Clarias gariepinus

The threshold concentration for NH3 in rearing water of African catfish (Clarias gariepinus) was assessed. African catfish with an initial mean (SD) weight of 141.0 (24) g were exposed to five different Tamm [sum of NH3 and NH4+] concentrations: 0.37 (Control), 1.06, 2.12, 5.16 and 19.7 mM, which concurs with NH3 concentrations of 4 (Control), 14, 38, 176 and 1084 μM. Plasma concentrations of NH4+, cortisol, glucose and lactate, plasma osmolality, gill morphology, branchial Na+/K+-ATPase activity, feed intake and specific growth rate were monitored. No effect of water NH3 on plasma NH4+ concentrations was detected. Feed intake and specific growth rate were severely affected at exposure to water NH3 concentrations above 90 μM (calculated EC10 values: 89 and 122 μM). No major disturbances in physiological blood parameters were observed at these NH3 concentrations, but gill morphology (a remarkably sensitive stress indicator) deteriorated significantly. Based on the lower limit of the 95% confidence interval for EC10, we advise for African catfish not to exceed a water NH3 concentration of 24 μM (0.34 mg NH3-N/L). This finding is relevant for design and management of African catfish production systems.

This review article set out the inventory of the various scientific and
technical contributions on the biological and zoo technical parameters of the catfish Clarias gariepinus. Several years of research shows that Clarias gariepinus is of great importance in fisheries and aquaculture in Africa and around the world, judging by the wealth of knowledge produced. The information provided in this review was collected from scientific articles, books and handbooks, technical reports, thesis, dissertations, and proceedings. The authors, through an inventory of the various scientific and technical contributions from 1971 to 2017, reported the biological characteristics of C.gariepinus, its diet and nutrition, its reproduction, its growth performance, its breeding systems and devices and some diseases to which it is subject. The biological characteristics of the African catfish were analyzed based on its description, taxonomic classification, habitat, ecological requirements and geographic distribution. The diet of the species has been addressed within its natural environment, in rearing and through nutritional needs and constraints. Reproduction of the species includes, age at first sexual maturity, incubation time, gonado-somatic index, absolute fertility, relative fertility and spawning frequency. Growth performance took into account the weight gain and the specific growth rate. Finally, breeding system and device and some diseases of C. gariepinus were reviewed.

Growth, feed utilization and survival of African catfish (Clarias gariepinus, Burchell 1822) reared in earthen ponds using hydrated lime and calcium carbide lime as the liming materials were studied for 24 weeks. Three treatments – hydrated lime ponds, calcium carbide lime ponds and control ponds were used in three replicates. Each pond was stocked with 300 fingerlings at an average weight of 26 g. fish were fed 4% body weight. Growth parameters and feed utilization were estimated. Some water quality parameters – dissolved oxygen, pH, temperature, alkalinity, hardness, nitrate, nitrite and ammonia were monitored bi-weekly using standard analytical procedures. Results show that there was no significant difference (p>0.05) in the levels of ammonia and temperature of the water among the treatments but significant difference (p<0.05) were recorded in the levels of total alkalinity, pH, nitrate, nitrite, and hardness values among treatment ponds. The mean weight gain of the fish were 824 g for the control ponds, 661 g for the calcium carbide lime ponds, while fish in the hydrated lime ponds had the least weight gain value of 551 g. Specific growth rate (SGR) among the treatments were 2.08, 1.93 and 1.85 for control ponds, calcium carbide lime ponds and hydrated lime ponds respectively. Food conversion ratio (FCR) was 3.21 for control ponds, 3.11 for calcium carbide lime pond and 2.49 for the hydrated lime ponds. The survival rate was 92.33%, 89.84% and 78.00% respectively for calcium carbide lime ponds, control ponds and hydrated lime ponds. The heavy metal contents on fresh weight basis among the treatment varied significantly from each other (p<0.05). The poor growth, feed utilization and survival rate obtained in hydrated lime ponds may be attributed to the heavy metal contents of the lime. The best growth and feed utilization values were obtained for fish in control ponds. However, values obtained for fish in the calcium carbide lime ponds were satisfactory. From this study, calcium carbide lime can be recommended for use by fish farmers.

