Effects of Jatropha Tanjorensis Leaf Meal on the Growth Performance and Physicochemical Parameters of Clarias Gariepinus

Essien, E. A.¹ , Okon, A. O¹ , Udoinyang, E. P.¹ , Legbara, H. D.² , Otukwude F. O.³ , Musa, S. O.⁴

¹Departmentof Animal and Environmental Biology, Faculty of Biological Sciences, University of Uyo, Akwa Ibom State, Nigeria

²Department of Microbiology, Faculty of Biological Sciences, University of Uyo, Akwa Ibom State, Nigeria

³Department of Pure and Industrial Chemistry, Abia State University, Nigeria

⁴Department of Zoology, University of Jos, Plateau State, Nigeria

Corresponding Author Email: emeritusessien49@gmail.coms

DOI : https://doi.org/10.51470/eSL.2025.6.4.14

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1.0.      Introduction

The Nigerian aquaculture industry has existed for approximately fifty years, yet the country still struggles to meet domestic fish production needs. Ita et al. [2], reported that Nigeria possesses about 13 mil of hectares of cultivable water bodies with the potential for aquaculture development. Numerous cultivable indigenous and exotic fish species have also been documented [3].

Fishmeal, soybeans, and maize constitute the major ingredients used in aquaculture feed formulation. Considering the high cost of conventional ingredients and the need to increase profitability for fish farmers, the search for alternative, affordable plant-based feed sources has become imperative. Plant-derived proteins are regarded as the most suitable substitutes for fishmeal in common freshwater fish diets [4]. The by-products of fish and plant protein sources have been identified as viable alternatives. With the increasing global demand for fish protein, a corresponding rise in fish feed production is expected. Plant protein ingredients are now incorporated more widely in aquafeeds due to their relatively low cost and favourable amino acid profile [5].

Jatropha species have been identified as potential low-cost plant sources for fish feed. In Nigeria, Jatropha tanjorensis is popularly referred to as “Hospital too far,” “Catholic vegetable,” [6]. The plant has a high yield potential, producing up to four tons of seed per hectare annually, which can generate about one ton of protein-rich kernel meal [7]. This suggests that Jatropha kernel meal could meet the increasing demand for plant protein in the aquaculture sector. The processed seeds, referred to as Jatropha seed meal, have shown promise; however, their application in animal nutrition has been constrained by toxicity associated mainly with phorbol esters [8]. The meal also contains anti-nutritional factors such as inhibitors, lectins, trypsin and phytates [7].

The toxic effects of Jatropha species are largely attributed to their phytochemical and anti-nutritional components, including saponins, tannins, protease inhibitors, alkaloids, and other toxic compounds that limit their use in animal diets [9]. Nonetheless, studies have shown that heat treatment which is done by solvent extraction can effectively remove phorbol esters and substantially reduce most anti-nutritional factors and toxins present in the plant [10].

Studies on Jatropha leaves generally focuses on distribution and cultivation practices. However, information on J. tanjorensis, a closely related species, and remains limited [11]. Existing studies have demonstrated the effectiveness of Jatropha seed-based diets for Carp (Cyprinus carpio) [12], Rainbow trout (Oncorhynchus mykiss) [13], Nile tilapia (Oreochromis niloticus), and African catfish (Clarias gariepinus) [14].

Fish is one of the majorly patronized nutritious protein sources globally. The rapid growth in human population has further increased its demand. Reports by CMFRI and SAARC [15] identify fish feed as one of the major constraints in aquaculture development and a contributing factor to the declining performance of the agricultural sector. The production of high-quality fish feed is critical to successful aquaculture operations [16]. However, access to quality protein feed ingredients such as soybean meal and fishmeal is increasingly limited due to higher demand for human consumption, industrial use, and livestock feed production [17]. Daily Trust [18] reported an 80 to 100 percent rise in fish feed prices within an eight-year period, forcing many fish farmers, particularly in Lagos State, out of the business. For example, a bag of Bluecrown feed purchased by Okon et al. [19] for N10,500 now costs approximately N24,400, representing an increase of about 138 percent [20].

