The haemoglobins of Labeo umbratus (Smith) and Labeo capensis (Smith)

The haemoglobins of both L. umbratus and L. capensis separated into four components on polyacrylamide electrophoresis. The isoelectric points of these fractions were found to be 9.35, 6.89, 6.63 and 6.40. Organic nucleotide triphosphate concentration in the blood of L. capensis was found to be 56.72 ± 18.01 mg% and 58.72 ± 17.9 mg% in the case of L. umbratus . It is not possible to distinguish between L. umbratus and L. capensis purely on the basis of the haemoglobin electropherogram.     

Partial separation of the pituitary proteins of Labeo umbratus, Smith (mudfish)

L. umbratus pituitary glands were partially separated by means of preparative polyacry-lamide electrophoresis and chromatography on DEAE-cellulose and Sephadex G-50. Eight fractions were obtaìned and it was found that fraction 1 contained potent adrenocorticotropic stimulating activity, with a molecular weight in the region of 6000. Fractions 3 and 4 contained potent gonadotropic and a lesser degree of exopthalmic producing activity, with molecular weights in the region of 14 000 to 20 000. Fraction 6 displayed pigeon-crop stimulating activity, with a molecular weight above 30 000. Fractions 7 and 8 displayed M.S.H. and vasopressinoxytocic activity respectively, with a molecular weight in the region of 5500–6500. Fractions 2 and 5 could not be identified. The fractions seemed to be glycoproteins and the results are discussed in relation to previous findings.     

The effects of toxicants on the haematology of Labeo umbratus (Teleostei: Cyprinidae)

The haematology of Labeo umbratus (Smith) was investigated after exposure to four toxicants under controlled static conditions. Statistically significant changes exist between the values of parameters of experimental and control fish. The concentration of haemoglobin fractions changes with different toxicants. Electrophoretograms of plasma proteins showed changing patterns as well as a decrease in fraction numbers.     

Blood respiratory properties of the mudsucker fish Labeo capensis (Smith)

For Labeo capensis (Smith) the increase in blood organic phosphates (ATP, GTP) in winter fish exceeds the increase in summer fish. Blood chlorides, blood osmotic pressure, hematocrit and hemoglobin concentration decrease significantly in winter fish when compared to summer fish. Four effectors, viz. temperature, organic phosphates, H+ and Cl-, could lower the oxygen affinity of whole blood, especially in summer fish.     

Digestive enzymes and metabolic profile of Labeo rohita fingerlings fed diets with different crude protein levels

Labeo rohita, commonly called rohu is one of the most important fish species for aquaculture in India. Digestive enzyme response and metabolic profile of fingerling L. rohita to different dietary crude protein (CP) levels (viz. 25, 30, 35 and 40%) were studied in an attempt to optimize a practical diet formulation for this species. After 45 days of feeding, activity of digestive enzymes and metabolite concentrations were assayed. Amylase, lipase and alkaline phosphatase (ALP) activities were not influenced by the dietary protein, but proteolytic and acid phosphatase (ACP) activities varied (P<0.05) between the treatments. Proteolytic activity showed a second order polynomial relationship with dietary crude protein (CP) as Y = 0.0734X(2) + 4.937X - 68.37, r(2)=0.97. A positive correlation was observed between dietary CP and amylase (r(2)=0.78). All the metabolites except muscle glucose showed significant change corresponding to the dietary protein levels. Glucose and glycogen levels corresponded to the dietary carbohydrate levels. Muscle and plasma pyruvic acid increased as the crude protein in the diet increased, whereas liver pyruvic acid showed the opposite trend. Muscle protein content was not affected by dietary CP. Protein fractions in plasma (total protein, albumin and globulin) showed maximum values in 30% CP fed group. It is concluded that proteolytic activity and ACP are the major digestive enzymes responsive to dietary CP in L. rohita fingerlings. Considering the cost effectiveness of the diet, and based on liver and plasma free amino acid levels and plasma protein fractions, 30% crude protein is recommended as the optimal dietary protein for L. rohita fingerlings.     

