Prevalence of Haplorchis taichui and Haplorchoides sp. metacercariae in freshwater fish from water reservoirs, Chiang Mai, Thailand

A parasitological investigation on trematode metacercariae was made on 62 freshwater fishes of 13 species in northern Thailand; Cyclocheilichthys apogon, Puntioplites proctozysron, Labiobarbus siamensis, Barbodes gonionotus, Barbodes altus, Henicorhynchus siamensis, Osteochilus hasselti, Notopterus notopterus, Mystacoleucus marginatus, Anabas testudineus, Systomus orphoides, Morulius chrysophykadian, and Hampala macrolepidota. The fish were caught over the summer period (February-May 2007) from 2 Chiang Mai water reservoirs, i.e., the Mae Ngad (UTM 47Q E 503200, 47Q N 2119300) and the Mae Kuang Udomtara (UTM 47Q E 513000, 47Q N 2092600) Reservoirs in Chiang Mai province, Thailand. The prevalence of heterophyid (Haplorchis taichui and Haplorchoides sp.) metacercariae in these fish was 83.9% and 74.2% in the Mae Ngad and Mae Kuang Udomtara Reservoirs, respectively. The highest intensity of heterophyid metacercariae in H. siamensis in the Mae Ngad was 120.4 and that in P. proctozysron in the Mae Kuang Udomtara was 180.0. The fish, A. testudineus, C. apogon, and M. chrysophykadian, were not found to be infected with H. taichui metacercariae. The results show that the freshwater fish in Chiang Mai water reservoirs are heavily infected with H. taichui and Haplorchoides sp. metacercariae.     

The influence of hunger on food‐stocking behaviour of climbing perch Anabas testudineus

The present study demonstrated that the climbing perch Anabas testudineus collected and stocked food pellets in its mouth, a behaviour that has not yet been reported in any other species of fish. In this species, food deprivation for 24 h increased food stocking, but not food intake.     

Rapid regulatory effect of tri-iodothyronine (T3) on antioxidant enzyme activities in a fish Anabas testudineus (Bloch): short-term in vivo and in vitro study

The short-term action of thyroid hormone tri-iodothyronine (T3) was studied in vivo and in vitro on antioxidant enzyme activities in a teleost Anabas testudineus (Bloch). T3 injection in vivo (200 ng) in normal fish decreased the lipid peroxidation products and increased superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities after 30 min. T3 in vitro (10(-6) M) increased the antioxidant activities of catalase, glutathione reductase (GR), GPx and glutathione level after 15/30 min, except SOD, substantiating in vivo effects in normal fish. The results suggest a rapid regulatory effect of thyroid hormone in vivo and in vitro, in the removal of reactive oxygen species in A testudineus.     

Starvation induced cholesterogenesis in hepatic and extra hepatic tissues of climbing Perch,Anabas testudineus (Bloch)

Cholesterol is a structural lipid, which may be differentially utilized or synthesized in response to stress or during insulin deficient states such as starvation. In the present investigation we estimated the levels of cholesterol in Anabas testudineus, which was subjected to brief (15 days) and prolonged fasting (60 days). Tissues such as liver, kidney, brain, accessory respiratory organ, pectoral and lateral line muscle were selected for the study. Cholesterol content was estimated by the Crawford method (1958). Both the starvation regimes showed a significant increase in cholesterol levels in almost all the tissues, but for liver, which strangely showed an insignificant decline during the short-term starvation. This overall upsurge in cholesterol levels observed in all extra hepatic tissues may be attributed to the synthesis of stress hormones such as glucocorticoids, which may promote gluconeogenesis and adrenocorticoids, which may help the animal to combat the stressful condition of starvation. Anabas adapted well to starvation stress and survived all throughout the experimental period.     

