Oyedapo Fagbenro | Federal University of Technology Akure (original) (raw)

Papers by Oyedapo Fagbenro

Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental stat... more Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental station in Onikan (Lagos State) and various Tilapia species were used (Longhurst 1961). Modern pond culture started with a pilot fish farm (20 ha) in Panyam (Plateau State) for rearing the common/mirror carp, Cyprinus carpio (Olaniyan 1961; Ajayi 1971), following the disappointing results with tilapias. Although the first years of Panyam fish farm's existence were hardly satisfactory, the trials nevertheless generated sufficient interest that regional governments established more fish farms. Small-scale farms comprise a large proportion of aquaculture ventures ranging from homestead concrete ponds (25-40 m 2) operated by individual farmer or family to small earthen ponds (0.02-0.20 ha) operated as part-time or off-season occupation by communities, institutions, associations or cooperative societies (Anyanwu et al. 1989). The available water surface suitable for aquaculture was estimated as 483,406 ha (Ita et al. 1985). Both indigenous and introduced species are cultivated in ponds, reservoirs and cages. Tilapias, clariid catfishes and the common/mirror carp have always been the most widely cultured fish in Africa (Dada 1975; Sagua 1976; Satia 1990; Vanden Bossche & Bernacsek 1990) and are suited to low-technology farming systems in many other developing countries. This is because of their fast growth rate, efficient use of natural aquatic foods, propensity to consume a variety of supplementary feeds, omnivorous food habits, resistance to disease and handling, ease of reproduction in captivity, and tolerance to wide ranges of environmental conditions (Fagbenro 1987a). One thing that is apparent from recent studies on tilapia that have relevance to aquaculture is that the most commonly studied species at present is O. niloticus (Linnaeus). It accounts for 64% of world production by weight, followed by O. mossambicus (10%), O. aureus (Steindachner) (3.6%) and O. andersonii (0.4%); while production by unspecified species is 2.7%. According to Adesulu (1997), the species and hybrids cultured in Nigeria are: O. niloticus; O. aureus; S. galilaeus (Artedi); S. melanotheron (Ruppell); T. zillii (Gervais); T. guineensis (Dumeril); O. niloticus x O. aureus. However, they are yet to reach their full aquaculture potential because of the problems of precocious maturity and uncontrolled reproduction, which often results in the overpopulation of production ponds with young (stunted) fish.

Journal of the World Aquaculture Society, 1994

Acetone-dried hypophyses from the common toad and bullfrog administered intramuscularly was an ef... more Acetone-dried hypophyses from the common toad and bullfrog administered intramuscularly was an effective inducing agent for spawning the African catfish Clarias gariepinus held in cisterns. A dosage schedule of 4-6 mg dry gland/kg female catfish applied in two installments (equal doses) is recommended. Toad and frog hypophyses were as good as or better than human chorionic gonadotropin or homoplastic injection to induce spawning of C. gariepinus under ambient temperature conditions (28-30 C).

Journal of Urban and Environmental Engineering, 2017

Thermal anomalies in built environments, known as Urban Heat Islands (UHI), are studied with sate... more Thermal anomalies in built environments, known as Urban Heat Islands (UHI), are studied with satellite-derived data. However, this information is insufficient to examine regions such as the Aburra Valley, where the city of Medellin is located. In this valley, atmospheric interferences are common and the rugged terrain influences the amount of solar radiation reaching the surface, which hinders the analysis of the UHI. Unmanned Aerial Vehicles (UAVs) can be used to obtain the Land Surface Temperature (LST) at a time and location that is more convenient. In this project, a UAV was equipped with a thermal sensor to collect data on natural (ground vegetation and trees) and artificial (concrete, asphalt, and clay roof tiles) land cover types in Medellin, Colombia. The thermal information provided by the drone overcame the limitations of the satellite-derived data in terms of spatial, temporal, and radiometric resolution. This data enabled the study of specific land-cover types in differe...