Clarias gariepinus is one most widely cultured freshwater species in Nigeria due to its rapid growth rate, adaptability to a variety of environmental conditions, hardiness, tolerance to low dissolved oxygen, and ability to thrive in high-density systems [21]. Its high protein content, palatability, and suitability for various Nigerian culinary preparations make it a significant component of the national diet. The species provides an essential source of animal protein, particularly in rural communities facing nutritional deficiencies [22].

For Nigeria to meet the FAO-recommended annual fish consumption rate of 12.5 kilograms per person, the country requires an estimated 1.5 million metric tonnes of fish annually to satisfy basic protein needs [23]. The persistent deficit in fish supply highlights the need for viable alternative ingredients in fish feed formulation to support optimal growth, survival, and nutritive value of cultured fish.

This study aimed to provide food scientists, aquafeed producers, public health professionals, and local farmers with a practical and cost-effective alternative through the utilization of eco-friendly feed ingredients that enhance profitability across the aquaculture value chain. Additionally, the study will contribute baseline data on the blood parameters and biochemical parameters of African Catfishfed Jatropha-based diets. Such data are crucial for evaluating the health status of fish fed Jatropha-derived feed in controlled systems. Considering the limited research on the performance of the growth and physiological responses of C. gariepinus fed Jatropha tanjorensis, this study seeks to fill existing knowledge gaps. Specifically, it evaluates the growth performance and physiological variations of African catfish fingerlings fed graded levels of Jatropha tanjorensis leaves.

2.0.      Materials and Methodology

2.1.      Experimental Location

This study was done in the Dept. of Animal and Environmental Biology, University of Uyo, Akwa Ibom State, Nigeria.

2.2.      Collection and Identification of Plant Material

Fresh branches of Jatropha tanjorensis were collected from naturally growing plants along roadsides in Uyo Local Government Area of Akwa Ibom State. The leaves and stems were subsequently taken to the Herbarium Unit, Department of Botany and Ecological Studies, University of Uyo, for taxonomic confirmation and proper botanical identification.

2.3.      Preparation of Jatropha tanjorensis Leaf Meal (JTLM)

Fresh Jatropha tanjorensis leaves were manually plucked and immersed in water for twenty-four hours to reduce anti-nutritional factors, following the procedure of [24]. The soaked leaves were oven-dried at 45°C for six hours until they became crisp. The dried material was milled into powder using a mechanical grinder and sieved through a 2 mm mesh to obtain a fine leaf meal, while coarse fibers were removed.

2.4.      Preparation of Other Feed Ingredients

Other feed components, including maize meal, soybean seeds, fishmeal, cassava flour, vitamin supplements, and other premixes of minerals were obtained from a commercial feed outlet in Uyo, Akwa Ibom State. The seeds of the soybean were toasted in line with the method reported by Tiamiyu and Solomon [24] and Okomoda et al. [25]. The other ingredients were used as purchased (pre-processed forms).

2.5.      Diet Formulation and Compounding

The powdered Jatropha tanjorensis leaf meal was mixed into a diet at inclusion levels of 0, 5, 10 and 20%. The formulated diets were designated as Control, JTLM 1, JTLM 2, and JTLM 3, respectively. Four iso-nitrogenous and iso-energetic diets were produced by mixing JTLM with soybean meal, maize meal, cassava flour, fishmeal and premixes following standard aquafeed production procedures.

All dry ingredients were homogenized using a milling machine. Warm water was gradually added to take a consistent dough, which was pelleted using a 1 mm pelleting machine and was further sun-dried to maintain a constant weight, allowed to cool, and stored in air-tight, opaque nylon bags until use. The composition in their different experimental diets is presented in Table 1.

2.6 Experimental Design and Feeding Procedure:

A total of 160 fingerlings Clarias gariepinus were obtained from Fish Feed Solution Cooperation, Osuk Ntan, Ibiono Ibom, Akwa Ibom State. The fish were acclimatized for seven days and maintained on a standard diet prior to the commencement of the experiment. Stocking was carried out in twelve experimental tanks arranged in a completely randomized design, representing four feeding treatments in duplicate.

