Embryonic and Larval Development of Reciprocal Crosses between Clarias gariepinus (Burchell, 1822) and Clarias jaensis (Boulenger, 1909) in West Cameroon

Establishing intraspecific breeding and hybridization programs and determining genetic variability are two important issues for aquaculture. However, interspecific hybridization to improve growth and feeding efficiency is limited. For this purpose, the embryonic and larval development of reciprocal crosses of Clarias gariepinus (Burchell, 1822) and Clarias jaensis (Boulenger, 1909) were studied under laboratory conditions. The fertilization rate varied from 63.33% to 92%, while the hatching rate ranged from 55.68% to 76% with the highest value in hybrids ♀Cg × ♂Cj. Crosses between ♀Cj × ♂Cj, ♀Cg × ♂Cj and ♀Cj × ♂Cg had embryonic stages similar to those of the pure sib ♀Cg x ♂Cg. All crosses, however, had different timing for the various embryological stages. Hatching occurred at 32 h 15 min and 38 h for ♀Cj × ♂Cj and ♀Cj × ♂Cg, and 23 h and 23 h 30 min, respectively, for ♀Cg × ♂Cg and ♀Cg × ♂Cj. However, both crosses produced viable larvae until the first external feeding. The external morphological features of the larvae were completely formed by the 10th day after hatching. The body forms of the crosses at this time were indistinguishable from the pure sib. This study thus laid the groundwork for further comparative studies on hybrid performance and characterization.

Effect of the Dietary Substitution of Fish Meal with Achatina fulica Meat Meal on the Growth Performance and Production Cost of African Catfish (Clarias gariepinus) Fingerlings

Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.

Fruit Powder of Tetrapleura tetraptera in Local Feed on Some Zootechnical Performances of Juveniles of Clarias gariepinus in Concrete Tank

This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 at the Massoma Fish Farm of Bojongo Mbeidi located in the Littoral Region, Department of Wouri, Douala IV district. The farm benefits from a climate favorable to aquaculture activity. For this purpose, five (5) treatments were tested including T0+ (imported feed), T0-, T0.3, T0.4, and T0.5 respectively for the treatments with 0% supplemented food;0.3%;0.4% and 0.5% of Tetrapleura tetraptera powder. A total of 450 Clarias gariepinus fry with an initial average weight of 7 ± 1.5 g, were distributed in happas of 0.49 m2 each placed in Triplicate in a completely randomized device. Four isoprotein foods with 38% crude protein were formulated to feed these fry at 7% of their biomass per day for 15 days then to their fullness until the end of the experiment. Intermediate fishing was carried out every fortnight. 75 days later, the results recorded show that the highest average survival rate (96.44% ± 3.5%) was recorded with the subjects fed feed supplemented with 0.4% T. tetraptera powder. The average weight (120.93 ± 67.20), weight gain (113.93 ± 67.20), specific growth rate (3.64 ± 0.79% g/d) and total lengths and standard (26.43 ± 1.9 and 23.66 ± 1.76) the highest were recorded with the T0+ treatment (imported feed). The highest conditioning factor K (2.14 ± 0.15) was recorded with the treatment supplemented with 0.4% T. tetraptera. The lowest conversion ratio (1.28) was recorded with the treatment fed with imported blue crown food (T0+). Furthermore, the lowest production cost was recorded with the treatment supplemented with 0.4% T. tetraptera. It appears from this study that the juveniles of C. gariepinus better value the feed substituted with 0.4% of the powder of four sides (Tetrapleura tetraptera).

