Jana, B. B. and Chakrabarti, R. 1988.
Some factors determining the feeding optima in carp fingerlings. Archiev für
Hydrobiologie 113: 121-131.
optima and feeding time were examined in different species of carp (Catla catla, Cirrhinus mrigala, Cyprinus
carpio) and tilapia (Oreochromis
mossambicus) fingerlings under normal light and dark conditions. The
feeding optima in different species varied by a factor of 2.8 (31.25 to 87.5 mg
individual-1 day-1) depending upon the size of the test
fingerlings. The uptake rate was more than 80% higher in common carp than in
tilapia of similar body weight. The feeding level in the dark was reduced by 12
to 25% than under normal light. Exposure of fish to artificial light caused 9
and 49% enhanced grazing over the control during the day and night experiments,
respectively. The feeding activity in common carp was more intensified (32%) in
the morning () than in
the remaining part of the day.
Jana, B. B. and Chakrabarti,
R. 1990. Exogenous introduction of live plankton -a better approach to carp
growth than the direct manure system. The Progressive Fish Culturist 52:
of four species of carp-catla (Calla
catla), mrigal (Cirrhinus
mrigala); common carp (Cyprinus
carpio), and rohu (Labeo
rohita) was compared among three feeding schemes: (1)
exogenous introduction of zooplankton, (2) fertilization with manure, and (3) a
control system with addition of boiled rice and mustard oil cake. Growth or
fish was measured after 90 d in four separate tests conducted during September
1986-June 1987. Generally, frequency distributions of weight groups of fishes
at harvest were skewed toward larger fish in the live food system and toward
smaller fish in the control system. The instantaneous growth and net weight
gain of fish were significantly higher in the live-food system than in the
manured or control system. The better growth in the live-food system was
attributed to a greater abundance of plankton and better water quality
expressed in terms of lower values of chemical oxygen demand and higher
concentrations of dissolved oxygen.
Jana, B. B. and
Chakrabarti, R. 1990. Comparison of plankton intake by Indian carp fingerlings.
Journal of Applied Ichthyology 6: 1-13.
influence of different culture systems on the amount of plankton consumed by
fingerlings of three carp species (Labeo
rohita, Catla catla and Cirrhinus mrigala) was examined in outdoor culture
tanks during a 90 days growing period. The fish were raised under two basically
different feeding conditions: (a) fed with alIochthonous live plankton; (b) fed
with plankton grown autochthonously in the fish growing tanks fertilized with
manures. Both feeding regimes were compared with control groups. It was found
that the plankton intake for carp held in the live food system was
significantly higher than the manured and control systems. Related to maximum
intake, maximum abundance of plankton in the live food system was a consequence
of improved water quality expressed in terms of lower values of BOD and COD and
higher values of DO and pH; this was conducive to fast reproduction of some of
the zooplankton which constituted the major food items for the test carp, as
well as to the regular exogenous introduction of live plankton. The ingestion
of plankton was found to be related to carp body weight raised to the power b.
The exponent b ranged from 0.29 to 0.93 during the 90-day growing
Chakrabarti, R. and Jana, B. B. 1990.
Food preferences and selection by common carp (Cyprinus carpio) fry under different feeding regimes.
Journal of Applied Ichthyology 6: 223-230.
preferences of common carp fry were investigated in relation to qualitative and
quantitative abundance of plankton in five culture systems (live food system,
manured system, exchanged manured system, intermediate system and control
system), which differ in management protocols. While phytoplankton was strongly
avoided, as evident in the electivity index, cladocerans constituted an
important source of natural food for common carp fry held in all five culture
systems. There was a positive selection of cladocerans in the manured system as
well as rotifers in the live food system, although the environment was dominated
by copepods and cladocerans, respectively. While in all the culture systems
there was a gradual rise in the relative abundance of copepods,
cladocerans tended to decline in relative abundance in the diet of older common
carp held in the manured system.
Chakrabarti, R. and Jana, B. B. 1991.