Thyroid status alters gill ionic metabolism and chloride cell morphology as evidenced by scanning electron microscopy in a teleost Anabas testudineus (Bloch): short and long term in vivo study

Gill is the main organ of osmotic regulation in teleosts and chloride cells are the sites of ion transport across gill epithelium. Thyroid hormones are implicated in the regulation of osmotic balance in teleosts also. Treatment with 6-propyl thiouracil (6-PTU) inhibited the membrane bound enzyme Na+K+ ATPase in the gill while triiodothyronine (T3) injection stimulated it in a short-term in vivo study in the teleost Anabas testudineus. Na+, K+ and Ca2+ ions were also decreased in the 6-PTU treated fish and the T3 treatment increased their concentrations in the gill lamellae. The gill morphology also changed according to the thyroid status in the long term study. 6-PTU treatment altered the typical serrated morphology of the gill lamellae, while the T3 treatment reversed it. T3 injection increased the density of pavement and chloride cells as evidenced by scanning electron microscopy. The results demonstrate that physiological status of the thyroid influences gill Na+ pump activity and chloride cell morphological changes. Further, the study suggests a regulatory role of T3 on gill ions (Na+, K+ and Ca2+), Na+K+ and Ca2+ ATPase activity and the different gill cell types in A. testudineus.     

Changes in tissue free amino acid contents, branchial Na+/K+ -ATPase activity and bimodal breathing pattern in the freshwater climbing perch, Anabas testudineus (Bloch), during seawater acclimation

This study aimed to examine effects of short- or long-term acclimation to brackish water or seawater on the climbing perch, Anabas testudineus, which is an aquatic air-breathing teleost living typically in freshwater. A. testudineus exhibits hypoosmotic and hypoinoic osmoregulation; the plasma osmolality, [Na+] and [Cl-] of fish acclimated to seawater were consistently lower than those of the external medium. However, during short-term (1 day) exposure to brackish water (15 per thousand) or seawater (30 per thousand), these three parameters increased significantly. There were also significant increases in tissue ammonia and urea contents, contents of certain free amino acids (FAAs) in the muscle, and rates of ammonia and urea excretion in the experimental fish. The accumulated FAAs might have a transient role in cell volume regulation. In addition, these results indicate that increases in protein degradation and amino acid catabolism had occurred, possibly providing energy for the osmoregulatory acclimation of the gills in fish exposed to salinity stress. Indeed, there was a significant increase in the branchial Na+/K+ -ATPase activity in fish exposed to seawater for a prolonged period (7 days), and the plasma osmolality, [Na+] and [Cl-] and the tissue FAA contents of these fish returned to control levels. More importantly, there was a significant increase in the dependence on water-breathing in fish acclimated to seawater for 7 days. This suggests for the first time that A. testudineus could alter its bimodal breathing pattern to facilitate the functioning of branchial Na+/K+ -ATPase for osmoregulatory purposes.     

Cardiogenic motion of right lung parenchyma in anesthetized intact dogs

Recent investigation suggests that both ventilation (VE) and the chemical sensitivity of the respiratory control system correlate closely with measures of metabolic rate [O2 consumption (VO2) and CO2 production (VCO2)]. However, these associations have not been carefully investigated during sleep, and what little information is available suggests a deterioration of the relationships. As a result we measured VE, ventilatory pattern, VO2, and VCO2 during sleep in 21 normal subjects (11 males and 10 females) between the ages of 21 and 77 yr. When compared with values for awake subjects, expired ventilation decreased 8.2 +/- 2.3% (SE) during sleep and was associated with a 8.5 +/- 1.6% decrement in VO2 and a 12.3 +/- 1.7% reduction in VCO2, all P less than 0.01. The decrease in ventilation was a product primarily of a significant decrease in tidal volume with little change in frequency. None of these findings were dependent on sleep stage with results in rapid-eye-movement (REM) and non-rapid-eye-movement sleep being similar. Through all sleep stages ventilation remained tightly correlated with VO2 and VCO2 both within a given individual and between subjects. Although respiratory rhythmicity was somewhat variable during REM sleep, minute ventilation continued to correlate with VO2 and VCO2. None of the parameters described above were influenced by age or gender, with male and female subjects demonstrating similar findings. Ten of the subjects demonstrated at least occasional apneas. These individuals, however, were not found to differ from those without apnea in any other measure of ventilation or metabolic rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

