Successful crossbreeding between Oreochromis niloticus and Sarotherodon melanotheron to produce a commercial hybrid has been difficult.The karyotypes and isoenzyme of these two species and their reciprocal hybrids（O....Successful crossbreeding between Oreochromis niloticus and Sarotherodon melanotheron to produce a commercial hybrid has been difficult.The karyotypes and isoenzyme of these two species and their reciprocal hybrids（O.niloticus ♀ × S.melanotheron ♂,S.melanotheron ♀ × O.niloticus ♂,the last not included in the isoenzyme study） were investigated via metaphase chromosomes obtained from head kidney cells and electropherogram of lactate dehydrogenase（LDH） isoenzymes from the liver,kidney,white muscle,heart,and eye balls.The diploid chromosome number（2n=44） and the fundamental number（NF=50） of the four tilapia genotypes were the same.However,the karyotype of O.niloticus had three pairs of sub-metacentric（sm）,twelve pairs of sub-telocentric（st）,and seven pairs of telocentric（t） chromosomes,while S.melanotheron had one pair of metacentric（m）,two pairs of sm,12 pairs of st,and seven pairs of t chromosomes.The reciprocal hybrids both showed a mixed karyotype range between their parents：0.5 pair of m,2.5 pairs of sm,12 pairs of st,and seven pairs of t chromosomes.In view of the electropherogram of isozymes,only the LDH of the kidney showed significant clear bands,with five bands in O.niloticus,three bands in S.melanotheron,and duplicated six bands in the hybrids.The bands varied depending on their activities and mobilities.We considered that the differences in karyotype and isoenzyme were related to the genetic mechanism for post-mating isolation,and provided some additional basic genetic background of their taxonomy.展开更多
Alterations in blood variables of Sarotherodon melanotheron transmitted immediately from brackish water(salinity 13.71‰)to fresh water(salinity 0.12‰)were examined to evaluate the consequence of abrupt alterations i...Alterations in blood variables of Sarotherodon melanotheron transmitted immediately from brackish water(salinity 13.71‰)to fresh water(salinity 0.12‰)were examined to evaluate the consequence of abrupt alterations in the environment on fish blood parameters.The results acquired revealed that significant reduction(p<0.05)in mean values of Haemoglobin(Hb)from 7.37±1.22 to 4.30±0.82dl-1;Packed Cell Volume(PCV)23.48±3.22 to 15.08±2.97%;Red Blood Cell(RBC)5.99±0.72 to 3.31±0.77 Cells x106;Mean Corpuscular Haemoglobin Concentration(MCHC)31.68±3.66 to 28.48±2.03 pg;and Platelets(PLT)195.44±16.77 to 138.99±9.05103 uL-1.However,notable elevation was recorded in the values of Erythrocyte Sedimentation Rate(ESR)from 4.89±0.16 to 10.58±1.48 mm/hr;White Blood Cell(WBC)27.03±2.96 to 33.09±3.72 x 109 L-1;Mean Corpuscular Volume(MCV)39.33±3.07 to 45.88±7.03 fL Neutrophils(NEUT)41.71±3.08 to 48.30±7.99%;Lymphocytes(LYMP)54.60±3.99 to 46.36±9.87%and Monocytes(MON)3.80±1.04 to 5.97±1.99%.These variations in the blood parameters were more perceptible in adult than juvenile fish.Results from this study consequently imply that direct transfer of fish to a region of lower salinity may have damaging effect on the physiology of S.melanotheron as observed in this study.展开更多
The baseline study profiled Black-chin Tilapia(Sarotherodon.melanotheron),a fish farm pest species in Bataan,Philippines,in terms of yield(processing and fillet),proximate composition(moisture,ash,crude fat,and crude ...The baseline study profiled Black-chin Tilapia(Sarotherodon.melanotheron),a fish farm pest species in Bataan,Philippines,in terms of yield(processing and fillet),proximate composition(moisture,ash,crude fat,and crude protein),heavy metal load(cadmium[Cd],lead[Pb],arsenic[As],and mercury[Hg]),and microbial count(aerobic plate,Escherichia coli,and Staphylococcus aureus counts).The purpose was to establish the species’safety and quality for consumption and potential utilization in the processing of higher value fishery products.A completely randomized experiment using two factors,fish size(standard and small sizes)and collection season(dry and wet seasons),was employed.The collected data were also compared against food consumption and processing standards and/or previous reports on more valuable species.The results showed that the species has a comparable yield and mineral load with the more popular farmed Nile Tilapia(Oreochromis niloticus).It has high moisture and protein compositions.It is a lean fish that can serve as a cheaper functional raw material for processed fishery products.Moreover,the results showed that the species have no As,Cd,and Pb contamination,although traces of Hg,far below the permissible limits,were detected.The Hg load varies across collection season and fish maturity suggesting its manageability.For the microbial contents,the species’aerobic plate,Escherichia coli,and Staphylococcus aureus counts were far below the standard limits,although best post-capture practices are still suggested due to the kind of microbial parameters measured.It was concluded that the Sarotherodon melanotheron infesting Bataan farm ponds can be consumed safely and has the quality of potential raw material for processed fishery products.However,further information is still needed to establish the best post-capture handling on the species.Also,more studies must be done to determine the impact of storage and processing on its stability.展开更多
