Morphological and molecular appraisal of cyclophyllidean cestoda parasite Raillietina saudiae sp. nov. infecting the domestic pigeon Columba livia domestica and its role as a bio-indicator for environmental quality
PigeonsmembersoftheorderColumbiformesareacosmopolitangroupofbirdswithabundantandlargepopulations associated with human activities. Therefore, the current study was conducted to determine the parasiticinfectionswithinthedomesticpigeonColumbaliviadomestica.Eighteenpigeonswereexaminedforthe presenceofgastrointestinalhelminths,ofwhich77.78%wereinfectedwithacyclophyllideancestodaparasites. Themorphologyofthisparasitebasedonlightandscanningelectronmicroscopicstudies,revealedthepresence ofgravidworms,2.00–4.52cmlongand0.23–0.59mmwide;ascolexhadfoursuckersequippedby5–6rowsof minutehooksandretractablerostellumwith230–250hooks;genitalporesunilateral;ovaltesteswith27–37in number;bilobedovary;post–ovarianvitellinegland;and24–28eggcapsulespresentinuteruswith5–6sphericaleggsineachcapsule.MolecularanalysisbasedonsequencesofITS2andND1generegionswasperformed toconfirmthetaxonomyofthisparasitebasedonitsmorphology.Thisrevealedcloseidentityofupto92.0% and 72.0% for ITS2 and ND1 gene regions, respectively, with other cestoda species obtained from GenBank. Phylogenetic analysis supported the placement of this cycllophylid species within Davaineidae with close relationshipstothepreviouslydescribedspeciesofR.chiltoni,R.dromaius,andR.beveridgeibasedontheITS2gene regionandR.coreensisandR.soninibasedontheND1generegions.Heavymetalsaccumulationintherecovered parasite and its host showed significantly higher concentrations in the parasite compared to its host tissues. Generally, concentrations of metals exceeded the permissible limits recommended by the US Environmental Protection Agency. Therefore, pigeon cestodes can be regarded as useful bio-indicators when evaluating the environmentalpollutionofterrestrialecosystemsbyheavymetals.
Aedes aegypti (Culicidae), the mosquito that causes yellow fever, is regarded as a significant vector for
many disease agents. The current study sought to learn more about mosquito mid-gut…