Fish were stocked in eight tarpaulin tanks (100 × 50 cm) at 15 fingerlings per tank. Each tank was filled with 15000 ml of dechlorinated water. Fish were weighed before the initial feeding and subsequently fed twice daily at 07:00 and 18:00 hours at a feeding rate of 5 percent of the weight of their body [26]. On sampling days, feeding was carried out three hours after biometric measurements. Feed quantities were adjusted weekly according to changes in body weight. The water in the tanks was renewed two times, and the feeding trial lasted for ten weeks (70 days).

2.7 Analysis of Physicochemical Properties of Water: The quality of the physicochemical parameters of the water was monitored during the experimental period for pH, temperature, dissolved oxygen (DO), conductivity, , total suspended solids (TSS), and biological oxygen demand (BOD). The pH degree was measured using a pH-meter (Digital Mini-pH Meter, model 55 Fisher Scientific, Denver, CO, USA). The temperatures of the water samples were determined using a mercury-glass thermometer calibrated in o C to 100 °C. The thermometer was dipped into the sample and left for about five minutes for equilibrium before the reading was recorded. DO was measured using an oxygen meter (YSI model 58, Yellow Spring Instrument Co., Yellow Springs, OH, USA). Conductivity was measured using an electrolytic conductivity meter. Total Suspended Solids was determined using the Mohr method as described in APHA [27]. Biological Oxygen Demand (BOD₅) was conducted 5 over five days. 2.8.       Evaluation of Growth Performance and Feed Utilization

The growth performance indices and the utilization of nutrient were calculated using established formulae by Dabrowski [28], Jauncey [29], Jamabo and Alfred-Ockya [30], and Pangni et al. [31]. The parameters were weight gain, feed conversion ratio, protein efficiency ratio, specific growth rate, and other standard growth metrics.

1. Mean weight gain (MWG) (g): This is calculated by subtracting the initial weight from the Final weight.

MWG = Final weight – Initial weight

2. Mean Total Length Gain (MTLG) (cm): This is calculated by subtracting the initial length from the final length.

MTLG = Total Length Gain (cm) = Final Length – Initial Length

3. Mean Standard Length Gain (MSLG) (cm): This is calculated by subtracting the initial length from the final length.

MSLG = Final Standard Length – Initial Standard Length

4. Specific growth rate (SGR) % day^-1: This is the relationship of the difference in the weight of the fish within the experimental period.

SGR (%) =100 × (In final weight – In initial weight) g

                                                                  T

5. Daily growth rate (DGR) g day^-1: This is calculated by the difference between the final weight and the initial weight divided by culturing days

DGR       =         (Final weight – Initial weight)                                                                                                                   T

Where T is the number of days

6. Feed conversion ratio (FCR) (g): This is achieved by dividing the quantity of feed consumed by the weight gained.

=                           Feed consumed (g)                .    

                           (Final weight + Initial weight) (g)

7. Protein Index (PI): This is calculated by subtracting the number of survivors after the experiment from the number stocked, divided by culturing days.

PI = Survival (W₁ – W₂)

                                       Time (days)

8. Survival rate (SR) %: This is the percentage of the number of fish stocked divided by the number of surviving fish at the end of the experiment.  

SR = 100 ×    Final number of fish        .

Initial number of fish

9. Condition Factor (K): This is calculated by multiplying the body weight gain of each treatment by 100 and dividing by the length (centimeter) raised to the power 3

K = Wt × 100

             L³

Where; K         = Condition factor

Wt       = Final body weight

L          = Final Total length

2.11     Statistical Analysis    

The data obtained from the study were subjected to a statistical tool; analysis of variance (ANOVA) to ascertain significant differences in growth rate, haematological variables, and biochemical profile of fish fed different inclusion levels (0%, 5%, 10% and 20%) of JTLM. With the use the IBM-SPSS statistical package of version 22. An acceptable value of p≤0.05 was considered to be statistically significant.

2.12     Ethical Consideration

This study strictly adhered to the principle of Reduction, Refinement, and Replacement (3Rs) to minimize distress and ensure animal welfare. It was followed by internationally accepted ethical principles known as the 3Rs when using animals in research [32].

Reduction: The least number of animals necessary to obtain reliable results. The goal is to avoid unnecessary use of animals while still ensuring the research has enough data to be valid.

Refinement: We improved the experimental methods and care to minimize pain, suffering, or stress for the animals. This was done by changing the water twice weekly as the residuals were polluting the water.

