Dietary requirement of tryptophan for growth and survival of the Indian major carp, Cirrhinus mrigala (Hamilton-Buchanan) fry

The experimental diets (40% protein) contained graded levels of tryptophan (0.60, 0.75, 1.00, 1.25, 1.50, 1.75%) of dietary protein. Each test diet was fed to triplicate groups of mrigal fry twice daily at 10% of the total biomass for 8 weeks. The dietary tryptophan requirement was estimated by plotting weight gain against dietary levels of tryptophan using two separate regression equations, the point of intersection of two equations was taken as optimum level, which occurred at 0.48% of the diet (1.20% of dietary protein).     

Goat serum as an alternative to establish cell culture from Indian major carp, Cirrhinus mrigala

Serum from goat, calf, and chicken sources were evaluated in terms of attachment, growth, and proliferation of explants of Indian major carp, Cirrhinus mrigala. The attachment of explants viz. heart, liver, and kidney was directly proportional to the concentration of the serum. Among these sera, the highest percentage of attachment, growth, and proliferation was recorded for 10% goat serum and 15% newborn calf serum without affecting their cell morphology. On contrary to these sera, chicken serum at 15% concentration was found to be mildly toxic for all the explants. The cell count was significantly high for the kidney, liver, and heart at 10% goat serum among all the tested sera as well as concentration. Similarly, the liver, heart, and kidney explants were found to survive up to the tenth, seventh, and ninth passage, respectively. Therefore, the goat serum at 10% concentration can be used as effectively as newborn calf serum for routine culture of fish cells.     

Dietary total aromatic amino acid requirement and tyrosine replacement value for phenylalanine in Indian major carp: Cirrhinus mrigala (Hamilton) fingerlings

Two 8‐week growth trials were conducted to determine total aromatic amino acid requirement and tyrosine replacement value for phenylalanine in Cirrhinus mrigala fingerlings. To determine the phenylalanine requirement, 20 fish were randomly stocked in triplicate groups in 55‐L indoor polyvinyl flow‐through circular tanks and fed six experimental diets containing graded levels of phenylalanine (5.0, 7.5, 10.0, 12.5, 15.0 and 17.5 g kg^?1, dry diet) with 10 g kg^?1 tyrosine. Maximum weight gain (287%), best FCR (1.44) and PER (1.74) occurred at 12.5 g kg^?1 dietary phenylalanine. Quadratic regression analysis of weight gain, FCR and PER data indicated phenylalanine requirement at 13.5, 12.9 and 12.7 g kg^?1 of dry diet, respectively. Protein deposition was significantly (P < 0.05) higher at 12.5 g kg^?1 dietary phenylalanine. Based on the above results, phenylalanine requirement of C. mrigala is recommended at 13.0 g kg^?1 of dry diet, corresponding to 32.5 g kg^?1 of protein. On the basis of the above requirement, a second experiment with a similar design was conducted using six diets containing graded levels of tyrosine (2.1, 4.0, 6.0, 8.0, 10.0 and 12.0 g kg^?1) with 13.0 g kg^?1 phenylalanine fixed in all diets to determine the phenylalanine replacement value with that of tyrosine. Maximum weight gain (315%), best FCR (1.47) and PER (1.69) was at 8.0 g kg^?1 dietary tyrosine. Quadratic regression analysis of weight gain, FCR and PER data indicated tyrosine requirement at 9.0, 8.4 and 8.2 g kg^?1 of dry diet, respectively. Protein deposition was significantly (P < 0.05) higher at 8.0 g kg^?1 dietary tyrosine. On the basis of the above results, 8.5 g kg^?1 tyrosine, corresponding to 21.3 g kg^?1 of protein, is taken as the optimum requirement and the replacement value is 39.53% on a weight and 36% on a molar basis. Thus, the total aromatic amino acid requirement is 21.5 g kg^?1 of diet, corresponding to 53.8 g kg^?1 of protein for optimum C. mrigala growth.     

Seasonal variations in the histology of the pituitary gland of Cirrhinus mrigala (Ham.) an Indian freshwater major carp, in relation to gonadal activity.