Growth, and Stock Status Assessment of African Catfish, Clarias anguillaris (Linnaeus, 1758) from Burkina Faso Newly Man-Made Lake Samandeni

The Samandeni reservoir in Burkina Faso, impounded in 2017, hosts a significant diversity of fish, including the Clariidae family. The fish stocks have been exploited since 2019, when the reservoir was opened to fishermen. However, no assessment of the status of these stocks has been conducted. The present study focused on the dynamics of Clarias anguillaris exploitation in order to have reliable information that can contribute to the planning of its sustainable exploitation. Length-frequency data on 323 individuals were sampled from commercial catches from March 2021 to February 2022. The growth parameters were determined using ELEFAN method and the stock assessment was done using the Bayesian Length-Based Biomass (LBB) method. The growth analysis showed isometry for both male and female fishes with allometric coefficient value of 3.03, 3.01 and 3.17 respectively for mixed sexes, male and female. Estimates values (0.6 and 0.4) of the growth oscillation intensity indicate the existence of seasonal growth. The relative biomass (B/B0) estimated for C. anguillaris was less than the relative biomass that produces the maximum sustainable yield (BMSY/B0) indicating biomass overfishing. In addition, the length at first capture was less than the optimal length at first capture indicating a growth overfishing status. Therefore, it would be desirable to increase the mesh size of the fishing gear so that juveniles are not caught, which will ensure an ecological sustainability of the exploitation of the Clariidae.

Investigation of heavy metals and lipid peroxidation level in the muscles of Clarias gariepinus from IBI,Gindin-Dorowa and D onga community rivers in Taraba State,Nigeria

Heavy metals have harmful effects on human health,and exposure to these metals has been increased by industrial and anthropogenic activities and modern industrialization.Heavy metals content of the liver tissues was determine d using Atomic Absorption Spectrophotometer method,while lipid peroxidation was carried out.Heavy metals analyzed include;lead(Pb),cadmium(Cd),zinc(Zn),Arsenic(As),and Mercury(Hg).The findings revealed that the heavy metal Zinc(Zn)has high concentrations in the muscles of the fish species,the concentration of this heavy metal Zinc is high in River Gindin Dorowa th a n in River Ibi and River Donga shows less concentration of this heavy metal though it’s above WHO permissible limits.Results revealed that only Zn and Cd were present in the muscle from the three rivers.Pb was found only in the liver from Gindin-Dorowa at the concentration of 0.017 mg/kg,which is not significant(P<0.05)when compared with other locations,while Hg and As were absent in all the muscle samples.The highest concentration of Zn was found in the muscle sample from Gindin-Dorowa(7.450 mg/kg)followed by Ibi(6.16 mg/kg)and the least being Donga(4.365 mg/kg)which are significantly(P<0.05)different from one another.However,there was no significant(P<0.05)difference among the Cd composition of muscle from Gindin-Dorowa(0.025 mg/kg),Donga(0.024 mg/kg)and Ibi(0.015 mg/kg),respectively.The TBA was found in the hepatic tissue sample from Gidin-Dorowa,which has the highest Zn,Cd and no Pb content,followed by Ibi and then the Donga sample.This suggests that there is a positive relationship between heavy metals and the effect of TBA on the hepatic tissues,justifying the fact that heavy metals affect the hepatic tissues of fish,while on the cerebral tissue.In conclusion,it revealed that there is a negative relation between heavy metals and the effect of TBA on the cerebral tissues to protect or save aquatic habitat s of fish quality and aquatic life.

Studies on Heavy Metals Levels in Hepatic Tissues of Cat Fishes(Clarias gariepinus)from River Ibi,Donga and Gindin-Dorowa in Taraba State Nigeria,in Relation to key Enzyme of heme Biosynthetic Pathway