Replacement: If live animals must be used, researchers ensure that there are no suitable alternatives available. There were no suitable alternatives.

3.0.      Results and Discussion

3.1       Results

3.1.1.   Proximate Composition of the Soaked and Oven-dried Jatropha tanjorensis Leaf Meal (JTLM)

Table 2 reveals that the proximate composition of Jatropha tanjorensis leaf meal (JTLM) used in this study contained 25.5% crude protein, crude fibre content of 5.0%, crude fat (20.3%), ash content (9.5%), moisture level (0.9%), and the nitrogen-free extract (38.8%).

3.1.2.   Physicochemical Parameters of Water

The average values across the 10 weeks are presented in Table 3. pH and temperature did not record significant differences across treatments. All pH values remained stable around neutral, and temperature variations were minimal and within the optimal range for Clarias gariepinus. The DO decreased with increasing JTLM inclusion. DO in the 20% JTLM group (4.8 mg L^-1was significantly lower than the control (5.3 mg L^-1). Conductivity increased significantly from 430 µS cm^-1 (0%) to 470 µS cm^-1 (20%). The TSS increased significantly in the 10% and 20% JTLM groups. BOD progressively increased with higher JTLM inclusion. The 20% group (2.6 mg L^-1) had significantly higher BOD than the control (1.8 mg L^-1). All parameters remained within the optimal range for Clarias gariepinus culture throughout the study. No significant adverse variation was observed between treatments.

Note: Values with different superscripts across rows are tagged significantly different at p ≤ 0.05 using Duncan’s Multiple Range Test. JTLM = Jatropha tanjorensis Leaf Meal; DO = Dissolved Oxygen; TSS = Total Suspended Solids; BOD = Biological Oxygen Demand.

Levels of Jatropha tanjorensis Leaf Meal (JTLM)

Note: Superscripts (a, b, c) within rows indicate statistically significant differences (p ≤ 0.05). Values with the same letter are not significantly different, while those with different letters are significantly different

3.1.3.   Growth Performance and Feed Utilization of Clarias gariepinus Fingerlings

The growth indices of Clarias gariepinus fingerlings fed diets containing 0%, 5%, 10%, and 20% JTLM for 10 weeks are shown in Table 4. Each group started with distinct average initial weights and length parameters.

Fish fed 5% and 10% JTLM diets exhibited significantly higher final weights and weight gains (p ≤ 0.05) compared to the control (0%) and 20% groups. These groups were statistically similar, which showed maximum performance. The daily growth rate recorded was in highest in the 5% (0.132 ± 0.01 % g day^-1) JTLM group, followed closely by 10% (0.130 ± 0.01) JTLM group. While the SGR was recorded highest in 10% (1.56 ± 0.03 % g day^-1) JTLM group, followed closely by 5% (1.52 ± 0.03% g day^-1). Both were significantly better than 0% and 20%. Best (lowest) FCR was recorded in the 5% and 10% groups (3.58 ± 0.05 and 3.52 ± 0.06), which were statistically superior to both the 0% (3.94) and 20% (4.18) inclusion levels. For protein index, 5% JTLM group had the highest protein utilization (0.109 ± 0.01g protein g day^-1), followed closely by the 10% group.

The highest K was observed in the control group (1.70). However, fish in all groups maintained a healthy range (>1.0). The survival rate was high across treatments (75.0% to 92.5%), but 20% JTLM (75%) had a significantly lower survival rate than the others. Statistical analysis (ANOVA) revealed significant differences (p ≤ 0.05) in weight gain, DGR, SGR, FCR, PI, and K among treatments. Post hoc Duncan’s test showed that 5% and 10% JTLM groups were significantly better than the 0% and 20% for growth indices.

Figure 1 is a graphical representation of some growth parameters in this study.

