bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of handling on endocrinology and reproductive performance of the fathead minnow
Authors: Kahl M. D. , Jensen K. M. , Korte J. J. , Ankley G. T.
Published: April 2005

Anaesthesia with MS‐222 followed by intra‐peritoneal (ip) injection (with a 10% ethanol in corn oil carrier) of fathead minnow either as one or three (weekly) treatments did not affect survival, behaviour or secondary sexual characteristics of the fish. Fecundity of the fish, as indicated by fertility and hatching success, was also unaffected. Gonadal condition (relative gonad mass, histopathology) was not altered in either sex. Male and female plasma sex steroids (β;‐oestradiol, testosterone, 11‐ketotestosterone) and male vitellogenin concentrations were not significantly affected by the treatments. Females subjected to either ip treatment regime had significantly higher plasma vitellogenin concentrations than control females. However, based on previous data, this difference did not appear to be treatment‐related. Overall, exposure of fathead minnows to chemicals via the ip route should not confound the interpretation of toxicity tests with potential endocrine disrupting chemicals.
Feeding and territorial behaviour in juveniles of three co‐existing triggerfishes
Authors: Chen T‐C. , Ormond R. F. G. , Mok H‐K.
Published: April 2005

Of three coexisting triggerfishes, in the intertidal and immediate subtidal zones of a coral reef within the Kenting National Park, southern Taiwan, Balistoides viridescens was observed only in the subtidal zone and foraged preferentially by nipping directly at small invertebrates among algal covered substrata. They fed also, although at a lower frequency, by using a water‐jet technique to uncover prey on sandy substrata. Territory size ranged from 61·05 to 161·57 m2 but was not related to rates of feeding or defence. Feeding frequency was, however, positively related to the area of algae present in the territory, and inversely related to the frequency of defence. In contrast to B. viridescens, Rhinecanthus verrucosus and R. aculeatus foraged mainly in the intertidal zone when the tide was high. They fed preferentially off rocky substrata and used only nipping (not water‐jetting) to secure prey.
Food of anadromous brown trout at sea
Authors: Knutsen J. A. , Knutsen H. , Gjøsæter J. , Jonsson B.
Published: April 2005

The food of migratorySalmo truttain coastal marine waters along the Norwegian Skagerrak coast varied significantly with age, season and habitat of the fish. The main prey categories in terms of frequency of occurrence were fishes followed by crustaceans, surface insects and polychaetes. Seasonal variation in diet and within habitats was found, supporting the view that brown trout is an opportunistic feeder. An ontogenetic niche shift was observed with post‐smolts feeding on inshore and shallow water prey communities, while larger brown trout fed mainly on pelagic fishes.
Acid stress increases pelvic spine asymmetry in juvenile three‐spined sticklebacks
Authors: Mazzi D. , Bakker T.C.M.
Published: April 2005

In the evaluation of the effect of acidic water on the symmetrical development of the pelvic spines in juvenile three‐spined sticklebacksGasterosteus aculeatus, directional rather than fluctuating asymmetry was found, with left spines being, on average, longer than the right. Fish that were exposed for a period ofc.2 months to acidic pH levels grew significantly more asymmetrical pelvic spines than their control full‐siblings held in unmanipulated water. Average spine size was not affected by the experimental treatment.
Influence of plasma lipid changes in response to 17β‐oestradiol stimulation on plasma growth hormone, somatostatin, and thyroid hormone levels in immature rainbow trout
Authors: Mercure F. , Holloway A. C. , Tocher D. R. , Sheridan M. A. , Kraak G. , Leatherland J.F.
Published: April 2005

Plasma total lipids were significantly higher in 17β‐oestradiol(E2)‐treated immature rainbow troutOncorhynchus mykissat week 4 after implantation, due to increases in polar and neutral lipids. The lipid classes responding were phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, sterols and sterol esters, in a proportion that approximately reflected the increase in plasma vitellogenin (VtG) levels as measured by a non‐competitive enzyme‐linked immunosorbent assay (ELISA). Plasma non‐esterified fatty acids and triacylglycerol were not affected by E2treatment. Plasma growth hormone GH levels were increased, and plasma somatostatin‐14 (SRIF) levels decreased in E2‐treated fish, responses which could be secondary to elevated plasma lipid (VtG) content, although a direct E2action on somatotroph function is possible. Plasma T4concentrations were not affected by E2treatment, but plasma T3concentrations were significantly lower than in controls 1 week after implantation when plasma E2concentrations were the highest; this is in support of the hypothesis that E2has a suppressive action on T3production.
A review of the catfish genusPterocryptis(Siluridae) in Vietnam, with the description of two new species
Authors: Ng H. H. , Freyhof J.
Published: April 2005

Of the silurid catfish genusPterocryptisin Vietnam, a total of four species are recognized as valid, of whichPterocryptis crenulaandP. verecundaare described here as new. The type locality ofP. cochinchinensisis restricted to central Vietnam, and the species is redescribed from topotypic material.Pterocryptis crenula(from northeastern Vietnam) can be differentiated from its congeners in having visibly confluent anal and caudal fins whileP. verecunda(from Cat Ba Island in northeastern Vietnam) can be differentiated from its congeners in having the genital papilla concealed behind the anus. Notes on the identity of other nominalPterocryptisspecies are also provided.
Spring cannibalism on 1 year walleye pollock in the Doto area, northern Japan: is it density dependent?
Authors: Yamamura O. , Yabuki K. , Shida O. , Watanabe K. , Honda S.
Published: April 2005