1. Seasonal variations in the histology of the pituitary gland of Cirrhinus mrigala (Ham.), an Indian freshwater major carp, in relation to gonadal activity has been studied during a one year period commencing, January, 1971. 2. The proximal pars distalis undergoes a great deal of seasonal variation in size, weight and nature of pituicytes. 3. The percentage composition of acidophils and cyanophils in the proximal pars distalis show a reciprocal relationship during the year. The acidophils predominate during the restitution phase of the gonads while the cyanophils preponderate among the different cell types during the breeding season. 4. The chromophobes do not show any significant fluctuation in numerical abundance in relation to gonadal activity. 5. Cyanophils of the proximal pars distalis undergo changes with change in gonadal activity Concentration of glycoproteinaceous material is extremely low during the restitution phase but high during the maturation phase. The cyanophils also undergo hypertrophy and hyperplasia during the spawning period. The latter discharge their contents and become vacuolated during the post spawning period. 6. The number and size of the globules in the cyanophils are related to gonadal activity. 7. Acidophils present in the rostral pars distalis and pars intermedia do not appear to be related to gonadal activity in C. mrigala. 8. The average weight of the gland is directly related to the state of maturation of the gonads, an observation being recorded here for the first time.     

Short-term mercury exposure on Na+/K+-ATPase activity and ionoregulation in gill and brain of an Indian major carp,Cirrhinus mrigala

Recently mercury pollution has been increased considerably in aquatic resources throughout the world and it is a growing global concern. In this study, the 96 h LC50 value of waterborne mercuric chloride for Cirrhinus mrigala was found to be 0.34 mg/L (with 95% confidence limits). Fingerlings of C. mrigala were exposed to 0.068 and 0.034 mg/L of mercuric chloride for 96 h to assess the Na⁺/K⁺-ATPase activity and ionoregulation (Na⁺, K⁺ and Cl^?) in gill and brain. Results showed that Na⁺/K⁺-ATPase activity and ionic levels (Na⁺, K⁺ and Cl^?) in gill and brain of fish exposed to different concentrations of mercuric chloride were found to be significantly (p < 0.05) decreased throughout the study period. Mercury inactivates many enzymes by attaching to sulfur atoms in which the enzyme Na⁺/K⁺-ATPase is highly sensitive to mercury. The inhibition of gill and brain Na⁺/K⁺-ATPase activity might have resulted from the physicochemical alteration of the membrane due to mercury toxicity. Moreover, inhibition of Na⁺/K⁺-ATPase may affect the ion transport and osmoregulatory function by blocking the transport of substances across the membrane by active transport. The present study indicates that the alterations in these parameters can be used in environmental biomonitoring of mercury contamination in aquatic ecosystem.     

Cross-priming of microsatellite loci in subfamily cyprininae (family Cyprinidae): their utility in finding markers for population genetic analysis in three Indian major carps

This study is aimed to identify polymorphic microsatellite markers and establish their potential for population genetics studies in three carp (family cyprinidae; subfamily cyprininae) species, Labeo rohita, Catla catla and Cirrhinus mrigala through use of cyprinid primers. These species have high commercial value and knowledge of genetic variation is important for management of farmed and wild populations. We tested 108 microsatellite primers from 11 species belonging to three different cyprinid subfamilies, Cyprininae, Barbinae and Leuciscinae out of which 63 primers (58.33 %) successfully amplified orthologous loci in three focal species. Forty-two loci generated from 29 primers were polymorphic in these three carp species. Sequencing of amplified product confirmed the presence of SSRs in these 42 loci and orthologous nature of the loci. To validate potential of these 42 polymorphic loci in determining the genetic variation, we analyzed 486 samples of three focal species collected from Indus, Ganges and Brahmaputra river systems. Results indicated significant genetic variation, with mean number of alleles per locus ranging from 6.80 to 14.40 and observed heterozygosity ranging from 0.50 to 0.74 in the three focal species. Highly significant (P < 0.00001) allelic homogeneity values revealed that the identified loci can be efficiently used in population genetics analysis of these carp species. Further, thirty-two loci from 19 primers were useful for genotyping in more than one species. The data from the present study was compiled with cross-species amplification data from previous results on eight species of subfamily cyprininae to compare cross-transferability of microsatellite loci. It was revealed that out of 226 heterologous loci amplified, 152 loci that originated from 77 loci exhibited polymorphism and 45 primers were of multispecies utility, common for 2–7 species.     