Background: The desire of a fish farmer is to produce table-sized fish within the shortest possible period. This can be achieved by providing a good feed since the growth of a fish is influenced by its feed utilization and the feed utilization is a function of the balanced nutrient composition of the feed. Haematological studies have been employed in aquaculture and are usually associated with the feed input because blood parameters have been proved to be valuable tools in determining the health status of the fish in response to the dietary manipulations. Objective: This study investigated haematological indices and growth performance of Clarias gariepinus fingerlings fed locally formulated (sinking) and commercial (floating) pelleted diets in tarpaulin tanks. Materials and methods: Ninety fingerlings of initial mean weight (4.87 g) were observed for an 8 weeks feeding trial with three replicates at a stocking density of 15 fish/m 2. The fish were fed three times daily at 5% biomass. Results: Results from growth parameters showed that C. gariepinus fingerlings fed floating (commercial) diet had significantly higher (p<0.05) final mean weight (921.73 g ± 47.44) than sinking (locally formulated) diet (184.22 g ± 20.54). Fish fed commercial diet had significantly higher (p<0.05) production index (1454.13 ± 101.28) than locally formulated (191.43 ± 33.27). Water quality parameters including temperature (°C), dissolved oxygen (mg/l) and pH were not significantly different (p>0.05) during the study and were maintained within acceptable range. Haematological analysis shows significant difference (p<0.05) in haemoglobin concentration (Hb) between fish fed floating (7.53 ± 0.20) and sinking (5.63 ± 0.18) diets. Packed Cell Volume (PCV) was significantly higher (p<0.05) in fish fed floating (24.67 ± 0.88) than fish fed sinking (17.00 ± 0.58) diets. Red Blood Cells (RBC) was also significantly higher (p<0.05) in fish fed floating (1.53 ± 0.07) than sinking (1.27 ± 0.03) diets. However, White Blood Cells (WBC) was significantly lower in fish fed floating (3.27 ± 0.09) than sinking (8.43 ± 0.09) feed. Mean Corpuscular Volume (MCV) was significantly higher (p<0.05) for C. gariepinus fed floating (141.67 ± 1.76) than sinking (124.67 ± 1.76). There was no significant difference (P>0.05) in Mean Corpuscular Haemoglobin (MCH) and Mean Corpuscular Haemoglobin Concentration (MCHC) for fish fed floating and sinking feed but both blood parameter was higher in fish fed floating (44.67 ± 1.76; 32.67 ± 0.88) than fish fed sinking (42.33 ± 0.88; 32.33 ± 0.88) respectively. Conclusion: Based on these findings, the different feed forms did not significantly affect blood parameters and at such can be utilized by catfish farmers but commercial feed is recommended since it gives better growth response.

This study evaluated growth performance, nutrient utilization and survival of cultured Clarias gariepinus fingerlings fed locally formulated (sinking) and commercial (floating) pelleted diets in tarpaulin tanks. Fingerlings of initial mean weight (72.99 g ± 3.09) were stocked in each treatment replicated 3 times. Fish were cultured for 8 weeks. The stocking rate was 15 fish per m2. The fish were fed three times daily at 5% body weight. Results showed that C. gariepinus fingerlings fed
floating (commercial) diet had significantly higher (p<0.05) final mean weight (921.73 g ± 47.44) than sinking (locally formulated) diet (184.22 g ± 20.54). Commercial feed had higher (p<0.05) specific growth rate (3.29 ± 0.07) than locally formulated diet (0.97 ± 0.20). Fish fed commercial diet has significantly lower (p<0.05) feed conversion ratio (0.83 ± 0.03) than locally formulated diet (3.23 ± 0.40). Protein efficiency ratio was significantly (p<0.05) lower in fish fed locally formulated diet (0.80 ± 0.11) than commercial diet (2.69 ± 0.09). There was no significant difference (p>0.05) in survival rate for fish fed commercial feed (95.55 % ± 2.22) and locally formulated feed (97.78 % ± 2.22). Water quality parameters including temperature (°C), dissolved oxygen (mg/l) and pH were not significantly different (p>0.05) during the study and were maintained within acceptable range. Proximate analysis of the dry matter of the two experimental feeds showed that the commercial feed had higher value of crude protein (45%) and crude lipid (14%) and lower value for crude fibre (2.5%), total ash (7.5%) and carbohydrate (28.2%) when compared with the sinking diet of lower crude protein (22.75%) and crude lipid (8.06%) and higher value of crude fibre (9.66%), total ash (11.50%) and carbohydrate (48.06%). Based on these findings, commercial feed is recommended for feeding C. gariepinus fingerlings since it showed higher growth performance, better nutrient utilization and greater survival.