The peak oxygen uptake of British children with reference to age, sex and sexual maturity

The purposes of this study were to provide baseline data on the peak oxygen consumption (VO2) of British children, aged 11-16 years and to examine the peak VO2 of children in relation to their pubertal stage of development. The peak VO2 of 226 boys and 194 girls was determined during either treadmill running or cycle ergometry. The sexual maturity of 320 of the children was estimated using Tanner's indices. Peak VO2 increased with chronological age in both sexes and from about the age of 12 years boys exhibited significantly higher (P less than 0.05) values than girls. Boys' peak VO2 in relation to body mass was consistent over the age range studied and was superior (P less than 0.05) to girls' values at all ages. It appears that mass-related peak VO2 is independent of sexual maturity in both sexes. The more mature boys demonstrated a significantly higher (P less than 0.05) peak VO2 (1.min-1) than the less mature boys on both ergometers. The more mature girls demonstrated significantly higher (P less than 0.05) peak VO2 (1.min-1) than the less mature girls only on the cycle ergometer. On both ergometers the differences between the peak VO2 of the girls and boys were more pronounced in the mature children whether expressed in relation to body mass or not. Comparison of the results with earlier data drawn from smaller samples failed to provide evidence to suggest that British children's peak VO2 has declined in recent years. No study with which to compare our maturity peak VO2 data appears to be available.     

Influence of reproductive status,sex hormones and temperature on plasma IGF-I concentrations in sunshine bass (Morone chrysops × Morone saxatilis)

Insulin-like growth factor-I (IGF-I) concentrations in male and female sunshine bass (Morone chrysops × Morone saxatilis) were determined in March, early April, and late April in outdoor ponds at a commercial farm. Female fish were always larger than male fish; however, plasma IGF-I concentrations tended to be higher in male fish and increased as pond temperature and feeding increased in both sexes. Gonadal development was greatest in both sexes in March and declined to a regressed state by the end of April and the same pattern of change occurred with plasma estrogen and testosterone. Growth and IGF-I concentrations in sunshine bass fed estrogen, methyl testosterone, or a control diet were also determined. Growth was reduced in fish fed both sex hormones. Fish fed the control diet had the highest IGF-I levels, androgen-fed fish had intermediate levels, and estrogen-fed fish had the lowest IGF-I concentrations after 4 weeks on the diet. Plasma IGF-I concentrations appeared to respond to increasing temperature in the ponds, and were inversely related to gonadal development and sex hormones. Exogenous sex hormones resulted in a decrease in plasma IGF-I, feeding activity and growth.     

Differential C-heterochromatin distribution in two species of freshwater fish, Anabas testudineus (Bloch.) and Puntius sarana (Hamilton.)

Anabas testudineus (2n = 46) had the more conserved pattern of its C-heterochromatin distributed mainly in the centromeric region, whereas Puntius sarana (2n = 50) exhibited a rather unorthodox pattern, many chromosomes showing interstitial, some telomeric and a few chromosomes showing centromeric C-band localization. Further, lateral asymmetry in distribution of heterochromatin was also noted in two pairs of chromosomes in P. sarana. The possible implications of the differential distribution noted in these two species has been discussed.     

Ultrastructure of the Sagitta Otolith in Different Body Size Groups of Climbing Perch Anabas testudineus (Anabantidae)

Journal of Ichthyology - The ultrastructural characteristics of the sagitta of the climbing perch, Anabas testudineus (Bloch, 1792) in different body size groups are described for the first time...     

