| the haemocytology and histology of the haemopoietic organs of south african fresh water fish. i. the haemopoietic organs of clarias gariepinus and sarotherodon mossambicus. | the haemopoietic organs of the catfish, clarias gariepinus, and the mozambique bream, sarotherodon mossambicus, were studied. in both species the primary haemopoietic organs are the pronephros, the mesonephros and the spleen. the peritoneum and, particularly in catfish, the omentum are of secondary importance in haemopoiesis. | 1979 | 551371 |
| two gonadotropin-releasing hormones from african catfish (clarias gariepinus). | two forms of gonadotropin-releasing hormone (gnrh) have been purified from brain extracts of the african catfish, clarias gariepinus, using reverse-phase high performance liquid chromatography (hplc) and radioimmunoassay (ria). the amino acid sequences of both forms of african catfish gnrh were determined using edman degradation after digestion with pyroglutamyl aminopeptidase. in addition, both gnrhs were studied by mass spectrometry. the primary structure of african catfish gnrh i is identical ... | 1992 | 1520292 |
| application of cryosubstitution in neurohormone- and neurotransmitter-immunocytochemistry. | pituitaries of the african catfish, clarias gariepinus, were prefixed in aldehyde fixatives, frozen in liquid propane and submitted to a cryosubstitution procedure. ultrathin sections of the lowicryl hm20-embedded tissue were treated with primary antisera raised in rabbits to gonadotropin releasing hormone (gnrh), vasopressin or gamma amino butyric acid (gaba) respectively. binding of the primary antisera was visualized with goat anti-rabbit (gar) labeled with gold. the general morphology of the ... | 1992 | 1559844 |
| a new member of the gonadotropin-releasing hormone family in teleosts: catfish gonadotropin-releasing hormone. | two forms of immunoreactive gonadotropin-releasing hormone (gnrh) were detected in extracts of brain-pituitary tissue from the african catfish, clarias gariepinus. catfish i gnrh eluted first from reverse-phase hplc and was present in larger amounts compared with catfish ii gnrh. chromatographic and immunological studies with four antisera provide evidence that catfish i gnrh is unique compared with identified gnrhs from mammal, chicken, salmon, and lamprey. catfish ii gnrh elutes in the same po ... | 1989 | 2676702 |
| reproductive biology of clarias gariepinus (syn. lazera) burchel (claridae) in lake manzalah, egypt. i. structure of the ovaries. | | 1986 | 3781403 |
| reproductive biology of clarias gariepinus (syn. lazera) burchell (claridae) in lake manzalah, egypt. ii. structure of the testes. | | 1986 | 3781404 |
| parasites of south african freshwater fish. ii. redescription of the african species of the genus phyllodistomum braun, 1899 (trematoda: gorgoderinae) and the description of a new species. | during 1980 a survey of the parasites of freshwater fish was conducted in the sabie and crocodile rivers in the southern part of the kruger national park, transvaal. a new species of phyllodistomum, braun, 1899, for which the name phyllodistomum bavuri is proposed, was found in the urinary bladder of many of the catfish, clarias gariepinus (burchell, 1822), examined. the new species resembles phyllodistomum linguale odhner, 1902 and phyllodistomum vanderwaali prudhoe & hussey, 1977, but may be d ... | 1984 | 6493727 |
| parasites of south african freshwater fish. i. some nematodes of the catfish [clarias gariepinus (burchell, 1822)] from the hartbeespoort dam. | a seasonal study of the parasites of fish in the hartbeespoort dam was undertaken in 1979. this paper deals with 4 nematode species recovered from catfish, namely, paracamallanus cyathopharynx (baylis, 1923), procamallanus laeviconchus (wedl, 1862), contracaecum sp. and skrjabinocara sp. total numbers of parasites recovered are tabulated and their seasonal variation illustrated diagrammatically. paracamallanus cyathopharynx was recovered from 23 out of 43 catfish examined and procamallanus laevi ... | 1982 | 7122064 |
| parasites of south african freshwater fish. vi. nematode parasites of some fish species in the kruger national park. | the nematode parasites of 30 spot-tailed robbers, brycinus imberi, five tiger-fish, hydrocynus vittatus, 77 large-scaled yellowfish. barbus marequensis, two mudsuckers, labeo molybdinus, 114 catfish, clarias gariepinus, 46 silver barbel, schilbe intermedius, 66 squeakers, synodontis zambezensis, three eels, anguilla spp., 83 mozambique bream, oreochromis mossambicus, 81 red-breasted bream, tilapia rendalli swierstrae and 32 large-mouthed bream, serranochromis meridianus, caught in the sabie, cro ... | 1994 | 7898896 |
| isolation, characterization and expression of cdnas encoding the catfish-type and chicken-ii-type gonadotropin-releasing-hormone precursors in the african catfish. | the cdnas encoding the catfish prepro-gonadotropin-releasing hormone and the chicken prepro-gonadotropin-releasing hormone ii of the african catfish (clarias gariepinus) have been isolated and sequenced. the catfish gonadotropin-releasing-hormone precursor and the chicken gonadotropin-releasing-hormone-ii precursor have the same overall architecture as other gonadotropin-releasing-hormone precursors identified so far; each is composed of a signal peptide, gonadotropin-releasing hormone and a gon ... | 1994 | 8020492 |
| replication, expression, and fate of foreign dna during embryonic and larval development of the african catfish (clarias gariepinus). | the transfer of exogenous dna in fish represents a powerful strategy to study the regulation of gene expression in vivo. the african catfish (clarias gariepinus) was chosen for this study because of its scientific and economic importance due to its easy husbandry, its short developmental period, and its value as a protein source in africa and asia. fertilized eggs (1- and 2-cell stage) were cytoplasmatically injected with either supercoiled or linearized plasmids harboring the fusion genes encod ... | 1994 | 8087184 |
| presence of gonadotropin-releasing hormone (gnrh) binding sites and compounds with gnrh-like activity in the ovary of african catfish, clarias gariepinus. | gnrh binding was characterized in the african catfish ovary by use of an analog of salmon gnrh (sgnrh- ; [d-arg6, trp7, leu8, pro9-net]-gnrh) as a labeled ligand. binding of sgnrh-a to catfish ovarian membrane preparation was found to be saturable, displaceable, reversible, and dependent on time, temperature, and tissue concentration. optimal binding was achieved after 70 min of incubation at room temperature (approximately 22 degrees c) at ph 7.6. addition of unlabeled sgnrh-a displaced the bou ... | 1994 | 8167236 |
| effects of gonadotrophin-releasing hormone during the pubertal development of the male african catfish (clarias gariepinus): gonadotrophin and androgen levels in plasma. | the sensitivity of the pituitary to gonadotrophin-releasing hormone (gnrh) and that of the testis to gonadotrophin (gth) was monitored in african catfish in vivo at different stages of pubertal development (20, 21, 24, 31, 39, 42 and 49 weeks of age). the fish were injected i.p. with chicken gnrh-ii (cgnrh-ii) or catfish gnrh (cfgnrh), their two endogenous gnrhs. blood samples were collected to quantify lh-like gth-ii and three androgens 11-ketotestosterone (11-kt), testosterone and 11 beta-hydr ... | 1994 | 8169559 |
| parasites of south african freshwater fish. v. description of two new species of the genus spinitectus fourment, 1883 (nematoda: cystidicolidae). | spinitectus petterae n. sp. was recovered from catfish, clarias gariepinus (burchell, 1822) and spinitectus zambezensis n. sp. from squeakers, synodontis zambezensis peters, 1852 in the kruger national park. the nematodes are easily differentiated from each other in that spinitectus petterae has an additional pair of papillae on the pseudolabia, the males have considerably longer spicules and a different configuration of the tips of the left spicule, and the vulva of the females is considerably ... | 1993 | 8332324 |
