Prem Prakash Srivastava

Breeding and Larval Rearing of Asian Catfish, Clarias batrachus (Linnaeus, 1758) on Live and Artificial Feed

A study was conducted to observe the breeding and larval rearing of Asian Catfish, Clarias batrachus fed with live and/or artificial feed for 21 days in an indoor hatchery. The brooders of C. batrachus (Av. wt of female 160 ± 10.5 g; Av. wt of male 120 ± 6.75 g) were procured from outside ponds and stocked in a pond near the experiment site 2-months prior to spawning. The fishes were successfully induced bred using ovaprim @ 1.0–2.0 ml/kg body weight (bw) to females and 0.5–1.0 ml/kg bw to males. Fertilization, hatching and survival percentages at spawn stage were respectively recorded 70.6 - 72.8, 60.7 - 55.3 and 54.3 - 56.2. After yolk-sac absorption, fry of three age groups 7, 14 and 21 days were subjected to feed trial using Artemia nauplii followed by laboratory made feed for 21 days. Weekly sampling indicated that higher age groups constantly maintained higher lengths and weights with highest survival in the age group of 14-days old fry and SGR in 7-days old. The quality of hatchery water was recorded for temperature 29 ± 1°C, pH 7.2 ± 0.2, DO 7.1 ± 0.3 mgL-1 and total alkalinity 132 ± 4.0 mgL-1 respectively.

Modulation of innate immune responses and induction of oxidative stress biomarkers in Pangasianodon hypophthalmus following an experimental infection with dactylogyrid monogeneans

Abstract Modulation of innate immune activity and oxidative stress response of Pangasianodon hypophthalmus through experimental infection with (Thaparocleidus sp.) dactylogyrid monogenean was studied. A standard cohabitation method was used to infect healthy experimental fish. After 14 days, dactylogyrid (gill monogenean) infested fish were sampled and categorised into three different infected groups namely (T1) low (<10 mean dactylogyrid per gill arch per fish), (T2) moderate (10–49 mean dactylogyrid per gill arch per fish) and (T3) high (>50 mean dactylogyrid per gill arch per fish) along with a control group T0 (un‐infested fish). Serum and tissues (gills and liver) were collected from experimental fish and analyzed for markers of innate immune and oxidative stress, respectively. The results showed that respiratory burst activity, myeloperoxidase level, serum lysozyme, &agr;‐2 macroglobulin and total serum immunoglobulin level were significantly (p < 0.05) elevated in fish with different degrees of parasite infestation compared to the control (un‐infested group). Similarly, cellular oxidative biomarkers superoxide dismutase, catalase, glutathione‐S‐transferase and Na+‐K+‐ATPase activities of gills and liver were significantly (p < 0.05) elevated in dactylogyrid infested fish in comparison to the control. However, significantly decreased level of albumin, albumin to globulin ratio, total serum antiprotease and ceruloplasmin were observed in fish infested with low degree of dactylogyrids, while no significant differences in these parameters were observed between moderately infested and the control groups. The results suggested that varying degree of gill monogenean dactylogyrid infestation not only modulated the innate immune response of P. hypophthalmus by lowering albumin, total serum antiprotease and ceruloplasmin and inducing respiratory burst activity, phagocytic activity, myeloperoxidase, lysozyme, &agr;‐2 macroglobulin and total immunoglobulins, but also the oxidative stress biomarkers. The baseline data obtained in the present study will be valuable in understanding the host‐parasite relationship and the dynamics of innate, oxidative stress responses and susceptibility of P. hypophthalmus to different degrees of parasitosis. HighlightsInnate immune responses in P. hypophthalmus were studied under various degrees of dactylogyrid infection.Moderate and high dactylogyrid loads suppress ceruloplasmin and serum antiprotease activity.Oxidative stress biomarkers in P. hypophthalmus were induced under various degrees of dactylogyrid infection.Higher dactylogyrid load induces GST and Na + ‐K + ‐ATPase activity in gills and liver.

Evaluation of Partial Replacement of Dietary Animal Protein from Plant Protein Blended with Glucosamine on Growth and Body Indices of Asian Catfish (Clarias Batrachus) Fingerlings