Hematological and plasma chemistry of Indian major carp,Labeo rohita (Hamilton, 1822)

Hematological and plasma chemistry indices are simple and essential diagnostic tools for monitoring the physiological and health status of fish. Aim of the present study was to obtain reference values for the hematological and plasma chemistry of wild populations of Labeo rohita captured in a freshwater pond between July 2008 and June 2010. These reference values and the mean were evaluated according to sex and season. In summer, the red blood cells (1.84 × 106 38 per cubic mm), haemoglobin (8.52 gm dl^?1) and haematocrit (31.49%) were highest in males, whereas the maximum values for white blood cells (5.635 × 103 40 per cubic mm) were found in females, however, no significant variation of mean corpuscular volume (MCV) or mean corpuscular haemoglobin (MCH) was observed between sexes. Various blood parameter levels between the sexes in summer were notably different from those measured in other seasons except for MCH and MCHC values (p < 0.05). Compared to most teleosts, the L. rohita has similar mean values for PCV and Hb. Throughout summer the glucose (76.0 mg dl^?1), lipid (3.41 gm dl^?1) and cholesterol (145.0 mg dl^?1) levels were highest. In spring the plasma protein levels were higher in males, but higher in winter for females. Consequently, the seasons are key factors when using blood parameters as biomarkers for environmental alterations.     

Electrophoresis of haemoglobin in single erythrocytes of Labeo umbratus (Smith) and Labeo capensis (Smith)

Electrophoresis of haemoglobin in single erythrocytes of Labeo umbratus and Labeo capensis showed that haemoglobin behaved in three distinct ways in both species. The majority of cells contained haemoglobin which moved as a broad band towards the anode. In a few cells haemoglobin moved towards both the anode and the cathode and in even fewer cells, haemoglobin moved as a sharp band to either the cathode or anode. These results are discussed in relation to other observations.     

Physical characteristics of the blood plasma of Labeo ruddi and Labeo rosae (Pisces: Cyprinidae).

1. The physical composition of blood plasma of Labeo ruddi and Labeo rosae males were determined during the breeding and post breeding phases. 2. The mean values for most blood electrolytes, pH and osmolality of the two species showed the same variation as was found for other cyprinids. 3. The ability to handle stress may be reflected in the presence of certain electrolytes in the blood and efforts are made to relate differences in the concentration of these parameters to interspecies differences between L. ruddi and L. rosae.     

Regulation of the physical and biochemical composition of blood and seminal plasma by the blood-testis barrier in Labeo ruddi and Labeo rosae (Pisces: Cyprinidae)

• 1.1. The physical and biochemical composition of the seminal and blood plasma of two cyprinid fish were studied as well as the quantitative presence of lipids, ATP, glucose and pyruvate in both body fluids during spawning and post spawning stages.
• 2.2. Statistically significant interspecific differences were determined both for the spawning and post spawning stages as well as differences found for a particular species during spawning and post spawning phases.
• 3.3. Based on the results obtained, it is shown that a blood-testis barrier exists in the two species studied.

     

Effect of endotoxin on the immunity of Indian major carp, Labeo rohita

Endotoxin, a lipopolysaccharide component of outer cell wall membrane of the Gram-negative bacteria is a factor responsible for a number of biological effects including immunostimulatory activities in different animal species including fish. In this study, L. rohita yearlings of weight ranging from 80 to 100g were injected intraperitoneally with 0.5, 1, 2, 5, 10 and 20 EU/fish dose of endotoxin to find out its effect on the immunity. The L. rohita yearlings were found to resist the endotoxin dose up to 20 EU/fish and at the lower doses, i.e., at 1 and 2 EU/fish; it acted as an immune potentiator. Different serum and immune parameters like protein, globulin, lysozyme, respiratory burst activity, myeloperoxidase activity, natural agglutination titre were found to be significantly high (p<0.01) at a dose of 1 EU/fish. While at 10 and 20 EU/fish, most of these parameters were lower thereby indicating the immuno-suppressive nature of the endotoxin at these higher doses.     