Growth induction of common carp (Cyprinus carpio L.) as a function of
plankton density and improve water quality. Aquaculture and Fisheries Management
22: 295 -307.
and ninety-eight fry of common carp, Cyprinus carpio L., were reared in
outdoor tanks containing 9580 l of water under five management schemes
-separate live-food system (LF), intermediate system (I), static manured system
(M), manured system with water exchange (EM) and supplementary food system (SF)
in triplicate for a growing period of 90 days. Examination of frequency
distribution of different weight groups of fishes at the time of harvest showed
a maximum proportion of larger and smaller fishes in the live-food and
supplementary food system, respectively. Maximum growth and production of
common carp in the LF treatment was the consequence of greater abundance of
plankton food and improvement of water quality expressed in terms of higher
values of pH and DO and lower values of COD and BOD.
Chakrabarti, R. and Jana,
B. B. 1991. Plankton intake as a function of body weight by common carp fry in
different feeding conditions. Aquaculture 93: 21-34.
intake by common carp fry was investigated in relation to composition and abundance
of plankton as well as water quality in five culture systems: live-food system
(LFS), manured system (MS), exchanged manured system (EMS),
intermediate system (IS), and reference control system (CS). The amount of
plankton consumed by the common carp fry tended to rise gradually with in-
crease in average body weight of carp held in all five culture systems. At a
given time, the plankton intake for LFS was significantly higher than for the
remaining four systems. Related to maximum intake, the maximum concentration of
plankton in the live-food system was a consequence of improved water quality.
Food consumption varied as a function of Wb, and estimates of the power b ranged from 0.479 to
0.864 in relation to culture systems and from 0.033 to 0.908 among age groups.
Chakrabarti, R. and Jana, B. B. 1992.
Effects of different levels of exogenously introduced plankton on growth of
common carp reared under favourable water quality. Aquaculture 103: 331-339.
One hundred ninety eight fry of common carp were
placed into each of nine outdoor tanks (9580 I) and subjected to three
different levels (dry weight) of exogenously introduced plankton, viz. 134 mg l-1
(normal), 264 mg l-1 (two-fold) and 412 mg l-1
(four-fold) every other day. Frequency distribution of different weight groups
of fishes at the time of harvest after a 90-day growing period revealed
significant differences between the normal live food system and the two-fold or
four-fold treatments, but no marked differences between the latter two treatments.
Mean weight of common carp was 20.76, 23.82 and 24.04 g in the normal, two-fold
and four-fold treatments, respectively, whereas yield per tank ranged from 3.69
to 4.37 kg. Carp growth in these three systems was found to be strongly
dependent on plankton density. The mortality of common carp did not differ from
one system to another, with values ranging from 8 to 10% in the three
treatments. Fish production in the four-fold treatment was not proportionate to
the rise in zooplankton density and, hence, the two-fold treatment was the most
appropriate for carp growth.
Chakrabarti, R. and Jana, B. B. 1992.
Diversity and abundance of plankton as indices of management strategies of
common carp culture. Archiev für Hydrobiologie 125: 499-509.
induced changes of plankton community structure has been inves- tigated in the
common carp (Cyprinus carpio L.)
culture under five treatments in triplicate: (a) introduction of live-plankton
(LFS), (b) direct tank fertilization (MS), (c) direct tank fertilization and
exchange of water (EMS), (d) intermediate condition with 50% manure application
and introduction of 50% of live-plankton (IS) and (e) introduction of boiled
rice and mustard oil cake (CS). There were altogether 30 trials during the
period of March 1987 to November 1988. Direct tank fertilization resulted in
the dominance of copepods and favoured the exclusive selection of Pediastrum
simplex and Asplanchna sp. whereas, introduction of live plankton
into the culture system favoured the dominance of cladocerans especially
Ceriodaphnia reticulata. The control system was conspicuous by the
absence of rotifers. The Shannon index for
phytoplankton and zooplankton were maximum for MS and LFS, respectively. The
indices of dominance for cladocerans and zooplankton were maximum in the LFS
and minimum in the CS and MS. The index value indicated maximum similarity
between LFS and IS followed by MS and EMS and
minimum between MS and CS.
