Growth Of Fry Research Articles

Aplikasi Duckweed (Lemna sp) pada Pakan Benih Ikan Lele Mutiara (Clarias gariepinus)

Pearl Catfish (Clarias gariepinus) is a type of freshwater fish that is widely cultivated by many people because of its economic value. Pearl catfish is a new strain of African catfish Clarias gariepinus Burchell, 1822 superior breeding results of the Sukamandi Fish Breeding Research Agency (BPPI) which has been declared passed in the Type / Variety Release Assessment on October 27, 2014, under the name MUTIARA (Peerless High Quality) catfish. This study aims to determine the effect of the addition of duckweed on feed on the growth and survival of pearl catfish fry. The test fish is a pearl catfish measuring 7-10 cm long and weighing 6 gr that is kept in a sized aquarium (120 cm x 50 cm x 40 cm), as many as 9 aquariums, three aquariums as a control, three aquariums for treatment A, three aquariums for treatment B, with each treatment A(5% dry duckweed), treatment B (10% dry duckweed) and treatment K (control) without treatment. . The results showed that dry dukweed can be used as an addition to fish feed, of the three feeds that provide the best growth, namely in the B treatment (10% dry duckweed) has a daily growth rate (GR) of 0.41 g, Specific Growth Rate 2,57%, absolute weight 19 g, absolute length is 11.31 cm with a survival of 90%.

Growth and mortality of sympatric Atlantic salmon and brown trout fry in fluctuating and stable flows

AbstractSub‐daily fluctuations in streamflow may have adverse effects on the biota downstream of dams in hydropeaking‐regulated rivers. Although the stranding of salmonid fry is one documented effect of hydropeaking, little is known about the species‐specific behavioural and subsequent growth effects of sub‐daily flow fluctuations. We investigated the effects of sub‐daily flow fluctuation on growth, mortality and behaviour of sympatric Atlantic salmon (Salmo salar) and brown trout (S. trutta) fry (29–34 mm) in a laboratory experiment. The fluctuating flow treatment negatively affected growth and increased mortality for trout but not for salmon. The level of aggressive behaviour was similar in the fluctuating‐ and stable‐flow treatments. Within the fluctuating flow treatment, there was a trend that more fishes were visibly active above the substrate during low than high flow. These findings suggest that hydropeaking‐induced flow fluctuations may affect fry of different salmonid species in different ways and that brown trout fry may be more vulnerable to hydropeaking effects than Atlantic salmon fry. It can therefore be important to consider the possibility of divergent reactions by different fish species under hydropeaking situations and to incorporate species‐specific strategies to conserve culturally and economically relevant riverine fish species.

Study on Reproductive Behavior and Fry Nursing of Koi Carp (Cyprinus rubrofuscus) in Sunsari, Nepal

A study was conducted emphasizing, the induced breeding techniques, breeding behavior and nursery rearing of koi carp at Everest Aquaponics and fish farm, Sunsari, Nepal. The study was done in the hatchery Unit of EAFF for 36 days including 28 days of fry nursing from 15 May to 26 June. Ten set of brooders in the ratio of 1:2 was used. The average body weight of the female brooders was 910±164.722 gm and a female weighing one kilogram gives approximate 70,219.78 eggs in induce breeding method by hand stripping. The percentage of average fertilization rate was 68.6±3.58 %, the average hatching rate was 75.75 ± 5.9% and average survival of spawn was 66.88±5.84%. The size of the fry after hatching also varied between 2.3-3 mm whereas the fry growth varied from 17- 24mm and the average survivability from fry to fingerling was 88.9±1.59%. The mean final weight of the fry in the nursery tank was 1.0845±0.0353 gm and the average weight gain after 28 days of nursery rearing was 0.9315gm±0.013298gm. The average of the water quality values including temperature was 27.5°C, pH was 7.975, dissolved oxygen was 6.55 mg/L, NO3 concentration was 3.75 mg/L during nursery raising whereas the average water parameters during breeding were 26.75°C, pH of 7.995, DO of 6.25 mg/L, NO3 of 4.375. Successful koi farming can reduce the uncertainty and unavailability of fingerlings, can increase large-scale production for export, and can be a potential area to meet national needs and help increase revenue in foreign currencies. Current research will certainly pave the way for startups to launch commercial production and commercialization of Koi carp in the coming days.