Sex differences in circulatory oxygen transport parameters of sockeye salmon (Oncorhynchus nerka) on the spawning ground

Upon reaching sexual maturity, several species of male salmonids possess a relative ventricular mass (rM_V) that may be up to 90% larger than females. This can increase maximum cardiac stroke volume and power output, which may be beneficial to increasing the oxygen transport capacity of male salmonids during the spawning period. It may be further hypothesized, therefore, that other variables within the circulatory oxygen transport cascade, such as blood oxygen-carrying capacity and heart rate, are similarly enhanced in reproductively mature male salmonids. To test this idea, the present study measured a range of circulatory oxygen transport variables in wild male and female sockeye salmon (Oncorhynchus nerka) during their spawning period, following a 150 km migration from the ocean. The rM_V of male fish was 13% greater than females. Conversely, the haemoglobin concentration ([Hb]) of female fish was 19% higher than males, indicative of a greater blood oxygen-carrying capacity (138 vs. 116 ml O₂ l⁻¹, respectively). Surgically implanted physiological data loggers revealed a similar range in heart rate for both sexes on the spawning ground (20–80 beats min⁻¹ at 10°C), with a tendency for male fish to spend a greater percentage of time (64%) than females (49%) at heart rates above 50 beats min⁻¹. Male fish on average consumed significantly more oxygen than females during a 13-h respirometry period. However, routine oxygen consumption rates ranged between 1.5 and 8.5 mg min⁻¹ kg⁻¹ for both sexes, which implies that males did not inherently possess markedly higher routine aerobic energy demands, and suggests that the higher [Hb] of female fish may compensate for the smaller rM_V. These findings reject the hypothesis that all aspects of the circulatory oxygen transport cascade are inherently superior in male sockeye salmon. Instead, it is suggested that any differences in between sexually mature male and female sockeye salmon can likely be attributed to activity levels.     

Evidence for an inverse relationship between the ventilatory response to exercise and the maximum whole body oxygen consumption value

Ventilatory responses to submaximal exercise loads indicate that in a population of 895 physically active and sedentary male and female subjects, exercise ventilation is inversely related to predicted VO2max. The correlation coefficients for males and females in this relationship are 0.61 (P less than 0.0001) and 0.26 (P less than 0.0001) respectively. The slopes of regression lines for VE/VO2 and VO2max in female and male subjects are -2.59 and -0.91 respectively. This is associated with changes in composition of the expired air in that PCO2 increases and PO2 decreases with greater VO2max. The difference between the mean oxygen and carbon dioxide partial pressures in expired air of individuals in the highest and lowest VO2max ranges are 1.2 kPa (9 mm Hg) and 0.8 kPa (6 mm Hg) respectively.     

Morphology of the Olfactory Organ in the Climbing Perch (Anabas testudineus,Anabantidae, Perciformes)

Biology Bulletin - The structure of the olfactory organ in the climbing perch (Anabas testudineus) has been studied by light microscopy. The anterior nostril is a short and narrow tube directed...     

Effect of Thiourea on Migratory Activity of Climbing Perch Anabas testudineus and Food Consumption

Journal of Ichthyology - The effect of thiourea (exposure to 0.05% solution) on the migratory activity of the climbing perch Anabas testudineus has been studied. It is established that thiourea...     

Indirect estimation of the maximal aerobic power of a male and female population from Brussels aged 6 to 23 years. Comparison with a direct technic for measuring maximal oxygen consumption

Validation of the maximal multistage 20 m shuttle run test with 1 min steps has been compared with a stepwise load increase on a bicycle ergometer among 201 male and female subjects ranging from 14 to 30 years. A slight underestimation of VO2 max (5.2%) amounting to 2.71 ml . min-1 . kg-1 was observed for the multistage shuttle test as compared to the bicycle test (r = 0.72). The analysis of the biological values collected after exercise does not show major differences between the two tests (plasma lactate, urinary total protein and albumin, creatinine). The renal handling of plasma proteins appears to be equally disturbed under the influence of exhaustive exercise. Maximal aerobic power regularly increases with age in both sexes, being more pronounced however for boys (1.16 to 3.37 l . min-1) than for girls (1.17 to 2.43 l . min-1) from 6 to 20 years old. Boys nearly sustain 50 ml . min-1 . kg-1 throughout childhood. On the contrary, from 8 years on girls progressively reduce their VO2 max down to 37.1 ml . min-1 . kg-1 at the age of 19. The decrease is more pronounced during the 11-16 years period. The present results constitute tentative norms on 1,025 brussels male and female subjects ranging from 6 to 23 years.     

