%), D. ghanense in B. macrolepidotus (1.9%) and N. polycotyleus in A. baremoze (1.9%) had a much lower prevalence (2.7%). Distribution of parasites was clearly seasonal. Dissolved oxygen (8.0-14.0) mg l )1 and pH (5.5-7.0) influenced the occurrence of the parasites whereas temperature (20.1-27.5 DC) showed no much effect. Résumé Les informations de référence sur les parasites des espèces fréquemment capturées de Characidés Hydrocynus vittatus, Alestes baremoze, Brycinus macrolepidotus et Brycinus leuciscus ont été étudiées dans la rivière Anambra entre aoû t 2004 et juillet 2005. Les parasites retrouvés sont le Myxosporidé, Myxobolus sp. (Protozoaire), les Polyopistocotylidés, Diplozoon ghanense et Neodipolzoon polycotyleus (Monogènes), les Caryophyllidés Caryophylleus sp. (Cestodes) et Rhabdochona sp. (Nématodes). La prévalence de Caryophylleus sp. chez B. macrolepidotus (14,2%) et A. baremoze (8,1%) ainsi que de Rhabdochon sp. et Myxobolus sp. chez H. vittatus (9,6% et 7,8% respectivement) était relativement forte (>7,0%), alors que les autres espèces de parasites, Myxobolus sp. chez B. leuciscus (2%), Dipolzoon ghanense chez B. macrolepidotus (1,9%) et Neodiplozoon polycotyleus chez A. baremoze (1,9%) avaient une prévalence beaucoup plus faible (2,7%). La distribution des parasites était nettement saisonnière. L'oxygène dissous (8,0-14,0 mg ⁄ l) et le pH (5,5-7,0) influençaient l'occurrence des parasites alors que la température (20,1-27,5°C) n'avait pas beaucoup d'effets.

Distribution of gill Monogenean parasites from Oreochromis niloticus (Linn, 1758) in man-made Lake Ayam I, Cte dIvoire

“…It is an established fact that many parasites have free living stages (eggs or larvae) which have complimentary behavioral reactions to the ambient environment (Echi and Ezenwaji, 2009), and therefore, the settling of oncomiracidia is likely to be influenced by water currents. Indeed, the strongest water current flowing through the middle part of the gill arches and the high respiratory water can provide a high number of parasites (Gutiérrez and Martorelli, 1994;).…”

Paradiplozoon vaalense n. sp. (Monogenea: Diplozoidae) from the gills of moggel, Labeo umbratus (Smith, 1841), in the Vaal River System, South Africa

“…This genus displays 8–10 pairs of clamps, in contrast to the two Paradiplozoon species which only display four. Afrodiplozoon polycotyleus has also been recorded from Barbus kerstenii Peters, 1868, Barbus neumayeri Fischer, 1884, Labeobarbus marequensis (Smith, 1841) Barbus trimaculatus Peters, 1852, Barbus neefi Greenwood, 1962 and A. baremoze in Nigeria, Uganda, Kenya, Tanzania and in the Limpopo province of South Africa (Paperna, 1973, 1979; Petr & Paperna, 1979; Khotenovsky, 1985; Chapman et al , 2000; Mashego, 2000; Echi & Ezenwaji, 2009).…”

Physico-chemical properties and heavy metal contents of a tropical estuarine ecosystem, Nigeria

“…Human disturbances, such as constant use and presence of human habitations in their vicinities, some undesirable activities of those that live along the banks of aquatic ecosystems can induce stress to aquatic organisms (Echi and Ezenwaji, 2010). Stress can permanently affect the organism by increasing the corticoid hormone production of the adrenal gland.…”