bluuebunny/crossref_metadata_2025 huggingface dataset:
Cis-acting expression quantitative trait loci in mice
Authors: Doss Sudheer , Schadt Eric E. , Drake Thomas A. , Lusis Aldons J.
Published: April 2005

We previously reported the analysis of genome-wide expression profiles and various diabetes-related traits in a segregating cross between inbred mouse strains C57BL/6J (B6) and DBA/2J (DBA). By considering transcript levels as quantitative traits, we identified several thousand expression quantitative trait loci (eQTL) with LOD score >4.3. We now experimentally address the problem of multiple comparisons by estimating the fraction of false-positive eQTL that are undercis-acting regulation. For this, we have utilized a classiccis–transtest with (B6 × DBA)F1mice to determine the relative levels of transcripts from the B6 and DBA alleles. The results suggest that at least 64% ofcis-acting eQTL with LOD >4.3 are true positives, while the remaining 36% could not be confirmed as trulycis-acting. Moreover, we find that >96% of apparentcis-acting eQTL occur in regions that do not share SNP haplotypes.Cis-acting eQTL serve as an important new resource for the identification of positional candidates in QTL studies in mice. Also, we use the analysis of the correlation structures between genotypes, gene expression traits, and phenotypic traits to further characterize genes expressed in liver that are undercis-acting control, and highlight the advantages and disadvantages of integrating genetics and gene expression data in segregating populations.
All are not equal: A benchmark of different homology modeling programs
Authors: Wallner Björn , Elofsson Arne
Published: April 2005

Modeling a protein structure based on a homologous structure is a standard method in structural biology today. In this process an alignment of a target protein sequence onto the structure of a template(s) is used as input to a program that constructs a 3D model. It has been shown that the most important factor in this process is the correctness of the alignment and the choice of the best template structure(s), while it is generally believed that there are no major differences between the best modeling programs. Therefore, a large number of studies to benchmark the alignment qualities and the selection process have been performed. However, to our knowledge no large‐scale benchmark has been performed to evaluate the programs used to transform the alignment to a 3D model. In this study, a benchmark of six different homology modeling programs— Modeller, SegMod/ENCAD, SWISS‐MODEL, 3D‐JIGSAW, nest, and Builder—is presented. The performance of these programs is evaluated using physiochemical correctness and structural similarity to the correct structure. From our analysis it can be concluded that no single modeling program outperform the others in all tests. However, it is quite clear that three modeling programs, Modeller, nest, and SegMod/ ENCAD, perform better than the others. Interestingly, the fastest and oldest modeling program, SegMod/ ENCAD, performs very well, although it was written more than 10 years ago and has not undergone any development since. It can also be observed that none of the homology modeling programs builds side chains as well as a specialized program (SCWRL), and therefore there should be room for improvement.
The crystal structure of calcium‐ and integrin‐binding protein 1: Insights into redox regulated functions
Authors: Blamey Chad J. , Ceccarelli Christopher , Naik Ulhas P. , Bahnson Brian J.
Published: April 2005

Calcium‐ and integrin‐binding protein 1 (CIB1) is involved in the process of platelet aggregation by binding the cytoplasmic tail of the αIIb subunit of the platelet‐specific integrin αIibβ3. Although poorly understood, it is widely believed that CIB1 acts as a global signaling regulator because it is expressed in many tissues that do not express integrin αIibβ3. We report the structure of human CIB1 to a resolution of 2.3 Å, crystallized as a dimer. The dimer interface includes an extensive hydrophobic patch in a crystal form with 80% solvent content. Although the dimer form of CIB1 may not be physiologically relevant, this intersub‐unit surface is likely to be linked to αIIb binding and to the binding of other signaling partner proteins. The C‐terminal domain of CIB1 is structurally similar to other EF‐hand proteins such as calmodulin and calcineurin B. Despite structural homology to the C‐terminal domain, the N‐terminal domain of CIB1 lacks calcium‐binding sites. The structure of CIB1 revealed a complex with a molecule of glutathione in the reduced state bond to the N‐terminal domain of one of the two subunits poised to interact with the free thiol of C35. Glutathione bound in this fashion suggests CIB1 may be redox regulated. Next to the bound GSH, the orientation of residues C35, H31, and S48 is suggestive of a cysteine‐type protein phosphatase active site. The potential enzymatic activity of CIB1 is discussed and suggests a mechanism by which it regulates a wide variety of proteins in cells in addition to platelets.
Gastric evacuation rate of burbot fed single‐fish meals at different temperatures
Authors: Pääkkönen J.‐P. J. , Marjomäki T. J.
Published: April 2005

