J.K. Jena

Comparative evaluation of production performance in varied cropping patterns of carp polyculture systems

Experiments to evaluate the production performance in multiple cropping systems with two crops in a year over single cropping, and single stocking and multiple harvesting system in carps polyculture were conducted in six ponds of 0.08 ha each during March 1996 to March 1997. The ponds were stocked with six carp species, viz., catla, rohu, mrigal, silver carp, grass carp and common carp in the ratio of 2:2:2:2:0.5:1.5, at a combined density of 10,000 fingerlings/ha with average weight of 17.5 g. While in treatment with single cropping (Treatment I), the fishes were harvested after rearing period of one year; in the case of treatment with single stocking and multiple harvesting (Treatment II), the fishes of larger size were harvested at monthly intervals from the seventh month onwards. However, in treatment with multiple cropping system (Treatment III), the fishes were harvested only after a rearing period of 6 months as first crop, which was restocked again after due pond preparation for second crop of 5.5 months. The gross and net production levels recorded in Treatments I, II and III were 6011.3 and 5843.8 kg/ha/year, 6487.8 and 6320.3 kg/ha/year and 7194.7 and 6828.4 kg/ha/year, respectively, showing significantly higher production levels in Treatment III (P 0.05). Further, with 40% and 60% higher feed provision in Treatments I and II, respectively, over Treatment III, the recorded feed conversion ratio (FCR) values in Treatments I, II and III were 3.16, 2.53 and 1.67, respectively, showing significant differences between the treatments (P<0.01). The studies found that two crop-system over an annual cycle was superior to single stocking-multiple harvesting, and single cropping, in terms of feed conversion ratios as well as yield rates.

Pathophysiology of experimental Aeromonas hydrophila infection in Puntius sarana: early changes in blood and aspects of the innate immune-related gene expression in survivors.

A decline in production of Puntius sarana worldwide and subsequent intensification of its culture as a measure for conservation and increase food fish production have led to emergence of diseases. Investigations on innate immunological changes in fish that survives an acute bacterial infection are a few or lacking. An attempt was made to study the detailed changes in innate immune responses in P. sarana following an intraperitoneal challenge with Aeromonas hydrophila at 2.24 × 10(7)colony-forming unit (CFU)/fish. Sequential changes in transcription of immune related genes in liver and kidney, innate immune status, haematological profile and histopathology of major organs were studied after different time intervals post-challenge in the survivors. A significant increase in serum myeloperoxidase, ceruloplasmin activities and total leucocyte count, and decline in alternative complement activity were observed at early infection periods. A significant decline in plasma glucose level, total erythrocyte count, haemoglobin content and packed cell volume in blood was noticed after challenge. Superoxide radical production and serum antiprotease activity increased significantly at later period of challenge. In addition, few immune related genes pertinent to acute phase reactants and inflammatory response viz., complement component 3 (C3), lysozyme G, lysozyme C, β2-microglobulin (B2M), transferrin, interleukin 1β, interleukin 8, manganese superoxide dismutase (MnSOD), natural killer cell enhancing factor-B and chemokine CXCa were modulated after bacterial challenge. In liver, a significant up-regulation of C3 and transferrin, and down-regulation of lysozyme G, interleukin 8, MnSOD and B2M were noticed in survivors. On the contrary, lysozyme G, lysozyme C, interleukin 1β, interleukin 8, CXCa, and MnSOD were found to be significantly up-regulated and C3 was down-regulated in the kidney. All these data suggest that the innate immune factors were highly modulated during infection process to render protection of P. sarana to this bacterium. This study also generated the primary information on many innate immune molecules/genes for this important medium carp species for the first time.

Grow-Out Production of Carps in India

ABSTRACT Asian aquaculture has been contributing in great measure to the global fish basket. The Indian subcontinent, with a rich biodiversity of fish species, has emerged as an important aquaculture country, particularly in the freshwater environment. Carps form the mainstay of culture practices in the country, supported by a strong traditional knowledge base and scientific input in various aspects of biology, environment, nutrition, and health management. New species and culture systems, integration with other farming systems, use of organic material as nutrient inputs, and depuration measures in waste-fed culture systems are being considered for enhancing aquaculture productivity. This article presents the status of grow-out production of carps in India and traces the growth of the practices over the decades as well as the potential of the sector.

Establishment of caudal fin cell lines from tropical ornamental fishes Puntius fasciatus and Pristolepis fasciata endemic to the Western Ghats of India.

