Growth and haematological response of sturgeon hybrids Russian sturgeon (Acipenser guldenstadti brandt) × beluga (Huso huso L.) to protein and lipid contents in the diet

• 1.1. Fingerlings of intergenious hybrid Russian sturgeon (Acipenser guldenstadti) × beluga (Huso huso) weighing 22 g reared in water with salinity 18 ppt were fed nine diets differing in protein and fat content.
• 2.2. The increase of dietary protein content (from 45 to 52%) improved the fingerlings growth rate, food and protein conversion efficiencies. No effect of further protein content increase to 60% was observed.
• 3.3. The increase of dietary fat content from 10 to 20% positively influenced all growth results.
• 4.4. The muscular lipid content increased following the increase in dietary fat due to accumulation of triacylglycerols.
• 5.5. Distinctive leucopenia in neutrophils and leucophilia in lymphocytes following dietary protein and fat content increase were observed.
• 6.6. It was concluded that within the analysed range of values the increase of dietary protein and lipid content improved the physiological status of sturgeon hybrid fingerlings.

     

Food consumption,energy, nutrient and mineral balances in a eurasian kestrel and a screech owl

• 1.1. The food consumption, energy, nitrogen, fat, ash, calcium, phosphate and magnesium balances of the Eurasian kestrel (Falco tinnunculus), and screech owl (Otus kennicotti) are compared.
• 2.2. Eurasian kestrel sample values were significantly greater than screech owl sample values in the energy, nitrogen, calcium, phosphate and magnesium content in pellets, and calcium content in excrement. Phosphate content in excrement was significantly greater in screech owl samples than in Eurasian kestrel samples.
• 3.3. The Eurasian kestrel ingested significantly greater amounts of calcium and phosphate, egested via excrement significantly greater amounts of ash, excreted or egested significantly greater amounts of energy, nitrogen, calcium and phosphate via excrement and pellets, and excreted significantly greater amounts of magnesium via excrement than did the screech owl. The screech owl assimilated significantly greater amounts of ash than did the Eurasian kestrel.
• 4.4. The metabolizability coefficient averaged 48.32% for the Eurasian kestrel, and 49.62% for the screech owl.

     

Effects of feeding,starvation, and refeeding on the fatty acid composition of channel catfish,ICtalurus punctatus,tissues

• 1.1. The effects of feeding, food deprivation (14 and 28 days) and refeeding (starved 14 then fed 14 days) on the fatty acid composition of white muscle, liver and brain of pond-raised channel catfish (Ictalurus punctatus) were investigated.
• 2.2. Levels of n-3 fatty acids were significantly higher (P < 0.05) in white muscle of fish starved 28 days (10.7%) than in fish fed throughout the study (8.0%), due primarily to an increase in 22:6(n-3) docosahexaenoic acid or DHA.
• 3.3. Significantly higher levels of 20:5(n-3) (eicosapentaenoic acid or EPA) were found in livers offish starved 28 days (P < 0.05) compared to fish fed throughout the study.
• 4.4. Results suggest that the fatty acid compositions of channel catfish white muscle and liver are subject to only limited perturbation during periods of starvation and refeeding and that the brain is extremely well protected.

     

Effects of a purine inhibitor,allopurinol, on urate metabolism in the german cockroach,Blattella germanica L. (Dictyoptera: Blattellidae)

• 1.1. Adult male and female cockroaches (Blattella germanica) were maintained on a positive nitrogen balance diet (66% protein) containing various levels of allopurinol (0–3%) to determine the effects of allopurinol on urate synthesis and storage.
• 2.2. Each insect was injected with [¹⁴C]hypoxanthine and after 1 week was analyzed for whole-body hypoxanthine, xanthine and urate radiolabel.
• 3.3. There was a general trend of decreased whole-body radiolabel retention, radiolabeled body urates and total-body urate content in both sexes with increasing amounts of dietary allopurinol.
• 4.4. Virgin female adults were allowed to feed on diets containing 0, 25 and 66% protein plus 0.1% allopurinol and were injected with [¹⁴C]xanthine.
• 5.5. After 1 week radiolabel content in the whole-body xanthine and urate pools was determined.
• 6.6. Females on the 0% protein diets contained less radiolabel in the whole-body and body urates than those on either 25 or 66% protein diets.