| two gonadotropin-releasing hormones in the african catfish, clarias gariepinus: localization, pituitary receptor binding, and gonadotropin release activity. | two gnrh peptides have recently been identified in brain extracts of the african catfish, chicken-ii gnrh ([his5,trp7,tyr8]gnrh, cgnrh-ii) and catfish gnrh ([his5,asn8]gnrh, cfgnrh). using three experimental approaches, we investigated whether both peptides are involved in the regulation of pituitary gonadotropin secretion. first, the presence of cfgnrh and cgnrh-ii in the pituitary was studied by biochemical and immunocytochemical techniques, as gnrh reaches the pituitary via axonal transport i ... | 1993 | 8404596 |
| one-step immunoaffinity purification and partial characterization of hypophyseal growth hormone from the african catfish, clarias gariepinus (burchell). | growth hormone (gh) was purified from african catfish (clarias gariepinus) pituitary extracts in a single step by use of immunoaffinity chromatography. a monoclonal antibody to chicken gh, which labels the catfish hypophyseal somatotropes in immunocytochemistry, was coupled to cnbr-activated sepharose, and crude alkaline pituitary extracts were run over the immunoadsorbent. reversed-phase high-performance liquid chromatography analysis of the eluted material suggested heterogeneity, whereas silv ... | 1996 | 8925443 |
| a radioimmunoassay for african catfish growth hormone: validation and effects of substances modulating the release of growth hormone. | a highly sensitive radioimmunoassay has been developed for measuring plasma growth hormone (gh) concentrations in the african catfish (clarias gariepinus). the lower detection limit of the assay was 0.1 ng/ml and the standard curve had an ed50 value of 0.5 ng/ml. the validity of the assay was established and the effects of several neurotransmitters on the release of gh were examined. in vitro experiments, using a static culture system for dispersed pituitary cells, demonstrated that the gh relea ... | 1996 | 8930605 |
| gonadotrophs but not somatotrophs carry gonadotrophin-releasing hormone receptors: receptor localisation, intracellular calcium, and gonadotrophin and gh release. | gonadotrophs are the primary target cells for gnrh in the pituitary. however, during a limited period of neonatal life in the rat, lactotrophs and somatotrophs respond to gnrh as well. also, in the adults of a number of teleost fishes (e.g. carp, goldfish, and tilapia but not trout), gnrh is a potent gh secretagogue. in studying hypophysiotrophic actions of the two forms of gnrh present in the african catfish (clarias gariepinus), chicken gnrh-ii ([his5,trp7,tyr8]gnrh; cgnrh-ii) and catfish gnrh ... | 1997 | 9071965 |
| control of microbiological quality and shelf-life of catfish (clarias gariepinus) by chemical preservatives and smoking. | fresh catfish (clarias gariepinus) were subjected to different concentrations of sodium benzoate or potasium sorbate and smoked traditionally before evaluation for microbiological, chemical and organoleptic characteristics during ambient tropical storage. unsmoked fish samples showed diverse microflora (enterobacter, escherichia, serratia, bacillus, staphylococcus, streptococcus, penicillium, aspergillus and achlya genera) while smoked samples were dominated by gram-positive bacterial flora (bac ... | 1996 | 9072517 |
| modulation of testicular androgen production in adolescent african catfish (clarias gariepinus). | at 6 months of age the first spermatozoa appear in the testes of the african catfish considered to be adolescent, since the development to adulthood (12 months of age) is accompanied by further morphological and functional differentiation of leydig cells. there are increasing plasma levels of 11-ketotestosterone (11-kt) and an increasing responsiveness to luteinizing hormone (lh) of testicular androgen secretion in vitro. whether treatment of adolescent males with key hormones of the brain-pitui ... | 1997 | 9378274 |
| characterization of mboi satellites in cirrhina mrigala and clarias batrachus (pisces). | we have cloned and characterized two highly reiterated, tandemly repeated, and a+t rich mboi dna fragments, one in cirrhina mrigala (cyprinidae), with a monomer size of 266 bp, and one in clarias batrachus (clariidae), with a monomer size of 227 bp. the mboi fragment in c. mrigala is species-specific and absent in other carps, such as catla catla and labeo rohita. the mboi fragment in c. batrachus was also present in two other catfishes tested, namely clarias gariepinus and heteropneustes fossil ... | 1998 | 9549057 |
| testosterone accelerates the development of the catfish gnrh system in the brain of immature african catfish (clarias gariepinus). | the effects of two endogenous steroids on the maturation of the catfish gnrh and the chicken gnrh-ii system in the african catfish were investigated. immature fish (2 weeks of age, which is before sexual differentiation; thus male and female genotypes present) were fed with food pellets containing either testosterone (t), 11beta-hydroxyandrostenedione (oha) or no steroid (control). after 2 and 4 weeks of treatment, the effects on the two gnrh systems were investigated immunocytochemically, using ... | 1998 | 9843644 |
| effects of dieldrin on life stages of the african catfish, clarias gariepinus (burchell). | early life stages of clarias gariepinus were found to be less sensitive to acute dieldrin toxicity than were those of nile tilapia, oreochromis niloticus; 96-h lc50 values for 37-day-old fry were 11. 7 and 4.95 microg liter-1, respectively. the growth of c. gariepinus fry was unaffected by 30 days of exposure to 2.4 microg liter-1 dieldrin under static conditions with water renewal every 96 h, whereas growth of o. niloticus fry was significantly reduced. adult c. gariepinus exposed to dieldrin f ... | 1999 | 9931234 |
| the african monogenean gyrodactylid genus macrogyrodactylus malmberg, 1957, and the reporting of three species of the genus of clarias gariepinus in south africa. | three different species of the genus macrogyrodactylus malmberg, 1957, collected from the gills and skin of clarias gariepinus (burchell, 1822) from the middle letaba dam and mokgoma-matlala dam in south africa were examined and identified. this is the first record of a species of the genus in south africa. the three species are m. congolensis (prudhoe, 1957)--found on the skin, m. clarii gussev, 1961 and m. karibae douellou & chishawa, 1995--found on the gills. the last species is elevated to t ... | 1998 | 10192833 |
| a comparative study of spermatozoal chromatin using acridine orange staining and flow cytometry. | spermatozoa obtained from fish (clarias gariepinus), human (homo sapiens), turkeys (meleagris gallapova), rats (rattus norvegicus), hamsters (mesocricetus auratus), and monkeys (macaca fascicularis) were stained with acridine orange before measuring fluorescence by flow cytometry. these mature sperm from various species produced different intensities of fluorescence while displaying similar ratios of red/green fluorescence. comparison of the green fluorescence values for the various species show ... | 1999 | 10629954 |
| inhibitory and stimulatory interactions between endogenous gonadotropin-releasing hormones in the african catfish (clarias gariepinus). | in the brain of all vertebrate classes, chicken (c) gnrh-ii ([his(5), trp(7),tyr(8)]gnrh, cgnrh-ii) is expressed in the mesencephalon. in addition, at least one other form of gnrh is expressed in the preoptical area/hypothalamus. in the human pituitary stalk and the mouse median eminence, cgnrh-ii is present together with mammalian gnrh. similarly, in the pituitary of several teleost fish (e.g., goldfish and eel, but not salmon or trout), a teleost gnrh is found together with cgnrh-ii. these gnr ... | 2000 | 10684817 |