Journal of Applied Aquaculture, 2004

Page 1. Use of High Percentages of Soy Protein Concentrate as Fish Meal Substitute in Practical D... more Page 1. Use of High Percentages of Soy Protein Concentrate as Fish Meal Substitute in Practical Diets for African Catfish, Clarias gariepinus (Burchell 1822): Growth, Diet Utilization, and Digestibility Oyedapo A. Fagbenro Simon J. Davies ABSTRACT. ...

Aquacultural Engineering, 1995

Fermented fish silage was prepared from whole mixed-sex tilapia (Oreochromis niloticus), 15% mola... more Fermented fish silage was prepared from whole mixed-sex tilapia (Oreochromis niloticus), 15% molasses and 5% Lactobacillus plantarum starter culture and used as protein source in tilapia diets. Four alternative binders (carboxymethyl cellulose, corn starch, guar gum or ...

Journal of Applied Ichthyology, 1990

... (1988). Non-detection of lactase, an enzyme associ-ated with milk digestion in mammals, in th... more ... (1988). Non-detection of lactase, an enzyme associ-ated with milk digestion in mammals, in the entire gut regions. validates the suggestion of OLATUNDE and OGUNBIYI (1977) that it is not commonly found in teleosts. ... OLATUNDE OGUNBIYI (1977) AKIN-(1985) TUNDE ...

Pakistan Journal of …, 2007

Abstract: The replacement value of palm oil for codliver oil in diets for juvenile African catfis... more Abstract: The replacement value of palm oil for codliver oil in diets for juvenile African catfish (initial weight 24.04 g) was investigated. For 8 weeks, fish were fed experimental diets in which there was either 9% codliver oil (Diet 1), 6% codliver oil, 3% palm oil (Diet 2), 3% ...

There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproduc... more There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproductive inhibitory agents in plants because they are less expensive and constitutes appropriate technology in developing countries. Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5MJ gross energy/kg diet) at 0, 0.5, 1.0, 1.5 or 2.0 g/kg diets and fed to mixed-sex Tilapia zillii for 60 days to evaluate the effects on growth and feed utilization, reproduction traits, and histology of gonads. There were no significant variations (p>0.05) in the growth parameters and food conversion ratio. Indices of reproduction traits decreased with increasing dietary NLM levels. Fish fed with the control diet had significantly higher and better indices of reproduction traits (P<0.05) than the fish fed with NLM diets. Fish fed 0g NLM/kg diet showed normal testicular and ovarian tissues, and no pathological lesions occurred. Fish fed 0.5g NLM/kg diet showed...

Animal Research …, 2008

Reference values for some haematological indices of Parachanna obscura, Malapterurus e ectricus a... more Reference values for some haematological indices of Parachanna obscura, Malapterurus e ectricus and Malapterurus minjiriya were determined. The mean ± SD values for erythrocyte count (Ec), leucocyte count (Lc), haematocrit (Hct), haemoglobin concentration (Hbc), erythrocyte sedimentation rate (ESR), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and plasma protein content (g/dl) determined for P. obscura were 2.

Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental stat... more Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental station in Onikan (Lagos State) and various Tilapia species were used (Longhurst 1961). Modern pond

Animal Research International, 2008

A total of 791 elephant fish, Mormyrus rume specimens of various sizes were sampled from River Os... more A total of 791 elephant fish, Mormyrus rume specimens of various sizes were sampled from River Ose, southwestern Ngera. Length-weight relationship and condition factor of the M rume specimens were studied. Their standard lengths ranged from 15.0 to 45.0 cm. Mean standard lengthfor males, females and combined sex were 27.86 cm, 3008 cm and 28.97 cm, respectvely. The body weight ranged from 75.5 to 610.0 g Mean body weight for males, females and combinedsex were 167.57 g 237.38 g and 202.48 g respectvely. Lengh-weight relatonship for males, emales andcombined sex were 1.699, 2.134 and 1990, respectively. The fsh exhibited alometrcgrowth in the river. The predictive equation was log W = -0.636 + 199 log L. The mean condition factor varied between seasons. The mean condition for males, females and combined sex were 0.787, 0.859 and 0.823, respectvely. The condtion factor decreased with increase in ndvidual sizes. Keywords : Length-weight relationship, Condition factor, Mormyrus rume , R...