Cannibalism in walleye pollock off the eastern coast of the Hokkaido Island, Japan was important only during spring (April to June), and its importance increased from 0% in dry mass for <200 mm LS fish to 48·9% for >400 mm LS fish. Most of the prey was represented by age 1 year fish, showing a unimodal body size distribution with a mode at 121–130 mm. Although cannibal body size was larger in deeper (>150 m) water, there was no difference in prey size by depth, suggesting impingement of the predators inhabiting deeper water into the shallow areas to cannibalize 1 year fish. The minimum ratio cannibal: prey size was 1·74. There was a positive but non‐significant correlation between the contribution of cannibalism to a potential predator's (>300 mm) diet and an estimate of the previous year's recruitment. This was due to an extremely high contribution of cannibalism during 1992, when a distinctly larger size of predators seemed to bias the contribution. When the 1992 data were removed from the analysis, a significant correlation was obtained (r2=0·77, P<0·01), showing that Pollock cannibalism is rather density dependent. Based on the results, it is hypothesized that the‘overflow’ of 1 year fish from the shelf waters due to their high abundance and the weak stratification in the spring water column results in increased co‐occurrence with adult fish and consequent cannibalism.
Background colouration influences body colour segregation in mollies
Authors: Bradner J. , McRobert S.P.
Published: April 2005

When given a choice of swimming against a black background near an empty black end compartment or swimming against a white background near an empty white compartment, black morph molliesPoecilia latipinnaspent significantly more time against the black background. The presence of a shoal (either white or black mollies) in the black compartment increased the preference of the test fish for the black background. However, black molly test fish spent significantly less time against a black background if a black shoal was present in the white compartment than in assays in which a white shoal was in the white compartment. In assays where test fish were given the choice between two black shoals, test fish spent significantly more time near the black shoal on the black background. Similarly, when given the choice between two white shoals, test fish spent significantly more time against the black background. The results suggest that the presence of cryptic backgrounds alter shoalmate choices in fish that assort according to body colouration.
The dorso‐lateral pit organs of the Port Jackson shark contribute sensory information for rheotaxis
Authors: Peach M. B.
Published: April 2005

Resting Port Jackson sharks Heterodontus portusjacksoni with dorso‐lateral pit organs ablated oriented with a mean angle of 263° to the current direction in a flume. This was significantly different (P<0·01) to controls (normal and sham operated) who had a pooled mean angle of 44° to the current. Thus the dorso‐lateral pit organs of H. portusjacksoni, like the free neuromasts of some teleosts, provide sensory information for rheotaxis.
Continuous remote monitoring of fish activity with restricted home ranges using radiotelemetry
Authors: David B. O. , Closs G. P.
Published: April 2005

Signal strength received by a fixed antenna increased as a transmitter was positioned closer to it and decreased as the transmitter was positioned further away. Depth and transmitter orientation also influenced signal strength, but these were less pronounced than the effect of distance. The variations in signal strength recorded from fixed distances, depths or orientations were low, suggesting that variation in signal strength only occurs if the transmitter is moved. The use of signal strength variation as a measure of fish activity over a 24 h period was compared with observed patterns of point habitat use of a live fish. Close correspondence of assessments of activity using signal strength variation and habitat use was observed. This study demonstrated the potential utility of radiotelemetry in association with point‐in‐time habitat use data to determine home‐range and diel and seasonal patterns of fish activity over 24 h periods.
Early sea mortality of mark‐recaptured juvenile chum salmon in open coastal waters
Authors: Fukuwaka M. , Suzuki T.
Published: April 2005

Estimates of instantaneous mortality rate of mark‐recaptured chum salmon Oncorhynchus keta juveniles in coastal waters of the Sea of Japan ranged from 0·033 to 0·268 day−1 in the 14–43 days after release. High mortality rate may have been caused by size‐selective mortality or poor ability to adapt to the coastal environment inhabited by chum salmon juveniles soon after release. The results indicated that large‐scale mark‐recapture experiments are useful for estimating mortality during the early sea life that is considered to be a critical period for Pacific salmon.
Spatial and temporal population structure of sea trout at the Island of Gotland, Sweden, delineated from mitochondrial DNA
Authors: Laikre L. , Järvi T. , Johansson L. , Palm S. , Rubin J‐F. , Glimsäter C. E. , Landergren P. , Ryman N.
Published: April 2005

In a study of the genetic relationships among 879 anadromous brown trout Salmo trutta from 13 streams at the Island of Gotland, Sweden, using RFLP analysis of a mitochondrial DNA segment (NADH dehydrogenase‐1 gene), six haplotypes were detected. Significant genetic divergence was observed among streams as well as between cohorts within streams. Approximately 8–9% of the total variation was due to differences between populations, and 4–5% was explained by differences between cohorts within populations. The female effective population size (Nef) was assessed from temporal haplotype frequency differences between consecutive cohorts; the estimated average Nef over all populations was just below 30, suggesting that these populations were effectively quite small. With such small effective sizes the populations are expected to loose genetic variability quickly, but the observed levels do not appear particularly low. This indicates that female migration between streams occurs. The observed level of differentiation does not support the presumption that a particular pre‐smolt migratory behaviour observed in Gotland streams, with large portions of fry leaving for the sea soon after hatching, results in a reduced homing ability. From a conservation management perspective the Gotland brown trout streams should be regarded as a population system where the vitality and survival of brown trout in one stream is dependent on the opportunity of contact and exchange of individuals from other streams.
Interannual variability in seasonal dynamics and species composition of drifting young‐of‐the‐year fishes in two European lowland rivers
Authors: Reichard M. , Jurajda P. , Ondračkovaá M.
Published: April 2005

