Animal Research International

1834 – 1839

Authors: MOHAMMADZADEH, S., KIANI, A., LORZADEH, N., MOHAMMADI, A. and RAFII, E.

Prolactin is a peptide hormone which is secreted from hypophysis. Prolactin concentration differs in male and female. Even though prolactin has lactotpope effect, it has disturbances effects on pulsatory secretion of gonadotropins as well as on ovulation. In spite of different plasma level of prolactin in different seasons, the effects of light regime on prolactin secretion still is unclear. Eighty Wistar rats were selected and divided into four groups. Each treatment was exposed in different photoperiod; natural light (control NL), 24 hours light (permanent light LL), 24 hours darkness (permanent darkness DD), and 12 hours light-12 hours darkness (light-dark LD). Blood samples from the heart were taken every 3 month during year. Prolactin concentration was determined using RIA. Data were analyzed using ANOVA and means were compared using Duncan multiple range test. Prolactin concentration in control (NL), dark (DD), light-dark (LD) and permanent light (LL) were 1.10, 1.00, 0.80 and 0.60 ng/ml, respectively. Light regime had a significant effect on prolactin concentration (p<0.05). Prolactin was significantly lower in permanent light than other treatments. Means of prolactin in permanent dark and light-dark weren’t differ with control (p>0.05). Permanent light will reduce the prolactin level. It seems to be one of the causes of short estrous cycles in permanent light is prolactin levels. These finding can be used as a model in human societies.

1851 – 1862

Authors: ALPHONSUS, Cyprian, AKPA, Gerald Nwachi, BARJE, Peter Pano, NWAGU, Bartholomew I. and ORUNMUYI, Modupe

Data from 13 primaparous and 47 multiparous Friesian-Bunaji (F1) crossbred cows were used to evaluate the reproductive performance of Friesian x Bunaji dairy cows. Four fertility traits; days to first insemination (DFI), days open (DO), Non-return rate 56 days after first insemination (NRR56) and numbers of insemination per conception (NIC) were analysed . The results revealed that the average days to first insemination (DFI), days open (DO) , number of insemination per conception (NIC), and non- return rate 56 days after first insemination (NRR56) were 122.29 days, 171.18 days, 1.64, and 61%, respectively. These traits were highly variability (CV = 54.01-80.90%). The effects of sire and sex of calf on the reproductive characteristics were not significant (p>0.05). The dam body condition score (BCS) had significant effect on all the reproductive characteristics. The DFI, DO and NIC decreased with increase in BCS. Dams with BCS of < 2.50 had longer DFI and DO, and required higher number of inseminations before conception (NIC), while those with BCS of >3.50 had shorter DFI and DO with minimum number of insemination per conception (1.00). Dam parity had no significant effect (p>0.05) on the reproductive characteristics except on NRR56 and NIC. However, the heifer had longer days to first insemination (DFI), and days open (DO) and required higher number of inseminations per conception than the older cows. Season of calving had no significant effect (p>0.05) on the reproductive characteristics except on NRR56. The cows that calved during the wet seasons (early and late dry) had higher NRR56 (69 – 71%), than those of the dry (early and late wet) seasons (40 – 59%). The reproductive performance of the cows depreciated significantly (p<0.05) within the 3 years (2010 - 2012) of this study; DFI increased from 88.47 to 131.49 days, DO increased from 80.39 to 269.14 days, NIC increased from 1.01 to 2.72, while the percentage non-return rate (NRR56) decreased from 86% to 42%.The heritability (h2) estimates for fertility traits was very low ranging from 0.014 to 0.087. Dam body condition score, parity, season and year of calving are important sources of variation in fertility traits of dairy cows. These results illustrate that environmental effects makes larger contributions to the variability of fertility traits than direct genetic effects, thus reproductive health and feeding management are very important determinant of reproductive performance of dairy cows.