Two new cell lines, PFF and CFF were established from the caudal fin of the Puntius fasciatus, and Pristolepis fasciata respectively. Since their initiation, these cell lines (PFF and CFF) have been subcultured in L-15 medium with 10% fetal bovine serum for more than 35 passages at 28°C and both the cell lines were characterized. Karyotyping analysis of PFF and CFF cells at 25th passage indicated that the modal chromosome number was 2n=50 and 2n=48 respectively. The cell line was cryopreserved in liquid nitrogen at -196°C and could be recovered from storage after six months with good cell viability. Polymerase chain reaction amplification of the fragments of two mitochondrial genes, 16S rRNA and COI confirmed that the cell lines originated from the respective species. The bacterial extracellular products from Vibrio cholerae MTCC3904 and Aeromonas hydrophila were found to be toxic to PFF and CFF. Both the cells were resistant to the marine viral nervous necrosis virus (VNNV). No CPE could be found in both cell lines inoculated with the fish samples and cell culture supernatants were demonstrated free of SVC, iridovirus and KHV by molecular methods. These results indicated the absence of SVC, iridovirus and KHV in the ornamental fishes collected from the Western Ghats of India.

Establishment and characterization of an epithelial cell line from thymus of Catla catla (Hamilton, 1822).

A cell line, CTE, derived from catla (Catla catla) thymus has been established by explant method and subcultured for more than 70 passages over a period of 400 days. The cell line has been maintained in L-15 (Leibovitz) medium supplemented with 10% fetal bovine serum. CTE cell line consists of homogeneous population of epithelial-like cells and grows optimally at 28°C. Karyotype analysis revealed that the modal chromosome number of CTE cells was 50. Partial amplification, sequencing and alignment of fragments of two mitochondrial genes 16S rRNA and COI confirmed that CTE cell line originated from catla. Significant green fluorescent signals were observed when the cell line was transfected with phrGFP II-N mammalian expression vector, indicating its potential utility for transgenic and genetic manipulation studies. The CTE cells showed strong positivity for cytokeratin, indicating that cell line was epithelial in nature. The flow cytometric analysis of cell line revealed a higher number of cells in S-phase at 48 h, suggesting a high growth rate. The extracellular products of Vibrio cholerae MTCC 3904 were toxic to the CTE cells. This cell line was not susceptible to fish betanodavirus, the causative agent of viral nervous necrosis in a large variety of marine fish.

Efficacy of two avermectins, doramectin and ivermectin against Argulus siamensis infestation in Indian major carp, Labeo rohita

The efficacy of two avermectins, doramectin and ivermectin via oral and parenteral routes and their prophylactic effects against Argulus siamensis infestation in Indian major carp, Labeo rohita was studied. Doramectin and ivermectin were fed once to L. rohita sub-adults naturally infested with A. siamensis parasites at graded levels of 1000, 750 and 500 μg/kg body weight and 500, 300 and 200 μg/kg body weight, respectively. The mean time of clearance of parasites was 24 ± 0.149 h for 1000 and 24 ± 0.210 h for 750 μg of doramectin/kg body weight fish, however, the dose of 1,000 μg resulted in adverse reactions and mortality in fish. A single dose of 500μg/kg body weight of ivermectin also cleared the infestation in 24 ± 0.258 h. In second experiment, L. rohita naturally infested with A. siamensis were administered with doramectin and ivermectin intramuscularly as single dose of 200, 150 and 100 μg/kg body weight. Both doramectin and ivermectin at 200 μg/kg body weight cleared the infestation in 4 ± 0.149 and 4 ± 0.258 h respectively, however, those resulted in adverse reactions viz., black pigmentation, lethargy and poor appetite in fish. The mean time of clearance of parasites from fish was 6 ± 0.210 and 12 ± 0.314 h for doramectin and ivermectin, respectively, when given at a lower dose of 150 μg/kg body weight. The prophylactic effects of both drugs were also evaluated by challenging naïve rohu with metanaupliar larvae of A. siamensis after feeding the fish single dose of the doramectin and ivermectin at 750 and 500 μg/kg body weight, respectively. The effects of both the drugs were found to last for 17-18 days. The effects of bath treatment with doramectin and ivermectin at different concentrations on adult A. siamensis and metanaupliar larvae of A. siamensis were also evaluated. The results suggested that ivermectin could act more rapidly compared to doramectin. However, detailed studies on the toxicity and pharmacokinetics of doramectin and ivermectin upon their administration to aquatic organisms and the environmental impacts of their usage are required to be undertaken before finally recommending the safe use of these drugs for control of parasitic infections.