Multi-species probiotics improve growth,intestinal microbiota and morphology of Indian major carp mrigal Cirrhinus cirrhosus

This study aimed to examine the effects of multi-species probiotic on growth, hematological status, intestinal microbes, and intestinal morphology of mrigal (Cirrhinus cirrhosus). The mrigal fries (average weight 0.51 g) were reared for 60 days by supplementing multi-species probiotics containing Bacillus spp. (1 × 10⁹ cfu/mL) and Lactobacillus spp. (1 × 10¹¹ cfu/mL) in the raising water at doses of 0 (control), 0.5, and 1.0 mL/L. The results indicated that fish reared with multi-species probiotics showed significantly higher growth performance and feed efficiency where the survival rate was similar in all cases. Accordingly, significant higher red blood cell (RBC) and white blood cell (WBC) were counted from the fish reared with multi-species probiotic. There was a considerable difference in bacterial microbiota between the experimental and control group. Multi-species probiotics significantly enhanced the length, width, and villus area. Several immune response indicators like fattening of intestinal mucosal fold, width of lamina propria, the width of enterocytes, and abundance of goblet cells were also increased significantly in fish that received multi-species probiotics. This study revealed that multi-species probiotics can significantly contribute to the growth of mrigal through upgrading intestinal microbiota and morphology, which can be suggested as an eco-friendly growth stimulator in mrigal farming.     

Acute and sublethal effects in an Indian major carp Cirrhinus mrigala exposed to silver nitrate: Gill Na+/K+-ATPase, plasma electrolytes and biochemical alterations

Due to prolonged use of silver in many applications, it enters into the freshwater and affects the aquatic organisms. Fingerlings of Cirrhinus mrigala were exposed to acute and sublethal concentrations of silver nitrate and the alterations of gill Na(+)/K(+)-ATPase, plasma electrolytes and biochemical parameters were assessed. The median lethal concentration of silver nitrate to the fish C. mrigala for 96 h was found to be 0.107 mg/l (with 95% confidence limits). 1/10th of LC 50 96 h value (0.0107 mg/l) was selected for sublethal study. During acute treatment branchial Na(+)/K(+)-ATPase activity was inhibited approximately 44.34% after 96 h of exposure. In sublethal treatment, silver nitrate could not produce a significant change in the activity of the enzyme at the end of 7th day. However, after 14th day, significant (p < 0.05) decrease was noted showing 22.52%-49.11% in rest of the study period. Silver intoxication resulted hyponatremia, hypokalemia, hypochloremia, and hypoproteinemia in both the treatments. Despite the decrease in these parameters, plasma glucose level was found to be increased in both the treatments to endure the silver toxicity. We suggest that the alterations in branchial Na(+)/K(+)-ATPase activity, plasma electrolytes, and biochemical parameters of fish may be useful in environmental biomonitoring and to assess the health of fish in freshwater habitat contaminated with silver.     

Responses of isolated scale melanophores of a fresh water carp,Cirrhinus mrigala (Ham.) to zidovudine

Zidovudine (AZT) induced concentration related aggregation in C. mrigala melanophores. Denervated melanophores failed to respond to AZT. Specific and nonspecific alpha adrenoceptor antagonists completely blocked the responses of fish melanophores to AZT. Histamine and prostaglandin antagonists also inhibited aggregation of the melanophores induced by AZT. The results suggest that AZT may release a mixture of neurotransmitter like substances, which cause the aggregation of this fish melanophores.     

On the origin, development and probable functions of taste bud in the lip and bucco-pharyngeal epithelia of an Indian freshwater major carp, Cirrhinus mrigala (Hamilton) in relation to food and feeding habits.