Length-weight relationship(LWR),condition factor(k)of the black chin tilapia,Sarotherodon melanotheron(Rüppel,1852)from Forcados River estuary Nigeria was investigated.The fish were collected monthly from fisherm...Length-weight relationship(LWR),condition factor(k)of the black chin tilapia,Sarotherodon melanotheron(Rüppel,1852)from Forcados River estuary Nigeria was investigated.The fish were collected monthly from fishermen for a period of 24 months(between April 2012 and March 2014).699 specimens of the fish species were collected.The Length-weight relationship(LWR)of the fish was evaluated using the equation:W=a L^(b) while the condition factor of the fish was determined using the equation;K=100W L^(b).The standard length of sampled S.melanotheron ranged from 4.15 to 18.92 cm,total length 6.01 and 22.5 cm while the weight ranged from 7.85-286.71 g.The b value 2.1299 was less than 3 indicating that the growth pattern of the fish was allometric.The correlation co-efficient(r)value for S.melanotheron was 0.7528.The condition factor for the combined sexes fluctuated monthly.The length-weight relationships and condition factor of S.melanotheron in Forcados river estuary indicated that the fish were above average condition.展开更多
Using microsatellite markers with 10 pairs of primers,genetic structure of Oreochromis niloticus,Sarotherodon melanotheron and their hybrids were analyzed.The results suggested that:① Six pairs of primers showed a ri...Using microsatellite markers with 10 pairs of primers,genetic structure of Oreochromis niloticus,Sarotherodon melanotheron and their hybrids were analyzed.The results suggested that:① Six pairs of primers showed a rich polymorphic,which can be used as genetic markers for the genetic diversity study of these tilapias.② The analysis based on the six pairs of primers showed that the average heterozygosity(H)ranged as:O.niloticus ♀× S.melanotheron♂(0.725),S.melanotheron ♀ × O.niloticus ♂(0.692),S.melanotheron(0.537),O.niloticus(0.485).The highest effective numbers of alleles(Ne)existed in O.niloticus♀×S.melanotheron♂(3.79),the lowest existed in S.melanotheron(1.92).The average polymorphism information content(PIC)of 4 tilapias was 0.584,the rank from high to low as,O.niloticus ♀ × S.melanotheron ♂(0.668),S.melanotheron ♀× O.niloticus ♂(0.643),O.niloticus(0.375),S.melanotheron(0.333).③ The fact of enhanced heterozigosity of hybrids suggested that there were the genetic basement of cross breeding in tilapia.展开更多
文摘Successful crossbreeding between Oreochromis niloticus and Sarotherodon melanotheron to produce a commercial hybrid has been difficult.The karyotypes and isoenzyme of these two species and their reciprocal hybrids（O.niloticus ♀ × S.melanotheron ♂,S.melanotheron ♀ × O.niloticus ♂,the last not included in the isoenzyme study） were investigated via metaphase chromosomes obtained from head kidney cells and electropherogram of lactate dehydrogenase（LDH） isoenzymes from the liver,kidney,white muscle,heart,and eye balls.The diploid chromosome number（2n=44） and the fundamental number（NF=50） of the four tilapia genotypes were the same.However,the karyotype of O.niloticus had three pairs of sub-metacentric（sm）,twelve pairs of sub-telocentric（st）,and seven pairs of telocentric（t） chromosomes,while S.melanotheron had one pair of metacentric（m）,two pairs of sm,12 pairs of st,and seven pairs of t chromosomes.The reciprocal hybrids both showed a mixed karyotype range between their parents：0.5 pair of m,2.5 pairs of sm,12 pairs of st,and seven pairs of t chromosomes.In view of the electropherogram of isozymes,only the LDH of the kidney showed significant clear bands,with five bands in O.niloticus,three bands in S.melanotheron,and duplicated six bands in the hybrids.The bands varied depending on their activities and mobilities.We considered that the differences in karyotype and isoenzyme were related to the genetic mechanism for post-mating isolation,and provided some additional basic genetic background of their taxonomy.
