Length-weight relationship of fishes from Anambra ... - Zoo-unn.org

OKAFOR, Fabian Chukwuemenam et al.65of the ecological factors relating to theiroccurrence in parts of southeast Nigeria.MATERIALS AND METHODSStudy Area: Location: This study is based oninsectivorous bats Tadarida Chaeraphonnigeriae (Thomas) collected between 1986 and2003 from Nsukka, Enugu-Ezike, Nnobi andNsugbe in southeastern Nigeria. The bats werecollected from well built houses which theyinfested.Climate: The climate of the study areas is thesame and is tropical, with heavy rain fall whichis seasonal, falling a little more in Nsugbe andNnobi than Nsukka and Enugu-Ezike.The rainy season is divided into 2 periods,separated by a short dry period in August. Mostof the rains fall between April and July andbetween August and October. The areas liewithin a large belt that experience meantemperature of between 22 0 C to 24 0 C andannual maximum temperature of between 28 0 Cto 32 0 C.Vegetation: The towns are located in thetropical rain forest belt. Some areas havedeveloped into a Guinea Savannah forestmosaic due to human activities. Palm treesabound in these areas and form a major sourceof revenue for the rural communities.Capture of bats: The bats were capturedalive from residential houses in the 4 townsusing long handled large sweep nets. Usuallycapture is effected as the bats leave the roost oras they return from their foraging flights.Trapped animals were transported to thelaboratory where data on sex, age, capturedates, locality, and physical conditions weretaken after anaesthesia using chloroform. Agingwas done using the method recorded in Mutere(1968).Examination for helminth parasites: (a)Blood was usually drawn from the branchialartery with a syringe, this is mixed withphysiological saline and thick smears made ofthem. These were used to screen formicrofilariae. (b) Anaesthesized animals fromwhich the blood samples had been examinedwere then dissected and the different portionsof the gut isolated and cut from each other.These gut parts were then placed in Petri dishescontaining saline. The peritoneal cavity of eachwas also scrapped into a Petri dish. The gutparts were then cut open and their contents andscrapings from their walls examinedmicroscopically for helminthes (either wholeworms or ova). (c) About 2 cm square section ofdiaphragm of each bat was examinedmicroscopically in a muscle press for Trichinellasp larvae.Treatment of Collected Helminths: All thehelminth parasites collected from each bat weretreated similarly. They were first transferred intowatch glasses, washed in physiological salineand later killed by placing them in Petri dishescontaining warm water at 40 0C . These wormsdie fully stretched. Subsequently thenematodes and trematodes amongst them werefixed in hot 70 % alcohol and then preserved in5 % formalin. A few drops of glycerin wereadded to give a concentration of about 5ml of5% formalin and 0.5 ml glycerin. Cestodeswere compressed between two slides and tiedup with a cotton sewing thread and in thisposition fixed in Bouin’s fluid for 16 hours. Thiswas later washed off with 70% alcohol. Theslides separated and the worms stored in analcohol, formalin and acetic acid mixture (AFA).Staining: Nematodes and trematodes werecleared in cotton blue lactophenol for 5 minutesand then stained after washing in ErlichHaematoxylin for 20 minutes, andcounterstained with Eosin following the usualprocedures for H/E staining. The cestodes werestained with acetocarmine.Foods of bats: Samples of bats collected uponreturn from foraging flights were anaesthesizedimmediately and the stomachs dissected outand preserved in 10% formalin. The contentswere later examined in Petri dishes under themicroscope after soaking in 50 % isopropylalcohol for 12 hours. Thereafter, furthervolumes of 50 % isopropyl alcohol were addedand stirred, then left to evapourate. After thealcohol had evapourated the contents wereexamined under the low power of a microscope.Identification of animal parts was made bycomparison of fragments with collections ofcomparable field materials. Some of the morecharacteristics parts of the insects e.g. wings,legs, antennae and mouthparts were searchedfor in the samples. By these comparisons theprey identities were determined. Theunidentified objects were classified as‘unidentified matter’.