The gastric evacuation rates of burbot Lota lota, fed a single meal of vendace, Coregonus albula, were measured in the laboratory at five temperatures (1·3, 2·6, 4·8, 9·4 and 12·6° C). Gastric evacuation rate increased exponentially with increasing temperatrure, but the results suggest that gastric evacuation rates of burbot at low temperatures are lower than those of other freshwater fish species. Temperature and the ratio of meal weight to burbot weight were the most important factors affecting gastric evacuation rate. There was no significant difference in gastric evacuation rate between three different prey species: vendace, perch Perca fluviatilis, and smelt Osmerus eperlanus.
Cloning and expression of the SPARC cDNA from rainbow trout
Authors: Tang S. , McKeown B. A.
Published: April 2005

A trout SPARC cDNA has been isolated and the sequence is highly conserved. The encoded protein shows 76% identity and 91% similarity between trout and human. Like the frog protein, trout SPARC deduced protein has one potential n‐glycosylation site in position 96. SPARC mRNA was detected from brain tissue as early as hatching day. The transcript level increased rapidly during the early postnatal period and maintained high levels in adulthood. By week 7, the mRNA level was 11 times higher than that at hatching day. The pituitary gland showed a strong signal of SPARC mRNA, and it was detected also with high expression in muscle, gill and brain, and at the lowest level in the liver. These results demonstrate that SPARC is widely distributed in trout and suggest that SPARC has multiple functions. It may play a critical role in early brain development, such as cell migration, proliferation and angiogenesis. It is proposed also that SPARC modulates pituitary hormone release through regulation of the degradation of the extracellular matrix.
Differences in feeding between 1+ and 2+ hatchery brown trout exposed to low water temperature
Authors: Pirhonen J. , Koskela J. , Jobling M.
Published: April 2005

Both 1 + and 2+ brown trout fed during the day and at night when held in hatchery tanks at low temperatures (2·7–3° C). Over 60% of the daily ration was consumed during daylight hours, but there were differences in feeding behaviour between fish of the two age groups: the 1 + trout had greater feeding activity at night than the 2+ fish.
Penetration of phosphorothioate oligodeoxynucleotides into rainbow trout brain in vivo. A technique for chronic infusion of substances into the brain of free‐living adult fish
Authors: Levy A. , Baker B. I.
Published: April 2005

This paper describes a method for infusing chronically substances into the cranial cavity of free‐living rainbow trout Oncorhynchus mykiss for several weeks. The efficacy of the method was established by examining the penetration of radioactively labelled phosphorothioate oligodeoxynucleotides and a blue‐coloured dye, xylene cyanole, into brain tissue. No problems with pump patency were encountered, and the contents of the pump diffused consistently throughout the brain ventricular system, including the anterior lateral ventricles of the olfactory lobes, the third ventricle under the optic tecta and into the hypothalamus, including the lateral ventricular recesses. Autoradiographic examination of frozen sections demonstrated variable penetration of labelled probe into brain interstitium to a depth of up to approximately 200 μm. At the end of the experiment, >50% of radioactivity within brain tissue was shown to be of similar size to intact, labelled oligodeoxynucleotides.
Influence of dissolved organic matter on copper binding, and calcium on cadmium binding, by gills of rainbow trout
Authors: Hollis L. , Muench L. , Playle R. C.
Published: April 2005