1871 – 1880

Authors: IHEDIOHA, Thelma Ebele, OMOJA, Valentine Uneojo and ASUZU, Isaac Uzoma

This study evaluated the effects of methanolic stem bark extract of Cassia sieberiana (MSBECS) on fasting blood glucose (FBG) and serum lipid profile (SLP) of alloxan-induced diabetic albino rats. The extract was prepared by cold maceration and administered orally at the dose of 12.5, 25, 50, 100 and 200 mg/kg body weight to evaluate the effects on fasting blood glucose (FBG) of the diabetic rats, and at 50, 100 and 200 mg/kg body weight (bw) for the serum lipid profile (SLP) assay. A total of 78 male albino rats (Rattus norvegicus) of 12 weeks of age were used for the study; 42 were used to evaluate the effects of the extract on FBG, while 36 were used for the SLP assay. Data from the study showed that the optimum anti-hyperglycemic activity of the C. sieberiana extract on the diabetic rats was recorded in the rat group given 50 mg/kg bw of MSBECS, and this did not differ significantly (p>0.05) from that of glibenclamide-treated rats. Treatment of the diabetic rats with the extract at the doses of 100 and 200 mg/kg bw produced a significant (p<0.05) increase/improvement in the serum high density lipoprotein cholesterol (HDLC), while rat groups given 50, 100 and 200 mg/kg bw of the extract had a significantly (p<0.05) lower serum triglyceride and very low density lipoprotein cholesterol (VLDLC). It was concluded the administration of MSBECS at 50 mg/kg bw led to significant reduction in FBG of diabetic rats comparable to that obtained in the control group treated with a standard anti-hyperglycaemic drug (glibenclamide), while treatment at doses of 50, 100, and 200 mg/kg bw led to favorable effects on the lipid profile of the diabetic rats. These findings validate the traditional use of the stem bark of C. sieberiana in the management of diabetes mellitus and its dyslipidaemia complications.

1889 – 1898

Authors: IHEDIOHA, John Ikechukwu and DANIEL-IGWE, Gloria

The objective of this study was to develop an experimental albino rat (Rattus norvegicus) model for studies on sub-acute blood loss anaemia. A total of 160 albino rats of either sexes, between the ages of 10 and 12 weeks were used for the study. One hundred and thirty of the rats were randomly assigned into thirteen groups (groups 1 – 13) of ten each for the first experiment. Baseline values of the haematological indices were determined before the commencement of the study. Rats in group 1 were not bled and served as control. Blood (1 or 2 ml/100g body weight) was removed for specified periods of time from the remaining 12 groups (groups 2 – 13). At the end of the specified period of bleeding for each group, the haematological indices were re-assessed in order to select which group met the target of halving the red blood cell (RBC) count, haemoglobin concentration (Hb) and packed cell volume (PCV) with minimal stress. The selected group was tested for reproducibility in experiment 2 using the remaining thirty rats randomly assigned into three groups (A, B and C). Results showed that in experiment 1, the PCV, Hb and RBC counts of the rat groups that were bled (groups 2 – 13) decreased significantly (p<0.05) after bleeding to varying degrees across the groups based on the volume of blood removed and the duration. Among all the rat groups bled, males of group 12 which were bled 2ml/100g body weight every other day for 20 days ranked topmost among others with the highest reductions in the RBC counts (46.62%), Hb (55.25%) and PCV (46.20%), and no mortality. The results recorded for the two rat groups bled in experiment 2 did not significantly (p>0.05) differ from each other and from that recorded in experiment 1 for the group 12 male rats. Based on the results of the study, removal of 2ml of blood/100g body weight from 10 – 12 weeks old male albino rats every other day for 20 days was recommended for the induction of experimental sub-acute blood loss anaemia.