1. Various developmental stages of taste bud have been observed in the fry, fingerling and adult of Cirrhinus mrigala (Hamilton). 2. The fries are zooplankton-feeders (carnivorous) and sight-feeders. Therefore, functional taste buds are absent in the lip and bucco-pharyngeal epithelia. Only formative stages of taste bud are present. Some epithelial cells aggregate together to form this structure which has no function in gustation. Moreover, the fires have low R. L. G. valle (0.71;..1.20) due to the carnivorous diet. 3. In the fingerling, the stages of elongation, differentiation and maturation of taste bund develop from the formative stage present in the fries in order to adjust to changed food and feeding habit. The value of R. L. G; (1.21...3.10) also increases. 4. Fully formed taste buds along with the stage of differentiation are found in the adult stage. The adult fish becomes herbivorous and bottom-feeder. Consequently, the value of R.L.G. 3.11...12) becomes highest in this stage.     

Evidence for presence of GABA-ergic receptor mediated dispersion in isolated scale melanophores of a carp,Cirrhinus mrigala Ham

Effects of GABA-ergic agonists and antagonists were examined on the melanophores of a carp C. mrigala in vitro. GABA and baclofen both induced concentration - related dispersion in fish melanophores. Denervation of the melanophores by reserpine treatment potentiated the sensitivity of the melanophores to GABA. While denervation by cooling treatment inhibited the sensitivity of the melanophores to GABA, atropine, bicuculline and pentylenetetrazole all inhibited the dispersal responses of the melanophores induced by higher concentrations of GABA. 5-aminovaleric acid also significantly inhibited the dispersion of the melanophores induced either by GABA or baclofen. It is concluded that GABA-ergic agonist induced dispersal responses in C mrigala melanophores are mediated through specific GABA receptors. The presence of both GABAA and GABAB receptors in this fish melanophores has been indicated.     

Patterns of population structure at microsatellite and mitochondrial DNA markers in the franciscana dolphin (Pontoporia blainvillei)

The franciscana dolphin, Pontorporia blainvillei, is an endemic cetacean of the Atlantic coast of South America. Its coastal distribution and restricted movement patterns make this species vulnerable to anthropogenic factors, particularly to incidental bycatch. We used mitochondrial DNA control region sequences, 10 microsatellites, and sex data to investigate the population structure of the franciscana dolphin from a previously established management area, which includes the southern edge of its geographic range. F‐statistics and Bayesian cluster analyses revealed the existence of three genetically distinct populations. Based on the microsatellite loci, similar levels of genetic variability were found in the area; 13 private alleles were found in Monte Hermoso, but none in Claromecó. When considering the mitochondrial DNA control region sequences, lower levels of genetic diversity were found in Monte Hermoso, when compared to the other localities. Low levels of gene flow were found between most localities. Additionally, no evidence of isolation by distance nor sex‐biased dispersal was detected in the study area. In view of these results showing that populations from Necochea/Claromecó, Monte Hermoso, and Río Negro were found to be genetically distinct and the available genetic information for the species previously published, Argentina would comprise five distinct populations: Samborombón West/Samborombón South, Cabo San Antonio/Buenos Aires East, Necochea/Claromecó/Buenos Aires Southwest, Monte Hermoso, and Río Negro. In order to ensure the long‐term survival of the franciscana dolphin, management and conservation strategies should be developed considering each of these populations as different management units.     

Randomly amplified polymorphic DNA analysis of four different populations of the Indian major carp, Labeo rohita (Hamilton)

The level of genetic variation provides the raw material for selective improvement of a stock. Random amplified polymorphic DNA (RAPD) assay was used to assess the genetic variation in three rivers: the Halda, the Jamuna and the Padma as well as in one hatchery population of the commercially important Indian major carp, Labeo rohita. RAPD markers were amplified from DNA samples of 35 fish from each of the four populations using six decamer random primers. The polymorphic loci proportions were 0.33, 0.28, 0.28 and 0.26 and Nei's gene diversity values were 0.06, 0.07, 0.06 and 0.05 for the Halda, the Jamuna, the Padma and the hatchery populations, respectively. The pairwise population differentiation (F_ST) values indicated a low level of genetic differentiation between the population pairs. From the unweighted pair group method of arithmetic mean (UPGMA) dendrogram based on Nei's genetic distances a correlation between genetic affinities and geographical area was found. The populations were segregated into two groups: the Halda in one group and the Jamuna, the Padma and the hatchery in another group. Overall, the RAPD technique can be introduced as a tool in the population genetics of the rohu fish to provide information on their genetic stock structure.     