Assessment of the impact of density on the growth of fry (Oncorhynchus mikiss) at the salmon farming station in the Middle Atlas Morocco

The objective of this study is to determine the impact of the load of the nursery ponds (density) on the growth of the rainbow trout fry (Oncorhynchus mikiss), this study was conducted at the fish farming station of Ras Al Ma Ifrane, Morocco. The results obtained for the densities D1 (7.48 Kg / m3), D2 (9.31 Kg / m3) and D3 (11.21 Kg / m3) during this nursery phase which lasted 30 days, the results indicate that the zootechnical parameters evaluated vary according to the density of the fry in different nursery ponds. In average, the final weight of the fry for D1 is 12.73g, for D2, the final average weight is 11.39g against only 9.56g for ponds with density D3. As such, the growth in size of the fry evolves in the same way as the growth in weight.

Lowered nutritional quality of prey decrease the growth and biomolecule content of rainbow trout fry.

Diet quality is crucial for the development of offspring. Here, we examined how the nutritional quality of prey affects somatic growth and the lipid, carbohydrate, protein, amino acid, and polyunsaturated fatty acid content of rainbow trout (Oncorhynchus mykiss) fry using a three-trophic-level experimental setup. Diets differed especially in their content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are physiologically essential polyunsaturated fatty acids for a fish fry. Trout were fed with an artificial diet (fish feed, DHA-rich), marine zooplankton diet (krill/Mysis, DHA-rich), or freshwater zooplankton diet (Daphnia, Cladocera, DHA-deficient). The Daphnia were grown either on a poor, intermediate, or high-quality algal/microbial diet simulating potential changes in the nutritional prey quality (EPA-content). Trout fed with the fish feed or marine zooplankton entirely replaced their muscle tissue composition with compounds of dietary origin. In contrast, fish tissue renewal was only partial in fish fed any Daphnia diet. Furthermore, fish grew five times faster on marine zooplankton than on any of the Daphnia diets. This was mainly explained by the higher dietary contents of arachidonic acid (ARA), EPA, and DHA, but also by the higher content of some amino acids in the marine zooplankton than in the Daphnia diets. Moreover, fatty acid-specific carbon isotopes revealed that trout fry could not biosynthesize ARA, EPA, or DHA efficiently from their precursors. Our results suggest that changes in the zooplankton and macroinvertebrate communities' structure in freshwater habitats from DHA-rich to DHA-poor species may reduce the somatic growth of fish fry.

Effect of vitamin C and mineral enriched diet on growth and survival of Labeo rohita fry

The present study was conducted to understand the effect of vitamin C and mineral enriched diet on growth, survival and mineral accumulation in Labeo rohita fry. The study was conducted for a period of 60 days and it was found that the growth and survival rate increased when local ingredients were fortified with commercially available and commonly used vitamin-mineral mixture, vitamin C and selected mineral elements (Zn, Cu and Mn). The best survival rate (76%) was recorded when feed was supplemented with all the three components (vitamin-mineral mixture, vitamin C and mineral supplement), followed by vitamin-mineral mixture + vitamin C (75.3%) and vitamin-mineral mixture. The Zn, Cu and Mn fortification in the diet also reflected higher deposition of these three minerals in the whole body as well as 38.4% reduction in the cost of production and 152.6% higher revenue generation compared to commercial feed (control). Keywords: Copper, Labeo rohita, Manganese, Vitamin C, Zinc

INDUCED BREEDING AND FRY NURSING OF MYSTUS VITTATUS (BLOCH 1797)

The work is related to optimization of PG dose and survivability of the spawn of Mystus vittatus in the tank nursery at Arabpur Fish Farm in Jessore, Bangladesh during 2000 to 2002. Trial doses of PG used for induced breeding of M. vittatus were 1 to 4 mg PG in the first dose and 4 to 8 mg in the second dose for female. On the other hand, the male fishes were administered only a single trial dose of 2, 3 and 4 mg PG. Induced breeding was successfully done in M. vittatus with 3 mg of PG kg-1 body weight in first dose and 6.0 mg PG in second dose for female and a single dose of 3 mg PG for male for virgin fish, F1 and F2 generation. The tank nursery performance of the fry was studied in regard to length, weight, production and survivability rate. Live animal feeds (rotifers) were used. The highest growth and survivability of the fish fry was obtained by using rotifers of 40 cumm-1 and 20 cumm-1, respectively.