Fishes are excellent markers of the extent of pollution from heavy metals in aquatic environments given that they are found at various levels of the food chain.This study aimed to investigate the bioaccumulation of heavy metals(Zn,Pb,Cd,As,and Hg)as well as the activity of delta-aminolevulinic acid dehydratase(δ-ALA-D)in the livers of cat fishes(Clarias gariepinus)collected from three rivers(Donga,Ibi and Gindin-Dorowa)in Taraba State,Nigeria.The concentrations of heavy metals in the liver tissues were determined using an atomic absorption spectrophotometer in accordance with the method of AOAC(2019),while theδ-ALA-D activity was assayed using the method of Sassa(1982).Results revealed that only Zn and As were present in the liver samples from the three rivers.Pb was found only in the liver from Gindin-Dorowa at the concentration of 0.0012mg/kg which is not significant(P<0.05)when compared with other locations,while Hg and Cd were absent in all the liver samples.The liver sample from Gindin-Dorowa had the highest concentration of Zn(4.2500 mg/kg),followed by Ibi(3.2067 mg/kg),and Donga having the least(2.5500 mg/kg),which were all substantially(P<0.05)different from one another.However,there was no significant(P<0.05)difference in the As composition of liver from Donga(0.0013 mg/kg),Ibi(0.0012 mg/kg)and Gindin-Dorowa(0.0010 mg/kg).The result ofδ-ALA-D activity showed that the highest enzymatic activity was found in the liver sample from Donga which has the least Zn and no Pb content,followed by Ibi sample.This validates the report that heavy metals impairδ-ALA-D activity.Nonetheless,the concentrations of all metals in fish livers from all regions do not exceed the acceptable limits set by international law,making them safe for human consumption and possibly not having a negative impact on public health.Since there is little or no industrial activity in the studied locations,these levels may be consequent to low anthropogenic inputs.The current situation should be safeguarded to prevent pollution of the river’s aquatic biota in the near future,and more appropriate steps should be made to guarantee higher fish quality and life in the rivers.

胡子鲇qRT-PCR内参基因的筛选

实时荧光定量PCR(qRT-PCR)是研究基因表达有效的工具之一,选取合适的内参基因,是获得可靠的基因表达结果的关键。本研究以胡子鲇(Clarias fuscus)为研究对象,采用qRT-PCR技术检测了13个候选基因(actb1、actb2、ef1a、eef1b2、rpl13a、rpl13、ccdc124、cfl1、nm23、eif3g、rap1a、ikbkg和ywhab)在胡子鲇性腺不同发育阶段和成鱼不同组织中的基因表达情况,并利用BestKeeper、GeNorm、NormFinder和RefFinder软件分析其表达稳定性,以筛选在胡子鲇性腺发育和不同组织中稳定表达的内参基因。结果显示,13个候选内参基因的定量PCR引物均可获得特异性扩增产物。在性腺不同发育阶段,候选基因表达稳定性顺序为actb2>rpl13>actb1>cfl1>rap1a>ef1a>rpl13a>ikbkg>eif3g>nm23>eef1b2>ywhab>ccdc124,成鱼不同组织中稳定性顺序为actb2>rpl13>cfl1>rap1a>ef1a>rpl13a>ikbkg>eif3g>nm23>actb1>eef1b2>ywhab>ccdc124。随后,选择稳定性前二的actb2和rpl13作为候选内参基因,分析zp3、atp2b3、slc13a5和parp8基因在胡子鲇雌、雄性腺中的相对表达量,结果进一步证实,以actb2为内参时,其雌雄性状差异基因表达水平更接近于转录组结果。综合分析表明,actb2基因可作为内参基因用于今后胡子鲇性腺不同发育时期和不同组织间功能基因表达特征的研究。

革胡子鲇生长激素基因表达定量PCR分析的引物设计与评估

以革胡子鲇(Clarias gariepinus)为试验对象,对其生长激素(GH)基因进行荧光定量PCR(qPCR)的引物设计与评估。将合成的5对引物通过常规PCR电泳结果选择出符合条件的GHF-GHR引物,并进行qPCR引物的评估。结果显示:扩增GH基因片段的引物GHF-GHR扩增时熔解曲线为单一峰,说明引物具有良好的特异性;通过标准曲线得出GHF-GHR引物的扩增效率为93.3%,标准曲线的R2值为0.982,说明引物的扩增效率良好。上述结果说明GHF-GHR引物能用于待检样本的GH基因表达的qPCR分析。