Complexation of Cu by 5 mg Cl−1 dissolved organic matter (DOM) from a marsh kept Cu from binding to gills of small rainbow trout Oncorhynchus mykiss in 9‐day exposures to 0.5 μM Cu in soft water. The protective effect of DOM occurs because the formation of Cu‐DOM complexes reduces the amount of free Cu in the water, so the disruptive effects of Cu on ionoregulation, such as inhibited Na uptake, cannot develop. The Cu‐DOM complexes themselves do not bind to the gills. Calcium (1100 μm) reduced the accumulation of Cd by trout gills in short, 2‐h exposures through competition for gill binding sites but not over longer, 7‐day exposures to 0–14 μM Cd. However, the protective effect of Ca against Cd toxicity persisted throughout the longer experiment, likely due to the decrease in the electrochemical gradient for diffusive loss of Ca from the fish to the water. Rainbow trout and fathead minnows Pimephales promelas accumulated Cu and Cd on their gills in a similar manner; thus, binding constants for metal‐gill interactions determined for one species of fish can be generalized to other fish species. When literature binding constants determined for fathead minnows were applied to our studies with rainbow trout, computer modelling of Cu‐gill and Cu‐DOM interactions simulated our results well. In contrast Cd‐gill and Ca‐gill modelling predicted the initial competitive effect of Ca against Cd accumulation by trout gills, but did not predict the longer‐term accumulation of Cd by trout gills.
The effects of acute hypoxia and hypercapnia on oxygen consumption of the freshwater European eel
Authors: Cruz‐Neto A. P. , Steffensen J. F.
Published: April 2005

When exposed to hypoxia, eels Anguilla anguilla were able to regulate and maintain Vo2 down to a water oxygen tension (Pwo2) of about 25 mmHg, a value far below those reported in other studies. When exposed to hypercapnia, eels showed a depression in Vo2 as water carbon dioxide tension (Pwco2) increased. Faced with combined hypoxia‐hypercapnia, eels showed an increase in their sensitivity to hypoxia, and the critical oxygen tension increased to 40–45 mmHg. The possible mechanisms underlying these responses were discussed, and the implications of such findings for extensive culture of eels were highlighted.
The effects of initial length and body curvature on shrinkage of juvenile Atlantic salmon during freezing
Authors: Armstrong J. D. , Stewart D. C.
Published: April 2005

Fork length was measured in two groups of salmon parr (32–139 mm, frozen in a straight posture and frozen in a curved posture) before (L1) and after (L2) freezing and thawing. All the fish shrank. The decrease in length was significantly greater in the curved fish than the straight fish. The absolute reduction in length (L1–L2) was related directly to L1, whereas the percentage reduction in length [(L1–L2)/L1× 100] was related inversely to L1.
Gonadal development and sex steroids in a female Arctic charr broodstock
Authors: Frantzen M. , Jaohnsen H. K. , Mayer I.
Published: April 2005

Gonadal development and plasma levels of sex steroids were investigated in female Arctic charr at 3‐week intervals over a 12‐month period. Circulating levels of oestradiol‐17β (E2), testosterone (T) and 17,20β‐dihydroxy‐4‐pregnen‐3‐one (17,20β‐P) were measured by radioimmunoassay, and gonadal status assessed through histological examination and measurement of gonadosomatic index (GSI) and frequency distribution of oocyte size‐classes. Gonadal recrudescence during March‐July was characterized by modest but insignificant increases in plasma levels of E2 (2–4 ng ml−1) and T (2–5 ng ml−1) and recruitment of oocytes into yolk accumulation. Only a small and insignificant rise in GSI and no apparent increase in oocyte diameter occurred during this period, indicating that the rate of yolk formation and oocyte growth was low. Following transformation from stage V (peripheral yolk granule stage) to stage VI (yolk granule migration stage) in late July, the vitellogenic oocytes entered a phase of rapid growth which resulted in a marked rise in GSI until ovulation commenced in late September. Gonadal growth during this period was accompanied by increases in plasma levels of E2 and T which peaked at 11 ± 1 (mid‐August) and 71 ± 5ng ml−1 (late September), respectively. The levels of both steroids dropped rapidly during final maturation and ovulation, followed by a surge in plasma levels of 17,20β‐P which peaked at an average of 74 ± 17 ng ml−1 in early October. All three steroids returned to basal levels within a month after ovulation, and all steroids, except E2, remained low until March of the following year. A slight increase in E2 detected in February and March during the second season may have been associated with recruitment into vitellogenesis of a new generation of oocytes. It is suggested that the abrupt increase in vitellogenesis in late July may reflect a condition‐dependent decision to proceed with maturation, once the energy reserves have been repleted during spring‐early summer.
First record of the eastern Asiatic gobionid fish Pseudorasbora parva from the Asiatic part of Turkey
Authors: Wildekamp R. H. , Van Neer W. , Küçük F. , ÜNlüsayin M.
Published: April 2005