Methionine played a positive role in improving the intestinal digestion capacity, anti-inflammatory reaction and oxidation resistance of grass carp, Ctenopharyngodon idella, fry

A study was carried out to appraisal the function of methionine on intestinal digestion and the health of grass carp (Ctenopharyngodon idella) fry (initial weight 0.36 ± 0.01 g). The fry were fed graded dietary methionine levels (0.33%–1.20% dry matter) in 18 recirculatory tanks (180 L). After an 8-week breeding experiment, the results revealed that 0.71%–1.20% dietary methionine levels markedly upregulated the mRNA levels of intestinal digestion including trypsin, amylase, chymotrypsin and AKP, and 0.71%–0.87% dietary methionine level significantly increased intestinal trypsin activities compared with the 0.33% dietary methionine level. For inflammation, 0.71%–1.20% dietary methionine levels downregulated the mRNA levels of NF-κBp65, IL-1β, IL-6, IL-8, IL-15 and IL-17D, whereas upregulated the mRNA levels of anti-inflammatory cytokines, including IL-4/13B, IL-10 and IL-11. In terms of antioxidants, although dietary methionine levels had no significant effect on the expression of most core genes of the Nrf2/ARE signaling pathway, such as Nrf2, Keap 1, GPx4, CAT, Cu/Zn-SOD. Furthermore, dietary methionine levels had no significant effect on the expression of p38MAPK, IL-12p35, TGF-β2 and IL-4/13A. 0.71%–1.20% dietary methionine levels still increased the mRNA levels of GPx1α, GSTR and GSTP1. Furthermore, higher intestinal catalase activity and glutathione contents were also observed in fry fed 0.71%–1.20% diets. In summary, 0.71%–1.20% dietary methionine levels played a positive role in improving the intestinal digestion capacity of digestion, anti-inflammatory reaction and oxidation resistance of grass carp fry. This study provided a theoretical basis for improving the survival rate and growth of grass carp fry.

PERTUMBUHAN IKAN NILA NIRWANA (Oreochromis niloticus) PADA SISTEM BIOFLOK DENGAN SUMBER KARBON EKSTERNAL DARI TEPUNG SORGUM MANIS (Sorghum bicolor)

Biofloc technology (BFT) is an alternative that can be used to provide additional feed source in addition to control and improve water quality for aquaculture. BFT can be done by adding an organic carbon source to increase the C/N ratio in the culture media to stimulate the growth of heterotrophic bacteria. The results of the observation were that the highest specific growth rate was obtained in treatment B (5ml floc) with an average value of 2.80 grams/day. The highest average length value in treatment B (5ml floc) reached 10.26 cm. The highest survival rate was in treatment B (5ml floc) with an average value of 86.78%. The highest efficiency value was found in treatment B (5ml floc) with an average of 95.90%. Based on Duncan's further test (p<0.05) the application of biofloc with an external carbon source from sweet sorghum had a significant effect on the specific growth rate, absolute growth, survival rate and feed efficiency of tilapia fry. Keywords : Biofloc; Sweet Sorghum; Tilapia Nirwana ; Aquacukture

Effect of Different Stocking Densities on Survival and Growth of Pomfret (Colossoma macropomum)