Blood sugar as an indicator of stress in the freshwater fish, Labeo capensis (Smith)

Factors involved in the determination of the blood sugar level of L. capensis have been studied. The stress of capture and transportation produces a marked increase in the blood sugar concentration. The relationship between blood sugar concentration and oxygen saturation of water and between blood sugar concentration and ammonium ion concentration was also investigated. Increases in ammonium ion concentration and decreases in oxygen saturation of water produce increases in the blood sugar concentration. The results are discussed in relation to the phenomenon of 'asphyxiation hyper-glycemia'.     

Physiological consequences of an altered flow regime on Alabama bass (Micropterus henshalli)

There are numerous studies on the effects of dams on aquatic biota, yet relatively little is known about whether hydropeaking activities cause physiological change in fish. Using Alabama bass (Micropterus henshalli) as a model, we evaluated whether hydropeaking in a regulated river altered glucocorticoid stress responsiveness relative to fish from an unregulated tributary. Blood samples were collected at the time of capture (baseline) and then collected again after a 1‐hr period of confinement (response). Leukocyte profiles (blood smears) were created and plasma was extracted to assess plasma cortisol levels and neutrophils and lymphocyte (N:L) ratios, between sites and times to evaluate differences between sites and the two sampling periods. Baseline cortisol levels were higher in fish collected from the regulated river compared to those from unregulated site, but response levels of cortisol were similar between sites. Baseline and response level N:L ratios did not differ between sites. High baseline levels of cortisol suggested that fish exposed to regulated flows expressed an altered stress response and were likely in an allostatic state, i.e., attempting to acclimate. Further research is needed to understand how altered stress responses due to hydropeaking flows may be affecting fish.     

The Role of Phospholipids in Plasma Membrane ATPase Activity in Vigna radiata L. (Mung Bean) Roots and Hypocotyls

Root and hypocotyl plasma membrane H⁺-ATPases were partially purified from deoxycholate-solubilized fractions of microsomes in mung bean (Vigna radiata L.) plants in the presence of glycerol. Certain properties of the ATPases and the manner in which phospholipids affect their activity were compared. Root ATPase was similar to hypocotyl ATPase with respect to substrate specificity, salt stimulation, pH dependence, K_m for ATP·Mg²⁺ and inhibitor sensitivity, except for inhibition by vanadate. Both purified ATPases required phospholipids for their activation. Optimum concentrations of exogenously added phospholipid mixture (asolectin) to hypocotyl and root ATPase mixture were 0.03% and 1.0%, respectively. Root ATPase activation did not decrease if more than 1.0% asolectin was added. Qualitatively, phosphatidylserine and phosphatidylcholine brought about greater ATPase activation than other phospholipids. The hypocotyl ATPase was activated by phosphatidylinositol, phosphatidylserine and phosphatidylglycerol to a greater extent than the root ATPase. Root, but not hypocotyl ATPase, was slightly inhibited by the addition of phosphatidylinositol, phosphatidylethanolamine, and phosphatidic acid. The hypocotyl plasma membrane contained phosphatidylinositol + phosphatidylserine, phosphatidylglycerol and phosphatidic acid, and unsaturated fatty acids in greater abundance than the root plasma membrane. The differential activation of the plasma membrane ATPases may arise from these differences.     

Freezing characteristics of fresh water fish (Labeo rohita) by liquid nitrogen vapor

The lean fish Labeo rohita was subjected to liquid nitrogen vapor in a batch freezer to determine its freezing characteristics. The moisture content of the fish muscle tissue was about 75%. The initial and average freezing points were found to be − 1.34 and − 5.25 °C, respectively. The fish slab sample showed a decreased rate of temperature change in that region. The suggested cut-off freezing temperature was − 30 °C, corresponding to about 90% of total water frozen. Continued freezing below − 30 °C resulted in negligible freezing of residual liquid water in the sample. The effects of low-density polyethylene (LDPE) bags and aluminum foil on the freezing times and the overall heat transfer coefficients were sufficiently small that the authors recommended thicknesses of up to 0.1 and 0.5 mm for LDPE bags and aluminum foil, respectively. In these cases there was only 5% increase in freezing time compared to unpackaged fish samples.     