There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproduc... more There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproductive inhibitory agents in plants because they are less expensive and constitutes appropriate technology in developing countries. Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5MJ gross energy/kg diet) at 0, 0.5, 1.0, 1.5 or 2.0 g/kg diets and fed to mixed-sex Tilapia zillii for 60 days to evaluate the effects on growth and feed utilization, reproduction traits, and histology of gonads. There were no significant variations (p >0.05) in the growth parameters and food conversion ratio. Indices of reproduction traits decreased with increasing dietary NLM levels. Fish fed with the control diet had significantly higher and better indices of reproduction traits (P<0.05) than the fish fed with NLM diets. Fish fed 0g NLM/kg diet showed normal testicular and ovarian tissues, and no pathological lesions occurred. Fish fed 0.5g NLM/kg diet showe...

ag.arizona.edu

Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5M... more Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5MJ gross energy/kg diet) at 0, 0.5, 1.0, 1.5 or 2.0 g/kg diets and fed to mixed-sex Tilapia zillii for 60 days to evaluate the effects on histology of the testes and ovaries. Male T. zillii fed 0g NLM/kg diet showed normal testicular tissues; and no pathological lesions occurred. Fish fed 0.5g NLM/kg diet showed alteration in testicular architecture and cystic seminiferous tubules. Fish fed 1.0g NLM/kg diet showed severe testicular atrophy. Fish fed 1.5g NLM/kg diet exhibited cystic seminiferous tubule and atrophy of tissue. Fish fed 2.0g NLM/kg diet showed severe tissue atrophy, sperm cells disintegration and necrosis. Female T. zillii fed with control diet (0g NLM/kg diet) showed normal ovary histology and no pathological lesions were observed. Typical bilateral lobes of the ovaries were evident and with normal olive green colour of ovaries. Fish fed 2.0g NLM/kg diet revealed ovarian colour change. There was evidence of hydropic degeneration, ruptured follicle, granulomatous inflammation in the insterstitium and necrosis. Histological observations of testes and ovaries in T. zillii fed high dietary NLM levels revealed that neem leaves may be effective as sterility-inducing agents as they were destructive to testes and ovaries tissues.

Digestive enzyme assays in the different gut regions (oesophagus, stomach, caecum, duodenum, ileu... more Digestive enzyme assays in the different gut regions (oesophagus, stomach, caecum, duodenum, ileum, and rectum) of three commercial African freshwater fish species: Nile tilapia Oreochromis niloticus, African snakehead fish Parachanna obscura, and African long knife fish, Gymnarchus niloticus, revealed an array of glycosidases (amylase, sucrase, maltase, lactase, and cellulase); proteases (chymotrypsin, pepsin, and trypsin) and lipases. The pattern of distribution and relative activity of the enzymes showed that the fishes are capable of digesting carbohydrates, proteins and lipids such that they complemented the different dietary habits of the three fish species. Enzyme activity was not detected in the oesophagus and rectum of the three fish species. The relative distribution and activity of the various enzymes were possibly induced by the nutritional requirements of the fishes.

Raw heads of the river prawn, Macrobrachium vollenhovenii, were fermented with Lactobacillus plan... more Raw heads of the river prawn, Macrobrachium vollenhovenii, were fermented with Lactobacillus plantarum at 30 °C using molasses or cassava starch as the carbohydrate source. After incubation for 7 days, a desirable and stable pH w w ) and solar-dried. The dried shrimp head silage meals were incorporated as protein supplements into pelleted semi-purified diets for catfish, Clarias gariepinus. Apparent digestibility coefficients of dry matter, crude protein, gross energy and essential amino acids in the silage by catfish fingerlings was high (> 70%). It was concluded that dried fermented fish silage is suitable and has a potential as a protein feedstuff in fish diets.