Freshwater pomfret (Colossoma macropomum) is one of the fishery commodities with high economic value. This encourages the supply of pomfret for consumption to increase, so that the supply of seeds for rearing is also increasing. The purpose of this study was to determine the growth and survival of pomfret fry. The test fish used were Freshwater Pomfret with an initial length of 3 -5 cm with an initial weight of 2.1 - 2.5 grams, which were kept in a 30 liter container. The research method used is an experimental method using a completely randomized design (CRD), consisting of 5 levels of treatment with 3 replications. The results showed that treatment A (stocking density 50 birds/25 liters) showed the highest growth of 4.01 grams, with a length of 5.67cm, survival of 96.67%, and FCR of 6.98 The lowest growth was in treatment P1 ( stocking density of 10 fish/25 liters) was 2.97 grams, with a length of 4.31 cm, survival of 96.67% and FCR of 1.45. The results of observations of water quality measured during the study were still within the tolerance limits for the growth and development of Freshwater Pomfret. From the results of the research conducted, it is known that the best stocking density for growth and survival in the maintenance of Freshwater Pomfret is P5 treatment (stocking density of 50 fish/25 liters) with an average absolute weight of 4.01 grams, a growth rate of 0.100 grams/day. absolute length 5.67 cm. 100% survival. 

Pengaruh Suhu Terhadap Kualitas Larva Dan Pertumbuhan Benih Gurami (Osphronemus gouramy)

Gouramy (Osphronemus gouramy) is a freshwater fishery commodity with a large enough demand and a fairly expensive price compared to other freshwater fish. The purpose of this study was to determine the effect of temperature on larval quality and growth of gouramy fry. The research method used is an experimental method using a Completely Randomized Design (CRD) consisting of two treatments of water media temperature, namely 1) Treatment A = The temperature of the media follows room temperature (control treatment), and 2) Treatment B = The temperature of the medium was set constant at a temperature of 30ᵒC. Each treatment was repeated six times to obtain 12 experimental units. Research parameter data were analyzed statistically using variance (ANOVA) at a 95% confidence level using the t-test. The results showed that the degree of hatching of gouramy eggs, larval size, absolute growth, relative growth, daily specific growth rate and survival rate of gouramy larvae at room temperature and 30°C were 90.38% and 98, respectively. 76%; 0.54 cm and 0.66 cm; 0.86 cm and 0.87 cm; 157.52% and 133.26%; 3.99% and 3.58%; and 74.78% and 91.22%. The study concluded that eggs incubated at room temperature (25-28°C) and 30°C gave significantly different effects on hatching rates and post-hatching larvae size. Larval rearing at room temperature and 30°C gave no significant effect on absolute growth but significantly different on relative growth, daily specific growth rate and survival rate

Addition of turmeric (Curcuma longo LINN) extract on artificial feed to increase feed eficiency and the growth of gouramy fry (Osphronemus goramy

Artificial feed consisting of anting spinach flour (Acalypha indica L) and mung bean sprout waste (Vigna radiata) with the addition of turmeric extract is a fish feed that has not been widely used as a source of vegetable protein raw materials. This study aims to determine the effect of adding turmeric extract (Curcuma longa LINN) to the feed formula on increasing feed efficiency and growth of Osphronemus gourami. Materials and methods, the test fish used was gourami with an average individual weight of 5.04±0.5 g/head. Feeding at 08.00, 12.00 and 16.00 with feeding at satition. The test fish were reared with a stocking density of 13 fish/20 L, using a 30 liter bucket container with a maintenance period of 42 days. This research was conducted by experimental method using Completely Randomized Design (CRD) with 4 treatments and 3 replications. Each treatment contains 31.5-32.33% crude protein. The treatment is A: without spinach anting flour and bean spout flour, B: 100% spinach anting flour and 0% bean sprout flour, C: 50% spinach anting flour and 50% bean sprout pulp flour, D : 100% test feed of bean sprout pulp flour and each treatment was repeated three times. The treatment tested was the same dose of turmeric extract added to the feed with treatments A, B, C and D, each dose was given the same (15 ml/kg feed). The observed data included feed consumption rate (TKP), feed utilization efficiency (FUE), protein efficiency ratio (PER), feed conversion ratio (FCR), protein eficiency ratio (PER), net protein utilization (NPU), relative growth rate (RGR), survival rate ( SR) and water quality. The best EPP treatment was C 95.92±2.49%, and FCR value 1.67±0.03. PER value 3.00±0.077%. NPU value... The treatment with the best growth was treatment C, which was RGR 6.11±0.07%/day. The water quality in the rearing media was in the appropriate range for rearing the test fish.