st young‐of‐the‐year (YOY) fishes in two lowland rivers in the Czech Republic (Danube Basin) drifted from mid‐May to mid‐July and almost exclusively at night. The peak of drift density lasted c. 3 weeks and depended on water temperature (by its effect on fish spawning), but not on discharge. Peak drift densities varied between years and rivers from 80 to 1354 fish 1000 m−3. More than 98% of drifting fish were cyprinids. Rutilus rutilus, Rhodeus sericeus, Gobio spp., Alburnus alburnus and Abramis brama were dominate in the 22 species encountered in the River Morava. Carassius auratus gibelio and R. sericeus were the most common of 17 species in the River Kyjovka. Species composition of drifting fishes was similar among years in the Morava but varied in the Kyjovka. The species composition of drifting fishes did not differ from those of the YOY fish assemblage in nursery areas during the drift season. Relative abundances in nursery areas decreased after the drift season in species that dominated in the drift, but increased in those that avoided drift. It is suggested that drift is a regular part of the life history of many cyprinid fishes and interannual variability in density and species composition of drifting YOY fish can be explained by variable spawning success among years. Differences in the relative abundances of the YOY fish assemblage in nurseries during and after the drift season suggests that drift may cause significant mortality.
Long‐term cryopreservation of sperm of Japanese eel
Authors: Tanaka S. , Zhang H. , Horie N. , Yamada Y. , Okamura A. , Utoh T. , Mikawa N. , Oka H. P. , Kurokura H.
Published: April 2005

After cryopreservation in a diluent (D#5‐D), containing 76·2 mM NaHCO3, 137·0 mM NaCl, 1·4% soya lecithin and 10% dimethyl sulphoxide, for 30–180 days, Japanese eel Anguilla japonica sperm was 61·4–70·6% motile compared with fresh sperm. Cryopreserved sperm was used for fertilizing three batches of eggs and hatchability ranged from 20·7 to 69·1%. These results indicate that D#5‐D is an useful diluent for sperm cryopreservation in Japanese eel.
Annual changes in germinal epithelium determine male reproductive classes of the cobia
Authors: Brown‐Peterson N. J. , Grier H. J. , Overstreet R. M.
Published: April 2005

Five reproductive classes of cobia Rachycentron canadum, caught along the Gulf of Mexico and the south‐east Atlantic coast of the U.S.A., are described during the annual reproductive cycle. These are based upon changes in the testicular germinal epithelium and the stages of germ cells that are present: early maturation, mid maturation, late maturation, regression and regressed. During early maturation, the germinal epithelium is continuous from the testicular ducts to the periphery of the testis and active spermatogenesis occurs throughout the testis. In mid maturation, the germinal epithelium near the ducts becomes discontinuous, but it remains continuous distally. In late maturation, a discontinuous germinal epithelium extends all along the lobules to the testicular periphery; lobules are swollen with sperm and there is minimal spermatogenesis. The regression class is characterized by a discontinuous epithelium throughout the testis, sperm storage and widely scattered spermatocysts. Spermatogonial proliferation also occurs along the lobule walls and at the periphery of the testis. In regressed testes, spermatogonia exist only in a continuous or discontinuous germinal epithelium, although residual sperm are nearly always present in the lobules and ducts. The presence or absence of sperm is not an accurate indicator of reproductive classes. At the periphery of the testis in the regression and regressed classes, the distal portions of lobules elongate as cords of cells containing spermatogonia and Sertoli cells. All reproductive classes can be identified in paraffin sections, although plastic sections provide better resolution. Using maturation classes defined by changes in the germinal epithelium to describe testicular development and spermatogenesis gives a more accurate picture than does using the traditional terminology.
Cortisol and glucose responses in juvenile brown trout subjected to a fluctuating flow regime in an artificial stream
Authors: Flodmark L. E. W. , Urke H. A. , Halleraker J. H. , Arnekleiv J. V. , Vøllestad L. A. , Poléo A. B. S.
Published: April 2005

In an artificial stream channel, wild 1 year old brown trout Salmo trutta were exposed to fluctuations in flow and water level to simulate hydro‐peaking conditions downstream of a hydropower installation. Blood plasma cortisol concentrations reached a maximum of 59·4 ± 35·3 ng ml−1 (mean ± 95% CL) 2h after the end of down‐ramping. Return to the pre‐exposure cortisol level was achieved within 6 h. When subjected to daily cyclical fluctuations over 7 days, plasma cortisol levels were significantly elevated (61·3 ± 26·8 ng ml−1) on the first day compared to undisturbed fish (4·9 ± 3·7 ng ml−1). On the fourth and seventh day, no elevation in plasma cortisol above control levels was observed. No changes in blood glucose that could be attributed to the stressor were found. There was no correlation between plasma cortisol and blood glucose levels. The short‐lived cortisol response to daily fluctuations indicates a rapid habituation to this Stressor.
Genotyping of archival Atlantic salmon scales from northern Quebec and West Greenland using novel PCR primers for degraded mtDNA
Authors: Knox D. , Lehmann K. , Reddin D. G. , Verspoor E.
Published: April 2005

