Characteristics of the Egyptian African catfish (Clarias gariepinus) strain introduced to Indonesia has not been extensively explored yet, especially the red strain. Previous studies suggested that at the same body length, body weight of the red strain was higher and it was more rotund than that of the normal (black) ones. These differences need to be further investigated to find out which parts of the body mainly contributed to shape the differences. The present study was carried out to explore morphological differences of the red strain of Egyptian African catfish compared to the black strain through morphometric and meristic characterizations. Meristic and morphometric characterizations in the present study were carried out following standard method for morphological characterization of Clarias catfish. The fish samples consisted of each 35 red and black table-sized fish samples resulted from inbred and outbred spawnings. Results of the morphometric and meristic analysis in the present study revealed that the red strain of Egyptian African catfish resulted from inbred spawning of red strain brooders was morphologically different from that of either parental fishes or the black strains. At the same body length, head of the red strain was bigger (wider and longer) than other strains, and its body was stumpy (more rotund and shorter than other strains), deviated from those normal characteristics of the Egyptian African catfish. Its meristic characters were also differed from those of other strains, assigned by reduced dorsal and anal fin rays number.
Genetic improvement of the African catfish (Clarias gariepinus) in Indonesia for increasing growth performance has been conducted by Research Institute for Fish Breeding at Sukamandi through mass selection. Collection and characterizations of the founder populations, building the synthetic base population, first generation and second generation through mass selection were conducted during 2010-2013. Later, in 2014 it was followed by building the third generation. The present study aimed to find out the genetic gain in the third generation in term of response to selection for body weight. Fifty-two pairs of the selected (fast growing) individuals from the second generation were mated to produce the third generation. As a comparison, five pairs of average-sized individuals were mated to produce the control population, as a second generation representative. Larval rearing, nursery and grow-out phases were respectively held for 25 days in the aquaria, 30 days in the concrete ponds and 60 days in the concrete ponds. At the end of each phase, individual samplings of body weight were undertaken. The results showed that mean body weight of the third generation was higher than that of control population at the end of larval rearing phase (0.21 Â± 0.26 g versus 0.20 Â± 0.15 g), nursery phase (6.12 Â± 2.93 g versus 5.80 Â± 3.50 g) and grow-out phase (198.67 Â± 82.82 g versus 165.22 Â± 71.09 g). Those results revealed that response to selection for body weight of the third generation was positive, i.e. about 20.24% (33.45 g).
Inbreeding has been one of central issues with regard to genetic quality of aquacultureÂ species, including giant fresh water prawn (GFP). Conventional methods for theÂ estimation of inbreeding level are available, such as pedigree analyses which requiresÂ a good pedigree record which, unfortunately, is rarely available. Likewise,Â microsatellite molecular markers commonly applied to obtain the coefficientÂ inbreeding estimates are both laborious and expensive. Hence, an alternative methodÂ of inbreeding assessment which is relatively easy but reliable is in need. This studyÂ was aimed to explore the applicability of RAPD fingerprinting, which is known to beÂ simple and affordable, to estimate inbreeding level of GFP population. Three GFPÂ populations namely inbred, outbred, and farm populations with inbreeding level ofÂ 25%, 0%, and unknown, respectively, were genotyped using five polymorphic RAPDÂ primers. The inbreeding levels mentioned within the first two populations wereÂ determined using pedigree analysis. RAPD banding patterns were then used toÂ calculate band sharing index (BSI) and inbreeding coefficient (F). Assessment of theÂ applicability of inbreeding level estimates obtained by RAPD markers was performedÂ by comparing them to those estimated by pedigree analysis. Results show that RAPDÂ fingerprinting was capable of delineating populations differing in their inbreedingÂ coefficients. The pattern resulted from molecular inbreeding coefficient within theÂ inbred and outbred groups, was congruent with that shown by pedigree analysis,Â while the farm population showed closeness to the inbred group. While the accuracyÂ of the estimate needs to be verified further, this study suggests that RAPDÂ fingerprinting is applicable to estimate population inbreeding level, particularly dueÂ to its technical simplicity and cost affordability.