| discrepancy between molecular structure and ligand selectivity of a testicular follicle-stimulating hormone receptor of the african catfish (clarias gariepinus). | a putative fsh receptor (fsh-r) cdna was cloned from african catfish testis. alignment of the deduced amino acid sequence with other (putative) glycoprotein hormone receptors and analysis of the african catfish gene indicated that the cloned receptor belonged to the fsh receptor subfamily. catfish fsh-r (cffsh-r) mrna expression was observed in testis and ovary; abundant mrna expression was also detected in seminal vesicles. the isolated cdna encoded a functional receptor since its transient exp ... | 2001 | 11369589 |
| development of three distinct gnrh neuron populations expressing two different gnrh forms in the brain of the african catfish (clarias gariepinus). | the early development of both the catfish gonadotropin-releasing hormone (cfgnrh)- and the chicken gnrh-ii (cgnrh-ii) system was investigated in african catfish by immunocytochemistry by using antibodies against the gnrh-associated peptide (gap) of the respective preprohormones. weakly cfgnrh-immunoreactive (ir) neurons and fibers were present at 2 weeks after hatching (ph) but only in the ventral telencephalon and pituitary. two weeks later, cfgnrh fibers and neurons were also observed in more ... | 2001 | 11494258 |
| chaetotaxy of the monogeneans macrogyrodactylus clarii and m. congolensis from the gills and skin of the catfish clarias gariepinus in egypt, with a note on argentophilic elements in the nervous system. | a comparison has been made between the chaetotaxy of the gyrodactylid monogeneans macrogyrodactylus clarii gussev, 1961 and m. congolensis (prudhoe, 1957) yamaguti, 1963 from the gills and skin, respectively, of the catfish clarias gariepinus (burchell) from the river nile in egypt. bilaterally arranged argentophilic structures on the surface of these parasites are presumed to be sensilla and are more abundant in m. clarii than in m. congolensis especially on the ventral surface (124 vs. 66). in ... | 2001 | 11699655 |
| chimaeric gonadotropin-releasing hormone (gnrh) peptides with improved affinity for the catfish (clarias gariepinus) gnrh receptor. | the gonadotropin-releasing hormone (gnrh) receptor in catfish differs from its mammalian counterparts in showing a very low affinity for the hypothalamic gnrh form [i.e. catfish gnrh (cfgnrh)] and a very high affinity for the highly conserved mesencephalic gnrh, chicken gnrh-ii (cgnrh-ii). in the present study we investigated the molecular interactions between ligand and receptor involved in determining the ligand selectivity of the catfish gnrh receptor. studies on the binding characteristics o ... | 2002 | 11802781 |
| environmental issue of exotic catfish culture in uttar pradesh. | a survey was conducted in uttar pradesh to enlist the available exotic fish species in culture. the culture and feeding details of unofficially introduced clarias gariepinus was collected from 419 ponds existing in rural areas of 23 districts of uttar pradesh. the data indicated that 32% ponds were culturing exotic fishes of which 79% cases are of monoculture of exotic african catfish. feeding analysis of these exotic african catfish revealed that 7% cases subsist on natural pond feed while 29% ... | 2001 | 12017262 |
| gonadotropin-releasing hormone does not directly stimulate luteinizing hormone biosynthesis in male african catfish. | besides gonadotropin release, gnrh stimulates gonadotropin subunit gene transcription and translation in gonadotrophs. in the african catfish, clarias gariepinus, chicken gnrh-ii (cgnrh-ii: [his5,trp7,tyr8]-gnrh) and catfish gnrh (cfgnrh: [his5,asn8]-gnrh) are two endogenous forms of gnrh. studying their effects on lh subunit steady-state mrna levels, lh de novo synthesis, and lh release in primary pituitary cell cultures of adult males, we found that cgnrh-ii hardly influenced the steady-state ... | 2002 | 12021037 |
| immunological study of muscle parvalbumin isotypes in three african catfish during development. | eleven parvalbumin isotypes expressed during the development of clariids heterobranchus longifilis and clarias gariepinus and claroteid chrysichthys auratus were purified and electrophoresed on sodium-dodecyl-sulfate polyacrylamide gels. immunochemical cross-reactions among these proteins were investigated by immunoblotting, using purified antibodies raised against three isotypes chosen at different stages of fish development. antibodies raised against h. longifilis pa i (larval-juvenile isotype ... | 2002 | 12091103 |
| histopathological and ultrastructural studies of henneguya suprabranchiae landsberg, 1987 (myxosporea: myxobolidae) parasitizing the suprabranchial organ of the freshwater catfish clarias gariepinus burchell, 1822 in egypt. | serious loss in the length and weight of the economically important catfish clarias gariepinus was caused by a high intensity of infestation with henneguya suprabranchiae, parasites which infect the hyaline cartilage of the suprabranchial organ of fish. fish were collected from three different localities: the river nile in the cairo and giza provinces, some giza markets and agricultural drains in kalyubia province. all harbored cysts at the tips of the secondary bronchioles. these measured betwe ... | 2002 | 12107453 |
| studies on the fungal infestation of five traditionally smoke-dried freshwater fish in ago-iwoye, nigeria. | samples of traditionally smoke-dried clarias gariepinus (burchell), chrysichthys nigrodigitatus (lacepede), sarotherodon galilaeus (trewavas), heterotis niloticus (cuvier) and heterobranchus bidorsalis (geoffroy) were obtained from oja oba market, ago-iwoye, nigeria and examined for fungal infestation. the fish samples incubated on potato dextrose agar (pda) for 7 days showed fungal infestation. fungi isolated and identified included mucor sp., aspergillus sp., rhizopus sp. and fusarium sp. six ... | 2002 | 12206317 |
| effect of some pulverised plant materials on the developmental stages of fish beetle, dermestes maculatus degeer in smoked catfish (clarias gariepinus) during storage. | the effectiveness of pulverised plant materials; tithonium diversifolia, afromomum melegueta, nicotiana tabacum, monodora myristica and piper guineense as ovicidal, larvicidal and adult deterents of fish beetle (dermestes maculatus) in smoked catfish (clarias gariepinus) during storage were evaluated. leaves of t. diversifolia, n. tabacum and seeds of a. melegueta, m. myristica and p. guineese were dried and pulverised into powder. adults and larvae of third generation (f3) of d. maculatus were ... | 2002 | 12227542 |
| immature stages and re-description of henneguya suprabranchiae (myxosporea: myxobolidae), an intestinal parasite of the catfish clarias gariepinus in the river nile, egypt. | a new morphological description, supported by light microscopy photographs, is presented for various immature stages and for mature henneguya suprabranchiae landsberg, 1987 spores infecting the intestine of the nile catfish clarias gariepinus, burchell, 1822 (syn.: c. lazera). large cysts of 2 to 4.5 mm diameter, containing immature and mature stages, were present in the outer layer of the intestine. they caused severe damage to the smooth muscle and atrophy due to the increased size and resulta ... | 2002 | 12465876 |
| cloning and functional characterization of a gonadal luteinizing hormone receptor complementary dna from the african catfish (clarias gariepinus). | a cdna encoding a putative african catfish (clarias gariepinus) gonadal lh receptor (cflh-r) has been cloned. multiple sequence alignment of the deduced amino acid sequence revealed that the cflh-r had the highest identity with vertebrate lh receptors (>50%). overall sequence identity between the cflh-r and the african catfish fsh receptor (cffsh-r) is 47%. sequence analysis of part of the cflh-r gene revealed the presence of an intron typically found in other vertebrate lh-r genes. abundant cfl ... | 2003 | 12493722 |