3.2.      Discussion

The nutritional composition of a feed ingredient is crucial in determining its suitability for fish diets. The proximate analysis of Jatropha tanjorensis leaf meal (JTLM) used in this study showed the crude protein (25.5%), crude fibre (5.0%), Crude Fat (20.3%), ash (9.5%), moisture (0.9%), and nitrogen-free extract (38.8%). These values were familiar to those reported by Obikaonu et al. [33]. But disagrees with other results [13], with a higher CP level. However, our result was lower than the 35-45% protein requirement of Clarias gariepinus fingerlings [23]. The protein content of JTLM is moderate and suitable for partial inclusion in fish diets, if other components are efficiently composited. However, Clarias gariepinus fingerlings generally require diets with crude protein ranging from 35-45% for optimal growth [23]. While JTLM cannot be used as the sole protein source, its 25.5% protein content is significant for a plant-based supplement and complements higher-protein ingredients such as soybean meal and fishmeal. This makes JTLM a promising alternative or supplemental protein source for cost-effective aqua feeds [34]. They also reported a similar CP value. However, Kumar et al. [12] reported 35.3% and 35.6% crude protein for prepared and raw JTLM. Ugbogu et al. [35] reported similar crude protein of 29.4% for raw Jatropha curcas seeds. It is a well-established fact that protein is given priority in fish feed and production. This is because, among other nutritional requirements, protein is the most required in large amounts and currently expensive amongst all [36], so replacement with a low-cost product without compromising the health of culture organisms or general production output has been a thing of great concern to aquaculturists.

The improved growth performance observed in fish fed diets containing 5% and 10% JTLM aligns with the nutritional adequacy of the protein level. It suggests that at moderate inclusion levels, JTLM can enhance the protein matrix of the feed without causing a nutritional deficiency.

Crude fibre levels in JTLM are relatively high compared to conventional fish feed ingredients. High fibre content can be detrimental to nutrient digestibility and feed conversion, especially in carnivorous fish like C. gariepinus that are not well-equipped to digest large amounts of cellulose and lignin [37]. The decreased growth and increased FCR observed at the 20% inclusion level in this study may be linked to the high fibre content of JTLM. However, fibre also plays a functional role in gut motility and detoxification. At lower inclusion levels (5-10%), the fibre may aid digestion without negatively affecting performance, which supports the higher specific growth rate (SGR) and better FCR observed in these treatments. Excessive fibre, as present in the 20% JTLM diet, likely exceeded the digestive threshold for C. gariepinus, leading to reduced feed utilization efficiency and growth. High fibre can reduce nutrient digestibility and increase FCR, especially in carnivorous fish like C. gariepinus [37].

According to NRC [38], the Crude Fat content of JTLM is modest, indicating the presence of beneficial lipids such as unsaturated fatty acids. Lipids are essential for energy supply, membrane structure, and hormone production in fish [38]. This level is considered modest, providing sufficient energy without risking fat accumulation in tissues. The moderate fat level could explain why diets with JTLM supported reasonable growth without leading to lipid accumulation, especially at 5% and 10% inclusion. Additionally, Jatropha tanjorensis is known to have phytochemicals such as flavonoids and saponins, which may offer antimicrobial and antioxidative benefits, potentially improving overall fish health [39].

The ash content is a function of the total mineral composition. The observed value (9.5%) is acceptable and suggests the presence of essential minerals such as potassium, calcium, magnesium, and phosphorus. Although, thorough screening was not done to that effect, several studies have presented ash content to comprise such minerals [38]. 

The moisture content was within safe limits for storage and feed formulation. Moisture above 12% can promote microbial growth and reduce shelf life [40]. The 9.8% moisture observed suggests that the drying and storage conditions were adequate to maintain feed quality. This supports the high rates of survival recorded in all treatment groups and suggests that spoilage or feed contamination was not a factor influencing growth outcomes.

The NFE reflects the carbohydrate fraction of the leaf meal. While carbohydrates are not essential nutrients for fish, they can provide an inexpensive source of energy, sparing proteins for growth and tissue synthesis. However, Clarias gariepinus has a limited capacity to digest complex plant polysaccharides, so excessive NFE could reduce feed efficiency [40].

The high NFE in JTLM suggests that at higher inclusion levels (20%), excessive carbohydrates may have diluted the energy-protein balance, contributing to reduced performance. In contrast, at 5–10% inclusion, the carbohydrate contribution likely complemented protein energy metabolism effectively, which may explain the better growth indices in those groups [41].