PCR primers were successfully designed to amplify small ND1 gene fragments for RFLP genotyping of degraded Atlantic salmon Salmo salar mtDNA. Analysis of archival scales with these primers, when existing primer sets failed, show Atlantic salmon from the George River, Quebec, to include European haplotypes and those from the Kapisidlit River, West Greenland, to be fixed for a European haplotype characteristic of Baltic populations.
Development of a bioenergetics model for fish embryos and larvae during the yolk feeding period
Authors: Jaworski A. , Kamler E.
Published: April 2005

A mechanistic model of an energy budget in fish embryos and yolk‐sac larvae was developed using data for five freshwater fish species: rainbow trout Oncorhynchus mykiss, nase Chondrostoma nasus, carp Cyprinus carpio, tench Tinca tinca and African catfish Clarias gariepinus, based on the existing models for adult and juvenile fishes. The model simulates changes in the components of the budget under various conditions. Besides the effects of body mass and temperature on consumption and metabolic rate, the dependence of ration size on amount of available yolk and initial egg size was implemented in the model. The model parameters were found through optimization. A sensitivity analysis of the model was conducted by varying its parameters and observing changes in the output. A comparative analysis showed that the values generated by the model closely approximated independent empirical observations. Simulations of energy budgets demonstrated that the overall pattern of energy partitioning was the same for different species, irrespective of egg size and temperature preferences. Most energy was allocated to body growth. Clarias gariepinus showed the fastest growth and had the highest yolk conversion efficiency.
Geometric morphometrics reveals body shape differences between sympatric redfish Sebastes mentella, Sebastes fasdatus and their hybrids in the Gulf of St Lawrence
Authors: Valentin A. , Sévigny J.‐M. , Chanut J.‐P.
Published: April 2005

Significant body shape differences were observed between two commercially important redfish species Sebastes fasdatus and Sebastes mentella, in the Gulf of St Lawrence, first classified according to the variability at the MDH‐A* locus, a diagnostic criterion for the two species in allopatry. The observed sexual dimorphism was probably related to the presence of gravid females in the sample. Sebastes mentella appeared to be more fusiform than S. fasdatus, a characteristic that may reflect the more pelagic behaviour of S. mentella. The body shape of their hybrids was closer to that of S. mentella. Similarities between hybrids and S. mentella were also observed for meristic characteristics and depth distribution. The implications of these similarities for introgression are discussed. Body shape variability of specimens of hybrid origin was greater than that of either parental species, with features ranging from S. mentella‐like to S. fasciatus‐like. The role of introgression in generating morphological variability is emphasized.
Diel diet shift of roach and its implications for the estimation of daily rations
Authors: Haertel S. S. , Eckmann R.
Published: April 2005

In a small, 12 ha, mesotropic lake, roach Rutilus rutilus performed diel habitat shifts that clearly influenced the composition of their diet. During daytime, roach stayed in the littoral zone and concentrated on littoral prey. At night they were found in the pelagic zone, and pelagic prey items such as Daphnia spp. or Chaoborus flaricans dominated their food. On a seasonal scale, there were shifts in the importance of different food items and in the diel pattern of feeding intensity. Bioenergetics modelling in combination with an evacuation rate method for estimating daily rations allowed for changes in feeding modes to be taken into account, and so food item specific daily rations over the season could be determined. With the evacuation rate method applied on selected days, diel changes in diet compositions and feeding intensities could be quantitatively accounted for. When the 24 h integrated diet proportions were then used as an input parameter for bioenergetics modelling, food item specific consumption could be determined over the entire sampling season. The consideration of the diel diet shifts proved to be essential for the model output. If only the daytime or the night‐time diet composition (derived from one single daily sampling) was taken into account for bioenergetics modelling, severe under‐ or overestimations of daily rations for specific food items resulted.
Comparative efficiency of clove oil and rotenone for sampling tropical reef fish assemblages
Authors: Ackerman J. L. , Bellwood D. R.
Published: April 2005

A quantitative examination of the reef fish assemblage at Orpheus Island, Great Barrier Reef, contrasting clove oil and rotenone, sampled 365 individuals of 47 species with clove oil v. 536 individuals of 53 species with rotenone. Number of species and individuals were not found to differ significantly between the two techniques, largely due to variation among samples. Neopomacentrus bankieri (Pomacentridae) and Eviota queenslandica (Gobiidae) were the most dominant in the samples using either technique. Although the samples appeared to be comparable, only 31 species (45%) in eight families were common to both techniques. Fishes often recovered before collection when using clove oil and were not driven out of the reef during induction to anaesthesia. Although the samples collected with clove oil approximate the results obtained using rotenone, enclosed rotenone stations are the preferred method for providing relatively complete quantitative samples.
Mixed‐species brooding between two Baikal sculpins: field evidence for intra‐ and interspecific competition for reproductive resources
Authors: Munehara H. , Sideleva V.G. , Goto A.
Published: April 2005

In an examination of the distribution of nesting spaces of two Baikal sculpins, Paracottus kneri and Cottus kessleri, along two transects offshore at Bolshye Koty, a total of 43 P. kneri nests, 32 C. kessleri nests and one Batrachocottus baicalensis nest was found. Males of these species established breeding nests under overhanging stones in the same manner as most freshwater sculpins, but nests of each species were clearly partitioned in separate zones. Cottus kessleri nests were found where the lake floor was mostly covered with overhanging stones. Paracottus kneri nests, however, were found where the lake floor was moderately covered with overhanging stones. Two mixed‐species brooding nests with a C. kessleri guarding male were found in an area bounded by the two zones. Each of these nests comprised one P. kneri egg mass and several C. kessleri egg masses, guarded by a C. kessleri male. The nest distribution of these fishes appears to reflect intra‐ and interspecific competition for overhanging stones as a reproductive resource rather than interspecific difference of nest selection.
Thiaminase activity of gastrointestinal contents of salmon and herring from the Baltic Sea
Authors: Wistbacka S. , Heinonen A. , Bylund G.
Published: April 2005