| enzyme activities in fish spermatozoa with focus on lactate dehydrogenase isoenzymes from herring clupea harengus. | the activities of nad- and nadp-dependent dehydrogenases and creatine kinase were compared in extracts of spermatozoa from herring (clupea harengus), carp (cyprinus carpio) and catfish (clarias gariepinus). the activity of malic enzyme in herring spermatozoa was approximately 5 and 36 times higher than in carp and catfish spermatozoa. in contrast, lactate dehydrogenase activity in herring spermatozoa was very low. herring spermatozoa possess two isoenzymes of lactate dehydrogenase: ldh-a(2)b(2) ... | 2003 | 12628371 |
| cloning and functional characterization of a testicular tsh receptor cdna from the african catfish (clarias gariepinus). | a cdna encoding a putative thyroid-stimulating hormone receptor (cftsh-r) was cloned from the testis of the african catfish (clarias gariepinus). the cftsh-r showed the highest amino acid sequence identity with the tsh-rs of other fish species. in addition, an insertion of approximately 50 amino acids, specific for the tsh-r subfamily, was also present in the carboxy terminus of the amino-terminal extracellular domain of the cftsh-r. next to the testis and thyroid follicles, abundant cftsh-r exp ... | 2003 | 12683945 |
| sublethal effects of tannery effluent on some hematological indices and growth of clarias gariepinus (teugels). | | 2003 | 14756289 |
| oral vaccination of african catfish with vibrio anguillarum o2: effect on antigen uptake and immune response by absorption enhancers in lag time coated pellets. | the impact on antigen uptake and antibody response by the addition of absorption enhancers to vibrio anguillarum o2 antigen was studied in oral vaccination trials of african catfish (clarias gariepinus). oral vaccination was achieved by feeding lag time coated pellets. the lag time coat prevents premature release of the encapsulated vaccine in the tank, before ingestion of the pellets by the fish. to monitor the antigen uptake, a competitive elisa was used. the antibody response was measured usi ... | 2004 | 15123307 |
| the occurrence of contracaecum sp. larvae (nematoda: anisakidae) in the catfish clarias gariepinus (burchell) from lake chivero, zimbabwe. | clarias gariepinus were collected from lake chivero, zimbabwe, and examined for nematode parasites from november 2000 to may 2002. of the 202 specimens collected, 42.6% were infected with third-stage larvae of contracaecum sp. in the body cavity. the intensity of the infection was 1-7 worms per fish (mean intensity = 2.2). seasonal variation in the prevalence of the parasite was not obvious and there was no significant difference in the prevalence of infection between males and females (chi 2 = ... | 2004 | 15185573 |
| neuromusculature of macrogyrodactylus clarii, a monogenean gill parasite of the nile catfish clarias gariepinus in egypt. | phalloidin fluorescence technique, enzyme cytochemistry and immunocytochemistry in conjunction with confocal scanning laser microscopy have been used for the first time to describe the nervous and muscle systems of the viviparous monogenean gill parasite, macrogyrodactylus clarii. the gross spatial arrangement of muscle and associated cholinergic, peptidergic and aminergic innervations has been examined. the central nervous system (cns) consists of paired cerebral ganglia from which emanate thre ... | 2004 | 15322920 |
| tissue distribution and evolution of fructosamine 3-kinase and fructosamine 3-kinase-related protein. | fructosamine 3-kinase (fn3k) and fn3k-related protein (fn3k-rp) catalyze the phosphorylation of the amadori products ribulosamines, psicosamines, and, in the case of fn3k, fructosamines. blast searches in chordate genomes revealed two genes encoding proteins homologous to fn3k or fn3k-rp in various mammals and in chicken but only one gene, encoding a protein more similar to fn3k-rp than to fn3k, in fishes and the sea squirt ciona intestinalis. this suggests that a gene duplication event occurred ... | 2004 | 15331600 |
| mucosal response in african catfish after administration of vibrio anguillarum o2 antigens via different routes. | the aim of this study was to investigate the possibility of mucosal vaccination in african catfish (clarias gariepinus) with vibrio anguillarum o2 bacterins. the antigen was administered via different routes: anal intubation, oral administration, intraperitoneal injection and immersion. to monitor the antigen uptake, a competitive elisa was used. the antibody response was measured using an indirect elisa. increased antibody levels were found in bile and mucus upon anal intubation, which was not ... | 2005 | 15475309 |
| histological evidence of intersex in feral sharptooth catfish (clarias gariepinus) from an estrogen-polluted water source in gauteng, south africa. | this is the first histological evidence of intersex in a fish species inhabiting a south african water source. one hundred catfish (clarias gariepinus) were collected randomly from the marais dam (md) and the rietvlei dam (rvd) in the rietvlei nature reserve (rnr), south africa. these dams drain water from a stream that receives effluent from industrial sites, agricultural activities, informal settlements, and municipal treatment plants. each fish was evaluated macroscopically and had blood draw ... | 2004 | 15526264 |
| food composition and feeding habits of some fresh water fishes in various water systems at abbassa, egypt, with special reference to snails transmitting diseases. | study of feeding habits of freshwater fishes collected from ponds at world fish center (iclarm) showed that the african catfish, clarias gariepinus and forskal catfish, bagras bayad had the highest proportion of full stomachs (31-58% & 44-45% respectively). in cichlid fishes, the rate of full stomachs was much lower, being 0.0-12.5% and showed higher incidence of empty stomachs that varied from 37.5% for oreochromis niloticus to 78.3% for sarotherodon galilaeus. food items were analyzed by the p ... | 2005 | 16083073 |
| bioaccumulation of cadmium in an experimental aquatic food chain involving phytoplankton (chlorella vulgaris), zooplankton (moina macrocopa), and the predatory catfish clarias macrocephalus x c. gariepinus. | the accumulation of cadmium (cd) was studied in an experimental aquatic food chain involving the phytoplankton chlorella vulgaris as the primary producer, the zooplankton moina macrocopa as the primary consumer, and the catfish clarias macrocephalus x clarias gariepinus as the secondary consumer. c. vulgaris was first exposed to cd solutions at 0.00, 0.35, and 3.50 mg l(-1), referred to as control group and experimental groups 1 and 2, respectively. subsequently, each group was fed to three corr ... | 2006 | 16504313 |
| neuromusculature of macrogyrodactylus congolensis, a monogenean skin parasite of the nile catfish clarias gariepinus. | phalloidin fluorescence technique, enzyme cytochemistry and immunocytochemistry, in conjunction with confocal scanning laser microscopy, were used to describe the neuromusculature of the monogenean skin parasite macrogyrodactylus congolensis from the nile catfish clarias gariepinus. the body wall muscles are composed of an outer layer of compactly arranged circular fibres, an intermediate layer of paired longitudinal fibres and an inner layer of well-spaced bands of diagonal fibres arranged in t ... | 2007 | 16896654 |
| nematode parasites of clarias gariepinus (burchell, 1822) from the rietvlei dam, south africa. | catfish, clarias gariepinus, from the rietvlei dam near pretoria, south africa were examined for nematode parasites. two species, procamallanus laeviconchus in the stomach and contracaecum spp. larvae in the abdominal cavity, were found. the morphology of these species, based on light and scanning electron microscopy, and how they compare with previously described specimens are discussed. infection rates were mild compared to previous surveys although contracaecum spp. had a high prevalence of 8 ... | 2006 | 16958258 |
