Pharmacokinetics and physio‐metabolic response of single and multiple dose of fenbendazole in Labeo rohita (Hamilton, 1822) fingerlings

An experiment was carried to determine the plasma fenbendazole (FBZ) concentration and physio‐metabolic responses in juveniles of Labeo rohita (90 ± 4 g) after oral administration of single doses at 10, 20 and 50 mg, 20 mg FBZ/kg b.wt. in multiple times on 1st, 3rd and 7th day. The blood samples were collected at 0.5, 1, 2, 4, 8, 12, 24, 30, 48, 72, 96 and 120 hr, after single‐dose administration, and regularly (upto 15 day) in multiple dose. Plasma FBZ concentration was determined up to the limit of detection (LoD) of 0.09 µg/ml by HPLC. There was no parent drug detected in plasma for administration of 10 mg FBZ/kg b.wt. The drug attained the peak concentration (C_max) 1.85 and 3.09 µg/ml in plasma at 4 hr (T_max) after administration of 20 and 50mg FBZ/kg b.wt. respectively. Plasma FBZ was detectable up to 96 and 120 hr with concentration 0.09 ± 0.007 and 0.098 ± 0.006 µg/ml, respectively, after single‐dose administration of 20 and 50mg/kg b.wt. In case of multiple‐dose administration, the maximum concentration of FBZ was 1.01 ± 0.03 µg/ml on 7th day that was less than to the single dose at 50 mg/kg b.wt. However, FBZ was detected up to 11 day after multiple doses. The study revealed that the hepatic antioxidant enzymes activities like superoxide dismutase, catalase and glutathione‐S‐transferase were significantly affected by increasing FBZ in single and multiple doses. The results of the present study could reveal that single‐ or multiple‐oral administration of FBZ at 20 mg/kg b.wt. in feed as antihelminthic drug in L. rohita could be considered as the safe dose.     

Effect of feeding Spirulina platensis on the growth, proximate composition and organoleptic quality of common carp, Cyprinus carpio L.

The effect of feeding Spirulina platensis on the growth, carcass composition, organoleptic quality, digestive enzyme activity and digestibility of common carp, Cyprinus carpio L., was studied through a culture trial lasting 120 days. Four experimental diets were employed by replacing fish meal protein from the standard diet at 25%, 50%, 75% and 100% through the incorporation of Spirulina. Another diet with Spirulina as the sole source of protein was also used. The final weight gain, specific growth rate, food conversion ratio and protein efficiency ratio of common carp were not affected by Spirulina supplementation. However, the diet with Spirulina as the sole source of protein resulted in better net protein retention. The muscle RNA:DNA ratio of fish fed Spirulina diets was higher than that of fish fed control diet. There was no significant difference in carcass moisture and protein content in the fish fed Spirulina diets as compared to fish-meal-based control diet. The carcass ash and fat contents were positively and negatively correlated with dietary Spirulina level, respectively. Organoleptic evaluation revealed no effect of Spirulina feeding on the quality of both raw and cooked fish. The gut digestive enzyme activity did not show any definite trend with respect to Spirulina supplementation. Spirulina improved the protein digestibility of the diets.     

Enzymological,histological, and serum biomarker responses of snubnose pompano on complete replacement of fishmeal using cottonseed meal supplemented with lysine and methionine in the diet

Fish Physiology and Biochemistry - In a feeding experiment, cottonseed meal (CSM) was used to replace fishmeal (FM) in the diet of snubnose pompano, Trachinotus blochii, supplemented with lysine...     

Insulin-like growth factor signalling and its significance as a biomarker in fish and shellfish research

The insulin-like growth factor signalling system comprises insulin-like growth factors, insulin-like growth factor receptors and insulin-like growth factor-binding proteins. Along with the growth hormones, insulin-like growth factor signalling is very pivotal in the growth and development of all vertebrates. In fishes, insulin-like growth factors play an important role in osmoregulation, besides the neuroendocrine regulation of growth. Insulin-like growth factor concentration in plasma can assess the growth in fishes and shellfishes and therefore widely applied in nutritional research as an indicator to evaluate the performance of selected nutrients. The present review summarizes the role of insulin-like growth factor signalling in fishes and shellfishes, its significance in aquaculture and in evaluating growth, reproduction and development, and discusses the utility of this system as biomarkers for early indication of growth in aquaculture.

     

Evaluation of random amplified polymorphic DNA (RAPD) markers in Hevea brasiliensis

The applicability of random amplified polymorphic DNA (RAPD) markers in the cultivated rubber tree, Hevea, was evaluated using 43 decamer oligonucleotide primers in a set of 24 clones selected in different South-East Asian countries. A total of 220 0.35–3.5 kb DNA fragments were amplified, of which 111 were polymorphic. Of these, 80 fragments (RAPD markers) which were repeatable and clearly scorable across all genotypes were used to estimate genetic distances among the clones tested. The estimated genetic distances ranged from 0.05 (RRII 308 and PB 5/51) to 0.75 (RRIC 100 and SCATC 88–13). A mean genetic distance of 0.5 indicates a rather high genetic variability among the tested clones. As expected, because of the breeding history of Hevea, UPGMA cluster analysis and Principal Coordinate Analysis (PCoA) indicated the absence of a distinct geographical grouping. The possible application of RAPD markers for clone identification and also for analysis of genetic relationships among Hevea clones is discussed.     