1905 – 1916

Authors: IBEMENUGA, Keziah Nwamaka and AVOAJA, Diana Akudo

This study assessed the quality of 60 groundwater wells within the Bombali District of Sierra Leone. Water samples from the wells were analysed for physical (temperature, turbidity, conductivity, total dissolved solids and salinity), chemical (pH, nitrate-nitrogen, sulphate, calcium, ammonia, fluoride, aluminium, iron, copper and manganese) parameters using potable water testing kit; and bacteriological (faecal and non-faecal coliforms) qualities. Results show that 73% of the samples had turbidity values below the WHO, ICMR and United USPHS standards of 5 NTU. The electrical conductivity (µS/cm) of 5% of the whole samples exceeded the WHO guideline value, 8% of the entire samples had values higher than the WHO, ICMR and USPHS recommended concentration. In terms of iron, 25% of all the samples had values in excess of WHO, ICMR and USPHS recommended value of 0.3mg/l. For manganese, 12% of the entire samples had values more than the WHO and ICMR standards. On the other hand, more water samples (22%) had manganese values above USPHS guideline value. For bacteriological quality, 28% of the wells were polluted by faecal and non-faecal coliforms. 60% and 40% of the entire samples had faecal and non-faecal coliforms respectively above the WHO standard. Remedial measures recommended include regular monitoring of the physico-chemical and bacteriological quality of water yield from these wells as well as teaching of the communities' basic sanitation and hygiene practices.

1747 – 1751

Authors: KONYA, Roseline Sonayee, ZITTE, Leelee Famii and CHUKWU, Kenneth Obinna

The effect of Euphorbia kamerunica latex on the blood of albino rat (Rattus novergicus) was studied. Two different samples were prepared, one with 10% E. kamerunica latex in blood of albino rat and the other, whole blood. Blood from each of the two samples was analyzed haematologically for the packed cell volume (PCV), haemoglobin (Hb), red blood cell (RBC), white blood cell (WBC) and neutrophils. The results of the study showed that there was a drop in all the blood parameters in the blood sample with the latex as compared with the whole blood. The PCV dropped from 17% to 9%, (47.06% reduction), Hb reduced from 5.1g/dl to 3.2g/dl (37.25% reduction), RBC had a three log reduction from 3.7x10 12 to 2.7x10 9 (99.88% reduction), WBC fell from 4.2x10 9 to 3.2x10 7 (99.24 % reduction) while neutrophils dropped from 20% to 15% (25.00% reduction) in the blood with latex. The proximate analysis of the latex revealed that it contains 62.13 ± 0.48 % lipid, 0.16 ± 0.01 % carbohydrate, 3.69 ± 0.05 % protein and 3.86 ± 0.24 % ash. The result of this in vitro study demonstrated that Euphorbia kamerunica has some toxic effects on the blood of Rattus novergicus.

1779 – 1785

Authors: IGWEBUIKE, Udensi M., UGWUOKE, Wilfred I. and UDOUMOH, Anietie F

The study evaluated the histological characteristics of the tongue in ten adult common pigeons, with a view to highlighting the relationship between structure and function of the tongue in the common pigeon. The results showed that the entire dorsal surface of the tongue was covered by a non-keratinized stratified squamous epithelium, while the ventral surface of the tongue exhibited a keratinized stratified squamous epithelium in the tongue body and apex. In addition, intraepithelial taste buds occurred in the dorsal epithelium of the tongue body and apex. The dense fibrous sub-epithelial connective tissue of the tongue root and body showed presence of mucus-secreting lingual glands and solitary lymphoid nodules. These were absent in the tongue apex. Furthermore, skeletal muscle fibres were abundant in the root and body of the tongue but not in the tongue apex. A paraglossum composed of hyaline cartilage was situated in the core of the tongue, extending from the tongue body to the tongue apex. In longitudinal section, the papillary crest appeared as evaginations of the dorsal lingual epithelium at the boundary between the root and body of the tongue. The evagination, composed entirely of epithelial cells lacked a connective tissue core. It was concluded that these histological features are essential adaptations that support the functions of the tongue during food intake, especially in the common pigeon which feeds mainly on grains and seeds

1792 – 1798

Authors: IBEMENUGA, Keziah Nwamaka

The contamination of the aquatic systems with heavy metals from natural anthropogenic sources has become a global problem which poses threats to ecosystems and natural communities. Hence this study reviews the effects of heavy metals in freshwater fishes. Fishes bioaccumulate heavy metals (including cadmium, zinc, lead and copper) through various organs such as gills, liver, stomach and intestine. The effects of these heavy metals are highlighted.