| on cestode and digenean parasites of clarias gariepinus (burchell, 1822) from the rietvlei dam, south africa. | sharptooth catfish, clarias gariepinus, from the rietvlei dam near pretoria, south africa were examined for internal platyhelminth parasites. two adult cestodes, polyonchobothrium clarias (stomach) (prevalence 71%, mean intensity = 5, n = 7) and proteocephalus glanduliger (anterior intestine) (prevalence 14%, mean intensity = 2, n = 7), were found in the gut while metacercariae of one larval digenean, ornithodiplostomum sp. (prevalence 14%, mean intensity = 140, n = 7), were found encysted in th ... | 2006 | 16958260 |
| affinity purification and partial characterization of igm-like immunoglobulins of african catfish, clarias gariepinus (burchell, 1822). | igm like macroglobulin from bovine serum albumin (bsa)-immunized african catfish c. gariepinus was purified by affinity chromatography and partially characterized. the molecular weight of this macroglobulin was 840 kda, as estimated by gel filtration chromatography. purified macroglobulin was analyzed using sds-page under reducing and non-reducing conditions. the molecular weight (mw) of heavy and light chain was 74.8 kda and 27.2 kda respectively, in presence of a reducing agent. in non-reducin ... | 2006 | 17176677 |
| assessment of heavy-metal profile of the new calabar river and its impact on juvenile clarias gariepinus. | we have determined the heavy-metal status of the lower reaches of the new calabar river in the niger delta region over a 40-km-long distance, and its impact on the development of catfish (juvenile clarias gariepinus). the total mean concentrations of dissolved trace metals in the river were 0.01, 0.85, 0.56, 2.08, 0.05, 12.0, and 6.59 mg/l for hg, pb, cd, cu, cr, fe, and zn, respectively. the accumulated concentration of trace metals in the muscles of different mature fish caught from the river ... | 2006 | 17193219 |
| monitoring of nuclear abnormalities in peripheral erythrocytes of three fish species from the goksu delta (turkey): genotoxic damage in relation to water pollution. | goksu delta is a specially protected area in the mediterranean region of turkey. the delta is classified as a wetland of international importance according to the ramsar convention on wetlands of international importance. increases in population have recently taken place in this region due to heavy agricultural activities and discharges of anthropogenic wastes. in the present study, frequencies of erythrocytic nuclear abnormalities such as, micronuclei (mn) and nuclear buds (nb) were investigate ... | 2007 | 17380383 |
| natural origins of off-flavours in fish related to feeding habits. | the objective of our study was to survey the accumulated 2-methylisoborneol (mib) and geosmin (gsm) in fillets of five important farmed fish species in hungarian aquaculture in relation to mib and gsm concentrations in water and sediment in the aquatic systems where they were raised: (the planktivorous silver carp (hypophthalmichthys molitrix), the herbivorous grass carp (ctenopharyngodon idella), the bottom-feeding omnivorous common carp (cyprinus carpio), the omnivorous tilapia (oreochromis ni ... | 2007 | 17489423 |
| biomarkers of oxidative stress and heavy metal levels as indicators of environmental pollution in african cat fish (clarias gariepinus) from nigeria ogun river. | levels of zn, cu, cd, as, and pb in the kidney, liver, gills and heart of african cat fish (clarias gariepinus) from the ogun river in ogun state located close to six major industries in the south western part of nigeria, were determined using bulk scientific atomic absorption spectrophotometer. fishes were also collected from government owned fish farm in agodi, ibadan which was considered a reference site. the activities of superoxide dismutase (sod), catalase (cat), glutathione s-transferase ... | 2007 | 17617680 |
| neuromusculature of gyrodactylus rysavyi, a monogenean gill and skin parasite of the catfish clarias gariepinus. | phalloidin fluorescence technique, enzyme cytochemistry and immunocytochemistry in conjunction with confocal scanning laser microscopy were used for the first time to describe the nervous and muscle systems of the viviparous monogenean parasite, gyrodactylus rysavyi inhabiting the gills and skin of the nile catfish clarias gariepinus. the body wall muscles are composed of an outer layer of circular fibres, an intermediate layer of paired longitudinal fibres and an inner layer of well-spaced band ... | 2007 | 17662646 |
| determinants of the parasite community of clariid fishes from lake victoria, tanzania. | the factors that determine parasite assemblages among the clariid fishes of lake victoria, tanzania were studied between august 2003 and february 2005. six hundred and fifty-six fish belonging to seven species were necropsied and examined for parasites, from which 31 species of metazoan parasites were recorded. the community was dominated by the nematodes both in species and numbers. most species were generalists with only two trematodes, diplostomum mashonense and tylodelphys species, being spe ... | 2008 | 18005464 |
| characterization of the structural gene encoding nisin f, a new lantibiotic produced by a lactococcus lactis subsp. lactis isolate from freshwater catfish (clarias gariepinus). | lactococcus lactis f10, isolated from freshwater catfish, produces a bacteriocin (bacf) active against staphylococcus aureus, staphylococcus carnosus, lactobacillus curvatus, lactobacillus plantarum, and lactobacillus reuteri. the operon encoding bacf is located on a plasmid. sequencing of the structural gene revealed no homology to other nisin genes. nisin f is described. | 2008 | 18039827 |
| monitoring of dna breakage in embryonic stages of the african catfish clarias gariepinus (burchell, 1822) after exposure to lead nitrate using alkaline comet assay. | increasing lead contamination in egyptian ecosystems and high lead concentrations in food items have raised concern for human health and stimulated studies on monitoring ecotoxicological impact of lead-caused genotoxicity. in this work, the alkaline comet assay was modified for monitoring dna strand breakage in sensitive early life stages of the african catfish clarias gariepinus. following exposure to 100, 300, and 500 microg/l lead nitrate, dna strand breakage was quantified in embryos at 30, ... | 2008 | 18247419 |
| helminth parasites of clarias gariepinus (clariidae) in lekki lagoon, lagos, nigeria. | a total of 360 randomly selected specimens of clarias gariepinus (clariidae) recovered from lekki lagoon were examined for intestinal helminth parasites. parasite prevalence and worm burden were low; 17 (4.72%) of the specimens examined were infected with gastrointestinal helminths. the helminth worms recovered include, three cestodes polyonchobothrium clarias, stocksia pujehuni and wenyonia acuminata and a nematode, paracamallanus cyathopharynx. there was no statistically significant difference ... | 2006 | 18457179 |
| recombinant novel pituitary adenylate cyclase-activating polypeptide from african catfish (clarias gariepinus) authenticates its biological function as a growth-promoting factor in low vertebrates. | nowadays, the studies of pituitary adenylate cyclase-activating polypeptide (pacap)-related peptide (prp) and pacap in non-mammalian vertebrates, especially in fish, have paid attention mainly to the localization, cloning, and structural evolution of the peptides, but very little is known about its biological functions as growth-promoting factors in low vertebrates. in this work, we have cloned and characterized the prp/pacap cdna from the commercially important north african catfish clarias gar ... | 2008 | 18492822 |