Triiodothyronine and melatonin influence antioxidant defense mechanism in a teleost Anabas testudineus (Bloch): in vitro study

The effect of the hormones triiodothyronine (T3) and melatonin on antioxidant defense system was studied in 6-propyl thiouracil (6-PTU)-treated or photoperiod-exposed teleost Anabas testudineus. 6-PTU (2 microg/g) treatment or photoperiod exposure (24 h) increased malondialdehyde (MDA) and conjugated dienes (CD) concentrations, indicating increased lipid peroxidation (LPO) in the experimental conditions. T3 or melatonin (10(-6) M) treatment for 15 min in vitro in PTU-treated fish reversed the activity of superoxide dismutase (SOD), catalase and glutathione content. T3-treated group showed no change in glutathione peroxidase (GPx) activity, whereas melatonin treatment decreased its activity. T3 inhibited glutathione reductase (GR) activity. Photoperiod exposure (physiological pinealotomy) induced a stressful situation in this teleost, as evidenced by LPO products and antioxidant enzyme activities. Melatonin and T3 treatment for 15 min in vitro also reversed the effect of photoperiod on peroxidation products and the SOD and catalase activities. GR activity decreased in photoperiod-exposed group and melatonin and T3 treatment reversed the activities. The antioxidant enzymes responded to the stress situation after 6-PTU treatment and photoperiod exposure by altering their activities. The study suggested an independent effect of T3 and melatonin on antioxidant defence mechanism in different physiological situations in fish.     

Determination and validity of critical velocity as an index of swimming performance in the competitive swimmer.

The purpose of this investigation was to test whether the concept of critical power used in previous studies could be applied to the field of competitive swimming as critical swimming velocity (vcrit). The vcrit, defined as the swimming velocity over a very long period of time without exhaustion, was expressed as the slope of a straight line between swimming distance (dlim) at each speed (with six predetermined speeds) and the duration (tlim). Nine trained college swimmers underwent tests in a swimming flume to measure vcrit at those velocities until the onset of fatigue. A regression analysis of dlim on tlim calculated for each swimmer showed linear relationships (r2 greater than 0.998, P less than 0.01), and the slope coefficient signifying vcrit ranged from 1.062 to 1.262 m.s-1 with a mean of 1.166 (SD 0.052) m.s-1. Maximal oxygen consumption (VO2max), oxygen consumption (VO2) at anaerobic threshold, and the swimming also velocity at the onset of blood lactate accumulation (vOBLA) were also determined during the incremental swimming test. The vcrit showed significant positive correlations with VO2 at anaerobic threshold (r = 0.818, P less than 0.01), vOBLA (r = 0.949, P less than 0.01) and mean velocity of 400 m freestyle (r = 0.864, P less than 0.01). These data suggested that vcrit could be adopted as an index of endurance performance in competitive swimmers.     

Effect of hormones and pharmacological drugs on the blood of Anabas testudineus (Bloch).

Effect of different gonadal steroids, hydrocortisone, catecholamines and antithyroidal agent on certain haematological parameters in an air breathing fish, Anabas testudineus (Bloch) commonly known as climbing perch, have been made. The treatment of hydrocortisone, adrenaline, noradrenaline and testosterone brings about a significant increase in RBC counts (polycythemia), Hb content and PCV values as compared to control which were subjected to the treatment of normal saline. Males were more susceptible to the treatment of hydrocortisone, catecholamines than females. Ovocyclin, Duogynon forte and Fertyl treatments bring about anaemia in this fish, i.e. a decrease in RBC number, Hb content and PCV was clearly marked out. Females were more susceptible to Fertyl than males. Lutocyclin failed to bring any significant changes in these blood parameters. Though the treatment of thiouracil could not bring about significant changes in different blood parameters, a tendency of increase in RBC counts, Hb content and PCV was observed. The absolute values for different blood parameters have also been calculated. Possible reason and the mechanism of such changes in different blood parameters are discussed in detail.