Enhanced survival and immunity in β-glucan or sodium alginate or thyroxin stimulated fry of bluefin bream, Sparidentax hasta

Bluefin bream (Sparidentax hasta) fry were immunostimulated using β-glucan (BG) or sodium alginate (SA) or thyroxine sodium (Eltroxin™, T4) at 45 mg, 3 g and 0.01 mg per litre, respectively. The fry were stocked @ 15 fry per litre in each one-ton tank under a triplicated random design. The tanks were supplied with filtered aerated seawater. The best enhancement in growth and survival (12.91 ± 3.48%) of fry until 14 dps was with T4 treatment while, BG was better than T4 at 21 dps. Immune parameters suggest a superior performance of the immunostimulated fry in their phagocyte response, lysozyme activity, hemagglutinin, and bacterial agglutinin levels. Expression of IgM, IL-1β and Mx genes were upregulated with T4 and BG treatments at all the three samplings. All the treatments were subjected to a bath challenge test using live Proteus vulgaris (107 colony forming unit (CFU ml−1)). Survival response was the best in fry stimulated with SA and T4 (92% and 88% respectively) followed by BG-stimulated fry (75%). Vaccine efficacy was also improved in immunostimulated fry (60 dph) when treated with BG and T4 with a memory factor (MF) of 1.87 and 1.25, respectively.

Black soldier fly (Hermetia illucens, L.) larvae meal improves growth performance, feed efficiency and economic returns of Nile tilapia (Oreochromis niloticus, L.) fry

AbstractInsects have been proposed as potential alternative animal protein sources to replace fishmeal (FM), which is expensive and has limited availability for fish feed formulation. However, studies on the effects of replacing FM with black soldier fly (Hermetia illucens) larvae (BSF‐L) on growth performance of Nile tilapia (Oreochromis niloticus) fry, water quality and economic benefits are currently limited. This study determined the effects of replacing 100% FM, 75% FM, 50% FM, 25% FM and 0% FM with cheap BSF‐L meal, hereafter referred to as BSF‐L0, BSF‐L25, BSF‐L50, BSF‐L75 and BSF‐L100 diets, respectively for rearing all‐male Nile tilapia fry produced by YY technology. The study further determined the optimum percentage of BSF‐L meal for maximum growth of Nile tilapia fry. A total of 2400 visually healthy Nile tilapia fry weighing 0.001 g were randomly stocked into 20 plastic tanks (120 fry per tank, four replicates per treatment) and fed the BSF‐L diets for 12 weeks. The BSF‐L75 diet increased significantly specific growth rate, total weight gain, Zihler's index of fry and nitrate in the culture water but reduced feed conversion ratio of diet and total suspended solids in the culture water (p < 0.05). Feeding the Nile tilapia fry with BSF‐L50 diet increased significantly hepatosomatic index (p < 0.05). The diets with BSF‐L75 and BSF‐L100 reduced significantly the incidence cost by 31.97% and 28.77% (p < 0.05), and increased profit index by 3.97 and 3.44%, respectively. The optimum percentage of BSF‐L inclusion required for maximum growth performance of Nile tilapia fry was estimated as 81% to 84% based on polynomial analysis. Taken together, feeding Nile tilapia fry with diets containing 81% to 84% BSF‐L meal improved growth performance. The BSF‐L75 diet enhanced feed efficiency and had no deleterious effect on the liver and intestines. Meanwhile, it improved nitrate concentration for increased natural productivity. Incorporating 75% BSF‐L meal in diets for Nile tilapia fry reduced 30% of feed cost leading to 4% higher economic returns.