The dietary habits of the giant African clariid catfish, Heterobranchus bidorsalis (Geoffroy St. ... more The dietary habits of the giant African clariid catfish, Heterobranchus bidorsalis (Geoffroy St. Hilaire 1809) inhabiting Owena Reservoir (Southwestern Nigeria) were investigated. Stomach content analyses established that it had an euryphagous diet. The diet comprised mainly plankton, insects, fish and detritus although, plant parts, benthic invertebrates and tadpoles were consumed. Detritus was very prominent accounting for between 68.1–74.5% occurrence and 13.9–19.6% volume in all sizes of fish examined, which indicated that it was a benthic feeder. There was a progression from planktivorous diet in fish below 12 cm standard length (SL) through a transitional insectivorous phase (SL, 12–27 cm) to a predominantly piscivorous diet in fish above 27 cm SL. It was capable of filter feeding only when young but later became predatory, consuming appropriately sized prey organisms as it grew older. No seasonal variation was established in food preference of any size of fish.

ABST CT Analyses of stomach contents of 330 Malapterurus electricus (Standard length, 10.1-30.5cm... more ABST CT Analyses of stomach contents of 330 Malapterurus electricus (Standard length, 10.1-30.5cm) in Mahin Lagoon (Southwestern Nigeria) established it as a bottom feeder. There was a preponderance of insects accounting for >80% occurrence and > 25% of total volume in stomachs of specimens, suggesting a stenophagous predatory habit. Qualitative and quantitative assays of digestive enzymes in the different regions of the gut (oesophagus, stomach, doudenum, ileum, rectum) were investigated. CarbohydraseS (amylase, maltase), chitinase, proteases (pepsin, chymotrypsin, trypsin) and lipases were detected in different gut regions with different activity. The pattern of distribution and relative activity of the enzymes correlated with his predatory diet.

Aquaculture Nutrition, 1995

... g kg-' and triplicate samples were taken for chemical analysis (Table 1). In experiment ... more ... g kg-' and triplicate samples were taken for chemical analysis (Table 1). In experiment 1, CPHM replaced maize at 0%, 15%, 30% or 45% dry weight in ... Theobromine was extracted with chloroform and analysed according to the methods described by Delbeke & Debackere (1991 ...

Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental stat... more Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental station in Onikan (Lagos State) and various Tilapia species were used (Longhurst 1961). Modern pond culture started with a pilot fish farm (20 ha) in Panyam (Plateau State) for rearing the common/mirror carp, Cyprinus carpio (Olaniyan 1961; Ajayi 1971), following the disappointing results with tilapias. Although the first years of Panyam fish farm's existence were hardly satisfactory, the trials nevertheless generated sufficient interest that regional governments established more fish farms. Small-scale farms comprise a large proportion of aquaculture ventures ranging from homestead concrete ponds (25-40 m 2) operated by individual farmer or family to small earthen ponds (0.02-0.20 ha) operated as part-time or off-season occupation by communities, institutions, associations or cooperative societies (Anyanwu et al. 1989). The available water surface suitable for aquaculture was estimated as 483,406 ha (Ita et al. 1985). Both indigenous and introduced species are cultivated in ponds, reservoirs and cages. Tilapias, clariid catfishes and the common/mirror carp have always been the most widely cultured fish in Africa (Dada 1975; Sagua 1976; Satia 1990; Vanden Bossche & Bernacsek 1990) and are suited to low-technology farming systems in many other developing countries. This is because of their fast growth rate, efficient use of natural aquatic foods, propensity to consume a variety of supplementary feeds, omnivorous food habits, resistance to disease and handling, ease of reproduction in captivity, and tolerance to wide ranges of environmental conditions (Fagbenro 1987a). One thing that is apparent from recent studies on tilapia that have relevance to aquaculture is that the most commonly studied species at present is O. niloticus (Linnaeus). It accounts for 64% of world production by weight, followed by O. mossambicus (10%), O. aureus (Steindachner) (3.6%) and O. andersonii (0.4%); while production by unspecified species is 2.7%. According to Adesulu (1997), the species and hybrids cultured in Nigeria are: O. niloticus; O. aureus; S. galilaeus (Artedi); S. melanotheron (Ruppell); T. zillii (Gervais); T. guineensis (Dumeril); O. niloticus x O. aureus. However, they are yet to reach their full aquaculture potential because of the problems of precocious maturity and uncontrolled reproduction, which often results in the overpopulation of production ponds with young (stunted) fish.