精油复配乳酸菌对鲶鱼肉风干肠品质及安全性的影响

为探究香辛料精油与乳酸菌共同使用对鲶鱼肉风干肠品质和安全性的影响,将前期优选出的八角精油和紫苏精油组合(star anise essential oil and perilla oil,AP)与商业乳酸菌发酵剂PRO-MIX5复配,作为实验组(AP-PRO组),以不接菌的AP组作为对照。以水分活度、水分质量分数、pH值、硫代巴比妥酸反应物值、亚硝酸盐残留量、乳酸菌数、肠杆菌科数、假单胞菌数、生物胺含量及发酵终点的N-亚硝胺含量为评价指标,分析乳酸菌复配精油对鲶鱼肉风干肠成熟期间品质及安全性的影响。结果表明:发酵过程中风干肠的水分质量分数和水分活度均明显降低,脂肪氧化程度降低;在成熟终点,AP-PRO组的风干肠中含有较多的肠杆菌科数,而假单胞菌的数量相对较少,AP组和AP-PRO组乳酸菌含量分别为8.4、8.7(lg(CFU/g));AP-PRO组风干肠中生物胺和N-亚硝胺总量均显著低于AP组(P<0.05),抑制率分别为14.5%和41.0%。综上,AP-PRO组在改善鲶鱼肉风干肠品质和提高安全性方面的效果优于AP组。

Water Quality and Heavy Metal Monitoring in Water, Sediments, and Tissues of the African Catfish Clarias gariepinus (Burchell, 1822) from the River Nile, Egypt

Water quality of the river Nile and trace elements of the water, sediments and fish tissues were investigated in the current work. Eighteen different sampling points were selected along the whole course of the River Nile from its spring at Aswan to its estuaries at Rosetta and Damietta. Higher mean value of conductivity, alkalinity, chemical oxygen demand (COD), total organic carbon (TOC), ammonia (NH3), nitrate (NO3), total solid (TS), sulphate (SO4), chloride (Cl), orthophosphate were recorded in the water of Damietta and Rosetta branches comparing to other sites. Also trace metals in the water, sediments and tissues of Clarias gariepinus increased significantly (P Fe > Cu > Pb > Mn > Cr> Cd > Hg. In the gill tissues theses metals were accumulated in the following order Fe > Zn > Mn > Pb > Cr > Cu > Cd> Hg. The low accumulation of metals in muscle may be due to lack of binding affinity of these metals with the proteins of muscle. This is particularly important because muscles contribute the greatest mass of the flesh that is consumed as food.

Effect of garlic peel on growth,hematological parameters and disease resistance against Aeromonas hydrophila in African catfish Clarias gariepinus(Bloch) fingerlings

Objective:To evaluate the efficacy of dietary doses of garlic(Allium sativum L.) peel on the hematological and disease resistance of African catfish[Glorias gariepinus(C.gariepinus)] fingerlings against the infections caused by opportunistic bacterial pathogen Aeromonas hydrophila.Methods:Powdered garlic peel was incorporated into the diets at(0%,0.5%,1.0% and 1.5%) and fed to catfish fingerlings for 20 days.After the feeding trial,biochemical(serum total protein,albumin and globulin),hematological parameters(white blood cells and red blood cells) of the fish were examined.Fish were challenged with Aeromona hydrophila(A.hydrophila) after 20 days of post feeding and percentage mortalities were recorded up to 10 days after post challenge.Results:Enhanced serum protein,albumin and globulin in fish fed with all the dosages of garlic peel when compared to control group.Significantly highest red blood cell and white blood cell counts were recorded in garlic peel incorporated diet fed groups compared to control group.The results also demonstrate that low survival rate(55.5±11.0)%in control groups and significantly higher survival rates were recorded in all the garlic peel fed groups after challenging with A.hydrophila.However no significant impact was noticed with regard to body weight gain,specific growth rate and food conversion ratio of fish fed with different levels of garlic peel inclusion and control group.Conclusions:These results indicate that garlic peel enhances the hematological parameters even at a low level(0.5%) incorporation and makes C. gariepinus highly immunopotent and more resistant to infection by A.hydrophila.