     

Effects of dietary estradiol-17β on feminization,growth and body composition in the Japanese eel (Anguilla japonica)

• 1.1.Juvenile Japanese eels (Anguilla japonica) were fed on a diet supplemented with estradiol-17β (E₂) at doses of 25, 50 and 75 mg/kg. The effects on growth, sex distribution and body composition were investigated in two groups of gonadally undifferentiated stages (early and later juvenile stages).
• 2.2.Feminization (95–100%) was observed in all E₂-treated groups.
• 3.3.The growth rate of fish treated with 25 and 50 mg/kg E₂ diet at the early juvenile stage was significantly increased.
• 4.4.The amount of protein in muscle decreased and that of fat increased in the E₂-treated groups except in the early juvenile stage fed with 25 mg/kg E₂.

     

Correlation between body color and behavior in the upside-down catfish,Synodontis nigriventris

• 1.1. Unlike common fishes and as its Latin name implies, the upside-down catfish, Synodontis nigriventris, possesses dark ventral skin. Microscopic observation reveals that melanophores are present on both the ventral and the dorsal skin but differ in size and density of distribution.
• 2.2. The darkness of both sides of the fish changes in accordance with that of the background.
• 3.3. At night, the fish are very active and the body becomes pale. The change in color is more noticeable in the dorsal than the ventral skin.
• 4.4. When melatonin was added to the bathing water, the fish became pale and swam restlessly even when they were exposed to the black background.
• 5.5. It was found that the catfish preferred the black background to the white one.

     

Unsaponifiable matter of liver oil of intensively reared sea bass (Dicentrarchus labrax): Sterols and aliphatic alcohols

• 1.1. Sterols and aliphatic alcohols of sea bass (Dicentrarchus labrax) liver oil intensively reared and fed on three different diets were studied, with the aim of verifying any differences due to diets and seasonal variations.
• 2.2. Ten components of the sterol fraction were found; the largest component was cholesterol.
• 3.3. Nineteen linear chain alcohol components were identified: there were between 14 and 32 carbon atoms, mainly saturated; the 28:0 and the 30:0 were the most abundant.
• 4.4. Evident differences were not due to the three diets adopted, but to the seasonal conditions; the quantity of sterols present in the liver decreased in the cold months, in connection with reproduction.

     

Response of rainbow trout to source and level of supplemental dietary methionine

• 1.1. Methionine and total sulfur amino acid (TSAA) requirements of rainbow trout (Salmo gairdneri) were investigated by feeding graded isosulfurous levels of l- and dl-methionine, l-cystine, and the free acid and calcium forms of methionine hydroxy analog (MHA).
• 2.2. Added cystine did not promote growth, survival or prevent cataracts.
• 3.3. l-methionine produced fastest growth, followed by dl-methionine, CaMHA and free acid MHA.
• 4.4. Trout fed CaMHA gained 85.7 and 92.3% as much as those fed l-methionine and dl-methionine.
• 5.5. Within each experiment, the level of L-methionine isomer that prevented cataracts was constant (1.86 g/100g protein in experiment (1), 1.45 in experiment (2) and was lower than for maximum growth (2.89 and 2.15 g) regardless of methionine source.