R. and Sharma, J. G. 1998. Influence of management protocols on common carp
growth under nursery conditions: relative importance of food and water quality.
Journal of Aquaculture International 6: 293-301.
outdoor holding tanks (10 m-3 each), were filled with ground water
and grouped into five feeding schemes: live zooplankton cultured outside the
fish growing tank (LFS); direct nursery pond fertilization schedule in static
(MS) as well as in exchanged water (EMS); intermediate conditions between the
LFS and MS (IS); and supplementary food system using mixture (1:1) of finely
ground mustard oilcake and boiled rice (SFS). Two hundred common carp (Cyprinus carpio) fry were
introduced into each of the twenty outdoor tanks maintained at ambient
temperature outside the laboratory. After 90 days of rearing, the fish were harvested
and analysed for various growth parameters and food conversion efficiency. The
average weight of carp attained in the LFS was significantly higher than that
in the other four feeding schemes. The frequency distribution of final body
weight of common carp showed the preponderance of large and small fish in the
LFS and MS, respectively. Likewise, plankton intake by the carp fry was highest
in the LFS. The rate of survival was much higher in the LFS as compared with
the rest of the treatments. The water quality remained far better in the former
than the latter.
Chakrabarti, R. and Jana, B. B. 1998.
Effects on growth and water quality of feeding exogenous plankton compared to
use of manure in the culture of mrigal, Cirrhinus mrigala, and rohu, Labeo
rohita, fry in tanks. Journal of Applied Aquaculture 8: 87-95.
Advanced fry (2.0-3.5 g) of mrigal, Cirrhinus
mrigala, and rohu, Labeo rohita were cultured in 9,580-L tanks for
90 days. Individual weight gain and total yield were compared among five culture
regimes: (1) live zooplankton fed to fry stocked at 1,312 fry/tank (LF); (2)
fry stocked at 1,642 fry/tank (HLF); (3) manure- based system (1,312 fry/tank)
without water exchange (M); (4) manured-based system (1,312 fry/tank) with
water exchange (EM); (5) a control (1,312 fry/tank) (C) fed with mustard oil
cake and boiled rice treatment. There were three replicates for each treatment.
Weight gain of both species of carp stocked at the LF rate and fed zooplankton
was significantly higher (P<0.05) than that of fish in the other
treatments. Survival of rohu and mrigal was significantly higher (P<0.05) in LF treatment
than that in M treatment. Yields for both species in the HLF were significantly
higher (P<0.05) than
those in the remaining treatments. Dissolved oxygen was lower in M (P<0.05) than that in other
treatments. Mean BOD, COD, phosphate, nitrate-N were markedly higher (P<0.05) in the M treatment
compared to measurements in other systems. The results suggest that raising
carp fry in nursery ponds using exogenous feeding of zooplankton is of
considerable importance because such feeding would support high rates of
survival and growth through maintenance of better water quality and greater
abundance of zooplankton in culture systems.
Sharma, J. G. and Chakrabarti, R. 1999.
Larval rearing of common carp Cyprinus carpio: A comparison between
natural and artificial diets under three stocking densities. Journal of World
Aquaculture Society 30: 490-495.
Common carp Cyprinus carpio larvae were cultured under two
feeding conditions: live food or an artificial diet for 40 d in recirculating
systems. Three stocking densities of 25 (low). 50 (medium) and 100 (high)
larvae/15-L aquarium were maintained for each feeding treatment. Significantly
higher survival (91%) and growth (401.08±2.61 mg) were observed in the low
density live food system. Average weight of larvae in the live food system was
3 to 5-fold higher than larvae at the same stocking density for the artificial
diet. Proteolytic activity showed a direct relationship with the length of the
digestive tract (r=0.95). The
highest enzyme activity was observed in the low density live food system.