文摘Alterations in blood variables of Sarotherodon melanotheron transmitted immediately from brackish water(salinity 13.71‰)to fresh water(salinity 0.12‰)were examined to evaluate the consequence of abrupt alterations in the environment on fish blood parameters.The results acquired revealed that significant reduction(p<0.05)in mean values of Haemoglobin(Hb)from 7.37±1.22 to 4.30±0.82dl-1;Packed Cell Volume(PCV)23.48±3.22 to 15.08±2.97%;Red Blood Cell(RBC)5.99±0.72 to 3.31±0.77 Cells x106;Mean Corpuscular Haemoglobin Concentration(MCHC)31.68±3.66 to 28.48±2.03 pg;and Platelets(PLT)195.44±16.77 to 138.99±9.05103 uL-1.However,notable elevation was recorded in the values of Erythrocyte Sedimentation Rate(ESR)from 4.89±0.16 to 10.58±1.48 mm/hr;White Blood Cell(WBC)27.03±2.96 to 33.09±3.72 x 109 L-1;Mean Corpuscular Volume(MCV)39.33±3.07 to 45.88±7.03 fL Neutrophils(NEUT)41.71±3.08 to 48.30±7.99%;Lymphocytes(LYMP)54.60±3.99 to 46.36±9.87%and Monocytes(MON)3.80±1.04 to 5.97±1.99%.These variations in the blood parameters were more perceptible in adult than juvenile fish.Results from this study consequently imply that direct transfer of fish to a region of lower salinity may have damaging effect on the physiology of S.melanotheron as observed in this study.
文摘The baseline study profiled Black-chin Tilapia(Sarotherodon.melanotheron),a fish farm pest species in Bataan,Philippines,in terms of yield(processing and fillet),proximate composition(moisture,ash,crude fat,and crude protein),heavy metal load(cadmium[Cd],lead[Pb],arsenic[As],and mercury[Hg]),and microbial count(aerobic plate,Escherichia coli,and Staphylococcus aureus counts).The purpose was to establish the species’safety and quality for consumption and potential utilization in the processing of higher value fishery products.A completely randomized experiment using two factors,fish size(standard and small sizes)and collection season(dry and wet seasons),was employed.The collected data were also compared against food consumption and processing standards and/or previous reports on more valuable species.The results showed that the species has a comparable yield and mineral load with the more popular farmed Nile Tilapia(Oreochromis niloticus).It has high moisture and protein compositions.It is a lean fish that can serve as a cheaper functional raw material for processed fishery products.Moreover,the results showed that the species have no As,Cd,and Pb contamination,although traces of Hg,far below the permissible limits,were detected.The Hg load varies across collection season and fish maturity suggesting its manageability.For the microbial contents,the species’aerobic plate,Escherichia coli,and Staphylococcus aureus counts were far below the standard limits,although best post-capture practices are still suggested due to the kind of microbial parameters measured.It was concluded that the Sarotherodon melanotheron infesting Bataan farm ponds can be consumed safely and has the quality of potential raw material for processed fishery products.However,further information is still needed to establish the best post-capture handling on the species.Also,more studies must be done to determine the impact of storage and processing on its stability.
文摘Length-weight relationship(LWR),condition factor(k)of the black chin tilapia,Sarotherodon melanotheron(Rüppel,1852)from Forcados River estuary Nigeria was investigated.The fish were collected monthly from fishermen for a period of 24 months(between April 2012 and March 2014).699 specimens of the fish species were collected.The Length-weight relationship(LWR)of the fish was evaluated using the equation:W=a L^(b) while the condition factor of the fish was determined using the equation;K=100W L^(b).The standard length of sampled S.melanotheron ranged from 4.15 to 18.92 cm,total length 6.01 and 22.5 cm while the weight ranged from 7.85-286.71 g.The b value 2.1299 was less than 3 indicating that the growth pattern of the fish was allometric.The correlation co-efficient(r)value for S.melanotheron was 0.7528.The condition factor for the combined sexes fluctuated monthly.The length-weight relationships and condition factor of S.melanotheron in Forcados river estuary indicated that the fish were above average condition.
文摘Using microsatellite markers with 10 pairs of primers,genetic structure of Oreochromis niloticus,Sarotherodon melanotheron and their hybrids were analyzed.The results suggested that:① Six pairs of primers showed a rich polymorphic,which can be used as genetic markers for the genetic diversity study of these tilapias.② The analysis based on the six pairs of primers showed that the average heterozygosity(H)ranged as:O.niloticus ♀× S.melanotheron♂(0.725),S.melanotheron ♀ × O.niloticus ♂(0.692),S.melanotheron(0.537),O.niloticus(0.485).The highest effective numbers of alleles(Ne)existed in O.niloticus♀×S.melanotheron♂(3.79),the lowest existed in S.melanotheron(1.92).The average polymorphism information content(PIC)of 4 tilapias was 0.584,the rank from high to low as,O.niloticus ♀ × S.melanotheron ♂(0.668),S.melanotheron ♀× O.niloticus ♂(0.643),O.niloticus(0.375),S.melanotheron(0.333).③ The fact of enhanced heterozigosity of hybrids suggested that there were the genetic basement of cross breeding in tilapia.