Pseudorasbora parva is recorded for the first time from southern Anatolia, the Asiatic part of Turkey. Its presence at three locations in the main course of the Aksu River is probably due to involuntary introduction with common carp.
The ontogeny of schooling behaviour in the striped jack
Authors: Masuda R. , Tsukamoto K.
Published: April 2005

The ontogeny of schooling behaviour was investigated in laboratory‐reared striped jack Pseudocaranx dentex larvae and juveniles. Mean separation angle between nearest individuals averaged 78 and 82° in 10‐ and 12‐mm fish, respectively, and decreased to 57° in 16‐mm fish. In addition, interindividual distance decreased from three times body length in 12‐mm fish to twice the body length in 16‐mm individuals; this value continued to decrease gradually to 1·3 at 19 mm to 0·79 at 30 mm. Mutual attraction due to visual recognition was observed in 12‐mm fish and increased with total length. The optokinetic response (Ro, the ability of a fish to keep station with moving patterns) first appeared in 4–6‐mm larvae. In spite of the traditional emphasis of the importance of Ro in schooling behaviour, the onset of Ro was insufficient to result in school formation. The emergence of mutual attraction seems essential for the ontogeny of schooling.
Feeding and growth of early juvenile Japanese sardines in the Pacific waters off central Japan
Authors: Watanabe Y. , Saito H.
Published: April 2005

Larval and early juvenile growth was backcalculated for individual Japanese sardines Sardinops melanostictus using the biological intercept method based on the allometric relationship between otolith radii and fish lengths. Sardines grew at 0·81 mm day−1 during the larval stage. In the early juvenile stage, they grew from 32·3 to 45·4 mm fork length (L) over a 20‐day period (0·64mm day−1). Using the observed relationship between L and wet body weight (W), W = 0·00942 L2.99, W of the sardine juveniles was calculated to increase from 306 to 832 mg during the 20‐day period. The carbon (C) requirement to achieve this growth in weight was estimated to increase from 5·7 to 9·6 mg day−1. Stomach contents of the sardines were composed mostly of copepods (73%) and larvaceans (25%). Wet stomach content weight (Ws) was expressed by a power function of the W, Ws=0·731 W0·658. Carbon and nitrogen constituted 41·7 ± 1·5 and 10·0 ± 0·4% of the dry Ws, respectively. Stomach C content increased from 2·0 to 3·9 mg during the 20‐day period. Three to four cycles of the daily turnover of stomach contents during the 16 h of daytime, corresponding to a gastric evacuation rate of 0·2–0·3 h−1 under continuous feeding, met the C requirement to achieve the backcalculated growth in early juvenile sardines. The Kuroshio frontal waters seem to provide Japanese sardine juveniles with favourable growth conditions.
Biochemical and morphological correlates of growth in diploid and triploid rainbow trout
Authors: Suresh V. , Sheehan R. J.
Published: April 2005

Diploid and triploid rainbow trout contained the same amount of RNA per unit weight of white muscle tissue at a given growth rate. This finding, along with a previous finding that the protein content of triploid muscle tissues is not different from that of the diploids, indicates that triploid nuclei produce more RNA than their diploid counterparts. This increased production of RNA is probably due to the expression of the extra set of chromosomes in triploid nuclei. RNA‐based growth correlates and liver somatic index (IH) were valid predictors of growth for both triploid and diploid fish. RNA concentration appeared to be better than RNA/DNA and RNA/protein in predicting growth.
Analysis of tissue responses to fin tagging in Australian carcharhinids
Authors: Heupel M. R. , Simpfendorfer C. A. , Bennett M. B.
Published: April 2005