Survival and growth of common carp larvae are influenced by both the stocking
density and the type of food.
Sharma, J. G. and Chakrabarti, R. 2000.
Replacement of live-food with refrigerated-plankton food for Cyprinus carpio
(L) larvae cultured with three different types of biological filters.
Current Science 79: 214-219.
carp, Cyprinus carpio (L.) larvae were cultured with either live-food or
refrigerated-plankton food in the recirculating system. Three types of
biological filters: (i) pebbles, foam and weed (Lemna major) filter system (PFWS), (ii) pebbles and foam
filter system (PFS), and (iii) only weed (Lemna
major) filter system (WS) were used for each feeding scheme. After
40 days of culture, a significantly higher (P<0.01) rate of survival was obtained with the
live-food system (LFS) than the refrigerated-plankton food system (RPFS)
regardless of filtration type. The final average weight was influenced by both
filtration unit and food. Significantly higher (P<0.05) values for average weight (130±1.5 mg),
specific growth rate (4.69±0.01), and RNA/DNA ratio (5.60±0.13) were obtained
in the PFWS of live-food treatment. Food was more efficiently utilized in the
LFS as indicated by the significantly lower (P<0.05) values of food conversion ratio (0.93 to
1.60) compared to the RPFS (3.87 to 4.91). Amylase (0.09-0.162 mg maltose/mg
protein/h) and proteolytic enzyme (2.52-4.70 mg tyrosine/mg protein/h)
activities were significantly higher in the LFS than the RPFS. Significantly
higher values for ammonia (0.014±0.031 mg/l), phosphate (0.150-0.157 mg/l) and
COD (197-207 mg/l) were observed in the PFS than for the other two filter
systems. Results indicate that use of Lemna major alone or in
conjugation with pebbles and foam helped in the maintenance of improved water
quality in the culture system, which resulted in the better performance of carp
Chakrabarti, R. and Kumar, S. 2001.
Effect of feed protein manipulation on the survival, growth and enzyme
activities of Cirrhinus mrigala larvae. In: larvi 2001, Fish and
Shellfish Symposium (Eds. C.I. Hendry, G. V. Stappen, M. Wille M. and P.
Sorgeloos). European Aquaculture Society, Special Publication No.30.
Belgium, pp. 129 -132.
performance of Cirrhinus mrigala
larvae fed with artificial diet containing three different levels of (30, 40
and 50%) protein and the effects of food protein concentration on enzyme
activities were studied. Survival rate was 100% in all the three feeding
regimes. Average weight of mrigal was significantly higher in the group
(510.07±7.57 mg) fed with diet containing 40% protein, followed by 30% protein
(364±18.8 mg) and 50% protein rich diet (338.4±7.21 mg) fed fish. Food
conversion ratio was significantly lower in 40% protein rich diet
(2.65±0.07) fed group than other two
treatments. Proteolytic enzyme activity was significantly higher in 40% protein
fed group (107±14.7 µg tyrosine mg-1 protein h-1)
followed by 50 (81.6±12.78 µg tyrosine mg-1 protein h-1)
and 30% (76.09±13.87 µg tyrosine mg-1 protein h-1)
protein fed groups. Whereas, amylase activity was significantly higher in 50%
protein containing diet fed larvae than other two treatments. The increasing
percentage of protein in diets also affected the water quality parameters
especially, dissolved oxygen, ammonia and nitrite levels.
Sharma, J. G., Gwak, W-S, Masuda, R., Tanaka, M. and Chakrabarti, R. 2006. Survival, growth and RNA/DNA ratio of Pagrus major cultured under three different feeding regimes during early development. Asian Fisheries Science (Asian Fisheries Society) 19: 389-400.