Genetic diversity at molecular level has been assumed to correlate with fitness related traits. However,Â accumulating evidences showed that the nature of that correlation has been variable. This study was aimedÂ to explore the nature and possible mechanisms underlying that correlation by focusing on growth relatedÂ traits in African catfish, Clarias gariepinus using microsatellite molecular markers. Fifty individual AfricanÂ catfish of 110 days-old were sampled and subjected to both morphological and molecular analyses. TheÂ standard length, total length and body weight as well as allelic scores of six microsatellite loci wereÂ measured on each individual. Indices of microsatellite diversity, namely individual multilocus heterozygosityÂ (MLH) and mean microsatellite allelic distance (mean d2) for individual level, and mean observedÂ heterozygosity (Ho) and single-locus heterozygosity (ho) for group level, were correlated to those traitsÂ using Pearson correlation coefficient (r). The Hardy Weinberg and linkage disequilibrium were carried outÂ to explore the possible mechanisms underlying correlation. The results showed that at individual level theÂ MLH and mean d2 were weakly correlated with standard length, (r=0.25, p<0.05) and (r=0.24, p<0.05),Â respectively. At group level, Ho was correlated with both standard and total length (r=0.99, p<0.05) whileÂ ho identified two loci, Cga03 and Cga06 significantly contributed to the correlation. Combining all relevantÂ information, present study identified associative overdominance, both local effect and general effectÂ hypotheses might responsible for the observed correlations.
Heritability estimates of commercially important traits are of important in order to seek the best strategy of selective breeding program to be implemented. A study aimed at estimating the magnitude of this parameter for growth related traits, expressed in wet weight (WW), total length (TL), and standard length (SL), has been carried out in giant freshwater prawn (GFP). Particular emphasis was given to investigate the effect of ages and culture conditions on the magnitude of the heritability estimates. Nineteen full-sib families were established through individual pair mating. The families, namely groups of offsprings derived from each mating pair were raised through three stages of rearing activities: first-stage nursery (40 days), second-stage nursery (70 days), and grow-out rearing (130 days). Heritability for growth at each stage was estimated through the method of full-sib analysis or intraclass correlation. Components of variance used to produce the heritability estimates were obtained through the method of analysis of variance. Results showed that heritability estimates varied with both ages and culture conditions. The heritability estimates (Â± standard errors) at 40 days for WW (0.69Â±0.151), TL (0.64Â±0.148), and SL (0.70Â±0.144) were higher than those observed at 70 days (WW = 0.24Â±0.15; TL = 0.22Â±0.15; and SL = 0.20Â±0.14) and 130 days (WW = 0.24Â±0.058; TL = 0.22Â±0.05; and SL = 0.20Â±0.60). A similar pattern was found with respect to the culture conditions. The estimates found in grow-out at lower stocking density (5 individual/ m2) days (WW = 0.24Â±0.058; TL = 0.22Â±0.05; and SL = 0.20Â±0.60) were higher than those observed at grow out at higher stocking density (20 individuals/m2) days (WW = 0.12Â±0.058; TL = 007Â±0.05; and SL = 0.14 Â± 0.60). The possible causes of the observed patterns and implications that these findings may have on the breeding program of GFP are discussed.
Indonesia is rich of giant fresh water prawn (GFP) germ plasms. Best utilization ofÂ these resources for the purpose of either aquaculture development or conservationÂ of genetic resources requires some information on the structure and levels of theirÂ genetic diversity. This study was aimed to characterize those GFP genetic resourcesÂ by applying RAPD genetic markers. Six Indonesian populations of GFP from Asahan,Â Barito, Ciasem, Ogan, GImacro and Papua were collected and analyzed for their geneticÂ variation using five RAPD primers. The results showed the diversity within theÂ populations, as revealed by the level of polymorphism, ranged from 29% to 76% whileÂ genetic divergence between populations as shown by genetic distance rangedÂ from 0.04 to 0.50. In terms of genetic divergence, two genetically distinct groups ofÂ GFP, namely the Papua GFP in one group and the remaining five GFP populations in theÂ other, were identified. The results also showed the presence of specific populationÂ markers that are useful for genetic identification of GFP populations. Implication ofÂ these finding with regard to breed development is discussed.