1805 – 1808

Authors: ODUOLA, Adedayo Olatunbosun, OBEMBE, Abiodun, ADEOGUN, Adedapo and AWOLOLA, Taiwo Samson

Baseline survey is an integral component of a malaria vector control programme, providing valuable information on mosquito behaviour that guide the suitability of chosen interventions. A need assessment of baseline entomological indices towards the future implementation of indoor residual spray (IRS) was conducted in Osun State, Nigeria. Indoor resting mosquitoes were collected in human households from three Local Government Areas. These were morphologically identified, subjected to species specific polymerase chain reaction (PCR) assay and analyzed for sporozoite infection and blood meal origin using enzyme linked immunosorbent assay (ELISA). All female Anopheles identified fed on human blood but tested negative to Plasmodium falciparum circumsporozoite antigen. The PCR analysis showed a predominance of An. gambiae s.s. (95%) over An. arabiensis (5%). The preponderance of indoor resting An. gambiae s.s and the incidence of exophilic An. arabiensis suggest a combination of IRS and long lasting insecticidal nets (LLINs) for this region.

1817 – 1825

Authors: AMAECHI, Ebube Charles, OHAERI, Carmelita Chima and UKPAI, Onyinye Mkpola

Soil transmitted helminths (STHs) are known to be endemic in developing tropical countries. A study on the prevalence and risk factors associated with STHs infections among children in three selected primary schools in Ukwa East Local Government Area of Abia State was undertaken between February and July, 2012. The stool samples collected from 338 children aged 5 – 13 years in the three primary schools were analyzed using direct normal saline and formal-ether concentration technique for the presence of STHs. Closed ended pre-tested questionnaire was used for collection of data on sociodemographic and personal health habits associated with STHs. Three different helminths were observed. These included Ascaris lumbricoides (8.2%), hookworm (5.1%) and Trichuris trichiura (3.9%). Multiple infections were however observed in individuals. Of the 338 stool samples examined, 256 were infected giving a prevalence of 75.7%. The prevalence of STHs was significantly higher in males than females in age group 5 – 7 years. A. lumbricoides was the most encountered parasites in the study, while Central Primary School, Obohia recorded the highest prevalence (90.2%) of infection in the three schools sampled. The month of July (peak of the rainy season) recorded the highest prevalence rate (92.9%). Those who defecated in bushes and other unhygienic places had the highest infection of 89.9%, while those that had water closet had the least infection of 40.5%. Those that used wells and streams as main source of water had an infection of 96.9%. Inadequate basic social amenities have contributed to the spread of parasite in the area. Government should make available the much needed amenities to the populace to alleviate the spread of the diseases in the study area and should also create public awareness on the dangers of the disease.

1699 – 1712

Authors: DIBUA, Uju M. Esther, KALU, Adindu, ATTAMA, Anthony A., ESIMONE, Charles Okechukwu and EYO, Joseph Effiong

The resistance of current drugs against malaria parasite is increasing, thus the need for evaluation of the haemozoin (HZ) concentration in malaria parasite as a novel strategy for malaria control. Haemozoin load in the blood of patients was measured after taking antimalarials or plants extracts. The tested plant extracts were established to reduce HZ concentration in vivo. Haemozoin was extracted from the blood samples of all the malaria positive patients studied by centrifugation and the concentration analyzed spectrophotometrically at 400 nm wavelength. Comparative anti-malaria activity of some conventional drugs: Maldox, Halfan, Artecxin, Amatem, Mefloquine (quinolines) and Malmed, the leaf and stem back extracts of Sarcocephalius latifolius and Alstonia boonei, containing potent pyhytochemicals including tannins, flavonoids, saponins, alkaloids, was evaluated to establish the most effective agent for haemozoin reduction and subsequently, malaria therapy. Each agent was administered to patients in each malaria episode, and the absorbance of haemozoin produced determined at 4000 nm wavelength. Packed cell volume (PCV) was estimated to establish the proportion of red blood cells before and after haemozoin production, using microhaematocrit reader. All the chemical antimalarial drugs used effected reduction in haemozoin concentration. However, Mefloquine (Quinolines) showed the highest activity with significant difference of 0.01 (p<0.05). The plant extracts similarly exerted significant reduction in the haemozoin concentration. Nevertheless, Alstonia boonei extract was the most effective in haemozoin reduction at 0.00 significant level (p<0.05). Of all the therapeutants (chemical and plant extracts) tested, Alstonia boonei stem back extract most significantly reduced haemozoin production (p<0.05), indicating its potential for use in novel anti-plasmodium and antimalaria drug formulation.