Potential thiaminase activity of Baltic herring Clupea harengus ranged from 0 to c. 55 nmol g‐1 min‐1 while potential thiaminase activity in Baltic salmon Salmo salar gastrointestinal (GI) contents ranged from 7 to c. 60 nmol g‐1 min‐1. About 30% of the Baltic herring analysed had a potential thiaminase activity equivalent to Baltic salmon GI contents. The results are consistent with the hypothesis that thiaminase in the forage fish of Baltic salmon may be an important link in the aetiology of the thiamine deficiency syndrome, M74, in Baltic salmon and indicate that Baltic salmon might feed selectively on Baltic herring with high thiaminase activity.
Alterations of dopaminergic and serotonergic activity in the brain of sea‐run Baltic salmon suffering a thiamine deficiency‐related disorder
Authors: Amcoff P. , Elofsson U. O. E. , Börjeson H. , Norrgren L. , Nilsson G. E.
Published: April 2005

Baltic salmon Salmo salar females displaying wiggling behaviour had significantly lower (P<0.05) hepatic and ovarian thiamine (vitamin B1) concentrations than the normal females, confirming that they suffered from a thiamine deficiency. A significantly (P<0.05) increased monoaminergic activity was found in the telencephalon and the hypothalamus of the wiggling individuals as indicated by [5‐hydroxyindoleacetic acid (5‐HIAA)]: [5‐hydroxytryptamine (5‐HT)] and [3,4‐dihydroxyphenylacetic acid (DOPAC)]: [dopamine (DA)] ratios. The 5‐HIAA concentrations of wiggling individuals were significantly (P<0.05) higher in the telencephalon and the hypothalamus compared to normal fish. Wiggling fish showed significantly (P<0.05) higher concentrations of the DA metabolite DOPAC in the hypothalamus and the brain stem compared to normal fish. Furthermore, the brain stem in wiggling fish contained significantly (P<0.05) less 5‐HT than in normal individuals, which was also reflected in a significant (P<0.05) increase in the (5‐HIAA): (5‐HT) ratio. These results demonstrate an increased serotonergic and dopaminergic activity in wiggling compared to normal fish. The altered monoaminergic activity may be directly related to altered brain thiamine metabolism, but a general stress caused by thiamine deficiency and an inability to regulate swim bladder inflation may contribute. Furthermore, a changed brain monoaminergic activity may contribute to the behaviour characterizing wiggling fish.
Gonadal sex differentiation in Atlantic halibut
Authors: Hendry C. I. , Martin‐Robichaud D. J. , Benfey T. J.
Published: April 2005

The process of gonadal sex differentiation in 338 Atlantic halibut Hippoglossus hippoglossus larvae, ranging in size from 10 mm Ls to 230 mm LF, is described histologically. Gonadal sex differentiation occurred by 38.0 mm LF, which coincided with the weaned, post‐metamorphic, settled stage in the life cycle. This was a gradual process that coincided with other organogenesis in the developing larvae.
Control region haplotype variation in the central Mediterranean common sole indicates geographical isolation and population structuring in Italian stocks
Authors: Guarnieo I. , Franzellitti S. , Ungaro N. , Tommasini S. , Piccinetti C. , Tinti F.
Published: April 2005

Nine common sole Solea vulgaris samples from five fishery Management Units (MUs) of the central Mediterranean exhibited differences in a control region sequence marker. Parsimony network showed two low‐divergent haplotype phylogroups. The former predominated in samples from the Ligurian, Tyrrhenian, Adriatic and north‐western Ionian Seas (MUs 9, 10, 17, 18 and northern part of 19, respectively), whereas the latter was abundant in the south‐western Ionian (southern part of MU 19). The geographical clustering of maternal lineages accounts for population structuring and indicates geographical isolation of common sole stocks in the Mediterranean. Several life‐history traits of common sole and hydro‐geographical features of the basin might support this pattern of differentiation. Haplotype frequency differences were detected among samples either from different MUs or within the same MU. This situation indicates the presence of partially subdivided or nearly panmictic population units, whose exploitation should be based on appropriate bio‐ecological features. The usefulness of control region sequence marker enhances the routinely use of the genetic stock structure analysis in low‐dispersal demersal marine resources.
Dispersion patterns of parasites in 0+ year three‐spined sticklebacks: a cross population comparison
Authors: Kalbe M. , Wegner K. M. , Reusch T. B. H.
Published: April 2005

Two ciliates and 16 metazoan parasites were identified in 434 0+ year three‐spined sticklebacks Gasterosteus aculeatus collected from two small rivers and four lakes located in Schleswig‐Holstein, Germany. By repeated sampling and analysis of dispersion patterns of six frequently occurring parasites no consistent evidence was found for mortality induced by a single parasite species. Linear log‐variance to log‐mean abundance ratios with slopes of c. 2 indicated negative binomial distributions for five of the six parasites. The numbers of these six parasites were combined as multiples of S.D. of each parasite species over all samples to form an ‘individual parasitation index’ (IPI), which showed that only in one locality a slight decrease in parasite burden occurred between September and April. In two of the lake populations, however, there was a distinct decline in the degree of dispersion in spring samples. This indicates that a combination of different species might cause parasite‐induced host mortality, undetectable by patterns obtained from single species. There were differences in parasite diversity and intensity of infection among river compared to lake populations suggesting a role for parasites as selective agents in the ecological divergence of three‐spined sticklebacks.
Variation in the carbon isotope composition of Semaprochilodus insignis, a detritivorous fish associated with oligotrophic and eutrophic Amazonian rivers
Authors: Benedito‐Cecilio E. , Araujo‐Lima C. A. R. M.
Published: April 2005