Cross-species microsatellite markers for elucidating population genetic structure in Arabidopsis and Arabis (Brassicaeae)

Species closely related to model organisms present the opportunity to efficiently apply molecular and functional tools developed by a large research community to taxa with different ecological and evolutionary histories. We complied 42 microsatellite loci that amplify under common conditions in four closely related Arabidopsis: A. thaliana; A. halleri; A. lyrata ssp. lyrata; and A. lyrata ssp. petraea, as well as in one more distantly related crucifer; Arabis drummondii. Variation at these loci is amenable to a diversity of applications including population genetics, phylogeographical analyses, mapping of inter and intraspecific crosses, and recombination mapping. Our analysis of microsatellite variation illustrates significant differences in population genetic parameters among three Arabidopsis species. A population of A. thaliana, an inbreeding annual plant associated with disturbed habitats, was highly monomorphic (P = 8% percent polymorphic loci) and only 0.2% heterozygous for 648 locus-by-individual combinations. A population of the self-incompatible perennial herb, A. halleri, was more genetically variable (P = 71%) and had an excess of heterozygosity that may reflect a recent population bottleneck associated with human-mediated founder events. A population of the self-incompatible perennial herb, A. lyrata ssp. petraea, was even more genetically variable (P = 86%) and appeared to be at mutation-drift equilibrium. Population structure estimated from neutrally evolving loci provides an empirical expectation against which hypotheses of adaptive evolution at functional loci can be tested.     

Development of microsatellite DNA markers of grass carp (Ctenopharyngodon idella) and their cross-species application in black carp (Mylopharyngodon piceus)

Thirty-four microsatellite DNA loci were developed for grass carp (Ctenopharyngodon idella) and used to determine the diversity of 42 individuals of grass carp and 16 individuals of black carp collected from Jingzhou fragment (the middle reach) of Yangtze River. All the 34 loci were polymorphic in grass carp. The number of alleles found in grass carp at these loci ranged from 2 to 24. The observed and expected heterozygosities varied from 0.238 to 1.000 and from 0.162 to 0.945, respectively. Thirty of the 34 loci cross-amplified the DNA of black carp (Mylopharyngodon piceus), and 21 of them revealed polymorphism (more than one allele each locus).     

Nitrite toxicity in Indian major carps: sublethal effect on selected enzymes in fingerlings of Catla catla, Labeo rohita and Cirrhinus mrigala

The effects of 96-h sublethal exposure of nitrite (1, 2, 4, 8 and 10.4 mg l(-1)) on selected enzymatic activities in serum and tissues of fingerlings of catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirrhinus mrigala) were studied for the first time in these species. All three species responded almost identically to nitrite exposure. With increasing nitrite concentration, reduction in activities was observed in acetylcholinesterase (AChE) in brain and liver; alkaline phosphatase (ALP) in serum, brain and gill; and acid phosphatase (ACP) in gill, while progressive increase in alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) activities in brain, gill and serum, and ACP activity in serum and brain was observed. Lactate dehydrogenase (LDH) activity increased in gill, liver, kidney, brain and serum of all three species with increasing nitrite concentration up to 8 mg l(-1) followed by reduction at 10.4 mg l(-1). The study revealed nitrite stress causing alteration in activities of all measured tissue and serum enzymes in the fingerlings, and so stresses the need for proper management of this particular nutrient in water during carp culture.     

Development of microsatellite markers for parentage analysis in the great tinamou (Tinamus major)

Eighteen microsatellite loci were isolated from great tinamous (Tinamus major), which are large terrestrial birds found in the Neotropics. These are the first primers developed for the Order Tinamiformes. Paternity analyses are possible because the levels of heterozygosity are sufficiently high (0.29-0.90).