     

The suitability of using cryopreservation of spermatozoa for the conservation of genetic diversity in African catfish (Clarias gariepinus)

• 1.1. The effect of cryopreservation of semen on expected Hardy-Weinberg proportions in the f₁ progeny of selected breeding pairs was evaluated.
• 2.2. Four different African catfish breeding pairs were selected, each pair displaying different heterozygous alleles at the glucose-6-phosphate isomerase-1 or 2 loci.
• 3.3. Equal volumes of ova from each female were artificially inseminated with cryopreserved or fresh semen obtained from males possessing corresponding genotypes.
• 4.4. A comparison of growth rates between f₁ groups of offspring produced from fresh and cryopreserved semen was made.
• 5.5. The G-test for goodness of fit showed no significant differences from expected Hardy-Weinberg proportions for allele frequencies obtained in the f₁ progeny.
• 6.6. The application of cryopreservation for the conservation of genetic diversity is discussed.

     

Kinetic studies of catechol-o-methyltransferase from the brain of the African catfish,Clarias gariepinus

• 1.1. Optimum in vitro conditions, and kinetics of the enzyme catechol-O-methyltransferase from the brain of the male African catfish were studied.
• 2.2. A saturated level for S-adenosylmethionine, as methyldonor, and magnesium as cofactor was reached at 5 μM and 10 mM, respectively.
• 3.3. The addition of ascorbic acid, as an antioxidant, and tranylcypromine, as a MAO inhibitor, was not necessary, during incubations with fore-brain homogenates.
• 4.4. Kinetic analysis of the methylation of catecholestrone, catecholestradiol and dopamine showed K_m values of 1.2, 0.6 and 0.5 μM, respectively.
• 5.5. The affinity of the catecholsubstrates for the enzyme catechol-O-methyltransferase is much higher in the brain of the African catfish than in tissues of mammals.

     

Bioenergetics of abbreviated larval development in the bromeliad crab,Metopaulias depressus (Decapoda: Grapsidae)

• 1.1. Larvae of the bromeliad crab, Metopaulias depressus Rathbun, were reared in the laboratory, and changes in dry weight (W), ash-free W (AFW), carbon, nitrogen, hydrogen, protein, lipid, carbohydrates and respiration rate were measured during development from hatching to metamorphosis.
• 2.2. Development was successful in rain-water from bromeliads (pH < 5–6), but not in river water from the same region (pH 8). It is abbreviated, with two non-feeding zoeal stages (2.5–3.5 days each) and a feeding megalopa (8.5–10 days). Development to metamorphosis can also be completed in the absence of food (facultative lecithotrophy).
• 3.3. Dry weight and other absolute biomass values per individual vary significantly between different hatches, whereas changes in the relative (% of W or AFW) composition follow quite invariable patterns: ash increases from hatching through the first part of megalopa development, organic biomass decreases concurrently.
• 4.4. Elemental and biochemical data show that lecithotrophy of the zoeal stages as well as continued endotrophic development in the megalopa depend chiefly on degradation of lipid reserves and less on protein. No significant growth was observed in organic constituents when food was available, but without food the megalopa reached metamorphosis with only half the lipid and less than two thirds the protein of fed siblings.
• 5.5. The relationship between C and lipid is similar in M. depressus larvae as in planktotrophic marine crab larvae, whereas that between N and protein differs; it indicates the presence of unusually large quantities of unidentified non-protein N.
• 6.6. Exuvial losses of late premoult biomass or energy are very low in the zoeal stages (2 and 3%), but increase in the megalopa (16% in W, 10% in C, 7–8% in N, H and energy).
• 7.7. Respiration rate per individual increases gradually during larval development (0.6–0.8 μg O₂/hr). Starved megalopa larvae reveal lower individual but higher W-specific metabolism than fed larvae.
• 8.8. Bioenergetic traits of abbreviated larval development are discussed in relation to those known from regular (planktotrophic marine) development of brachyuran crabs. M. depressus is highly adapted to life and development in a physically extreme terrestrial environment.