African catfish (Clarias gariepinus Burchell, 1822) has become a great important species in IndonesianÂ aquaculture. Several strains of the African catfish have been introduced to Indonesia for aquacultureÂ purposes, initiated by Dumbo strain from Taiwan in 1985, followed by Paiton strain from Thailand in 1998,Â then Egypt strain from Egypt in 2007, Masamo strain from Thailand in 2010 and later Kenya strain fromÂ Kenya in 2011. Since its introductions, there were no reports yet on their characterization studies. TheÂ present study was conducted to morphologically characterize the strains of African catfish introduced toÂ Indonesia, i.e. Dumbo, Paiton, Egypt, Masamo, and Kenya strains. Morphometric and meristic data obtainedÂ were analyzed using Principal Component Analysis. Results of the morphometric characterization in theÂ present study revealed that Dumbo, Paiton, Masamo, and Kenya strains were indistinguishable, whileÂ morphometric characteristic of Egypt strain was more or less different from those of the other strains. OnÂ the other hand, results of the meristic characterization suggested that meristic characteristics of all strainsÂ of the introduced African catfish were not different from each other. Therefore, to keep the genetic purityÂ of those introduced strains, they should be properly maintained in isolated places.
We have previously produced F-1 transgenic of African catfish from crosses between founder transgenic female and non transgenic male. The aim of this study was to evaluate distribution and expression PhGH growth hormone gene transgenic African catfish organs and to measure the concentration of IGF-I in plasma. Transgene was detected using the PCR method in various organs, namely pituitary, brain, liver, heart, spleen, kidney, intestine, stomach, muscle, gill, and eye. Transgene expression levels were analyzed using the method of quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR). Plasma samples were analyzed for Insuline-like Growth Factor (IGF-I) using Enzyme Linked Immunosorbent Assay (ELISA) method. The results showed that the PhGH was detected and expressed in all organs of the transgenic African catfish (F-1). Liver exhibited the highest level of PhGH mRNA (23 x 106 copies). The plasma IGF-I levels in transgenic individuals were not significant than non transgenic. The higher level of exogenous PhGH gene expression may not represent the production of IGF-1.
One of the important issues in catfish farming is motile aeromonad septicaemia (MAS) disease caused by the bacterium Aeromonas hydrophila. This study aimed to find the MHC-II marker potential for marker-based selection to generate MAS disease resistance of African catfish. PCR method was applied to identify catfish (body length: 7-8 cm) population that have MHC-II marker. Fish with and without the marker were then challenged by intraperitonially injecting of 0.1 mL/fish with A. hydrophila (105 cfu/mL). The results showed that the survival of fish having MHC-II marker (77.50 Â± 4.00%) was higher than that of fish without the marker (53.33 Â± 4.77%). Fish carrying MHC-II marker fish has also higher total erythrocytes, total leukocytes, phagocytic activity, and hematocrit levels than that of fish without the marker. The PCR results using specific primer for MHC-II showed a specific DNA band of 426 bp in fish having the marker, while there were no DNA bands in fish without the marker. Results of the PCR analyses showed that the percentage of progenies carrying MHC-II marker was 80%, while progenies from broodstock without the marker was 0%; this indicated that MHC-II marker could be inherited to the offsprings. Thus, the MHC-II marker could be used as a molecular marker of MAS disease resistance catfish.
In previous study, the fast growth transgenic founder of African catfish was producedÂ harboring a growth hormone (GH) gene construct containing a stripped catfish growthÂ hormone (PhGH) cDNA. This study was conducted to investigate transgene (PhGH)Â transmission and expression in F-1 transgenic African catfish. The transgenic foundersÂ (female) were crossed with non-transgenic (male) to produce heterozygous F-1Â progeny. PhGH gene was detected in the embryo, larvae, and seed of the transgenicÂ F-1 using PCR method. Expression levels of transgene in embryo and larvae wereÂ analyzed using real-time quantitative PCR (qPCR) method. The transgene was detectedÂ in embryo, larvae and seed of F-1 transgenic African catfish. Founder could transmitÂ PhGH gene to transgenic F-1 lines in ranged 36% to 48%. Expression level of PhghÂ gene in embryo was higher than that of the larvae; whereas in the embryo was 1.5 xÂ 105 - 5.2 x 105 copies or 0.49-9.82 fold, while in the larvae was 1.1 x 105 - 2.5 x 105copies or 0.19-5.80 fold.Â