The Amazonian freshwater fish, Semaprochilodus insignis, varies in carbon isotopic composition during residence in different habitats within its home range. The results indicate that carbon produced in black‐water systems contributes to fish stocks harvested from white‐water systems, and S. insignis populations in the Central Amazonia are more integrated than previously thought.
The effect of the cleaner fishLabroides dimidiatuson the capsalid monogeneanBenedenia loloparasite of the labrid fishHemigymnus melapterus
Authors: Grutter A. S. , Deveney M. R. , Whittington I. D. , Lester R. J. G.
Published: April 2005

The cleaner fishLabroides dimidiatusaffected the pigmented monogenean parasiteBenedenia loloon the fishHemigymnus melapterus(Labridae) held in aquaria. The effect of cleaner fish varied with the size class of fish; only small fish [a posteriorisize class <11.5 cm standard length (LS)] exposed to cleaner fish had fewer monogeneans compared with fish not exposed to cleaner fish. The abundance of monogeneans on large fish (a posteriorisize class <11.5 cmLS) was not affected by cleaner fish. The size‐frequency distributions of monogeneans on both size‐classes ofH. melapteruswere affected by cleaner fish. Fish exposed to cleaner fish had fewer large (>3 mm) and more small (<1 mm) monogeneans than fish not exposed to cleaner fish, suggesting cleaner fish selectively removed larger monogeneans. This difference was more pronounced on large fish. In the absence of cleaner fish, small fish had almost as many monogeneans as large fish; they also had more small monogeneans than the large fish, suggesting small fish were more vulnerable to infection by monogeneans than larger fish. This suggests that the cleaner fishL. dimidiatushas the potential to control benedeniine monogeneans on captive fish and highlights the importance of taking into account fish size in studies of the effect of cleaner fish on ectoparasites.
Lateral migrations of fishes between floodplain lakes and their drainage channels at the Lower Rhine: diel and seasonal aspects
Authors: Borcherding J. , Bauerfeld M. , Hintzen D. , Neumann D.
Published: April 2005

Although the total migratory activity of fishes from floodplain lakes in the Lower Rhine (Germany) into the connected drainage channels, estimated using electrofishing, fyke nets and visual observations, was low during summer 1997, conspicuous diel migrations of adult bream Abramis brama in June and July were recorded in one of the channels studied. A considerable proportion of the population of the floodplain lake immigrated into the channel at dusk and left it at dawn. During two winters (1994–1995, 1997–1998) the abundance of fishes increased considerably in the channels. The winter migrations, studied in detail in one of the channels in 1997–1998, started in late October, when the water temperature dropped below 10° C. In contrast to the mean of 500 fishes per 100 m channel length between May and October, >5000 fishes were found from November to March, with maximum values of >50 000 fishes per 100 m channel length in February 1998. More than 90% of these shoals were 0+ year fishes, dominated by roach Rutilus rutilus, bream, perch Perca fluviatilis and rudd Scardinius erythrophthalmus. These shoals entered the channel at sunrise and left it around sunset. Generally, the 0+ year fishes in the shoals swam separately from the older fishes, and different reactions towards the attack of predatory fishes were observed. The migrating shoals of juvenile fishes during the winter were interpreted as a strategy to minimize predation risk.
Patterns of diet overlap between populations of non‐indigenous and native fishes in shallow ponds
Authors: Declerck S. , Louette G. , De Bie T. , De Meester L.
Published: April 2005

No significant differences in the diet composition were detected for any of the populations of four non‐indigenous fish species (brown bullhead Ameiurus nebulosus, pumpkinseed Lepomis gibbosus, topmouth gudgeon Pseudorasbora parva and eastern mudminnow Umbra pygmaea) and two native fish species (gudgeon Gobio gobio and roach Rutilus rutilus), between two small shallow ponds and between habitats within the ponds, during late summer. Based on diet composition, groups of size classes within species (’functional groups‘) were distinguished. For most functional group combinations of exotic fishes, diet overlap values were low. Although chironomid larvae formed the most important food source, differential consumption of chironomid size classes allowed an important degree of niche differentiation between non‐indigenous fishes. In contrast, high diet overlap was found between the functional groups of indigenous gudgeon and of several non‐indigenous fishes, indicating a high potential for interspecific exploitative competition. The diet of roach consisted almost entirely of non‐animal remains (detritus and plant material). The high proportion of such low‐energy food in the diet of this species may be indicative for a competition induced niche shift to suboptimal food sources.
Adaptive search in juvenile plaice foraging for aggregated and dispersed prey
Authors: Hill S. , Burrows M. T. , Hughes R. N.
Published: April 2005