     

Adaptation of rainbow trout (Salmo gairdnerii) to sea water: Changes in calcitonin levels

• 1.1. The calcitonin content of the ultimobranchial body (UBB) and plasma levels of calcitonin, calcium and phosphate were measured in rainbow trout (Salmo gairdnerii) following their transfer from fresh to sea water.
• 2.2. The plasma calcium level remained unchanged throughout the experiment while the UBB calcitonin content, plasma calcitonin and plasma phosphate rose significantly during the hours immediately following transfer.
• 3.3. The levels of all three subsequently fall so that, 8–15 days later, a new equilibrium was established with lower than control (fresh water) levels of UBB calcitonin, plasma calcitonin and plasma phosphate.
• 4.4. It would appear, from these data, that calcitonin plays some part in the endocrine regulation of sea water transfer.

     

Scale regeneration of tilapia (Oreochromis niloticus) under various ambient and dietary calcium concentrations

• 1.1. Scale regeneration was examined in Oreochromis niloticus under normal, dietary calcium-deficient, and both dietary and ambient water calcium-deficient conditions.
• 2.2. Calcium contents of regenerating scales were dependent on the calcium status of the fish, but areal growth of the scales was independent.
• 3.3. Transient hypocalcemia accompanied with a loss of calcium from original scales was observed in descaled fish in dietary calcium deficiency, and intact and descaled fish in both dietary and ambient water calcium deficiency.
• 4.4. The results suggested that calcium mobilized from internal sources was insufficient and both water and dietary calcium were necessary for normal calcification of the regenerating scales.

     

Effects of milk fat,unhydrogenated and partially hydrogenated vegetable oils on serum lipoproteins in growing pigs

• 1.1. Crossbred Yorkshire (Yorkshire × Landrace) pigs were fed butter oil, cream, low erucic acid rapeseed oil, sunflower oil and partially hydrogenated sunflower oil in amounts representing 30% of energy for periods of up to 13 weeks.
• 2.2. After 13 wk of feeding serum total cholesterol levels of pigs fed milk fat were significantly higher than of pigs fed vegetable oils.
• 3.3. The difference in cholesterol was mainly due to an increase in the density range of 1.063–1.125 g/ml containing pig LDL₂ and some HDL.
• 4.4. A shift towards smaller LDL particle size was apparent in pigs fed milk fat.
• 5.5. The effects of dietary trans fatty acids did not differ from cis polyunsaturated or monounsaturated fatty acids.

     

Troponin C of the Antarctic icefish (Champsocephalus gunnari) white muscle

• 1.1. The troponin C (TN-C) from the Antarctic icefish (_{Champsocephalus gunnari}) has been isolated to homogeneity by a procedure involving extraction from acetone powder, DEAE-Sepharose 4B and AcA 54 column chromatography.
• 2.2. The calcium-induced conformational changes of apo TN-C have been studied by absorption difference spectroscopy, circular dichroism and intrinsic fluorescence.
• 3.3. The results indicate that the overall characteristics of icefish TN-C (such as amino acid composition, modifications of helix content and of the microenvironment of aromatic residues as a function of calcium binding) are quite similar to those of rabbit TN-C.
• 4.4. The intrinsic fluorescence properties are close to those reported for pike and carp TN-C.

     

Serum and urine biochemical indicators of nutritional status in adult female collared peccaries,Tayassu tajacu (tayassuidae)

• 1.1. Physiological responses of 13 adult female collared peccaries (Tayassu tajacu) to high quality and low quality diets, fed for 15 weeks, were examined. The low quality diet simulated energy and protein intake of peccaries during poor range conditions resulting from drought. Blood samples were collected after 10 and 15 weeks of dietary treatment; urine samples were collected after 15 weeks of treatment.
• 2.2. Females receiving the low quality diet for 15 weeks lost 27.4% of their original body weight, compared to no weight change among high quality-fed females.
• 3.3. Red blood cell counts, hematocrits, and hemoglobin concentrations were significantly greater among females fed a high quality diet compared to those receiving a low quality diet. High quality-fed females also had a higher mean corpuscular hemoglobin concentration. Plasma fibrinogen concentration was nearly twice as great among females receiving the low quality diet compared to the high quality group.
• 4.4. Consumption of the low quality diet resulted in significantly elevated serum levels of nonesterified fatty acids, alkaline phosphatase, phosphorus, alpha-2 globulin and alpha globulin: beta globulin ratio.
• 5.5. Consumption of the low quality diet resulted in significantly lowered serum levels of urea nitrogen, calcium, zinc, calcium: phosphorus, urea index, beta-1 flobulin, beta globulin: albumin ratio, thyroxine and triiodothyronine.
• 6.6. Serum levels ofcreatinine, total bilirubin, glucose, cholesterol, gamma glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, potassium, copper, magnesium, sodium chloride, total protein and gamma globulin were unaffected by diet quality.
• 7.7. Urine chemistry results suggested pH, osmolarity, albumin, creatinine phosphokinase, calcium and phosphorus concentrations might be useful indices for assessing nutritional status in female peccaries.