Journal of the World Aquaculture Society, 1994

Acetone-dried hypophyses from the common toad and bullfrog administered intramuscularly was an ef... more Acetone-dried hypophyses from the common toad and bullfrog administered intramuscularly was an effective inducing agent for spawning the African catfish Clarias gariepinus held in cisterns. A dosage schedule of 4-6 mg dry gland/kg female catfish applied in two installments (equal doses) is recommended. Toad and frog hypophyses were as good as or better than human chorionic gonadotropin or homoplastic injection to induce spawning of C. gariepinus under ambient temperature conditions (28-30 C).

Journal of Urban and Environmental Engineering, 2017

Thermal anomalies in built environments, known as Urban Heat Islands (UHI), are studied with sate... more Thermal anomalies in built environments, known as Urban Heat Islands (UHI), are studied with satellite-derived data. However, this information is insufficient to examine regions such as the Aburra Valley, where the city of Medellin is located. In this valley, atmospheric interferences are common and the rugged terrain influences the amount of solar radiation reaching the surface, which hinders the analysis of the UHI. Unmanned Aerial Vehicles (UAVs) can be used to obtain the Land Surface Temperature (LST) at a time and location that is more convenient. In this project, a UAV was equipped with a thermal sensor to collect data on natural (ground vegetation and trees) and artificial (concrete, asphalt, and clay roof tiles) land cover types in Medellin, Colombia. The thermal information provided by the drone overcame the limitations of the satellite-derived data in terms of spatial, temporal, and radiometric resolution. This data enabled the study of specific land-cover types in differe...

Journal of Applied Aquaculture, 2004

Page 1. Use of High Percentages of Soy Protein Concentrate as Fish Meal Substitute in Practical D... more Page 1. Use of High Percentages of Soy Protein Concentrate as Fish Meal Substitute in Practical Diets for African Catfish, Clarias gariepinus (Burchell 1822): Growth, Diet Utilization, and Digestibility Oyedapo A. Fagbenro Simon J. Davies ABSTRACT. ...

Aquacultural Engineering, 1995

Fermented fish silage was prepared from whole mixed-sex tilapia (Oreochromis niloticus), 15% mola... more Fermented fish silage was prepared from whole mixed-sex tilapia (Oreochromis niloticus), 15% molasses and 5% Lactobacillus plantarum starter culture and used as protein source in tilapia diets. Four alternative binders (carboxymethyl cellulose, corn starch, guar gum or ...

Journal of Applied Ichthyology, 1990

... (1988). Non-detection of lactase, an enzyme associ-ated with milk digestion in mammals, in th... more ... (1988). Non-detection of lactase, an enzyme associ-ated with milk digestion in mammals, in the entire gut regions. validates the suggestion of OLATUNDE and OGUNBIYI (1977) that it is not commonly found in teleosts. ... OLATUNDE OGUNBIYI (1977) AKIN-(1985) TUNDE ...

Pakistan Journal of …, 2007

Abstract: The replacement value of palm oil for codliver oil in diets for juvenile African catfis... more Abstract: The replacement value of palm oil for codliver oil in diets for juvenile African catfish (initial weight 24.04 g) was investigated. For 8 weeks, fish were fed experimental diets in which there was either 9% codliver oil (Diet 1), 6% codliver oil, 3% palm oil (Diet 2), 3% ...

There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproduc... more There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproductive inhibitory agents in plants because they are less expensive and constitutes appropriate technology in developing countries. Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5MJ gross energy/kg diet) at 0, 0.5, 1.0, 1.5 or 2.0 g/kg diets and fed to mixed-sex Tilapia zillii for 60 days to evaluate the effects on growth and feed utilization, reproduction traits, and histology of gonads. There were no significant variations (p>0.05) in the growth parameters and food conversion ratio. Indices of reproduction traits decreased with increasing dietary NLM levels. Fish fed with the control diet had significantly higher and better indices of reproduction traits (P<0.05) than the fish fed with NLM diets. Fish fed 0g NLM/kg diet showed normal testicular and ovarian tissues, and no pathological lesions occurred. Fish fed 0.5g NLM/kg diet showed...