Juvenile plaicePleuronectes platessain a laboratory arena used intensive search behaviour, characterized by short movements and frequent turning, in the five movements before and after attacking a prey in an aggregated distribution. They used extensive search behaviour with, on average, longer movements and less turning at all other times. Intensive search was, apparently, triggered by a high local density of prey but not by isolated prey. This response to local prey density resulted in area‐restricted search when prey were aggregated and win‐shift behaviour when prey were dispersed. There was no evidence that the use of intensive search increased with experience of aggregated prey. It therefore appears that the fish were able to exploit encountered prey distribution patterns using their immediate perceptions rather than prior experience.
Gait transition speed, pectoral fin‐beat frequency and amplitude in Cymatogaster aggregata, Embiotoca lateralis and Damalichthys vacca
Authors: Mussi M. , Summers A. P. , Domenici P.
Published: April 2005

Surfperches are labriform swimmers and swim primarily with their pectoral fins, using the tail to assist only at higher speeds. The transition, from pectoral to pectoral and caudal fins, occurs at a threshold speed that has been termed physiologically and biomechanically ‘equivalent’ for fishes of different size. The gait transition (UP‐C) of Cymatogaster aggregata occurred at a higher speed (measured in bodylengths s−1) for smaller fish than larger fish. At UP‐C, pectoral fin‐beat frequency was size‐dependent: smaller fish have a higher pectoral fin‐beat frequency than larger fish. In contrast, at low speeds (i.e. <60% of UP‐C) the pectoral fin‐beat frequency was independent of the size of the fish. Inter‐specific comparisons of UP‐C, pectoral fin‐beat frequency and amplitude among C. aggregata, Embiotoca lateralis and Damalichthys vacca showed that C. aggregata had a higher UP‐C than E. lateralis and D. vacca. The pectoral fin‐beat frequency at UP‐C showed no significant differences among species. Cymatogaster aggregata achieved higher UP‐C, in part, through increased fin beat amplitude rather than frequency. These differences in performance may be related to the different habitats in which these species live.
Composition changes in retinal pigments according to habitat of chum and pink salmon
Authors: Hasegawa E. I. , Saito T. , Seki J.
Published: April 2005

Juvenile chum Oncorhynchus keta and pink Oncorhynchus gorbuscha salmon change the composition of their visual pigments when they move from coastal waters to offshore in the Okhotsk Sea. Levels of the visual pigment rhodopsin were found to be high on the coast, while porphyropsin levels were high in offshore waters in both species. These facts suggest visual function may be similar, allowing them to coexist in the same sea area.
Liver and plasma lipids of spawning burbot
Authors: Mustonen A‐M. , Nieminen P. , Hyvaurinen H.
Published: April 2005

Levels of liver and plasma lipids of the burbot Lota lota were highest before reproduction and decreased during and after spawning. Triacylglycerols accounted for 95% of the liver lipids. High concentrations of leptin‐immunoreactive peptide were present in the burbot liver, suggesting that it may be secreted by this organ.
Laser Doppler imager (LDI) scanner and intradermal injection for in vivo pharmacology in human skin microcirculation: responses to acetylcholine, endothelin‐1 and their repeatability
Authors: Saez Anabelle M. Opazo , Mosel Frank , Nürnberger Jens , Rushentsova U. , Gössl Mario , Mitchell Anna , Schäfers Rafael F. , Philipp Thomas , Wenzel René R.
Published: April 2005

Aims

The purpose of this study was to evaluate the repeatability of forearm skin blood flow responses to intradermal injections of acetylcholine (ACh) and endothelin‐1 (ET‐1) using a double injection technique (DIT) and a laser Doppler imager (LDI) scanner in the human skin microcirculation.

Methods

We used a laser Doppler imager (Moor LDI V3.01) to continuously monitor the change in skin blood flow during intradermal administration of physiological saline (0.9% NaCl), acetylcholine (ACh 10−7, 10−8, 10−9 M) and endothelin‐1 (ET‐1 10−14, 10−16, 10−18 M) in 10 healthy male subjects. Subjects were examined on 3 different days for assessment of interday and interobserver repeatability. Injections of either drug were randomly placed on different sites of the forearm. Laser Doppler images were collected before and after injection at 2.5 min intervals for 30 min. Data were analysed after the completion of each experiment using Moor Software V.3.01. Results are expressed as changes from baseline in arbitrary perfusion units (PU).

Results

ACh caused a significant vasodilation (P < 0.0001 anova, mean ± SE: 766 ± 152 PU, ACh 10−9 M; 1868 ± 360 PU, ACh 10−8 M; 4188 ± 848 PU, ACh 10−7 M; mean of days 1 and 2, n = 10), and ET‐1 induced a significant vasoconstrictive response (P < 0.0001 anova, −421 ± 83 PU, ET‐1 10−18 M; −553 ± 66 PU, ET‐1 10−16 M; −936 ± 90 PU, ET‐1 10−14 M; mean of days 1 and 2, n = 10). There was no difference on the response to either drug on repeated days. Bland‐Altman analyses showed a close agreement of responses between days with repeatability coefficients of 1625.4 PU for ACh, and 386.0 PU for ET‐1 (95% CI: ACh, −1438 to 1747 PU, ET‐1, −399 to 358 PU) and between observers with repeatability coefficients of 1057.2 PU for ACh and 255.8 PU for ET‐1 (95% CI: ACh, −1024 to 1048 PU, ET‐1, −252 to 249 PU). The variability between these responses was independent of average flux values for both ACh and ET‐1. There was a significant correlation between responses measured in the same site, in the same individual on two different days by the same observer (ACh, r = 0.94, P < 0.0001; ET‐1, r = 0.90, P < 0.0006), and between responses measured by two different observers (ACh, r = 0.94, P < 0.0001; ET‐1, r = 0.91, P < 0.0003).