Tissue responses to the application of Rototags and Jumbo Rototags in the first dorsal fin of Carcharhinus melanopterus, C. obscurus and C. plumbeus were examined. The acute response included tissue tearing and haemorrhage and was present by 5 days post‐tagging. The intermediate response had begun by 20 days post‐tagging and continued beyond 207 days. This response involved decreased red blood cell activity as the inflammatory response commenced. The chronic response had begun by 301 days and was complete by 553 days with a layer of fibrous connective tissue walling off the tag. External damage to the fin was caused by continued abrasion by the tag. Repair scales were observed at 242 days using scanning electron microscopy and were confirmed histologically in 61‐ and 553‐day samples. Repair scales were not seen in areas of continuous abrasion. No infection was observed in tissues surrounding the wound. Disruption of the fin surface was observed due to abrasion by the tag, but did not appear to cause a severe tissue reaction. The tissue responses observed were consistent with a normal, but relatively slow, healing in the vicinity of the tag wound. Use of Rototags or Jumbo Rototags appears to be an efficient way of marking elasmobranchs with minimal damage to the shark.
Differential expression of Atlantic salmon thyrotropin β subunit mRNA and its cDNA sequence
Authors: Martin S. A. M. , Wallner W. , Youngson A. F. , Smith T.
Published: April 2005

To study the regulation of the thyroid system, an Atlantic salmon Salmo salar cDNA clone was isolated for thyroid stimulating hormone (TSH) β subunit gene. A cDNA (866 bp) was isolated from an adult Atlantic salmon pituitary cDNA library, this clone was sequenced and shown to be highly conserved when compared to other teleost β TSH subunit sequences. The cDNA was used as a probe for Northern blot analysis of total pituitary RNA from the different life cycle stages of Atlantic salmon. Northern blot analysis demonstrated that β TSH mRNA is expressed at all life cycle stages studied, including parr, smolt, immature fish at sea and sexually mature male fish. Densitometry of Northern blots showed that sexually mature male salmon had low levels of salmon β TSH mRNA compared to non‐mature fish. Stunts, fish performing poorly in salt water, were shown to have elevated levels of β TSH mRNA when compared to healthy fish.
Vertebral size‐at‐age heterogeneity in gummy shark harvested off southern Australia
Authors: Troynikov V. S. , Walker T. I.
Published: April 2005

Stochastic parametrization of growth heterogeneity was applied to investigate the distribution of vertebral band radius‐at‐age in three populations of gummy shark Mustelus antarcticus Günther harvested with very different fishing effort and different mesh‐sizes of gillnet. Three examples of four parameter growth models were developed where the random von Bertalanffy growth rate K is represented alternatively by three positive distributions to avoid negative tails in size‐at‐age distribution. Models with gamma and log‐normal distributions of K fitted the data equally well and both fitted better than a model with the Weibull distribution. Various results are presented from the model developed with the gamma distribution of K. Heterogeneity in vertebral growth is presented as a series of quantiles of distribution of band radius‐at‐age. Probability density functions of band radius are presented for sharks at four selected ages, and cross‐sections of these probability densities against age are presented for three selected values of band radius. Heterogeneity of growth rate K in a population is presented as tables of 10% quantiles and as graphs of probability densities. The differences in the patterns of vertebral growth for male and female sharks separately, between Bass Strait during 1973–1976, Bass Strait during 1986–1987 and South Australia during 1986–1987 are generally consistent with those determined from shark length‐at‐age in other published studies. However, the stochastic modelling approach adopted in the present study avoids having to make any assumptions about vertebral growth patterns of individual sharks and embraces heterogeneity in vertebral radius‐at‐age in the models which allows for better evaluation of alternative hypotheses for explaining the observed differences in growth patterns.
Changes in haematology during upstream migration to American shad
Authors: Leonard J. B. K. , McCormick S. D.
Published: April 2005

Heart mass of American shad Alosa sapidissima did not change during migration in the Connecticut River. Spleen mass decreased and there was an increase in available blood haemoglobin (+22%) and haematocrit (+9%). The decreases in spleen somatic index (‐29%) and spleen haemoglobin content (‐15%) were dependent upon distance travelled upriver and not seasonal migration timing or short‐term exercise events such as passage up a fish ladder. There was no effect of migration timing on any of the blood parameters measured, suggesting that any physiological responses during migration were based on distance travelled rather than seasonally variable conditions such as temperature, although blood haemoglobin (+24%) and haematocrit (+21%) increased after passage up a fish ladder. These changes in haematological physiology occurring during upstream migration may increase swimming performance and migratory success in American shad.
The influence of piscivory on life history traits of brown trout
Authors: Jonsson N. , Næsje T. F. , Jonsson B. , Saksgård R. , Sandlund O. T.
Published: April 2005