1723 – 1729

Authors: MOHAMMADZADEH, Saeid, ABASI, M., TAVAFI, Majid and KIANI, Ali.

Goats (Capra hircus) are economical animal in livestock production especially in rural areas. It is well known that goat can tolerate harsh conditions; however there are little information about its reproduction functions such as testis histomorphometry and efficiency of sertoli cells. This study aimed to estimate germ cell types and number per sertoli cell of an indigenous Iranian goat (Lori goat). Semen was collected from five Lori goats by means of an artificial vagina. Semen volume, concentration, normality and motility of spermatozoa were determined. After removing both testes, tissue paraffin section (5µ thickness) were prepared and stained using Haematoxylin and Eosin method. Mean weight of testis was 114.40 ±27.00 grams. Means of seminiferous tubule diameter and tubule length per gram testis were 197.20 ± 1.80 µm and 9956.00 ± 93.00 m, respectively. The mean number of spermatids per each tubule, spermatogonia and spermatocytes at stage I were 163.00 ± 99.9, 140.30 ± 28.60 and 146.40 ± 19.80, respectively. From this study it can be concluded that the Lori goat has high reproductive potentials probably due to high number of sertoli cell per germ cells.

1739 – 1746

Authors: IGWEBUIKE, Udensi M. and ANAGOR, Tochukwu A.

The study investigated the morphology of the oropharynx and tongue of the guinea fowl using gross anatomical and histological techniques. The results showed that the mouth and pharynx of the guinea fowl lacked a definite line of demarcation, and so formed a common oropharyngeal cavity. The roof of the oropharynx was formed by the hard palate and the choana. The hard palate was characterized by a broad v-shaped rostral mucosal swelling, a median palatine ridge that bifurcated caudally into left and right lateral palatine ridges, and para-median rows of caudally pointed conical papillae. The tongue of the guinea fowl was located on the floor of the oropharynx, but did not extend to the full limits of the lower beak. The caudal and rostral parts of the tongue were demarcated by a v-shaped row of papillae, the papillary crest. Histologically, the dorsal surface of the tongue was lined by a non-keratinized stratified squamous epithelium that contained intraepithelial taste buds, while the lining on the ventral surface of the tongue was a keratinized stratified squamous epithelium. Other features include a wide sub-epithelial connective tissue layer containing lingual glands, and a core of striated muscles. The lingual glands of the guinea fowl consisted of tubular secretory units made up of mucussecreting cells. These findings may be important in nutritional and medical management of guinea fowls especially under the intensive system of production. Furthermore, our study has provided a foundation for recognition of pathology in the oropharynx and tongue of the guinea fowl.

1665 – 1672

Authors: OLOFINTOYE, O. Rose and BOLU, Steve A.

A study was conducted to determine the effects of corn distillers’ dried grain (CDDG) on the performance and egg quality of laying hens. The hens were fed dietary inclusions of CDDG at 0, 10, 20, 30 and 40% for a period of eight weeks. Average feed intake, weight gain, feed conversion ratio and nitrogen economy varied ignificantly (P<0.05) among dietary treatments. Birds fed 30% dietary CDDG had the highest feed intake (127.00 g/bird/day). Feed conversion ratio (FCR) was inversely related to increasing levels of dietary treatments with CDDG. Among hens fed dietary CDDG, those fed 10% dietary the best feed conversion ratio (6.3) and highest weight gain 20.10 g/bird/day). Nitrogen retention was the highest (88.6%) in birds fed control diet and lowest (61.2%) in birds fed 30% dietary CDDG. Hen-day production (HDP) and Haugh Unit (HU) were significantly affected (P<0.05) by dietary treatments. Birds fed 20% dietary CDDG had the highest (61%) HDP, while birds fed 0% CDDG (control diet) had the lowest HDP (52.2%). Birds fed 20% dietary CDDG had the highest HU value (88.7) while birds fed 0% dietary CDDG (control) had the lowest (81.2) value. Birds fed 20% CDDG performed best in terms of HDP, egg quality, cost-benefit ratio. Laying hens can be fed CDDG at 10-20% inclusion level. Inclusion levels of CDDG above this level were observed to have counter-productive effects on the production performance of bird; this observation is as a result of high fibre level of CDDG.

