title: Bioconcentration of Lead in the Catfish, Heterobranchus longifilis, Valenciennes (1840) (Siluriformes: Clariidae).
abstract: BACKGROUND
  Although many studies have been conducted on heavy metals in fish, there is no available information on the bioconcentration of lead in the African, air-breathing catfish, Heterobranchus longifilis (Valenciennes, 1840). Relevant patents relating to bioconcentration of lead in fish species were reviewed. Fish are useful in the evaluation of bioconcentration of lead and other metal pollutants in water.
  
  
  METHODS
  The bioconcentration (uptake and depuration) of lead was determined by exposure of Heterobranchus longifilis (Valenciennes, 1840) fingerlings to untreated control and five sublethal concentrations of lead (0.0 - 0.3 mg-1) in three replicates under laboratory conditions. After acclimation of the test species for 7 days, the experiments were undertaken in two phases for 28 days, comprising 14 days for uptake and 14 days for depuration. Samples of fish were taken out at three-day intervals for lead analysis. Lead concentrations were determined using Flame Atomic Absorption Spectrophotometer (UNICAM 969 model).
  
  
  RESULTS
  Essential physical and chemical parameters of test media were determined, and the results were within the international standards. Generally, the concentration of lead increased from 0.0001 mg kg-1 (control) from 1 day of the experiment to 0.3305 mg kg-1 on the 14 day of uptake phase, and decreased to 0.3019 mg kg-1 on the 28 day of the depuration phase.
  
  
  CONCLUSIONS
  This study indicated that H. longifilis showed potential to accumulate and depurate lead.
authors.affiliation: Department of Fisheries and Aquatic Environmental Management, Faculty of Agriculture, University of Uyo, P. M. B. 1017, Uyo, Akwa Ibom State, Nigeria.
authors.forename: Blessing J
authors.initials: BJ
authors.lastname: Oribhabor
authors.forename: Emilia U
authors.initials: EU
authors.lastname: Edemiko
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D002397:Catfishes / Q000145:classification / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D013045:Species Specificity; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D014874:Water Pollutants, Chemical; D007854:Lead