A 12- week feeding trials was conducted to evaluate the use of animal and plant protein, in combination with Glucosamine source for Asian Catfish, Clarias batrachus (av. wt. 2.2+0.009 to 2.6+0.03 g). This study was performed to evaluate the effect on fish growth performance by replacing animal protein with vegetable protein sources. In experiment, six (37.40 to 43.52 % crude protein, 16.15 to 16.76 kJ/g energy, and crude lipid 3.33 to 6.69%) practical diets were formulated. The animal and plant protein component of the diets was progressively added with glucosamine 0.5, 5.0 and 10.0% with fish meal, silkworm pupae, soybean meal and casein (F-1, PAG 0:100:0.5; F-2, PAG 0:100:5.0; F-3, PAG 0:100:10.0; F-4, PAG 50:50:0.5; F-5, PAG 50:50:5.0; F-6, PAG 50:50:10.0). The experimental moist diets were fed to triplicate groups of fingerlings at 10% of body weight and results were compared with control feed. Growth performance and feed utilization efficiency of catfish, fed diets with animal protein are better than those of plant protein supplemented feeds. After 12-week study the final weight gain recorded as 18.6g, 19.7g, 19.9g, 14.6g, 14.9g, 13.9g and 13.1g in F1 to F6 and in control fed fishes respectively. The percentage weight gain among the animal protein group (F-1, F2, F-3) were recorded as 615.4%, 756.5% and 804.5%, respectively. And the percentage weight gain in 50% replaced feeds (F-4, PAG 50:50:0.5; F-5, PAG 50:50:5.0; F-6, PAG 50:50:10.0), recorded as 563.6%, 547.8% and 479.2% respectively whereas in control it was 403.8%. The results suggests that the growth is better in total animal protein feeds and the best percentage weight gain (p<0.05) recorded in the feed F3, incorporated with 10% glucosamine (804.5%). The FCR were of the diets along with glucosamine in animal protein content has better growth performances ranged between 1.56 ± 0.03 to 1.90 ± 0.04. The survival was recorded in F1 to F6 as 88 ± 2.4%, 83 ± 2.3%, 76% ± 3.4, 74 ± 4.4%, 71 ± 2.8% and 76 ± 4.7% respectively and in control it is recorded as 68 ± 2.7%. The Hepatosomatic and Viscerosomatic indices ranged between 0.67 ± 0.03 to 1.94 ± 0.19 and 1.90 ± 0.02 to 3.17 ± 0.2 respectively in F1 to F7. The feed efficiency in terms of feed conversion ratio recorded as 1.56 ± 0.03 to 1.90 ± 0.04 among all the feeding trials. The findings shows that feed F3, containing 100% animal protein with 10% glucosamine is performed best. Results indicate that animal protein rich diets with glucosamine were much acceptable than plant protein and/or natural diets (Artemia nauplii) for Asian catfish, Clarias batrachus. And to assess the potential for replacing animal protein with soybean meal in the diets of fish need more evaluation along with synergistic approach of incorporating glucosamine.

Histological Alterations in the Hepatopancreas and Growth Performance of Pacific White Shrimp (Litopenaeus vannamei, Boone 1931) Reared in Potassium Fortified Inland Saline Ground Water

1 Aquaculture Division, Central Institute of Fisheries Education, Off Yari Road, PanchMarg, Mumbai – 400 061, MS, India 2 Soil and Land use Survey of India 3 Central Institute of Fisheries Education, Off Yari Road, PanchMarg, Mumbai – 400 061, MS, India 4 Fish Nutrition, Biochemistry and Physiology Division, Central Institute of Fisheries Education, Off Yari Road, PanchMarg, Mumbai – 400 061, MS, India *Corresponding author

Regulation of compensatory growth by molecular mechanism in Labeo rohita juveniles under different feeding regimes

A study was carried out to assess the regulation of compensatory growth under different restriction feeding regimes in Labeo rohita juveniles by the interaction of various feed intake and growth regulating genes. A 60 day feeding trial was conducted with five treatment groups, Control (3% body weight, bw), T1 (alternate days), T2 (0.5% bw), T3 (1% bw) and T4 (2% bw) and feeding was done for first 30 days of the trial. For next 30 days, all the treatment groups were fed at a rate of 3% bw as in the control group. There was significant (p < 0.05) difference in the weight gain among the treatment groups with lowest FCR and highest PER was found in T2 group. Ghrelin gene mRNA levels were upregulated during first 30th days of the trial with highest expression levels in the T2 group. The expression levels of leptin gene mRNA were found significantly different (p < 0.05) among the treatments, which was down-regulated during initial 30 days and upregulated as the experiment progress towards 60th day. The IGF-1 mRNA expression levels were upregulated more in liver compared to the muscle tissue. The results of the study suggest that increased ghrelin levels and decreased leptin levels lead to hyperphagia during the onset of refeeding, which further triggers the compensatory growth in L. rohita. The present study describes the molecular mechanism behind the compensatory growth following a different feed restriction regime in L. rohita which is regulated due to the interaction of different energy homeostasis and growth regulating genes.

Effect of various dietary fats supplementation on the liver glycogen, protein and digestive enzymes activities in striped murrel, Channa striatus

A 84-days experiment was conducted to observe the effects of different feeds rich with different types of fats on selected biochemical parameters of Channa striatus grow-outs. There were seven treatments (F1, L3HUF; F2, H3HUF; F3, MUSOL; F4, LINOL; F5, MIXOL; F6, SATOL and F7, NATFO), fed to fish (avg. wt., 27.36 ± 0.09 to 32.54 ± 0.41 g). Results showed that the variation in liver glycogen content was recorded on addition of different fat content in the diet. Activity of intestine protease recorded significantly (p

A CYP19 Based Sex Determination and Monosex Production in Aquaculture Species Oreochromis niloticus L. and a Cyprinid Cyprinus carpio L.

The efficacy and effect of tamoxifen and letrozole on sex reversal in common carp and Nile tilapia was studied using free swimming fry of Cyprinus carpio and tilapia Oreochromis niloticus. Treatment of letrozole in the dose of 100 mg kg-1 feed brought about 79.39 ± 1.09% masculinisation in C. carpio and 87.91 ± 1.39% masculinisation in O. niloticus, while larger dose (200 mg kg-1 feed) produced 98.47 ± 1.34% male C. carpio and 99.65 ± 0.72% male O. niloticus. In the control group, there was 48.28% male and 50.78% female C. carpio while 46.38% male and 53.616% female O. niloticus. Letrozole significantly increased serum testosterone (T) level suppressing 17β-estradiol (E2) production and the androgenizing action was more potent when compared with tamoxifen treatment. The histological examination of letrozole treated C. carpio and O. niloticus revealed increased number of irregularly spread spermatids and there was hardly any difference in control testes and letrozole treated gonads. The results showed potent and complete action of letrozole (Cyp19) on sex reversal for monosex male fish production delineating its commercial application in aquaculture.