Response of African Catfish, <i>Clarias gariepinus</i>(Burchell 1822), Fingerlings Fed Diets Containing Differently Timed Wet-Heat-Treated Sesame (<i>Sesamum indicum</i>) Seedmeal

The response of catfish fed differently timed wet-heat-treated sesame seedmeal was evaluated in the diet of Clarias gariepinus using growth performance, nutrient utilisation and apparent digesti-bility coefficient as indices. Three batches of sesame seed, which were cooked for 10, 20 and 30 minutes, dried, milled, and mechanically defatted using locally made screw press. Each of these differently processed seedmeals was included in the diet of African catfish at varying replacement levels, 15, 30 and 45% with soybean meal. There was good growth performance and nutrient uti-lization by Clarias gariepinus fed with differently timed wet-heat-treated sesame seed that was not significantly different (p > 0.05) from fish fed control diet. More so, the apparent digestibility coef-ficient for organic matter, protein, energy, lipid, fibre, carbohydrate in Clarias gariepinus fed with differently timed wet-heat-treated sesame seedmeal based diets in this study were comparable with the results obtained for fish fed control diets.

Comparative Study of the Growth and Gonad Development of Clarias gariepinus （Burchell 1822） Fed Diets with Plant and Animal-based Ingredients in Concrete Tanks

A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus with an average weight of 205 ×5.09 g, were stocked in six concrete tanks （9 × 4 × 2 m3） containing 20 fish each. Experiment had 3 replicates and animals fed daily at 5% body weights. There was no significant difference （P 〈 0.05） in proximate compositions of the two experimental feeds and controls. Fecundity, gonad weight and gonasomatic index were higher in fish fed diet 13 than A and C. Similarly, growth indices were higher in fish fed diet B than in A and C. Histology of gonads showed a faster development of oocytes of eggs in fish fed animal-based ingredients than plant-based and combined plant and animal diets. Although there were slight differences in growth parameters and gonad development in favor of feed with animal-based ingredients, plant-based feed compared favorably in the growth and gonad development of C. gariepinus. Plant-based ingredients are recommended on the basis of affordability and availability as substitute for animal-based ingredients in C. gariepinus feed.

Relative Toxicity of Aldrin, Fenvalerate, Captan and Diazinon to the Freshwater Food-Fish, Clarias Batrachus

The median lethal concentrations (LC50s) of aldrin, fenvalerate, captan and diazinon were determined for Clarias batrachus by trimmed Spearman-Karber method. The potency ratios of toxicity among them were analysed by parallel-line bioassay with quantal responses. The LC50s for 40 day of exposure of aldrin, fenvalerate, captan and diazinon were 0.00036,0.0094, 0.5473 and 2.4186 ppm respectively. These values were lower than those obtained for an exposure of 96 hour. It shows the greater toxicity of the pesticides in a long-term exposure. The relative toxic potency of aldrin fenvalerate, captan and diazinon was in a ratio of 6807:241:4:1 respectively. Thus the chemically different groups of pesticides exhibit an order of toxicity as aldrin > fenvalerate >captan > diazinon for the freshwater catfish, Clarias batrachus. It infers that the catfish is most sensitive to aldrin and least sensitive to diazinon. The comparison of the sensitivity of various species tested against these pesticidal chemicals has also been done to review the available information.