Dietary protein:lipid ratio modulates somatic growth and expression of genes involved in somatic growth, lipid metabolism and food intake in Pejerrey fry (Odontesthes bonariensis)

Pejerrey is a freshwater fish from South America with high potential for aquaculture. This study was designed to determine the effects of different dietary protein:lipid ratio on growth rate and the expression of growth, lipid metabolism and feeding-related genes of this species during early developmental stages. Pejerrey fry were fed for 60 days with four experimental diets containing low (400 g Kg−1) or high (500 g Kg−1) protein (LP or HP, respectively) and low (120 g Kg−1) or high (200 g Kg−1) lipid (LL or HL, respectively), in the combinations: LP-LL; LP-HL; HP-LL and HP-HL. Measurements of growth, lipid and fatty acid content of fry, expression of genes from the endocrine axis (gh, ghrs, igfs), fatty acid metabolism (∆6-desaturase), and food intake behavior (nucb2/nesfatin-1) were collected. Fry fed with diets LP-LL and HP-LL showed the highest growth rate and growth hormone (gh) mRNA expression levels. The gene expression of ∆6-desaturase was high in head of fry fed with diet LP-HL. The mRNA expression of nucb2/nesfatin-1 and gh followed the same patterns in head, and the inverse pattern in body. In conclusion, diets with LL ensure a higher growth of pejerrey fry compared to those that contain HL, without altering the final lipid amount nor the fatty acid profile on fry. In LL groups, the expression of genes from the GH-IGF axis is associated with the observed promotion of somatic growth. The expression of nucb2/nesfatin-1 indicates an effect of this peptide not related to food intake regulation, e.g., a negative regulatory role on GH expression, that would warrant future research.

VARIASI PADAT PENEBARAN DAN PENGGUNAAN LARUTAN DAUN KETAPANG (Terminalia catappa L) TERHADAP PERTUMBUHAN BENIH IKAN NILA (Oreochromis niloticus)

This study aimed to determine the effect of stocking density, the dose of ketapang leaf solution (Terminalia catappa L.) and the interaction between stocking density and dose of ketapang leaf solution (Terminalia catappa L.) on the growth of tilapia fish (Oreochromis niloticus). This research was conducted in July-August 2022 for 30 days, located on Jl RO Ulin Gang Sapta Warga Rt.07 Rw.02 Banjarbaru City. This study used a factorial completely randomized design method with 2 levels of Factor A (10 and 15 stocking densities) and 2 levels of Factor B (dose of ketapang leaf solution 2ml/l and 3 ml/l) with 3 repetitions (2x2x3). The treatments obtained were A1B1 (10 stocking density and 2ml/l ketapang leaf solution), A1B2 (10 stocking density and 3ml/l ketapang leaf solution), A2B1(15 stocking density and 2ml/l ketapang leaf solution dose). ) and A2B2 (stocking density of 15 individuals and the dose of ketapang leaf solution was 3ml/l). The fish used is tilapia seeds measuring 3-5 cm. In the results of the stocking density study, the dose of ketapang leaf solution had no significant effect on absolute growth and relative growth of tilapia fry. However, the interaction between stocking density and dose of ketapang leaf solution had a significant effect on the survival of tilapia.

Optimal methionine supplementation improved the growth, hepatic protein synthesis and lipolysis of grass carp fry (Ctenopharyngodon idella)

Six experimental diets with graded methionine levels (0.33%, 0.55%, 0.71%, 0.87%, 1.03%, 1.20%, dry matter) were formulated to quantify the dietary methionine requirement, and assess the influence of dietary methionine levels on the metabolism of protein and lipid in Ctenopharyngodon Idella fry (initial weight 0.36 ± 0.01 g) during an 8-week feeding trial. The results showed that 1.03% dietary methionine significantly improved the growth performance, protein efficiency ratio and feed utilization, compared with 0.33% methionine. Dietary methionine supplementation slightly increased survival rate. 0.55%–0.87% methionine level increased the phosphorylated protein and mRNA levels of phosphatidylinositol 3-kinase (PI3K), target of rapamycin (TOR), eukaryotic initiation factor 4E binding protein-1 and ribosomal protein S6 kinase 1. Compared with 1.20% methionine, 0.55%–0.87% methionine levels significantly increased mRNA levels of hepatic insulin-like growth factor-1 (IGF-1), carnitine palmitoyl transferase-1, peroxisome proliferator-activated receptor α, adipose triglyceride lipase and hormone sensitive lipase. The highest mRNA levels of hepatic acetyl-CoA carboxylase, sterol regulatory element-binding protein 1, stearyl-CoA desaturase and fatty acid synthetase were observed in 0.33% methionine diet. Based on specific growth rate and feed conversion ratio, the dietary methionine requirement of grass carp fry was 1.03% of diet (2.67% of dietary protein), using the broken-line regression analysis. Suitable dietary methionine could improve the growth, feed utilization and lipolysis of fry and promote protein synthesis via the IGF-1/PI3K/TOR pathway. While methionine deficiency tended to enhance hepatic lipid synthesis.