| histological alterations observed in the gills and ovaries of clarias gariepinus exposed to environmentally relevant lead concentrations. | sublethal levels of pollutants usually cause biochemical or physiological effects at the subcellular level in an organism. death is too extreme a criterion for determination of whether a substance is harmful or not; it is therefore important to find biomarkers of health and sublethal toxicant effects. in the 11 local-government areas of ibadan, a large metropolitan area in nigeria, previous studies of lead levels in surface water and fish ponds revealed surface water levels in ranges of 0.5-2.35 ... | 2008 | 18517154 |
| histopathological alterations in the liver of the sharptooth catfish clarias gariepinus from polluted aquatic systems in south africa. | there is a need for sensitive bio-monitoring tools in toxicant impact assessment to indicate the effect of toxicants on fish health in polluted aquatic ecosystems. histopathological assessment of fish tissue allows for early warning signs of disease and detection of long-term injury in cells, tissues, or organs. the aim of this study was to assess the degree of histopathological alterations in the liver of c. gariepinus from two dams in an urban nature reserve, (gauteng, south africa). two dams ... | 2009 | 18528907 |
| a new genus and species of proteocephalidean (cestoda) from clarias catfishes (siluriformes: clariidae) in africa. | a new proteocephalidean cestode is described from 2 catfishes, clarias gariepinus (type host) and c. cf. anguillaris (siluriformes: clariidae), from ethiopia (type locality), sudan, tanzania, and zimbabwe, and a new genus, barsonella, is proposed to accommodate it. the genus belongs to the proteocephalinae because its genital organs (testes, ovary, vitellarium, and uterus) are situated in the medulla. barsonella lafoni, the type and only species of the new genus, is characterized mainly by the p ... | 2009 | 18576867 |
| assessment of the potential of competitor snails and african catfish (clarias gariepinus) as biocontrol agents against snail hosts transmitting schistosomiasis. | the objective of this study was to assess the potential of the snails physa acuta and melanoides tuberculata and the african catfish clarias gariepinus as biological control agents against the schistosoma mansoni intermediate host biomphalaria pfeifferi under laboratory conditions. groups of five target and five competitor snails were raised together in experimental aquaria and same number in separate aquaria as controls. shell size, number of eggs and mortality rate were recorded for twelve con ... | 2008 | 18582914 |
| 'in a nutshell' | risk assessment what is an appropriate level of protection? an example considering selenium exposure by aquatic birds, by david deforest, bill adams and peter chapman. an appropriate level of protection should focus on population viability and productivity, and should not be lower than an ec10. how can research contribute to risk assessment?, by steve sheppard, peter chapman and evert nieboer. research contributions to risk assessment can be direct, inferential, and/or confidence building. sedim ... | 2008 | 18636791 |
| variation in fatty acid composition in muscle and heart tissues among species and populations of tropical fish in lakes victoria and kyoga. | the composition of the fatty acids in muscle and heart tissue of seven fish species, nile perch (lates niloticus), nile tilapia (oreochromis niloticus), marbled lungfish (protopterus aethiopicus), african catfish (clarias gariepinus), lake victoria squeaker (synodontis victoriae), bagrus docmas, and tilapia zilli, from two locations in lake kyoga and one location in lake victoria was chemometrically determined. the muscle tissue was very lean, with an average of 3.4 mg total fatty acids per g ti ... | 2008 | 18712426 |
| redescription of proteocephalus glanduligerus (cestoda: proteocephalidea), a parasite of clariid catfishes in africa with a unique glandular apical organ. | the tapeworm proteocephalus glanduligerus (janicki, 1928) fuhrmann, 1933 (cestoda: proteocephalidea), a parasite of clariid catfishes (clarias spp.) in africa, is redescribed on the basis of an evaluation of voucher material and newly collected specimens from clarias gariepinus and c. cf. anguillaris from the sudan, ethiopia, and south africa. the most typical characteristic of p. glanduligerus (previously misspelled as p. glanduligera or p. glanduliger) is the presence of an extremely large gla ... | 2009 | 18788883 |
| genetic variation and population structure of endemic yellow catfish, horabagrus brachysoma (bagridae) among three populations of western ghat region using rapd and microsatellite markers. | random amplified polymorphic dna (rapd) and microsatellite markers were applied to evaluate the genetic variation in endemic and endangered yellow catfish, horabagrus brachysoma sampled from three geographic locations of western ghat, south india river systems. in rapd, of 32 10-mer rapd primers screened initially, 10 were chosen and used in a comparative analysis of h. brachysoma collected from meenachil, chalakkudy and nethravathi river systems. of the 124 total rapd fragments amplified, 49 (3 ... | 2009 | 18979230 |
| development of monoclonal antibodies to rohu [labeo rohita] immunoglobulins for use in immunoassays. | serum immunoglobulins [ig] of rohu [labeo rohita] were purified by affinity chromatography using bovine serum albumin as capture ligand. the purified rohu ig [r-ig] had a molecular weight [mw] of 880 kda as determined with gel filtration chromatography. the heavy chain of r-ig had an mw of 77.8 kda and that of light chain was 26.4 kda in sds-page. purified r-ig was used for the production of two anti-rohu ig monoclonal antibodies [d7 and h4] that belonged to subclass igg2b and igg1, respectively ... | 2008 | 18996722 |
| regulation of body mass growth through activin type iib receptor in teleost fish. | myostatin is a tgf-beta family member that plays a key role in regulating skeletal muscle growth. previous studies in mammals have demonstrated that myostatin is capable of binding the two activin type ii receptors. additionally, activin type ii receptors have been shown to be capable of binding a number of other tgf-beta family members besides myostatin. an injection of a soluble form of activin type iib receptor obtained from cho cells into wild-type mice generated up to a 60% increase in musc ... | 2009 | 19056390 |
| induction of cytochrome p450 1a1 as a biomarker of benzo-a-pyrene pollution in egyptian fresh water fish. | the activity of ethoxyresorufin-o-dealkylase (erod) in the liver of oreochromis niloticus and clarias gariepinus was evaluated as a response to experimental and natural contamination of water with benzo-a-pyrene and/or cadmium. the activity was measured fluorimetrically in the hepatic s9 fraction while the content of the enzyme was measured by elisa. the response appeared as early as six hours post exposure. this study also reveled that oreochromis niloticus exhibits higher values of erod activi ... | 2007 | 19069910 |
| goussia molnarica n. sp. (apicomplexa: coccidia) infecting the gut of the freshwater catfish clarias gariepinus in egypt. | a new coccidian (apicomplexa: coccidia), goussia molnarica n. sp., is described from the gut of the african catfish clarias gariepinus bürchell, 1822. elliptical sporulated oocysts measuring 14-16 x 9-10 microm were found in the feces and in the mucus covering the epithelium in 40.6% of examined catfish specimens. in histological sections, g. molnarica macrogamonts were found, infecting the first part of the intestinal epithelium. infection prevalence was highest in april and lowest in november. ... | 2008 | 19149381 |