The nutritional status of red sea bream Pagrus major (30-day-old) cultured under three different feeding regimes: 1) rotifer, Artemia and artificial diet (RAA), 2) rotifer and artificial diet (RA) and 3) artificial diet (A) only were evaluated depending on RNA/DNA ratios. The duration of the experiment was four weeks. The final average weight of fish was significantly (P< 0.05) higher in RAA (1555±119 mg) than RA (1010 ± 145 mg) and A (927 ± 170 mg). Specific growth rate was significantly (P< 0.05) higher in RAA (7.376) and RA (5.617) at the end of the first week of culture compared to the other weeks. In artificial diet fed fish, SGR was significantly (P<0.05) higher at the end of the second week (4.542) compared to the other weeks. The DNA concentration was significantly (P<0.05) higher at the end of the second week of feeding than in the remaining culture period regardless of feeding conditions. The RNA concentration increased from the first to the second week of culture, followed by a decrease in RNA concentration at the end of the third week and then a re-increase at the end of the fourth week in three treatments. The amount of RNA of fish was significantly (P<0.05) higher in RAA and RA treatments than in artificial diet fed fish at the end of the second week. The RNA/DNA ratio showed a direct relationship with growth rate in these three different treatments. The RNA/DNA ratio was significantly (P<0.05) higher in RAA than RA and A showing the superiority of this feeding regime during early development.
Kumar, S., Sharma, J. G. and Chakrabarti, R. 2007. Acute toxicity of ammonia to a freshwater teleost, Labeo bata larvae. Toxicology & Environmental Chemistry (Taylor & Francis) 89: 327-336.
Ammonia toxicity tests were performed with Labeo bata (bata) larvae of three different size groups. One hundred percent survival of larvae (500.0±4.0 mg) was recorded when exposed to ammonia concentrations of 1.0-13.56 mgL-1 at 96 h of exposure. Bata larvae exposed to ammonia concentrations of 15.8–25mg L-1 showed 10-74% mortalities. The 96 h LC50 value for 200 (±5), 250 (±2) and 500 (±4) mg bata larvae were 11.5, 16.8 and 22.5 mgL-1 un-ionised ammonia concentrations, respectively. When fish were exposed to different doses of ammonia, behavioural changes immediately occurred even at the lowest dose. At first, the fish became hyperexcitable, the skin darkened and they showed an increased ventilation frequency, fish behaviour became normal, 24 h after exposure. A 96 h LC50 value of un-ionised ammonia showed direct relationship with the increasing size of bata larvae.
Singh, S. P., Sharma, J. G., Ahmad, T. and Chakrabarti, R. 2013. Effect of water temperature on the physiological responses of Asian catfish Clarias btrachus. Asian Fisheries Science (Asian Fisheries Society) 26: 26-38.
Temperature plays significant roles in the life of poikilothermic aquatic animal fish. The physiological responses of Clarias batrachus (Linnaeus 1758), magur (80.60 ± 5.34 g) at different temperatures were observed. Fish were acclimated at 25 °C for 21 days and were exposed at 10, 15, 20, 25, 30 and 35 °C temperatures. Blood and muscle samples were analysed after 12 h and 7 days of reaching the assigned temperatures. Significantly (P<0.05) higher mortality of fish was found in 10 °C treatment compared to the other groups. At 10 °C, 50% fish died within 5 days. Serum protein was significantly (P<0.05) higher in fish exposed at 15 °C compared to the other treatments. Myeloperoxidase and reduced glutathione were significantly (P<0.05) higher in fish exposed at 30 °C and 25 °C, respectively compared to the other groups. Nitric oxide synthase was significantly (P<0.05) higher in fish maintained at 25 °C and 30 °C compared to the other treatments after 12 h and 7 days of exposure, respectively. Thiobarbituric acid reactive substance was significantly (P<0.05) higher in fish exposed at 10 and 15 °C compared to others after 12 h and 7 days of exposure, respectively. Lowering of temperature adversely affected physiological processes of magur.