The Community of Parasites Infecting <i>Clarias gariepinus</i>in the Tanzanian Waters: A Case of Lake Victoria

Quantitative variations in parasites were investigated with respect to sex and size of Clarias gariepinus, season and localities sampled. Parasitic infection in male and female fish was not significantly different;prevalence (Man-Whitney paired sample test, U = 135.5, p = 0.7697), mean intensity (U = 136, p = 0.7829). Based on Kruskal-Wallis test analysis, the prevalence and mean intensity of five parasite species varied significantly among the three localities sampled. Adult parasites in Clarias gariepinus showed high abundance during the dry season while the larval forms showed high abundance in the wet season. In most of the parasite species analyzed the abundance varied significantly with host size. The abundance of Dolops ranarum, Paracamallanus cyatopharynx and Eumasenia bangweulensis for instance, increased with fish size, while that of Diplostomum mashonense, Tylodelphys species, Astiotrema reniferum, piscicolid leeches and Monobothrioides woodlandi increased initially but decreased as fish length reached 31 - 40 cm. Total parasite burden increased in fish of 20 - 40 cm standard length. Generally, most parasites were highly overdispersed and the negative binomial model described their distribution.

Physico-Chemical Evaluation and Hematological Responses in <i>Clarias gariepinus</i>(Burchell 1822) Juveniles Exposed to <i>Adenium obesum</i>Stem Bark Acute Bioassay

The experiment was conducted to evaluate the acute toxicity of aqueous extract of Adenium obesum stem bark in juveniles of Clarias gariepinus by assessing the hematological responses of the exposed groups compared to the control in a static non-renewal bioassay for 96 hours. The fishes (N = 180, mean weight and length 21.48 ± 3.32 g and 11.37 ± 1.23 cm) respectively were randomly distributed 10 (ten) fishes per group in triplicates constituting six experimental groups as follows;G1 (Control), G2 (6.5 mg/l), G3 (7.8 mg/l), G4 (8.5 mg/l), G5 (9.5 mg/l) and G6 (11.5 mg/l). Red blood cell (RBC) count, packed cell volume (PCV) and hemoglobin concentration were decreased significantly (P < 0.05) as opposed to the significant (P < 0.05) increase in total white blood cell count (TWBC). Thus the study concludes that aqueous extract of Adenium obesum stem bark is toxic to erythrocytes while a converse adaptive response in the white blood cells.

Morphometric Indices and Enteroparasitic Infestation of <i>Clarias gariepinus</i>(Burchell, 1822) in a Tropical Reservoir

The study was carried out using 328 Clarias gariepinus specimens over a period of two years, from Oba reservoir (08&#176;3'N to 08&#176;12'N and 004&#176;6'E to 004&#176;12'E) Ogbomoso, Oyo State, Nigeria. Standard methods were used to determine length-weight relationship, condition factor, and enteroparasitic infestation of the fish in the reservoir. Generally, Fish growth was positively allometric, while infested male and female fishes had negative allometric growth. The general well-being of the male fish was better than that of the female fish. Smaller sized fishes were better adapted to the ecological conditions of the reservoir than the bigger fishes. Parasites recovered were two Nematodes (Procamallanus laevionchus, Paracamallanus cyathopharynx), three Cestodes (Anomotaenia sp. Monobothrium sp., Polyonchobothrium clariae), and one Acanthocephalan (Neoechinorhynchus rutili). Sex ratio was 1.3:1 (male: female). Parasitic prevalence and intensity in the fish were sex and season dependent. The effect of enteroparasites in the life of infested C. gariepinus was found to probably be a major factor responsible for the low percentage of good fit to the line of regression (R2) in females. Infestation also led to loss of weight in infested fishes and this affected morphometric values in which body weight was an index.