Discrimination between Oryza malampuzhaensis Krish. et Chand. and Oryza officinalis Wall ex Watt based on RAPD markers and morphological traits

Oryza malampuzhaensis, one of the tetraploid taxa of the genusOryza, is geographically restricted to Western Ghats of South India. Its taxonomic status is not well established and is generally treated as a tetraploid race of O. officinalis. Sixty-three morphological traits and 262 random amplified polymorphic DNA (RAPD) markers generated by 23 random decamer primers were used to assess the genetic relationship between O. malampuzhaensis and O. officinalis. Pair wise comparisons based on both RAPDs and morphological traits revealed 60% genetic distance between the two taxa and was significantly higher (p <0.01) than the corresponding intra-specific distances. Cluster and principal component analysis (PCA) of genetic distance estimations based on RAPDs and morphological traits clearly differentiated the two taxa. High frequency of discrete O. malampuzhaensis specific RAPDs (21%) and the significantly higher (p < 0.05) mean number of amplification products per individual in O. malampuzhaensis observed in the study reflect its allopolyploid nature. Low genetic diversity within O. malampuzhaensis revealed by RAPD analysis indicates the recent origin of this taxa. The RAPD analysis further revealed the possibility that the putative ‘C’ genomeprogenitor of O. malampuzhaensis is a close relative of O. officinalis. In addition, amplification products diagnostic to O. malampuzhaensis were identified. The results of the present study clearly demonstrated that the O. malampuzhaensis is a distinct entity, and support the recent conclusion that O. malampuzhaensis has diverged enough to deserve species status. This revised version was published online in August 2006 with corrections to the Cover Date.     

Crystal and molecular structure of a thymine-thymine adduct

Thymine-thymine adduct is a product isolated from thymine irradiated with ultraviolet light in frozen aqueous solution. This compound is presumably formed through the rearrangement of an initial photoproduct. Single crystal x-ray diffraction analysis has confirmed the molecular formula of the adduct, 5-hydroxy-6-4'-(5'-methylpyrimid-2'-one)-dihydrothymine, except for the possibility of a hydrogen atom on the 3' nitrogren rather than the 1' nitrogen, and has established the stereoconfiguration of the molecule.     

Feeding gelatinized carbohydrate in the diets of magur,Clarias batrachus (Linnaeus, 1758): Effects on growth performance,enzyme activities and expression of muscle regulatory factors

This study was conducted to illustrate the effect of dietary gelatinized starch (GS) on the growth performance, enzyme activities and expression of MyoD and Myf5 in magur, Clarias batrachus fingerlings. Four iso‐nitrogenous (37%) and iso‐lipidic (6%) diets containing 15% (D‐1), 25% (D‐2), 35% (D‐3) or 45% (D‐4) GS were fed to 240 fingerlings (2.5 ± 0.5 g) in triplicates groups for 8 weeks. The maximum weight gain %, specific growth rate, protein efficiency ratio, lower FCR and higher mRNA expression of MyoD or Myf5 were found in the D‐3 group fed with 35% GS. Higher hepatosomatic index, viscerosomatic index, body lipid and lower moisture content were found in the D‐4 group. Aspartate transaminase and alanine transaminase activities were found to be higher in the D‐1 group. Amylase, glucose‐6‐phosphate dehydrogenase and blood glucose were higher in the D‐4 group. Superoxide dismutase, catalase and hexokinase activities remain unaffected by the dietary GS levels. Hence, the overall results indicate that 35% GS can improve growth performance and upregulate myogenic regulatory factors, but 45% GS level will favor lipogenesis and compromise growth. Furthermore, Myf5 gene showed more immediate response than the MyoD to the dietary carbohydrate in magur.     

Impact of Fertility Variation on Gene Diversity and Drift in two Clonal Seed Orchards of Teak (Tectona grandis Linn. f.)

Two 25 year old teak clonal seed orchards comprising 15 (CSO-I) and 20 clones (CSO-II), respectively, selected mostly from moist forests of Western Ghats (latitude 10° N) in southern India, were evaluated for fertility, offspring diversity, and genetic drift. The orchards differed in fertility of clones as well as flower and fruit production per ramet. Fertility was highly skewed in CSO-II, where one clone (originating from higher latitude −17° N, in Eastern Ghats of peninsular India) produced 55% of the fruits and 68% of the flowers in the orchard, in contrast to a similar contribution from four most fertile clones in CSO-I. Fertility variation, measured as `sibling coefficient' (1.7 in CSO-I and 8.3 in CSO-II), was high in CSO-II resulting in high coancestry and low effective population size (3 times lower than CSO-I) in the seed crop. In CSO-I, 58% of the clones contributed effectively to seed production compared to only 12% effective contribution resulting in eight times higher genetic drift in CSO-II. Placing limits on how much seed can be collected per clone might be useful in restricting over representation of highly reproductive clones thereby increasing genetic diversity in the seed crop.