1681 – 1684

Authors: EWUIM, Sylvanus Chima

In this paper entomoremediation as a novel concept was critically projected as a bioremediation technique that needs to be harnessed in line with global realities of involving organisms like microorganisms and earthworms in soil decontamination. Entomoremediation is defined as a type of remediation in which insects are used in order to decontaminate a degraded soil. The candidacy of collembolans, ants, beetles and termites in entomoremediation is advocated because of their role as ecosystem engineers. The need for mass rearing of the insects to be used in proposed bioremediation is discussed. Bioremediation as a measure that requires interdisciplinary approach is emphasized. The need to use insects that are neither threatened or endangered in entomoremediation in order to achieve overall healthy balance of the soil environment is stressed.

1689 – 1698

Authors: EZENWAJI, Ngozi Evelyn, OBIEKWE, Emmanuel Chukwuma and NWAIGWE Chukwuemeka Onyekachi

The functional morphology of some organs of squirrels was investigated through histological observations. A total number of thirty two (32) ground squirrels (Xerus erythropus); 15 males with mean weight 220.0 ± 2.0 g and length 40.0 ± 0.2 cm, and 15 females with mean weight 229.8 ± 2.0 g and length 39.0 ± 2.0 cm were used. The ground squirrels were trapped using rodent traps, anesthetized identified to species level and dissected to expose the viscera. The organs (liver brain, heart, gonads (testes and ovaries) were dissected out, clean off ceolomic fluid, fixed in normal buffered saline prior to the histological studies of the tissues. The organs of squirrel from different zones were examined at the light microscopy. The results compared clearly showed normal tissues without degenerations, the tissue histology showed almost the same pattern and arrangement of the cells in the tissues. The liver develops embryologically outgrowth of the gut. The endocardium, with all its endothelial lining and supporting tissues, accommodates movement of the myocardium. The cerebellar cortex forms a series of deeply convoluted folds or folia. The spermatozoon is absorbed into the lumen of the tubule, where they are drawn into the epididymal walls of the testis while the primary oocyte is surrounded by a single layer of flattened follicular cells.

1613 – 1618

Authors: IKPEGBU, E., EZEASOR, D. N., NLEBEDUM, U. C., NWOGU, C., NNADOZIE, O. and AGBAKWURU, I. O.

The pharyngeal pad located dorsally on the oro-pharynx was processed for light microscopy. The epithelium was of stratified mucous type containing taste buds, club cells and teeth. The micromorphology revealed the co-localization of teeth and taste buds. Developing, erupting and erupted teeth were also seen. The thin bone of cancellous type with a marrow seen provided a point of origin and insertion for the skeletal muscle present. Osteoblasts were seen on the surface of the cancellous bone probably depositing bone matrix. The pad had a base of hyaline cartilage. Stratum adiposum was observed and may be the site for nutrient storage and also function in reducing friction between sliding muscle fibres since it was sandwiched between muscle fibres. The micromorphology suggests an organ used in the trituration and selection of food by gustation. The blood vessels in the bone marrow suggest haematopoietic function. The bone and cartilage present are for support.