| effect of butachlor on antioxidant enzyme status and lipid peroxidation in fresh water african catfish, (clarias gariepinus). | the present study was undertaken to evaluate the influence of butachlor, a widely used herbicide, on antioxidant enzyme system and lipid peroxidation formation in african cat fish (clarias gariepinus). fish were exposed to sub-lethal concentrations of butachlor 1, 2, 2.5 ppm and sacrificed 24hrs after treatment. a significant increase in malondialdehyde formation was observed in the liver, kidney, gills and heart of the fish following exposure to different concentrations of butachlor. superoxide ... | 2008 | 19151438 |
| tomid parasites in fish in the olifants and comati river systems, south africa. | during parasitological field surveys of freshwater fish, sebekiid and subtriquetrid pentastome larvae were recovered from the body cavity or swim bladder of several fish species from various localities in limpopo and mpumalanga provinces, south africa. sebekia wedli was recovered from the body cavity of marcusenius macrolepidotus (mormyridae) from flag boshielo dam, limpopo province, and alofia sp. and subtriquetra rileyi were found in the swim bladder of oreochromis mossambicus (cichlidae) from ... | 2008 | 19294988 |
| new evidences for the involvement of 20beta-hydroxysteroid dehydrogenase in final oocyte maturation of air-breathing catfish. | 20beta-hydroxysteroid dehydrogenase (20beta-hsd) synthesizes 17alpha,20beta-dihdroxy-4-pregnen-3-one, the steroid required for resumption of prophase-i arrested oocytes in teleosts. though 20beta-hsd cdnas have been cloned from few fish species, its role in final oocyte maturation (fom) is still questionable. to study the role of 20beta-hsd in fom more explicitly, we cloned and characterized 20beta-hsd from ovary of air-breathing catfish, clarias gariepinus. interestingly, escherichia coli expre ... | 2009 | 19401204 |
| cloning and expression of star during gonadal cycle and hcg-induced oocyte maturation of air-breathing catfish, clarias gariepinus. | complementary dnas encoding steroidogenic acute regulatory protein (star) have been isolated from different fish species, yet the relevance of star during gonadal cycle and more importantly in final oocyte maturation has not been assessed so far. a cdna encoding star was isolated from the ovarian follicles of air-breathing catfish, clarias gariepinus. catfish star exhibited 55 to 72% identity at nucleotide level with other vertebrate orthologs. rt-pcr analysis of tissue distribution pattern demo ... | 2009 | 19409506 |
| provisional clinical chemistry parameters in the african sharptooth catfish (clarias gariepinus). | pollution affects aquatic systems worldwide and there is an urgent need for efficient monitoring. fish are generally sensitive to their environment and are thus considered to be valuable bioindicator species. the african sharptooth catfish (clarias gariepinus) is particularly important in this respect because of its very wide distribution. in order to use c. gariepinus as a bioindicator species its baseline clinical chemistry must be defined. existing data are scarce, and the objective of this w ... | 2008 | 19496313 |
| variation in the morphometrics of diplostomid metacercariae (digenea: trematoda) infecting the catfish, clarias gariepinus in tanzania. | diplostomum species are economically important worldwide due to their metacercariae which parasitize the eyes of fish, in both natural and aquaculture systems. however, their striking morphological similarity, especially at the metacercarial stage, makes species separation difficult. three closely related diplostomid metacercariae, namely diplostomum mashonense (type 3), tylodelphys sp. 1 and 2 (type 1 and 2, respectively), coexist in the cranial cavity of the catfish, clarias gariepinus from mi ... | 2010 | 19619367 |
| diversity of metazoan parasites of the african catfish clarias gariepinus (burchell, 1822) as indicators of pollution in a subtropical african river system. | the relationship between parasite species diversity and organic pollution in the upper manyame catchment, zimbabwe, was investigated between october 2006 and january 2007. the parasite assemblage comprised 13 species in total. species richness in the unpolluted sites was high; in the moderately polluted sites, it was low, while in the polluted sites, only one parasite species was encountered. component community diversity, as measured by the shannon index (h'), decreased with increase in organic ... | 2010 | 19761628 |
| effect of different temperatures on viability of seven encysted metacercariae recovered from freshwater fishes in qualyobia, egypt. | encysted metacercariae (emc) from seven trematod-zoonotic parasites were exposed to different temperature mechanisms. boiling of the infected fishes was sufficient to kill the emc, frying of fishes for five minutes was quite sufficient to inhibit the viability of emc, but frying for 10 minutes killed all emc. grilling of infected tilapia zillii was sufficient to kill emc after 10 minutes; however five minutes were sufficient only to kill emc in clarias gariepinus. regarding chilling at 5 degrees ... | 2009 | 19795748 |
| metacercariae recovered from fresh-water fishes in the vicinity of qualkyobia governorate, egypt. | a total of 410 tilapia zillii, 70 clarias gariepinus, 30 bagrus bajad and 15 chlrysichthys auratus fishes were collected from different water bodies in qualyobia governorate. microscopic examination of samples showed infection in muscles and head region (gills & branchial cavity) with encysted metacercariae in 91.7% of t. zillii, 82.85% of cl. gariepinus, 70% of b. bajad and 86.66% of ch. auratus. the highest distribution of metacercarial infection among the t. zillii was in the muscles of poste ... | 2009 | 19795754 |
| influence of ethynylestradiol and methyltestosterone on the hypothalamo-hypophyseal-gonadal axis of adult air-breathing catfish, clarias gariepinus. | adult male and female air-breathing catfish clarias gariepinus were treated with ethynylestradiol (ee(2)) and methyltestosterone (mt) at concentrations of 1microg/l, respectively for 21 days. ee(2) treatment caused disappearance of spermatids/sperm from several testicular lumen/lobules in males while mt treatment to females led to precocious ovarian development. ee(2) caused significant fluid retention in all tissues including peritoneal cavity and seminal vesicles. immunocytochemical localizati ... | 2009 | 19836846 |
| brucella infection in fresh water fish: evidence for natural infection of nile catfish, clarias gariepinus, with brucella melitensis. | brucellosis is endemic among ruminants in the nile delta region of egypt, where recent reports suggest that the incidence of human infection is increasing. in this region the practice of throwing animal waste into nile canals is common. as a result, water can be contaminated with potential zoonotic pathogens such as b. melitensis that could infect fish. this study aimed at isolating and characterizing b. melitensis from nile catfish. serum samples from 120 catfish captured from nile canals and 1 ... | 2010 | 19880265 |
| effect of clarias gariepinus cultured in contaminated water on rats. | in this study, african catfish (clarias gariepinus) were cultured in water contaminated with phthalate, benzene and cyclohexane (10 microg/ml), respectively, over a period of 65 days. they were, thereafter, used as protein source to formulate feed for albino rats (wistar strain) for 28 days. the weights of the body and selected tissues of the rats were monitored and standard enzyme assays were conducted for some enzymes in the serum. results showed that rats in cyclohexane group gained 58% where ... | 2009 | 19887379 |
| effect of thyroid hormone depletion on monoamines and expression patterns of catfish gnrh in the air-breathing catfish, clarias gariepinus. | thyroid hormone is known to have profound effect on the efficient functioning of the reproductive system. the gnrh-gondaotropin (gth) axis is the crucial axis involved in regulation of the various aspects of reproduction like spermatogenesis, synthesis of sex steroids and regulation of courting and spawning behavior. earlier study from our laboratory has shown that thyroid hormone depletion causes a decrease in gth and gnrh levels in pituitary and preoptic area, respectively. gnrh secretion in p ... | 2005 | 20035457 |