Water quality remained stable and within optimal ranges throughout the trial, as recommended by APHA [27]. Mean temperature in all plastics was ~27–28 °C (optimal 23–32 °C for C. gariepinus and no treatment differences were observed (p>0.05). Similarly, pH was maintained at a neutral level (6.7-7.0) in all groups (permissible 6.0–9.0), with no significant difference (p>0.05). DO remained ≥4.8 mg L^-1in every plastic, which was above the minimal requirement (3 mg L^-1). Other parameters, such as conductivity, total suspended solids, and BOD, showed slight increases with higher Jatropha inclusion. This was likely attributed to organic load from undissolved materials. However, conductivity <500 µS cm^-1, TSS <50 mg L^-1,and BOD <10 mg L^-1 were all below critical limits. These results were similar to studies of formulated feed utilization on Clarias gariepinus fingerlings [42]. The values for DO, temperature and pH were within the optimal need for freshwater fish production [43, 19]. Parameters like temperature, pH, DO, and BOD remained within acceptable limits [28]. Slight increases in BOD and TSS in the 20% JTLM group were likely due to undigested plant material and organic load, as also observed by Silas et al. [44], Fagbenro [45], and Al-Thobaiti [46].

The present study on the growth status of Clarias gariepinus fingerlings fed varied inclusion levels of Jatropha tanjorensis leaf powder meal (JTLM) revealed significant differences (p<0.05) among treatments. Fish fed 10% JLM was considered the best in the culture of C. gariepinus. Studies have recorded the highest in 30% inclusion level [47]. This agrees with a previous study, which showed significantly higher growth response to plant meal when compared with commercial fish meal [46].

All groups started with similar initial weights and lengths. After 70 days, fingerlings fed 5% and 10% JTLM showed the greatest growth. Correspondingly, the SGR and DG were highest in the 10% and 5% treatments respectively and lowest in the 20% group. These trends mirror literature showing improved growth at moderate leaf-meal inclusion as seen in Asuquo and Ifon [47]. They reported SGR increased with the increase levels of J. tanjorensis inclusion (5.5% g day^-1 at 30% inclusion over 4.78% in control); by analogy, our study found that the optimal inclusion range was 10%.

Feed conversion ratios (FCR) were best (lowest) in the 5%–10% groups and worst in the 20% group, indicating more efficient feed use at moderate inclusion. This was in line with Fagbenro et al. [45] and Al-Thobaiti et al. [46], who support plant-based protein inclusion for cost-effectiveness when properly processed. By contrast, the control and 20%. Protein indices followed the same pattern; highest in 10% diets (0.121 g protein g day^-1) and lowest at 20%. This was also a similar trend in the results from Asuquo and Ifon [47].

These patterns are consistent with other studies showing moderate inclusion of Jatropha leaf meal of similar plant supplements; same genus [48]. They submitted that Jatropha can improve catfish growth. He added that 10% Jatropha curcas meal yielded the highest weight gain and lowest FCR in C. gariepinus, and Adesina et al. [49] reported maximal SGR (1.56% g day^-1) and best FCR for a 20% Jatropha diet, with declines at higher levels.

Condition factor K remained within normal range (>1.0) for all groups; fish in the 0% (1.70) and 20% (1.33) groups had slightly higher than the 5% and 10% groups, which reflected their lower length-weight ratios.

Survival was high across treatments, with a slight reduction at 20% (75.0%), likely due to higher anti-nutritional effects at high leaf levels. These growth patterns are consistent with reports on C. gariepinus fed levels of melon (Citrillus lanatus) seed peel meal that ranged between 82-86%. Jimoh et al. [50] also reported similar survival percentages of 82- 91% of Nile tilapia fed toasted Jatropha curcas seed meal. On the contrary, Musa et al. [14] reported 62-79% survival percentages of C. gariepinus fed processed Jatropha curcas kernel.

Overall, the moderate inclusion (5–10%) yielded the highest growth indices and best FCR (lowest values), whereas 20% inclusion gave significantly poorer growth. These findings agree with related studies where low to moderate leaf-meal levels enhance growth, while excessive levels can depress it [48].