     

Electrophoretic comparison of myosin light chains and parvalbumins of trunk and head muscles from two barbel (Barbus barbus) populations

• 1.1. Myosin light chains and parvalbumins have been compared in several trunk and head muscles from small and large size barbels (Barbus barbus) living in river or reared in hatchery.
• 2.2. These proteins isolated from white, red and ventricle fibres exhibit identical electrophoretic characteristics in the four batches.
• 3.3. The slow fibre content and the parvalbumin distribution are generally similar in river and hatchery barbels of the same size but differ between small and large barbels within a population.
• 4.4. Alterations of the mode of fertilization and breeding conditions do not modify the differentiation of myosin and parvalbumins in barbels.

     

The effect of cryopreservation and various cryodiluents on allozyme variation of glucose phosphate isomerase in the F1 progency of african catfish (clarias gariepinus)

• 1.1. African sharptooth catfish individuals, heterozygous for glucose phosphate isomerase (GPI-2), were selected as broodstock by using horizontal starch-gel electrophoresis.
• 2.2. Ova of one heterozygous female were inseminated with cryopreserved and fresh milt from a corresponding male.
• 3.3. Significant deviations from expected Hardy-Weinberg proportions occured for offspring obtained by using cryopreserved milt.
• 4.4. Differences in genotypic variation seems to relate to different cryodiluents and the fertility thereof.
• 5.5. Selection of breeding stock for aquacultural practices based on the above information is discussed.

     

The influences of individual variations in metabolic rate and tidal conditions on the response to hypoxia in Carcinus maenas (L.)

• 1.1. The oxygen consumption of crabs in normoxic and hypoxic (50% O₂) seawater was measured directly after collection.
• 2.2. The influences of size and lunar cycles were removed by scaling the data.
• 3.3. Strong negative correlations between low individual levels of O₂ consumption and the ability to compensate for hypoxia were apparent in Wicklow (subtidal) crabs.
• 4.4. Compensation for hypoxia was much greater on the flood tide than on the ebb.
• 5.5. Crabs from Roscoff (intertidal) had lower levels of compensation than those from Wicklow.
• 6.6. Size, sex and condition had no apparent effect upon these relationships.
• 7.7. Crabs acclimated to laboratory conditions have not shown this tidal variation in compensation for hypoxia.

     

Comparative study of proteolytic enzymes in the digestive tracts of the european sea bass and hybrid striped bass reared in freshwater

• 1.1. A comparative study of the proteolytic activity in four different sections of the digestive tracts of the European sea bass (Dicentrarchus labrax) and hybrid striped bass (Morone chrysops × M. saxatilis) reared in freshwater revealed minor differences between these fish.
• 2.2. Tryptic activity plays a major role in the proteolytic process in both fish.
• 3.3. The activity of seven intestinal proteolytic enzymes was detected utilizing a combination of specific substrates and inhibitors.
• 4.4. High levels of proteolytic activity were detected in both the proximal and distal sections of the fish intestine at a high pH range (9–10).
• 5.5. In situ monitoring of pH levels revealed a lower pH level in the intestinal proximal section of hybrid striped bass compared with the distal section.
• 6.6. In contrast, higher pH levels were detected at the proximal compared with the distal sections of D. labrax intestine.