Prevalence and Intensity of Helminth Parasites of African Catfish <i>Clarias gariepinus</i>in Lake Manzala, Egypt

The African catfish, Clarias gariepinus, is generally considered to be one of the most important tropical catfish species for aquaculture purposes. Parasitological investigation was performed in two hundred naturally collected fish samples during the period of February to December 2014. The prevalence of gastrointestinal helminth parasites infecting C. gariepinus was investigated. A total of 249 helminth parasites belonging to four genera were recovered from 130 (65%) examined fish samples. They were digenea Orientocreadium batrachoides, cestode Polyonchobothrium clariae, and nematode Procamallanus laevionchus and Camallanus polypteri. Majority of the recorded parasites were found in the intestine. Female fish samples had higher prevalence rate 72 (90%) than males 58 (48.33%), and there was no significant difference (P > 0.05) in infestation rate between the two sexes. The relationship of host size (weight/length) and parasite infection showed that there was no significant difference in the parasitic infection among three classes, although fish of larger sizes had more infections. In addition, this study determines the effect of fish age on the prevalence and intensity of gastrointestinal parasites.

Toxicological Assessment of <em>Chromoleana odorata</em>on <em>Clarias gariepinus</em>Juveniles

A study was carried out to investigate the toxicity effects of exposure of aqueous extract of Chromolaena odorata leave on gill/liver (histological) of juveniles catfish Clarias gariepinus. The leaves were harvested fresh, air dried for 7 days under ambient room temperature. 200 healthy juveniles catfish Clarias gariepinus specimen with average initial weight of 12.40 ± 2.46 cm (mean total length) and 8.26 ± 1.25 g (mean body weight) were exposed to aqueous extract of Chromolaena odorata leave at the concentration of 50, 100, 150, 200, 250 mg/l respectively. The physical reactions observed in the fish were: erratic swimming, gasping for air, loss of reflex, hyperactivities and skin discolorations which were more pronounced at high concentration and exposure time. The pH and dissolved oxygen significantly (P < 0.05) de-creased as the concentrations of C. odorata leaves extract increased. However, the values of Ammonia in the exposed media significantly (P < 0.05) in-creased as the concentrations of C. odorata leaves extract increased, compared to the control test medium. A high mortality rate was recorded, the histologi-cal conditions on gill and liver includes the deformation of gill tissue with overlapping of secondary lamella and disintegration of epithelial tissue lead-ing to diffuse mass of the gill lamella due to rapid cell lysis, gill clogging and gill structure disruption. Deformed primary and secondary lamella with dis-integrated gill filament, increasing vasculation, total fusion of gill filament lamella and filament length variation. Damage became severe with increasing concentration in C. odorata leaves to fish and exposure, while liver of Clarias gariepinus shows liver hepatocellular alteration and increase in hepatocyte disintegration, rupture blood cells in the entire cell with hemorrhage of the vessels and blur nature with severe breakage due to rupture.

Ameliorative Effects of Spirulina platensis on Deltamethrin-Induced Biochemical Alterations and Oxidative Stress in the African Catfish;Clarias gariepinus

The present study was carried out to determine LC50 of deltamethrin (DM) in the African catfish;Clarias gariepinus, investigate its effects on the biochemical parameters and the antioxidant status of various tissues, and assess the protective role of Spirulina platensis (SP) against DM induced toxicity in C. gariepinus. The fish were distributed into seven groups of 10 fish/each for 30 days as follows: Group 1, control;Group 2, orally administered saline;Group 3, oral SP (150 mg/kg b.w.);Group 4, exposed to 5.19 μg/l DM;Group 5, exposed to 5.19 μg/l DM and orally administered SP (150 mg/kg b.w.);Group 6, exposed to 12.97 μg/l DM;and Group 7, exposed to 12.97 μg/l DM and orally administered SP (150 mg/kg b.w.). Results revealed marked elevation in serum AST, ALT, ALP, creatinine, urea and uric acid. Significant decrease in serum total protein and albumin was recorded. At the same time, the level of malondialdehyde (MDA) was significantly increased in liver, kidney and gills. While, tissue level ofGSHand, SOD,CATandGSH-Px activities were reduced. Treatment with SP improved the biochemical parameters and attenuated the DM induced oxidative damage. Therefore, this study confirmed the protective role of SP as an antioxidant against the toxicity of DM in catfish.