Parasites and their Freshwater Fish Host

This study reviews the effects of parasites of fresh water fish hosts. Like other living organisms, fish harbour parasites either external or internal which cause a host of pathological debilities in them. The parasites live in close obligate association and derive benefits such as nutrition at the host\'s expense, usually without killing the host. They utililize energy otherwise available for the hosts growth, sustenance, development, establishment and reproduction and as such may harm their hosts in a number of ways and affect fish production. The common parasites of fishes include the unicellular microparasites (viruses, bacteria, fungi and protozoans). The protozoans i.e. microsporidians and mixozoans are considered in this review. The multicellular macroparasites mainly comprised of the helminthes and arthropods are also highlighted. The effects of parasites on their fish hosts maybe exacerbated by different pollutants including heavy metals and hydrocarbons, organic enrichment of sediments by domestic sewage and others such as parasite life cycles and fish population size. Keywords: Parasites, Helminths, Protozoans, Microparasites, Macroparasites, Debilities, Freshwater fishBio-Research Vol. 6 (1) 2008: pp. 328-33

Comparative Hypolipidaemic Effects of Allium cepa, Allium sativum and Zingiber officinale Aqueous Extracts on Alloxan-Induced Diabetic Rattus novergicus

This study compares the hypolipidaemic effects of the increasing dosages of A. cepa, A. sativum and Z. officinale aqueous extract on alloxan-diabetic Rattus novergicus for possible use in the management of hyperlipidaemia characteristic of diabetes mellitus. Diabetes mellitus was induced in 108 out of a total of 117 adult Rattus novergicus using 150mg/kg b wt of alloxan monohydrate. Increasing dosages (200, 250 and 300mg/kg bw ip) of A. cepa, A. sativum and Z. officinale aqueous extracts were given to the diabetic rats for six weeks while the control rats got either normal saline (1ml) or increasing dosage of glibenclamide ( 2.5, 3.8 and 5.0mg/kg b wt ip) during the same period. Total serum lipids and total serum cholesterol were assessed using routine methods. Increasing dosages of plants aqueous extracts produced a dose-dependent significant (P < 0.05) reductions in the total serum lipid and total serum cholesterol of diabetic rats. The most effective percentage reduction in total serum lipids and total serum cholesterol were observed at 300mg/kg bw ip and this was the same for the three extracts studied. A. cepa and A. sativum at 300mg/kg bw ip caused significant reductions in total serum lipids more effective than the diabetic control drug glibenclamide at 5.0 mg/kg bw ip. A. cepa at 300mg/kg bw ip was the most effective in reducing total serum lipids, reducing it by 44.4% (184.3 ± 8.4 to 129.7 ± 5.7). A. sativum at 300mg/kg bw ip was the most effective in reducing total serum cholesterol, 39.8%, that was from ( 128.7 ± 2.7 to 77.2 ± 4.9), A. cepa followed 27.2% (130.1 ± 3.7 to 94.7 ± 4.2) and Z. Officinale was next , 16.1% from (130.7 ± 4.4 to 109.7 ± 7.5). From our experimental findings, it can be concluded that the three plant extracts studied exhibited promising hypolipidaemic activity in alloxan-diabetic rats. The hypolipidaemic effect presents a protective mechanism against the development of atherosclerosis and hyperlipidaemia common in diabetes mellitus. Further studies on the extracts, their composition, mode of action and active ingredients are suggested. A research on the combined effects of the three plant extracts on hyperlipidaemia was recommended for future investigations. Keywords: Hypolipidaemic effects, Allium cepa, Allium sativum, Zingiber officinale Alloxan-Induced diabetic Rattus novergicus Bio-Research Vol. 6 (2) 2008: pp. 384-39

Induced propagation of African clariid catfish, Heterobranchus bidorsalis (Geoffrey Saint Hillarie, 1809) using synthetic and homoplastic hormones

Induced spawning of African giant catfish (Heterobranchus bidorsalis) was successfully carried out using synthetic hormone (Ovaprim) and natural hormone (homoplastic hormone-pituitary extract fromH. bidorsalis). The study which was carried out at Aquafish Farm, Ihiala, Anambra State, Nigeria, lasted 70 days (May to July). Sixty gravid females and twenty mature males of H. bidorsalis (weightrange of 310 to 550 g) were used for the study. In all, 10 trials were carried out with a control. The results showed that ovaprim performed significantly better (P < 0.01) in almost all the parametersinvestigated. The two hormonal materials gave slightly different results in terms of pre and post hormonal induced spawning mean somatic weight loss of 423.83 ± 14.19 g and 446.00 ± 13.37 g, meannumber of dead eggs of 396.10 ± 19.15 and 194.90 ± 11.00, hatchability of 9,180.13 ± 343.37 and 11,162.27 ± 362.00 hatched larvae, 35.80 ± 1.11 and 12.37 ± 1.54 deformed larvae, and 99.61 and 99.88% survival were recorded respectively for homoplastic hormone and ovaprim, respectively. Comparative cost benefit analysis showed that ovaprim which recorded better results, was also relatively cheaper.Ovaprim worth N3467.00 was used for induced breeding of H. bidorsalis with combined body weight of 13.38 kg while pituitary hormone was extracted from N 6350.00 worth of H. bidorsalis and used forinduced breeding of gravid H. bidorsalis with combined body weight of 12.72 kg. Because of its relatively cheap cost, ease of handling and better survival of hatchlings from H. bidorsalis, ovaprim ishighly recommended for hatchery users