Animal Research …, 2008

Reference values for some haematological indices of Parachanna obscura, Malapterurus e ectricus a... more Reference values for some haematological indices of Parachanna obscura, Malapterurus e ectricus and Malapterurus minjiriya were determined. The mean ± SD values for erythrocyte count (Ec), leucocyte count (Lc), haematocrit (Hct), haemoglobin concentration (Hbc), erythrocyte sedimentation rate (ESR), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and plasma protein content (g/dl) determined for P. obscura were 2.

Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental stat... more Aquaculture in Nigeria The first attempt at fish farming was in 1951 at a small experimental station in Onikan (Lagos State) and various Tilapia species were used (Longhurst 1961). Modern pond

Animal Research International, 2008

A total of 791 elephant fish, Mormyrus rume specimens of various sizes were sampled from River Os... more A total of 791 elephant fish, Mormyrus rume specimens of various sizes were sampled from River Ose, southwestern Ngera. Length-weight relationship and condition factor of the M rume specimens were studied. Their standard lengths ranged from 15.0 to 45.0 cm. Mean standard lengthfor males, females and combined sex were 27.86 cm, 3008 cm and 28.97 cm, respectvely. The body weight ranged from 75.5 to 610.0 g Mean body weight for males, females and combinedsex were 167.57 g 237.38 g and 202.48 g respectvely. Lengh-weight relatonship for males, emales andcombined sex were 1.699, 2.134 and 1990, respectively. The fsh exhibited alometrcgrowth in the river. The predictive equation was log W = -0.636 + 199 log L. The mean condition factor varied between seasons. The mean condition for males, females and combined sex were 0.787, 0.859 and 0.823, respectvely. The condtion factor decreased with increase in ndvidual sizes. Keywords : Length-weight relationship, Condition factor, Mormyrus rume , R...

There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproduc... more There is need to control unwanted/undesirable tilapia recruitment in ponds using natural reproductive inhibitory agents in plants because they are less expensive and constitutes appropriate technology in developing countries. Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5MJ gross energy/kg diet) at 0, 0.5, 1.0, 1.5 or 2.0 g/kg diets and fed to mixed-sex Tilapia zillii for 60 days to evaluate the effects on growth and feed utilization, reproduction traits, and histology of gonads. There were no significant variations (p >0.05) in the growth parameters and food conversion ratio. Indices of reproduction traits decreased with increasing dietary NLM levels. Fish fed with the control diet had significantly higher and better indices of reproduction traits (P<0.05) than the fish fed with NLM diets. Fish fed 0g NLM/kg diet showed normal testicular and ovarian tissues, and no pathological lesions occurred. Fish fed 0.5g NLM/kg diet showe...

ag.arizona.edu

Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5M... more Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet (350g crude protein and 18.5MJ gross energy/kg diet) at 0, 0.5, 1.0, 1.5 or 2.0 g/kg diets and fed to mixed-sex Tilapia zillii for 60 days to evaluate the effects on histology of the testes and ovaries. Male T. zillii fed 0g NLM/kg diet showed normal testicular tissues; and no pathological lesions occurred. Fish fed 0.5g NLM/kg diet showed alteration in testicular architecture and cystic seminiferous tubules. Fish fed 1.0g NLM/kg diet showed severe testicular atrophy. Fish fed 1.5g NLM/kg diet exhibited cystic seminiferous tubule and atrophy of tissue. Fish fed 2.0g NLM/kg diet showed severe tissue atrophy, sperm cells disintegration and necrosis. Female T. zillii fed with control diet (0g NLM/kg diet) showed normal ovary histology and no pathological lesions were observed. Typical bilateral lobes of the ovaries were evident and with normal olive green colour of ovaries. Fish fed 2.0g NLM/kg diet revealed ovarian colour change. There was evidence of hydropic degeneration, ruptured follicle, granulomatous inflammation in the insterstitium and necrosis. Histological observations of testes and ovaries in T. zillii fed high dietary NLM levels revealed that neem leaves may be effective as sterility-inducing agents as they were destructive to testes and ovaries tissues.