The water quality values observed here are typical of healthy catfish culture [14]. The growth trends of best performance at moderate inclusion are supported by earlier reports on J. tanjorensis and other leaf meals [45]. Fagbenro et al. [45], Al-Thobaiti et al. [46], Asuquo and Ifon[47], and other authors showed the need to adopt plant-based protein diets in the culture of fish and other aquatic organisms. Although toxic and other anti-nutritive substances in plant-based feed can affect feed intake with attendant poor growth, drying and conversion to powder has over time, been agreed to be one of the commonest methods adopted to remove anti-nutritional properties in Jatropha leaf meal. This resulted in improvement of the quality of feed, reduction in the cost of production, and growth of fish. Decreased growth, higher FCR, and lower survival in a 20% inclusion level may have resulted from high fibre and anti-nutritional factors such as saponins and tannins, which become problematic at higher levels and reduce palatability and feed intake, as documented by Musa et al. [14] and Jimoh et al. [50] in related Jatropha curcas studies. The findings support the consensus that excessive inclusion of leaf meal suppresses performance.

4.0       Conclusion, and Recommendation

4.1.      Conclusion

The results revealed that diets containing 5% and 10% JTLM significantly caused an improved growth metrics in WG, SGR, FCR, and PI, as in comparison to the control (0%) and the 20% JTLM group. The 10% JTLM group recorded the best overall performance, indicating an optimal balance of protein supplementation and digestibility. Water quality parameters such as pH, temperature, and dissolved oxygen remained within acceptable ranges across treatments, although BOD, TSS, and conductivity showed a slight increase at 20% inclusion. This suggests a threshold above which increased plant material may begin to compromise water quality and fish health. Furthermore, fish survival and condition factor remained high across all treatments, but a notable decline in survival rate at the 20% inclusion level indicates the possible impact of anti-nutritional factors and high fiber content at excessive JTLM incorporation. The proximate composition of JTLM, especially its moderate protein (22.5%), fat (4.3%), and carbohydrate level, supports JTLM as a potential cost-effective, plant-based ingredient in sustainable aquaculture feed formulation when properly included.

4.2.      Recommendations

Based on this and similar studies, it is recommended that Jatropha tanjorensis leaf meal be included at 5% to 10% of total feed composition for Clarias gariepinus fingerlings to achieve optimal growth and feed efficiency without compromising water quality or fish health. Also,

• JTLM should be well-dried, crushed, or fermented to reduce anti-nutritional compound such as tannins, saponins, and phytic acid, thereby improving nutrient availability and palatability.
  To enhance JTLM-based diets, it is recommended to supplement with higher-protein sources like fishmeal, soybean meal, or amino acid concentrates to meet the nutritional requirements of catfish, especially during early growth stages.
• Further studies should be done to examine the long-term effects of JTLM inclusion on their proximate analysis, biochemical, and haematological profiles.
• JTLM should be used in other aquaculture species, such as tilapia or Heterobranchus spp., for broader application.

Acknowledgements: I formally acknowledge the valuable contributions made by parents (Pastor and Dcn. A. O. Essien, my siblings (Victor, Godgreat, and Mkpoikanke), Edua Memorial Diagnostic Laboratory, Uyo, and Kokoette Raymond, Chemistry Department, University of Uyo, for his assistance on the proximate analysis and physicochemical studies.

Conflict of Interest: No author declared ‘’Any conflict of interest’’ regarding the publication and outcomes of this research. All procedures and analyses were conducted solely in pursuit of scientific knowledge and transparency.

Ethical Approval: The authors declared that this research was done in line with all international and/or institutional guidelines for the care and use of animals. The total number of fish used was 160 samples; which did not exceed the limit that is requiring for ethical approval; which is about 200 samples and above for local regulations. For these reasons, no formal ethical approval was needed to conduct this research.

Artificial Intelligence (AI): No AI tools were used in writing this manuscript.

Author’s Contribution

EEA: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Resources, Software, Validation, Writing – original draft, Writing – review & editing

OAO: Conceptualization, Data curation, Investigation, Methodology, Resources, Supervision, Validation, Writing – review & editing

UEP: Conceptualization, Resources, Supervision, Validation, Writing – review & editing

LHD: Methodology, Resources, Funding acquisition, Writing – editing

OOF: Methodology, Resources, Funding acquisition, Writing – editing

MSO: Conceptualization, Resources, Validation, Writing – review & editin

All authors read and approved the final manuscript

Data Availability

The data that support the findings of this study are available from the corresponding author on request.

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