Proximate and organoleptic characteristics of sun and solar dried fish

The sun and solar drier were evaluated for their drying effectiveness with three species of freshwater fish; Gymnarchus niloticus, Heterotis niloticus and Clarias gariepinus. The highest mean temperature that could be attained in the solar dryer was 700C at time 14.00 hour while the ambent temperature and insulation were 33.5 i 0C and 857.6 w/m2 respectively. Proximate and organoleptic characteristics of the sun and solar dried products were carried out. It was found out that quality of the fish products dried in the solar drier were superior to those sun-dried. Organoleptic characteristics of the solar dried were better, especially the odour and moisture reduction was more in solar than in sun dried products. It took only three days for the fish to be completely dried in the solar drier compared with sun dried fish products which took seven days to dry

Studies on the reproductive potential of homoplastic and heteroplastic pituitary hormones in Heterobranchus bidorsalis (Geoffroy Saint Hilaire, 1809)

Artificial induce breeding of gravid Heterobranchus bidorsalis was carried out using two hormonal materials – homoplastic and heteroplastic hormones. The study which involved 10 trials was carried out with 60 gravid female and 20 mature male. The broodfish used for the study were 18 months hatchery produced H. bidorsalis. The hormonal treatments led to the following results in terms of percentage weight loss (3.16 and 306%); fertilization rate (9522.77 ± 34813 and 8,857.93± 25557); and hatchability (9,18013± 34337 and 8,476.83 ± 34595) for homoplastic and heteroplastic hormones respectively. The mean numbers of dead eggs were 396.10± 19.15 forhomoplastic hormone injected catfish and 425.53 ± 17.09 for those injected heteroplastic hormone. Recorded deormed of larva were low (35.80 ± 1.11 and 34.27 ± 1.43) respectively for catfish injected homoplastic and heteroplastic hormones. Survival of hatchlings was high (99.61 and 9959 %) for gravid catfish inected homoplastic and heteroplastic hormones respectively. There was no significant difference (P < 005) in weight of pre and post female spawners. Although the two tested hormones investigated were effective inducers, homoplastic hormone is recommended as it recorded better results.Keywords: Homoplastic and Heteroplastic hormones, Induced spawning, Hatchability, Heterobranchus bidorsali

Parasitic infestation of Synodontis batensoda (Rüppell, 1832, Siluriformes, Mockokidae) at Rivers Niger-Benue Confluence, Nigeria

The Mockokid, upside down catfish, Synodontis batensoda caught with various fishing gears were studied for parasites for a period of 12 months (March 2007 to February 2008) in Rivers Niger and Benue at the Confluence. Out of 84 fish specimens examined, 61 (72.6%) fish hosts were infected, while 23 (27.4%) were uninfected. The total parasites recovered were 1196, comprising one protozoan ciliate (Trichodinids), two Digeneans (Allocreadim ghanensis and Metacercariae of Pygidiopsis genata), four Cestodes (Monobothrioides woodlandi, Bothriocephalus acheilognathii, Proteocephalus largoploglotis and Caryophyleus sp.), six Nematodes (Procamallanus laevionchus, Rhabdochona congolensis, Spinitectus guntheri, Oxyuris equi, Contracaecum microcephalum, Strongylides sp and larval Nematodes) and the Acanthocephalans (Acanthocephalus sp., Neoechinorhynchus prolixum and Acanthella sp. - the immature stages). Acanthocephalans had the highest prevalence among the parasites recovered. All parasites were recovered from the intestines except the Trichodinids which were recovered from the gills and skin of fish hosts. The relationship of host weight and parasite infection showed infection was highly significant (p &lt; 0.01) in fish of larger weight of 76 to 100 g and above. There was no significant (p &gt; 0.01) difference between the male and female fish hosts, both being equally infected. Multiple infections were recorded in several fish hosts, an indication of the rich parasitic fauna of the localities. This study provides an overview of parasites of S. batensoda in Rivers Niger and Benue at the Confluence.Keywords: Parasites, protozoan, helminths, nematodes, cestodes, acanthocephalans, Synodontis batensoda, Rivers Niger-Benue Confluence, NigeriaAfrican Journal of Biotechnology Vol. 12(20), pp. 3029-303

