title: Physical, chemical and biological characteristics in habitats of high and low presence of anopheline larvae in western Kenya highlands.
abstract: BACKGROUND
  Characteristics of aquatic habitats determine whether mosquitoes will oviposit, hatch, develop, pupate and successfully emerge into adults or not, thus influencing which mosquito species will occupy a habitat. This study determined whether physiochemical and biological characteristics differ between habitats with high and low presence of anopheline larvae.
  
  
  METHODS
  Physical, chemical and biological characteristics were evaluated in selected habitats twice per month within three highland valleys in western Kenya. Aquatic macro-organisms were sampled using a sweep-net. Colorimetric methods were used to determine levels of iron, phosphate, nitrate, ammonium and nitrite in water samples. Generalized Estimating Equations (GEE) was used to compare parameters between the two categories of anopheline presence.
  
  
  RESULTS
  Habitats with high anopheline presence had greater abundance of mosquito aquatic stages and tadpoles and two times more levels of nitrate in water, whereas habitats with low anopheline presence had wider biofilm cover and higher levels of iron in water.
  
  
  CONCLUSIONS
  Habitats of high and low presence of anopheline larvae, which differed in a number of physical, chemical and biological characteristics, were identified in valleys within western Kenya highlands. Differences in habitat characteristics are critical in determining the number of anopheline larvae that will fully develop and emerge into adults.
authors.affiliation: Department of Zoological Sciences, Kenyatta University, Nairobi, Kenya. bndenga@yahoo.com
authors.forename: Bryson A
authors.initials: BA
authors.lastname: Ndenga
authors.forename: Jemimah A
authors.initials: JA
authors.lastname: Simbauni
authors.forename: Jenard P
authors.initials: JP
authors.lastname: Mbugi
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Githeko
mesh_terms: D000818:Animals; D000852:Anopheles / Q000254:growth & development*; D002151:Calorimetry; D001517:Coleoptera / Q000254:growth & development; D017753:Ecosystem; D005260:Female; D005843:Geography; D007501:Iron / Q000032:analysis; D007630:Kenya; D007814:Larva / Q000254:growth & development; D008297:Male; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D063191:Odonata / Q000254:growth & development; D010710:Phosphates / Q000032:analysis; D011156:Population Density; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D012621:Seasons; D013696:Temperature; D014867:Water / Q000737:chemistry* / Q000469:parasitology*
chemical_list: D009566:Nitrates; D009573:Nitrites; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D014867:Water; D007501:Iron