Digestive enzyme assays in the different gut regions (oesophagus, stomach, caecum, duodenum, ileu... more Digestive enzyme assays in the different gut regions (oesophagus, stomach, caecum, duodenum, ileum, and rectum) of three commercial African freshwater fish species: Nile tilapia Oreochromis niloticus, African snakehead fish Parachanna obscura, and African long knife fish, Gymnarchus niloticus, revealed an array of glycosidases (amylase, sucrase, maltase, lactase, and cellulase); proteases (chymotrypsin, pepsin, and trypsin) and lipases. The pattern of distribution and relative activity of the enzymes showed that the fishes are capable of digesting carbohydrates, proteins and lipids such that they complemented the different dietary habits of the three fish species. Enzyme activity was not detected in the oesophagus and rectum of the three fish species. The relative distribution and activity of the various enzymes were possibly induced by the nutritional requirements of the fishes.

Raw heads of the river prawn, Macrobrachium vollenhovenii, were fermented with Lactobacillus plan... more Raw heads of the river prawn, Macrobrachium vollenhovenii, were fermented with Lactobacillus plantarum at 30 °C using molasses or cassava starch as the carbohydrate source. After incubation for 7 days, a desirable and stable pH w w ) and solar-dried. The dried shrimp head silage meals were incorporated as protein supplements into pelleted semi-purified diets for catfish, Clarias gariepinus. Apparent digestibility coefficients of dry matter, crude protein, gross energy and essential amino acids in the silage by catfish fingerlings was high (> 70%). It was concluded that dried fermented fish silage is suitable and has a potential as a protein feedstuff in fish diets.

The dietary habits of the giant African clariid catfish, Heterobranchus bidorsalis (Geoffroy St. ... more The dietary habits of the giant African clariid catfish, Heterobranchus bidorsalis (Geoffroy St. Hilaire 1809) inhabiting Owena Reservoir (Southwestern Nigeria) were investigated. Stomach content analyses established that it had an euryphagous diet. The diet comprised mainly plankton, insects, fish and detritus although, plant parts, benthic invertebrates and tadpoles were consumed. Detritus was very prominent accounting for between 68.1–74.5% occurrence and 13.9–19.6% volume in all sizes of fish examined, which indicated that it was a benthic feeder. There was a progression from planktivorous diet in fish below 12 cm standard length (SL) through a transitional insectivorous phase (SL, 12–27 cm) to a predominantly piscivorous diet in fish above 27 cm SL. It was capable of filter feeding only when young but later became predatory, consuming appropriately sized prey organisms as it grew older. No seasonal variation was established in food preference of any size of fish.

ABST CT Analyses of stomach contents of 330 Malapterurus electricus (Standard length, 10.1-30.5cm... more ABST CT Analyses of stomach contents of 330 Malapterurus electricus (Standard length, 10.1-30.5cm) in Mahin Lagoon (Southwestern Nigeria) established it as a bottom feeder. There was a preponderance of insects accounting for >80% occurrence and > 25% of total volume in stomachs of specimens, suggesting a stenophagous predatory habit. Qualitative and quantitative assays of digestive enzymes in the different regions of the gut (oesophagus, stomach, doudenum, ileum, rectum) were investigated. CarbohydraseS (amylase, maltase), chitinase, proteases (pepsin, chymotrypsin, trypsin) and lipases were detected in different gut regions with different activity. The pattern of distribution and relative activity of the enzymes correlated with his predatory diet.

Aquaculture Nutrition, 1995

... g kg-' and triplicate samples were taken for chemical analysis (Table 1). In experiment ... more ... g kg-' and triplicate samples were taken for chemical analysis (Table 1). In experiment 1, CPHM replaced maize at 0%, 15%, 30% or 45% dry weight in ... Theobromine was extracted with chloroform and analysed according to the methods described by Delbeke & Debackere (1991 ...