Effect of papaya (Carica papaya) leaf extract as dietary growth promoter supplement in red hybrid tilapia (Oreochromis mossambicus × Oreochromis niloticus) diet

The purpose of this experiment was to examine the potential use of Carica papaya leaf extract as a supplement to promote growth and improve feed utilization in red hybrid tilapia. Five diets were formulated containing isolipidic (80 g/kg) and isonitrogenic (350 g/kg) levels. All feeds contained similar types and amounts of raw materials but differed in the inclusion of papaya leaf extract (0, 5, 10, 20 and 40 g/kg feed). The initial size of fish used was 2.3 ± 0.01 g. Each diet was performed in triplicate tanks, and the feeding period was 12 weeks. Fish fed diet containing 2% papaya leaf extract (PLE) had the highest final weight, 31.14 ± 1.47 g, followed by 1% PLE (27.27 ± 1.75 g). These two diets (1% and 2%) were also showed significant improvements of weight gain, SGR, and feed efficiency of the red hybrid tilapia (p < 0.05). However, papaya leaf extract did not affect the HSI, VSI, PER, digestive enzymes activity, blood composition, and survival rate. Supplementing the diets with papaya leaf extract lowered serum urea. Findings of this research suggest that adding papaya leaf extract to the diet of red hybrid tilapia improves growth and feed efficiency without adversely affecting blood parameters. Therefore, an inclusion level between 1% and 2% of the papaya leaf extract is recommended as a feed additive to promote red hybrid tilapia fry growth.

Comparative growth performance and survival of hatchery-reared African catfish fry (Clarias gariepinus Burchell 1822) fed on live and artificial diets

Background: Feed determines to a large extent, the sustainability in aquaculture since the survival and growth of the fish fry depends on the quality of feeds. The comparative growth performance and survival in Clarias gariepinus fry fed with live and artificial feeds were carried out. Methods: Four hundred and eighty healthy fries collected from a commercial hatchery were randomly divided into four experimental groups of 40 fry with three replicates for each group, and fed with four different feeds (three live feeds and one artificial feed) to differentiate each group; Artemia Lush® (AL), Artemia Inve® (AI), Dried-ground Shrimp (S), and artificial feed Durante® (D) for three weeks. The proximate composition of feed samples was analyzed, Physico-chemical parameters and microbiological analysis of water in experimental tanks were analyzed on a weekly basis. The fish were assessed for growth performance and survival on a weekly basis. Results: There was a significant difference of P< 0.05 in all proximate compositions of the feeds analyzed, there was no significant difference (P> 0.05) in the Physico-chemical parameters of water in the experimental tanks within twenty-one days. The final weight, final length, specific growth rate, and survival of fry fed with live feeds Artemia were similar to artificial feed Durante®, but the economic analysis was reduced in artificial feed compared to live feeds while fry fed with Dried-ground Shrimp had poor growth and survival rate. Conclusion: The feeding of live and artificial feeds to Clarias gariepinus fry within the first twenty-one days produced a similar growth response and survival rate but an artificial diet required reduced cost than live diets, while dried-ground shrimp should not be recommended for feeding Clarias gariepinus fry.

Eco-engineering approach for color image processing determination of the number of hydrobionts and eggs on a flat surface

The number of objects (eggs) on a flat surface is determined. The method of processing color images in the MathCad software medium is applied. Using the “READRGB” operator, the constructed digital matrix of the image of caviar laid in one layer on a plain substrate is isolated. By applying the “submatrix” operator, the array area corresponding to one object (an egg) and the average size in pixels is determined. This method of determining the number of hydrobionts and eggs on the plane can be used to develop methods of technological record in such an area of agriculture as fish farming: planning the growth of fry, obtaining larvae during artificial reproduction, obtaining planting material for growing and feeding fish.