Conclusion

We have shown that interday and intraobserver responses to intradermal injections of ET‐1 and ACh, assessed using the DIT in combination with an LDI scanner, exhibited good reproducibility and may be a useful tool for studying the skin microcirculation in vivo.
Pharmacokinetic interaction on valproic acid and recurrence of epileptic seizures during chemotherapy in an epileptic patient
Authors: Ikeda Hiroaki , Murakami Teruo , Takano Mikihisa , Usui Tsuguru , Kihira Kenji
Published: April 2005

Aims

To report a pharmacokinetic interaction between valproic acid (VPA) and anticancer agents observed in an epileptic patient.

Methods

A 34‐year old male epileptic patient receiving VPA underwent cisplatin‐based chemotherapy for the treatment of a testicular tumour. The first chemotherapeutic cycle decreased the serum VPA concentration and caused severe generalized tonic‐clonic seizures. Thus, thereafter, the serum VPA concentration was monitored along with the chemotherapy.

Results

In a patient receiving VPA daily, severe seizures were observed 7 weeks after the first chemotherapeutic cycle, at which the serum VPA concentration was found to be reduced by approximately 50% of the initial level (90–100 µg ml−1). The following cycles (six cycles over a 7‐month period) also caused seizures in association with decreased serum VPA concentrations. In contrast, the serum concentration of phenytoin, which was given daily after the second chemotherapeutic cycle, remained at a therapeutic concentration (10–20 µg ml−1). After the completion of chemotherapy, the serum concentration of a tumour marker, hCGβ, decreased to 1.2 ng ml−1 from more than 120 ng ml−1 prior to the chemotherapy in this patient.

Conclusions

Careful monitoring of VPA concentrations are necessary during cisplatin‐based chemotherapy because anticancer agents can reduce the serum concentration and antiepileptic activity of VPA.
Khat chewing is a risk factor for acute myocardial infarction: a case‐control study
Authors: Al‐Motarreb A. , Briancon S. , Al‐Jaber N. , Al‐Adhi B. , Al‐Jailani F. , Salek M S. , Broadley K J.
Published: April 2005

Aim

Khat chewing is a common habit in Yemen and east African countries. Millions of people chew khat leaves daily for its euphoric and energetic effects and to increase alertness. Cathinone, the main active substance in fresh khat leaves, has sympathomimetic effects which increase heart rate and blood pressure. The aim was to examine the hypothesis that khat chewing is a risk factor for acute myocardial infarction (AMI) using a hospital‐based matched case‐control study.

Method

Between 1997 and 1999, we selected 100 patients admitted to the Al‐Thawra teaching hospital Sana’a ICU, Yemen with acute myocardial infarction. 100 control subjects, matched to cases for sex and age, were recruited from the outpatients clinics of the same hospital. A questionnaire was completed for case and control groups covering personal history of khat chewing, smoking, hypertension, diabetes and any family history of myocardial infarction. A blood sample was collected for performing lipid profiles. Cases and controls were compared by analysis conducted using conditional logistic regression which corrected for baseline imbalances leading to less biased estimations of odds ratio (OR). The risk associated with each classical factor and khat chewing habits was then investigated. OR values greater than 2.5 indicated a significant risk factor.

Results

Khat chewing was significantly higher among the AMI case group than control group (OR = 5.0, 95% CI 1.9–13.1). A dose–response relationship was observed, the heavy khat chewers having a 39‐fold increased risk of AMI.

Conclusion

This study indicates that khat chewing is associated with AMI and is an independent dose‐related risk factor for the development of myocardial infarction.
Influence of acute upper respiratory tract infection on the absorption of inhaled insulin using the AERx® insulin Diabetes Management System
Authors: McElduff Aidan , Mather Laurence E. , Kam Peter C. , Clauson Per
Published: April 2005

Aims

To assess the effects due to an uncomplicated acute upper respiratory tract infection (URTI) on the pharmacokinetics and glucose response of insulin when delivered by oral pulmonary absorption.

Methods

Normally healthy adult men (n = 11) and women (n = 9) received a single dose of inhaled human insulin, equivalent to ∼ 6 IU subcutaneous, using the AERx® insulin Diabetes Management System (iDMS), during and following recovery from an URTI. The first dose was administered with ongoing symptoms of < 3 days’ duration, the second dose following recovery, and within 3 weeks of the first. Blood sampling for determination of insulin pharmacokinetics (serum AUC(0−6 h), AUC(0−8), Cmax,tmax, t1/2, MRT) and glucose response (plasma AOC(0−6 h)) was performed from 15 min predose to 6 h postdose.

Results

Insulin pharmacokinetics were not different for subjects during and following recovery from URTI [e.g. URTI: no URTI ratio in serum AUC(0−6 h) = 0.92 (95% confidence interval 0.81, 1.05)]; this was reflected by a similar glucose response. Inhaled insulin delivered by AERx® iDMS was well tolerated by all subjects; no significant changes were observed in pulmonary function tests. No safety concerns arising from the mode of insulin administration were raised by either dose.

Conclusions

The results suggest that insulin can be administered via AERx® iDMS to nondiabetic subjects experiencing a URTI without any statistically significant changes in insulin pharmacokinetics or pharmacodynamics, and that the necessity for dose adjustments will not differ from subjects with an acute URTI who are receiving subcutaneous insulin.