Ahmad, T., Singh, S. P., Khangembam, B. K., Sharma, J. G. and Chakrabarti, R. 2013. Food consumption and digestive enzyme activity of Clarias batrachus exposed to various temperatures. Aquaculture Nutrition (Blackwell Science Ltd., doi: 10.1111/anu.12072)20: 265-272.
The effect of temperature on the food consumption rate and the digestive enzyme activities of Clarias batrachus (80.60 ± 5.34 g) were evaluated. Fish were exposed to six different temperatures of 10, 15, 20, 25, 30 and 35 °C following an acclimation temperature of 25 °C. The rate of temperature change was 2 °C day-1. Highest food consumption was recorded at 25 °C. It gradually reduced with decreasing water temperature. Food consumption rate was significantly (P < 0.05) lower at 10 °C compared with other treatments. 46.67, 8.20 - 23.58 and 1.02 - 6.15% reduced food consumptions were recorded in groups exposed at 10, 15 and 20 °C temperatures, respectively, compared with the 25 °C. The consumption rate was not affected in fish exposed at 30 and 35 °C. Total protease, trypsin and chymotrypsin activities were significantly (P < 0.05) higher in fish exposed at 25 °C compared with others. Lipase activity was significantly (P < 0.05) higher in fish exposed at 30 °C compared with others. Lowest enzyme activities were recorded at 10 °C. Water temperature below 25 °C affected the food consumption and digestive enzyme activities in fish that served as indicators of stress in fish.
Sharma, J. G., Singh, S., Mittal, P. and Chakrabarti, R. 2014. Impact of temperature gradient on the Indian major carp Catla catla larvae. Proceedings of National Academy of Sciences, India Section B (Springer, DOI 10.1007/s40011-014-0419-3).
Catla catla (Family: Cyprinidae) were exposed to 10, 15, 20, 25, 30, 33 and 35°C following 28°C acclimation temperature. Temperature change rate was 2°C/day. Mortality rate of fish was recorded. In 10°C temperature group, 17 and 65% mortality was recorded at 14 and 10°C, respectively. Significantly (P<0.05) higher mortality was recorded in fish exposed at 10-20°C as compared to other treatments. Cumulative mortality rates were 89, 43, 24, 18, 1, 2, and 3% in fish exposed at 10, 15, 20, 25, 30, 33, and 35°C, respectively. In 10°C temperature group, all fish died within 2 days, whereas in 15 and 20°C temperature groups, mortality was continued up to 11 days; it was 18 days in 25°C temperature group. With simple regression analysis for the temperature range (T<28°C and T>28°C), percentage changes of mortality per fall and increase of DT = 1°C was calculated in the log-linear regression model framework. When temperature was reduced from 28°C, the cumulative mortality increment in each 1°C fall was e.109 = 1.115 (P<0.05). High R-square value indicated a high variation (96.8 %) in log-transformed mortality for temperature difference. Beta coefficient was less steep when temperature increased beyond 28°C. The cumulative mortality e.075 = 1.077 (P<0.05) was obtained for each 1°C increase of temperature from 28°C.
Basu, M., Paichha, M., Sain, B., Lenka, S. S., Singh, S., Chakrabarti, R. and Samanta, M. 2015. Modulation of TLR2, TLR4, TLR5 and NOD2 receptor gene expressions and their downstream signaling molecules following thermal stress in the Indian major carp catla (Catla catla), 3 Biotech (Springer). DOI 10.1007/s13205-015-0306-5
Toll-like receptors (TLRs) and nucleotide binding and oligomerization domain (NOD) receptors are pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) and play crucial role in innate immunity. In addition to PAMPs, PRRs recognize endogenous molecules released from damaged tissue or dead cells [damage-associated molecular patterns (DAMPs)] and activate signalling cascades to induce inflammatory processes. In the aquatic environment, large variation in seasonal and diurnal water temperature causes heat and cold stresses in fish, resulting in tissue injury and mortality of fish. In the Indian subcontinent, catla (Catla catla) is an economically important freshwater fish species and is prone to thermal stresses. To investigate the response of pattern recognition receptors in thermal stress, we analyzed TLRs (TLR2, TLR4 and TLR5) and NOD (NOD1 and NOD2) receptors gene expression in catla following heat and cold stress. Analysis of tissue samples (gill, liver, kidney and blood) of the thermal stressed and control fish by quantitative real-time PCR (qRT-PCR) assay revealed significant (p < 0.05) induction of TLR2, TLR4 and NOD2 gene expression in majority of the tested tissues of the treated fish as compared to the control. The expression of TLR5 and NOD1 gene was also induced in the heat and cold stressed fish, but mostly restricted in the blood. The downstream signaling molecule of TLR and NOD signalling pathway viz., MyD88 (myeloid differentiation primary response gene 88) and RICK (receptor interacting serine-threonine protein kinase-2) was also induced in the thermal stressed fish suggesting the engagement of TLR and NOD signalling pathway during thermal stress.