| assessment of microcystis bloom toxicity associated with wildlife mortality in the kruger national park, south africa. | based on previous necropsy results, microcystis blooms in constructed water impoundments in the kruger national park (knp) have been identified as a cause of wildlife mortality. in response to wildlife mortality during 2007, water samples, containing algal bloom material, were collected during february 2007 and july 2007 from four dams (nhlanganzwani, mpanamana, makhohlola, and sunset) in the southeastern part of the knp as part of the follow-up investigation. the toxicity of the microcystis blo ... | 2010 | 20090022 |
| cloning, expression and enzyme activity analysis of testicular 11beta-hydroxysteroid dehydrogenase during seasonal cycle and after hcg induction in air-breathing catfish clarias gariepinus. | a full-length cdna encoding 11beta-hydroxysteroid dehydrogenase type 2 (11beta-hsd2) was cloned from testis of air-breathing catfish, clarias gariepinus which showed high sequence homology to zebrafish and eel. the open reading frame of 11beta-hsd2 was then transfected to cos-7 cells, which converted 11beta-hydroxytestosterone (11-oht) to 11-ketotestosterone (11-kt). using nad(+), 11beta-hsd2 from testicular microsomes oxidized 11-oht with apparent k(m) 56+/-4nm and v(max) 55+/-6pmol/h/mgprotein ... | 2010 | 20219674 |
| tissue responses of clarias gariepinus (catfish) to experimental eimeria subepithelialis infection. | coccidial infection is a common feature in most african fishes. as a result of the chronic nature of the disease in fish, mortality is gradual (kim and paperna, 1993a) and is often overlooked in most farms, with losses becoming evident only at the end of the production cycle. this study evaluates the tissue responses of clarias gariepinus (catfish) in an experimental infection with eimeria subepithelialis using 200 laboratory-bred juveniles. four groups (a, b, c and d) of 50 juveniles each were ... | 2010 | 20439137 |
| parasite hybridization in african macrogyrodactylus spp. (monogenea, platyhelminthes) signals historical host distribution. | macrogyrodactylus spp. from the gills of clarias gariepinus in zimbabwe and kenya, and c. anguillaris in senegal were identified using haptoral sclerite morphology and by sequencing the nuclear ribosomal dna internal transcribed spacers (its) 1 and 2, partial 18s and the complete 5.8s rrna gene. a molecular phylogeny was constructed using all sequenced macrogyrodactylus species to date. based on morphology, macrogyrodactylus congolensis, m. heterobranchii, m. clarii, and m. karibae were identifi ... | 2010 | 20444301 |
| cloning and differential expression pattern of vasa in the developing and recrudescing gonads of catfish, clarias gariepinus. | vasa gene codes for a dead box family protein, which plays a crucial role in primordial germ cell proliferation. in this study, we report cloning of vasa from gonads of air-breathing catfish, clarias gariepinus, a seasonally reproducing teleost fish. we studied the expression pattern of vasa during gametogenesis using real-time pcr. we also examined the hormonal regulation on vasa in gonads of catfish. rt-pcr analysis revealed that vasa was detectable only in the gonads. further, real-time pcr r ... | 2010 | 20462517 |
| isolation of sox9 duplicates in catfish: localization, differential expression pattern during gonadal development and recrudescence, and hcg-induced up-regulation of sox9 in testicular slices. | in vertebrates, sox9 is a transcription factor that plays a crucial role in testicular development and chondrogenesis. here, we report cloning of isoforms of sox9 (sox9a and sox9b) from air-breathing catfish clarias gariepinus, which undergoes an annual reproductive cycle. tissue distribution pattern showed differential expression of sox9 duplicates, wherein both forms were highly expressed in brain and gonads. furthermore, we observed a dimorphic expression pattern of sox9a and sox9b in both ad ... | 2010 | 20584991 |
| the biological role of pituitary adenylate cyclase-activating polypeptide (pacap) in growth and feeding behavior in juvenile fish. | to date, many technologies have been developed to increase efficiency in aquaculture, but very few successful biotechnology molecules have arrived on the market. in this context, marine biotechnology has an opportunity to develop products to improve the output of fish in aquaculture. published in vivo studies on the action of the pituitary adenylate cyclase-activating polypeptide (pacap) in fish are scarce. recently, our group, for the first time, demonstrated the biological role of this neurope ... | 2010 | 20853308 |
| physiological studies on the effect of copper nicotinate (cu-n complex) on the fish, clarias gariepinus, exposed to mercuric chloride. | female catfish, clarias gariepinus, were collected from the nile river at assiut region, were divided into 7 groups. the first group was left as control, and the second was treated with mercuric chloride (mc) for 3 weeks following by normal water for 1 week. the third, fourth and fifth groups were provided by mc (150 μg/ l of water). this treatment was continued for 3 weeks. then, the fish were received cn instead of mc, for 1 week, with 15 and 25 mg cn/100 g wet food. the fifth fish group recei ... | 2010 | 20927584 |
| gender differences in tryptophan hydroxylase-2 mrna, serotonin, and 5-hydroxytryptophan levels in the brain of catfish, clarias gariepinus, during sex differentiation. | tryptophan hydroxylase (tph) is the key regulator in serotonin (5-ht) biosynthesis that stimulates the release of gnrh and gonadotropins by acting at the level of hypothalamo-hypophyseal axis. in brain, 5-ht is expressed predominantly in preoptic area-hypothalamus (poa-hyp) region in teleosts. therefore, in the present study we isolated tph2 from catfish brain to evaluate its expression pattern in male and female brains during early development. tph2 cloned from catfish brain is 2.768 kb in leng ... | 2010 | 21156177 |
| lipid peroxidation and antioxidant defense enzymes in clarias gariepinus as useful biomarkers for monitoring exposure to polycyclic aromatic hydrocarbons. | the toxicological evaluations of crude oil, xylene, toluene and benzene were carried out against juvenile stages of clarias gariepinus. on the basis of lc(50) value, benzene (0.017 ml/l) was found to be the most toxic followed by xylene (0.086 ml/l), toluene (0.398 ml/l) and crude oil (2.219 ml/l) was the least toxic. the results of the lipid peroxidation assay showed that the level of malonaldehyde (mda) in liver and gills of fish exposed to all the test chemicals increased significantly (p < 0 ... | 2011 | 21213039 |
| influence of humic acid derived from composted wastes of nigeria origin on oxidative and antioxidant status of african mud catfish (clarias gariepinus). | the utilization of organic fertilizer, a product of composted organic wastes, is being advocated in nigeria as a solid waste management alternative. the application of such products near surface water could increase organic matter load of the aquatic environment, thus increasing the humic substance concentration that influence metal speciation and bioavailability in water. in this study, humic acid (ha), a major humic substance fraction, derived from composted organic wastes of nigeria origin wa ... | 2010 | 21313906 |
| dietary administration of bacillus thuringiensis on the cellular innate immune response of african catfish (clarias gariepinus) against aeromonas hydrophila. | an experiment was conducted to evaluate the use of bacillus thuringiensis (bt) as a probiotic to enhance the cellular innate immune response of the african catfish (clarias gariepinus) challenged with a bacterial fish pathogen, aeromonas hydrophila. | 2011 | 21381499 |