Phytobiotics are valuable materials in promoting growth and reducing pathogenic diseases in cultured fish diets. To this effect, a 12 weeks experiment was conducted in a 40- litres fresh water- filled rectangular plastic tanks to evaluating the growth, nutrient utilization potential and gasytointestinal microbes of Clarias gariepinus fed varying levels of Zingiber officinale root powder. 120 C. gariepinus fingerlings (2.33±0.07g average weight) were fed with 40% crude protein diets containing three concentrations of Z. officinale roots-powder: ZOP1–1%; ZOP2–2%; ZOP3–3%, and control–0% ad libitum twice daily for 12 weeks.  Significant differences (p < 0.05) occurred in the growth and nutrient utilization parameters except feed conversion ratio and specific growth rate. Survival rate decreased as concentration of powder increased. The total bacterial counts (TBC) and total fungal counts (TFC) decreased as inclusion levels of the supplements increased which were different (p < 0.05) from the control. The study concluded that 1% Z. officinale roots-powder dietary supplementation in cultured C. gariepinus could effectively promote growth and reducing the microbial load of the fish.

Key Words: Clarias gariepinus, Dietary supplement, Microbe, Growth, Z. officinale roots-powder.

The study was undertaken to evaluate the growth performance and feed utilization of African catfish, Clarias gariepinus, fed six diets (D) in which fishmeal (FM) was gradually replaced by a mixture of local plant by-products. In diets 1 and 2, FM (250 g kg−1) was replaced by sunflower oil cake (SFOC). In diets 3 and 4, FM (250 and 150 g kg−1, respectively) was replaced by SFOC and bean meal (BM) while FM was totally substituted by a mixture of groundnut oil cake (GOC), BM and SFOC in diets 5 and 6. Sunflower oil cake was cooked, soaked or dehulled in order to determine the appropriate processing techniques for improving the SFOC nutritive value and to evaluate the apparent digestibility coefficient (ADC) values of the alternative diets. No significant differences were observed for daily feed intake, weight gain, specific growth rate (SGR) and feed efficiency (FE) among fish fed D1, D2, D3 (250 g kg−1 FM), D4 (150 g kg−1 FM) and D6 (0 g kg−1 FM). The highest SGR (3.2% per day) and FE (1.2) were achieved in fish fed D3, and the lowest in fish fed D5 (0% FM), suggesting a maximum acceptable dietary concentration of hulled SFOC below 250 g kg−1 in African catfish juveniles. Protein efficiency ratio ranged from 2.2 to 3.2 for all dietary treatments and was positively influenced by FM inclusion. African catfish were able to digest plant protein very efficiently in all diets tested. ADC of protein ranged from 88.6 to 89.5%, while ADC of energy was relatively low for diets containing hulled sunflower oilcake (71–74%) and high when sunflower oilcake was dehulled (78.6–81.3%). Similarly, ADC of dry matter was higher when sunflower was dehulled (72.1%) when compared with crude SFOC (60.5%). Soaking increased ADC values for neutral detergent fibre (NDF), dry matter, energy, protein and amino acids (AA). There were no significant differences in protein ADCs (88–90%) with increased levels of dietary vegetable ingredients. Both soaking and dehulling of sunflower before incorporation helped in the reduction of NDF, antitrypsin and tannins. Digestibility of all AA was generally high, greater than 90% for both indispensable and non-indispensable AA. Based on the data obtained, it was possible to totally replace menhaden fish meal with a mixture of vegetable proteins (72% of total dietary protein) when diets contained a relatively low percentage of animal protein (28% based on blood meal and chicken viscera meal) without negative effects.