Isolation and characterization of hypoxia inducible heme oxygenase 1 (HMOX1) gene in Labeo rohita

The HMOX1 gene plays role in several biological processes and is also responsive to hypoxia stress. Freshwater carp fish, Labeo rohita, is reported as hypoxia sensitive, but the information of annotated hypoxia genes in public domain is very scanty for this species. Here, an attempt was made to isolate and characterize HMOX1 gene in L. rohita using information from zebrafish. HMOX1 gene was obtained by mapping HMOX1 protein of zebrafish over assembled genome of L. rohita. Aligned region was used for designing primers for HMOX1 amplification. Eight overlapping sets of primers were designed for amplifying ~540 bp long successive overlapping fragments. Splicing of overlapping amplicons generated 3715 bp fragment that was confirmed as HMOX1 gene having full coding region with 6 exons between 184 and 2156 bp positions. HMOX1 characterization is an initiative for L. rohita genes annotation to support the characterization of new genes in the important species.     

Linking ecology,morphology, and metabolism: Niche differentiation in sympatric populations of closely related species of the genus Littorina (Neritrema)

Divergence of ecological niches in phylogenetically closely related species indicates the importance of ecology in speciation, especially for sympatric species are considered. Such ecological diversification provides an advantage of alleviating interspecies competition and promotes more efficient exploitation of environmental resources, thus being a basis for ecological speciation. We analyzed a group of closely related species from the subgenus Neritrema (genus Littorina, Caenogastropoda) from the gravel‐bouldery shores. In two distant sites at the Barents and Norwegian Sea, we examined the patterns of snail distribution during low tide (quantitative sampling stratified by intertidal level, presence of macrophytes, macrophyte species, and position on them), shell shape and its variability (geometric morphometrics), and metabolic characteristics (metabolomic profiling). The studied species diversified microbiotopes, which imply an important role of ecological specification in the recent evolution of this group. The only exception to this trend was the species pair L. arcana / L. saxatilis, which is specifically discussed. The ecological divergence was accompanied by differences in shell shape and metabolomic characteristics. Significant differences were found between L. obtusata versus L. fabalis and L. saxatilis / L. arcana versus L. compressa both in shell morphology and in metabolomes. L. saxatilis demonstrated a clear variability depending on intertidal level which corresponds to a shift in conditions within the occupied microhabitat. Interestingly, the differences between L. arcana (inhabiting the upper intertidal level) and L. compressa (inhabiting the lower one) were analogous to those between the upper and lower fractions of L. saxatilis. No significant level‐dependent changes were found between the upper and lower fractions of L. obtusata, most probably due to habitat amelioration by fucoid macroalgae. All these results are discussed in the contexts of the role of ecology in speciation, ecological niche dynamics and conservatism, and evolutionary history of the Neritrema species.     

Reproduction in the greenback grey mullet, Liza subviridis (Valenciennes, 1836)

This paper presents data on the reproductive biology of Liza subviridis , a little studied mullet species. The fish is heterosexual, exhibiting external fertilization. Six maturity stages can be macroscopically identified in the testes and seven in the ovaries. The macroscopic changes in the gonads are manifestations of histological changes occurring in the development of sperm cells and oocytes. First sexual maturity is attained in the length ranges of 9.5–11.5 cm and 10.5–11.5 cm in male and female fish respectively. The fecundity for fish measuring 10.3–13.9 cm in standard length ranged from 40 000–145 000 eggs. The relationship between fecundity ( F ) and length ( L ) can be represented as: F = 1.9044 L ^4.2998. The spawning duration in L. subviridis is restricted to a short and definite period, with all ripe ova being released within a single spawning act. A pronounced spawning season can be detected to extend from June to November. However, during off-seasons, some spawning also occurs. The correlations between spawning, rainfall and air temperature is discussed.     