1625 – 1631

Authors: ADEYEMI, Samuel Olusegun

Some aspects of the biology of Hyperopisus bebe occidentalis at Idah Area of River Niger were studied between October and December 2010. A total of 129 fish samples were used for the study. The length-weight relationships were analyzed using the formula W = aLb and transformed to Log W = Log a + b Log L. Stomach contents were analyzed by frequency of occurrence method. The standard length for males, females, and combined sexes ranged between 10.9 – 21.04 (cm), 11.3 – 22.5 (cm), and 10.90 – 22.70(cm) with b – values of 3.2953, 3.5015, and 3.4071. The condition factors for the male, female, and combined sexes ranged from 0.56 – 0.98, 0.57 – 0.98, and 0.46 – 0.98, respectively. The result of the food and feeding habits showed that the fish feeds mainly on plant parts (23.2%), larvae (14.4%), mollusk (24.0%), sand grain (17.6%), detritus (24.8%), Worm (10.4%), Algae (28.8%) and unidentified item (25.6%), respectively. H. bebe occidentalis in the Idah area of River Niger could be referred to as an omnivore, feeding mainly on plant materials.

1638 – 1644

Authors: ADEYEMI, Samuel Olusegun

The zooplankton and phytoplankton community of Ajeko Stream, North Central Nigeria were assessed between October and December 2010. Before sampling, Temperature, Transparency, dissolved oxygen, and pH were evaluated. Zooplankton and phytoplanktons were sampled using a plankton net of 20µm diameter with a collecting bottle attached at the base. Water samples were collected between 8 and 9 am every fourth night from three different points on the stream namely the Lower Course, Middle Course, and Upper Course and labeled Stations A, B and C, respectively. Water samples obtained were brought to the Biological Sciences Laboratory of the Kogi State University Ayingba in sampling bottles for analysis of zooplankton and phytoplankton. 4% of formalin was used for the preservation of zooplankton and phytoplankton. Each sample was concentrated to 250ml volume of water using a pipette. 10ml was put to Petri-disc and the 1ml was quickly drawn with a wide-bore dropper. Samples were then introduced carefully into the counting chamber with a cover slip and observed under a light microscope. The result revealed that zooplanktons were made up of Rotifera (44%), Cladocera (23%), Copepoda (20%), and Protozoa (13%) respectively. Phytoplanktons were made up of Chlorophyta (79%), Bacillariophyta (17%), Euglenophyta (2.54%), and Cryptophyta (2.00%) respectively. The status of the stream could said to be eutrophic as indicated by the diversity of zooplankton and phytoplankton.

1654 – 1664

Authors: GABRIEL, Ugwemorubong Ujagwung, GBULUBO, Awotongha Jacob and DEEKAE, Suanu

Fourteen and twenty-one-day larvae were exposed to an abrupt stepwise change in salinity (2, 4, 6, 8, 10, and 12 ppt) for 96 hours to determine mortality, median lethal mortality, MLS, and median lethal time, MLT. The fourteen-day-old fry that were exposed to 0 – 6 ppt recorded 90%, 87.5% 77.5%, and 10% survival at the end of the 96 hours test period. Those that were subjected to 8 ppt and 10 ppt had 100% morality within 48 and 12 hours, respectively. The median lethal salinity at 96 hours (MLS-96) was 4.4 ppt which was about half the value for 6 ppt. The cumulative mortality of the graded salinities did not differ in 4 and 8 ppt but differed in 6 and 10 ppt, whereas the time intervals differed at 24 and 36 hours but did not differ at 48 – 96 hours, p<0.05. The 21-day-old fingerlings transferred into 8, 10, and 12ppt, recorded 100% mortality with 12, 3, and 2 hours, respectively. Those transferred into 0, 4, and 6 ppt had 100%, 80%, and 10% survival, respectively at the end of the 96-hour test period. The median lethal salinity (MLS-96) for 6 and 12 hours was the same 7.19 ppt, while that for 48 hours was 4.79 ppt. The median lethal time (MLT50) for 8 ppt was 8.55 hours, which was seven and a half times the value for 4 ppt. The cumulative mortality of the various salinity concentrations was not different in 10 and 12 ppt but differed in 4 – 8 ppt, p<0.05. Mortality at various time intervals did not differ at 36 – 96 hours, but did at 3 and 6 hours, p<0.05.