Variations in the Physico-Chemical Parameters of a Natural, Tropical, Rainforest Lake

A study of the physico-chemical parameters of Agulu Lake was made from January to December 2003. Except for surface temperature, the other parameters were markedly season-dependent. Conductivity, total residue, DO, alkalinity, turbidity, calcium, N-NO3, P-PO4 values were higher in the rainy than the dry season. Conversely, pH, visibility and free CO2 were higher in the dry season. There was no significant seasonality in surface temperature. Keywords: Physico-chemical parameters, Agulu LakeBio-Research Vol. 6 (2) 2008: pp. 371-37

Co-infection and morphometrics of three clinostomatids (Digenea: Clinostomatidae) in Tilapia guinensis Bleeker, 1862 from Opi lake, Nigeria

Co-infection and morphometrics of helminth parasites of Tilapia guinensis in Opi Lake (GPS N06.75275*, E007.49104*), were studied from (Nov 2007– Oct 2008) using multiple fishing gear techniques; cast nets, hook and line, and seine nets (150 mm – 200 mm). The parasites recovered were C. tilapiae, C. complanatum and E. heterostomum. The prevalence was low, indicative of parasitic infection in the wild. Prevalence of (33.9 %) was recorded in C. complanatum, (7.2 %) in E. heterostomum and (12.6 %) in C. tilapiae. But high mean intensity was suggestive of heavy parasite burden; C. complanatum (4.8), C. tilapiae (2.8), and E. heterostomum (5.1). Morphometrics of the parasites showed no significance difference in the distance between oral and ventral suckers. However, they differed in all other parts significantly (p < 0.05). In the rank-abundance curve for parasite communities, C. complanatum was most abundant (pi 0.63). Differential parasitic effects were due to selection for relatively better adaptiveness to host’s microhabitats, more population size, better host location, and larger body size. Consequently, this resulted in a trade-off between larger morphometric parts and population size among the parasite

The Extent of Implementation of Orientation Programme among Public and Private Secondary Schools in Cross River State of Nigeria

This study investigates the implementation of orientation programme among public and private secondary schools in Cross River State of Nigeria. The aspects of the study were on the regularity, content and problems of orientation programme. Using three (3) null hypotheses, the study using a descriptive survey, sampled 672 teachers drawn from fifty percent (50%) of public and private secondary schools in the State. From the independent ttestused for data analysis, the findings of the study show that there aresignificant differences between public and private secondary schools in theregularity and content of their orientation programme. There is nosignificant difference in problems faced by the two groups of school inimplementing orientation programme. Because of the strategic nature oforientation programme to the new entrants in the school system, it isrecommended that heads of school should ensure regular and adequateorientation programme in their schools. Government can also facilitate theprogramme by making it compulsory through better funding of schools.Guidance counselors should be effectively used in conducting orientationprogramme

Growth performance of hybrid catfish (Heterobranchus bidorsalis (♀) x Clarias gariepinus (♂)) at various stocking densities in varied culture tanks

Stocking density effect of Heterobranchus bidorsalis (&#129;&#352;) and Clarias gariepinus (&#129;&#8240;) hybrid juveniles stocked at densities of 7, 14 and 21 catfishes m-2 in three varied culture tanks (concrete, metal and plastic) were studied for 20 weeks. Total length and weight of catfish juveniles were recorded every fortnight. Plastic tanks with stocking density of 7catfishes m-2 had the best weight gain (4.89 &#129;} 6.81 g) while the least weight gain (1.39 &#129;} 2.16 g) was recorded in concrete tank with stocking density of 21 catfishes m-2. There was significant difference between stocking density of 7 catfishes m-2 (4.13 &#129;} 5.38 g) and 21 catfishes m-2 (1.82 &#129;} 2.26 g) (P &lt; 0.05). There was no significant difference inspecific growth rate, feed efficiency and condition factor of catfishes in all culture tanks and stocking densities. The best total length of 12.23 &#129;} 5.22 cm was obtained in concrete tank with stocking density of 7 catfish m-2. The least mean total length (9.44 &#129;} 4.04 cm) was recorded in plastic tank with stocking density of 21 catfishes m-2. The effect of stocking density on total length was significant between stocking densities of 7 catfishes m-2 (11.85 &#129;} 5.52 cm) and 21 catfishes m-2 (9.54 &#129;} 4.01 cm) (P &lt; 0.05)