Microsatellite Markers to Determine Population Genetic Structure in the Golden Anchovy, Coilia dussumieri

Coilia dussumieri (Valenciennes, 1848) commonly called as golden anchovy, constitutes a considerable fishery in the northern part of both the west and east coasts of India. Despite its clear-cut geographic isolation, the species is treated as a unit stock for fishery management purposes. We evaluated 32 microsatellite primer pairs from three closely related species (resource species) belonging to the family Engraulidae through cross-species amplification in C. dussumieri. Successful cross-priming was obtained with 10 loci, which were sequenced for confirmation of repeats. Loci were tested for delineating the genetic stock structure of four populations of C. dussumieri from both the coasts of India. The number of alleles per locus ranged from 8 to 18, with a mean of 12.3. Results of pairwise FST indicated genetic stock structuring between the east and west coast populations of India and also validated the utilization of identified microsatellite markers in population genetic structure analysis.

Use of Rotenone as Piscicide: Toxicity Levels in a Few Common Freshwater Predatory and Weed Fishes

Toxicity of rotenone was studied in a few common freshwater predatory and weed fishes through wet laboratory experiments for its use as a piscicide during pond preparation. Cube root powder (CRP) (ENT-133 Rotenone) containing 9% rotenone was used as the toxicant source. Lethal concentration of CRP for these common predatory and weed fishes varied between 0.75–2.70 mg L−1 (0.068–0.243 mg L−1 of rotenone). Acute toxicity study revealed Puntius sophore to have more susceptibility to rotenone toxicity with 24 h LC50 value of CRP at 0.50 mg L−1 (0.045 mg L−1 rotenone) compared to 1.17 mg L−1 (0.105 mg L−1 rotenone) in Anabas testudineus and 1.90 mg L−1 in Channa punctatus (0.171 mg L−1 rotenone); while Heteropneustes fossilis showed higher tolerance with 24 h LC50 value at 2.42 mg L−1 (0.218 mg L−1 rotenone). Such result suggested rotenone toxicity to depend on the respiratory behavior of fish. The marginal reduction in 48 h LC50 of CRP compared to its 24 h value and no fish mortality beyond 48-h in all tested species suggested faster degradation of the toxicant in water. Since application of the piscicide aims at eradication of all commonly available species of predatory and weed fishes in the culture pond, the study suggested a dose of 2.5 mg L−1 of CRP (0.225 mg L−1 rotenone) for pond application.

Notonectids as Live Food for Olive Barb, Puntius Sarana

A feeding experiment was conducted in 40-L tanks each stocked with four fry of olive barb (2.05 ± 0.22 g). Dead notonectids (T1), live notonectids (T2), co-feeding of live notonectids and prepared diet (T3), prepared diet (T4), and plankton concentrate (T5) were fed ad libitum as the five treatments, each maintained with four replications. Proximate composition revealed higher protein and crude lipid contents in both notonectids and plankton concentrate compared to the prepared diet. The insect consumption rate was significantly higher with provision of dead insects (T1), followed by co-feeding of live insect and prepared diet (T3), and the live form (T2) (P < 0.05). Fry showed significantly higher final body weight and net weight gain, as well as specific growth rate, in co-fed group compared to those provided with live or dead insects. Growth performances decreased significantly when fed with prepared diet or plankton concentrate alone. While olive barb fry exhibited a preference for notonectids over the other diets, co-feeding appeared to offer a better nutritional profile for achieving higher growth. The study also indicated possibility of using olive barb as a good candidate for in situ biological control of notonectids during fingerling rearing of barbs and carps.

Cube root powder is a better piscicide than bleaching powder for pre-stocking carp nursery pond preparation

Yard and pond applications of cube root powder (CRP) at 2.5 mg L−1 and bleaching powder (BP) at 10 mg L−1 Cl− produced total fish kill within 14–24 h. Safe periods for stocking fingerling and fry of carps were on 8th and 11th day following CRP application against 4th day for BP. Pond chlorophyll concentrations did not change with CRP application, but was markedly affected by BP. Zooplankton population reduced by 88–95% with BP application compared to 70% with CRP. Initial zooplankton densities were revived in ponds up to 84.6 and 120.5% on 12th and 20th day, respectively with CRP application, while similar BP applications failed to reach initial levels even after 20 days. Based on the result, the study revealed CRP to be a better piscicide than bleaching powder for pre-stocking pond preparation.