A 12-week feeding trial was carried out in concrete tanks to examine complete and partial replacement (75%) of fish meal (FM) with poultry by-product meal (PBM), meat and bone meal (MBM) and soybean meal (SBM) in practical feeds for African catfish Clarias gariepinus. Triplicate groups of fish (initial body weight ranged from 90.33 to 93.93 g fish−1) were fed seven isonitrogenous and isocaloric diets of 20% digestible protein and 300 kcal 100 g−1 of digestible energy. The control contained 25% herring meal, whereas in the other six diets, PBM, MBM and SBM replaced 75% or 100% of the FM. Final body weight (FBW) and specific growth rate (SGR) of the fish fed diets containing PBM (75% and 100%), SBM (75% and 100%) and MBM (75%) were all higher, but not significantly different than those for fish fed the control diet. Replacing 100% of the FM by MBM significantly lowered FBW and SGR. Concerning whole body composition, there were no significant differences in ash and gross energy content of whole-body among fish; fish fed diets containing PBM-100% recorded significantly lower protein content compared with the control diet, while fish fed diet SBM-100% recorded significantly lower moisture content compared with the control diet. Also fish fed diets SBM-100% and PBM-75% recorded higher lipid and gross energy contents compared with the control diet. The study revealed that satisfactory growth and feed utilization responses could be achieved through the replacement of FM by PBM, SBM and MBM in the diet of African catfish.

The present study discusses the Length-Weight Relationship, Condition factor (K) and Relative condition factor(Kn)of the aliencatfish Clarias gariepinus(Burchell, 1822)from Mattupetty reservoir, one of the premier reservoirs located at the high altitude terrains of Kerala. A total of 52 individuals were measured,size ranging from 16 to 63 cm (SL)and 60 to 2550 gm(Weight).Regression coefficient, 'b'for male, female and sexes combined were not signif icantly different from the isometric growth coefficient value,3.Correlation coefficient , 'r' for male and female were 0.9939 and 0.9852(p<0.0001).The meancondition factor (K) for male,female and sexes combined during pre-monsoon, monsoon and post-monsoon were greater than one(K>1). The mean relative condition factor (Kn) for individuals at different seasons was not significantly different. Sexual differences have no significant effect (p>0.05) on length-weight relationship (ANCOVA).

An experiment was conducted to evaluate the changes in haematological parameters from copper sulphate (CuSO4.5H2O) exposed African catfish, Clarias gariepinus with or without simultaneous treatment of water with taurine or garlic extract. Fishes of average weight 98.43± 24.09 g and length 20.5±2.5 cm were selected as test organisms in this study. Fishes were divided into seven groups (I to VII) containing 20 fishes in each group. Significant decrease was reported in the values of Hb concentration, RBC count and PCV in the copper sulphate (4 and 8 ppm) exposed fishes both in respect to con-centration and exposure. The erythrocyte indices MCV, MCH showed significant increase in their values by copper sulphate concentrations when compared to the control group, while MCHC decreased non-significantly (P>0.05) throughout the experimental period. Prevalence of slightly higher values of Hb content, RBC count and PCV and minimum alterations in erythrocyte indices were reported in the blood of copper sulphate treated fish along with 5 ppm each of taurine or garlic extract in comparison to groups treated with copper sulphate alone, however values were still altered when compared with control group I. The reduction in copper induced toxicity on haematological parameters was highest in taurine treated groups followed by garlic extract treatment. The results suggest that taurine and garlic extract have potential to partly mitigate the copper induced stress by modulating the deranged haematological parameters.