Sharma, J. G., Singh, S.P. and Chakrabarti, R. 2017. Effect of temperature on digestive physiology, immune-modulatory parameters, and expression level of Hsp and LDH genes in Catla catla (Hamilton, 1822). Aquaculture (Elsevier B.V.) 479: 134-141.
Fish face the challenge of diurnal and seasonal fluctuations of temperature in culture and it is essential to
understand their physiological responses to thermal stress. Indian major carp Catla catla, catla (7.52 ± 0.22 g)
were acclimated at 28 ± 1 °C for 21 days and then exposed at six different temperatures: 10, 15, 20, 25, 28 and 35 °C. Blood and tissue samples were collected after 12 h and 7 days of reaching the assigned temperature. Significantly (p < 0.05) higher mortality of fish was recorded at 10 °C. Exposure of catla below 25 °C affected food consumption and digestive enzyme activities. It caused immunosupression as significantly (p < 0.05) lower serum lysozyme, myeloperoxidase and nitric oxide synthase levels were found in fish. Significantly (p < 0.05) higher thiobarbituric acid reactive substances indicated higher lipid peroxidation in catla exposed at 10–15 °C compared to other treatments. The expression of heat shock protein (Hsp) genes Hsp60, Hsp70 and Hsp90 and lactate dehydrogenase, LDH-A was evaluated in hepatopancreas and muscles. Hsp60 was sensitive towards lowering of temperature, whereas Hsp70 was responsive at highest temperature in both tissues. This study highlighted the impacts of cold environmental conditions on the physiology of this species.
Ngasainao, Nilssen, K. J. and Chakrabarti, R. 2017. Effect of dietary supplementation of vitamin C and seeds of Achyranthes aspera on physiology of snow trout Schizothorax richardsonii. Madridge Journal of Aquaculture Research & Development (Madridge Publishers). doi: 10.18689/mjard.2017-105
Nutrition plays significant role in the survival, growth and physiology of fish. Snow trout Schizothorax richardsonii larvae were cultured under three feeding regimes: control diet (diet D1) and test diets, supplemented with vitamin C (800 mg/kg diet, diet D2) and Achyranthes aspera seeds (5 g/kg diet, diet D3). There was no significant (P > 0.05) difference in the survival rate of larvae cultured under three different feeding regimes. Significantly (P < 0.05) higher average weight and specific growth rate and lower food conversion ratio were found in D3 diet fed larvae compared to others. Amylase, total protease, trypsin and lipase activities were significantly (P < 0.05) higher in D3 diet fed larvae and chymotrypsin activity was significantly (P < 0.05) higher in D2 diet fed larvae compared to others. Dietary supplementation of vitamin C and Achyranthes aspera seeds improved immune system as myeloperoxidase and nitric oxide synthase levels were significantly (P < 0.05) higher in enriched diets fed larvae compared to the control one. Reduced lipid peroxidation was recorded in enriched diets fed larvae as thiobarbituric acid reactive substances level was significantly (P < 0.05) lower in D2 and D3 diets fed larvae compared to the control diet fed larvae.