Effect of fasting on nychthemeral concentrations of plasma growth hormone (GH), insulin-like growth factor I (IGF-I), and cortisol in channel catfish (Ictalurus punctatus)

This experiment was conducted to characterize the effect of fasting versus satiety feeding on plasma concentrations of GH, IGF-I, and cortisol over a nychthemeron. Channel catfish fingerlings were acclimated for two weeks under a 12L:12D photoperiod, then fed or fasted for 21 d. On day 21, blood samples were collected every 2 h for 24 h. Weight of fed fish increased an average of 66.2% and fasted fish lost 21.7% of body weight on average. Average nychthemeral concentrations of plasma GH were not significantly different between fed (24.7 ng/mL) and fasted (26.8 ng/mL) fish, but average nychthemeral IGF-I concentrations were higher in fed (23.4 ng/mL) versus fasted (17.8 ng/mL) fish. An increase in plasma IGF-I concentrations was observed in fasted fish 2 h after a peak in plasma GH, but not in fed fish. Average nychthemeral plasma cortisol concentrations were higher in fed (14.5 ng/mL) versus fasted (11.0 ng/mL) fish after 21 d. Significant fluctuations and a postprandial increase in plasma cortisol were observed in fed fish and there was an overall increase in plasma cortisol of both fasted and fed fish during the scotophase. The present experiment indicates little or no effect of 21-d fasting on plasma GH levels but demonstrates fasting-induced suppression of plasma IGF-I and cortisol levels in channel catfish.     

Altered sexual maturation and gamete production in wild roach (Rutilus rutilus) living in rivers that receive treated sewage effluents.

Disruption in gonadal development of wild roach living in U.K. rivers receiving large volumes of treated sewage effluent is manifest in a variety of ways, ranging from malformation of the germ cells and/or reproductive ducts to altered gamete production. Intersex fish were also found to have an altered endocrine status and an elevated concentration of plasma vitellogenin. Gonadal growth was inhibited only in severely intersex fish, whereas progression of spermatogenesis was delayed in a large proportion of all intersex and exposed male fish. In contrast to the effects observed in the intersex and exposed male fish, the maturation of ovaries in female fish inhabiting effluent-contaminated rivers appeared to be less obviously affected, although a higher incidence of oocyte atresia was found in the effluent-exposed fish compared with the reference fish. A positive correlation was found between the proportion of female tissue in the gonads of intersex fish and their plasma vitellogenin concentration, suggesting that vitellogenin can be an indicator for the level of gonadal disruption in intersex roach. The estradiol-17beta concentration in intersex fish was intermediate between the concentration found in males and females, and the plasma testosterone was between 2- and 3-fold higher in intersex fish compared with male fish. These data suggest a link between altered endocrine status in intersex and female fish and gonadal disruption. Spermiation was also affected in roach living in effluent-impacted rivers: a lower proportion of fish were found releasing sperm, and in those intersex fish that were spermiating, a reduced milt volume and a reduced sperm density were found. All intersex fish had malformations of the reproductive duct(s), and in severely affected fish, the ducts were occluded, thus preventing release of gametes. In view of the widespread occurrence of intersexuality in wild fish populations in rivers throughout the United Kingdom, assessment of the reproductive capabilities of these intersex roach is clearly needed to understand the impact of this phenomenon on roach fertility.     

Functional characteristics of leukotriene C4- and D4-metabolizing enzymes (gamma-glutamyl transpeptidase, dipeptidase) within human plasma

Several properties of the leukotriene C4- and leukotriene D4-metabolizing enzymes within human plasma were studied after fractionation of the plasma proteins using ammonium sulfate precipitation. Leukotriene D4-metabolizing enzymes were widely distributed among the fractions obtained. They showed different pH optima (pH 6.5, pH 7.0 and pH greater than or equal to 8.5) and revealed a different degree of thermal stability. The results indicate the presence of more than one enzyme in plasma which interacts with leukotriene D4. EDTA and L-cysteine inhibited the metabolism of leukotriene D4. Two leukotriene C4-metabolizing activities (gamma-glutamyl transpeptidases) differing in their molecular weights were detected after gel filtration. Their molecular weights were estimated to be Mr greater than or equal to 150 000 and Mr between 55 000 and 100 000.