Brown trout in Lake Femund migrated from the nursery streams mainly at 2 years old, but ranging between 1 and 8 years. Brown trout switched to piscivory from 3 years onwards, and a body length of 17·5 cm, according to back calculation from scales. Fast growers switched to piscivory at a younger age and smaller size than slow growers. The most slow‐growing trout switched to fish feeding at 9 years old and a mean body length of 36 cm. The growth of the invertebrate feeders was almost rectilinear to c. 45 cm and 11 years of age. Switching to a fish diet induced increased growth rates. Age at sexual maturity increased with the age at which the fish became piscivorous. The invertebrate feeders matured at an age similar to that of the most fast growing piscivorous trout. The mortality rate of sub‐adults and adults did not differ significantly between fish and invertebrate feeding trout. Longevity of piscivorous trout was estimated at 11 years and of invertebrate feeders at 10 years.
Individual space use strategies of wild juvenile Atlantic salmon
Authors: Armstrong J. D. , Huntingford F. A. , Herbert N. A.
Published: April 2005

Movements of 60 stream‐dwelling wild Atlantic salmonSalmo salar(97–118 mm), each tagged with a passive integrated transponder, were monitored during four trials in an enclosed section (24 m long, 45·1 m2total area) of a stream at a range of densities (four, eight, 16 and 32 fish per enclosure). Patterns of space use differed markedly between individuals, with 80% of fish establishing home ranges within 8 days of introduction to the enclosure (settlers) and the remainder continuing to move throughout the length of the enclosure (non‐settlers). Although aggressive interactions were quite frequent and dominant fish were observed chasing subordinates, there was considerable overlap of home ranges of settlers at all densities; this was the case even at lower densities at which only a fraction of the enclosure was used by the fish. Thus, rather than adopting fixed territories, the salmon showed a high level of space sharing. Individual fish used the same local area in different ways, ranging from highly localized feeding on drifting food items to a wider‐ranging strategy of specialising on benthic food. Among the fish that settled absolute growth rates were inversely related to body size, and at high densities fish lost weight. These results suggest that space use in wild juvenile salmon is more complex than a mosaic of territories, that salmon demonstrate significant variability in individual space use patterns, and that large fish may suffer disproportionately when populations are at the carrying capacity of their environment.
Lunar spawning in Siganus canaliculatus
Authors: Hoque M. M. , Takemura A. , Matsuyama M. , Matsuura S. , Takano K.
Published: April 2005

A major spawning of the seagrass rabbitfish Siganus canaliculatus occurred 4 days after the new moon in both May and June 1993, and 7 days after the new moon in 1994. The gonadosomatic index (IG) and serum vitellogenin (VTG) levels fluctuated according to the lunar cycle; IG and VTG levels showed peaks at around the new moon and the waning moon, respectively, suggesting that spawning of this species is synchronized with the lunar cycle. Vitellogenic oocytes appeared on day 2 after the first spawning and were fully mature on day 30. When a greater percentage of the most advanced oocytes attained the tertiary yolk stage, they formed a batch and separated from the adjacent group of smaller pre‐vitellogenic oocytes, indicating that S. canaliculatus is a multiple spawner with an ovary belonging to the group‐synchronous type of oocyte development. Batch fecundity, assessed using batches of oocytes at and after the tertiary yolk stage, ranged from c. 0·52 to 2·56 million eggs. The relationship between batch fecundity (F) and fork length (1) can be represented as F=0·0536854L5·07292.
Influence of larval feeding history on the body condition of Amphiprion melanopus
Authors: Green B. S. , McCornick M. I.
Published: April 2005

The cellular condition of liver hepatocytes and the height of gut epithelium cells of larval Amphiprion melanopus were sensitive indicators of feeding condition. Muscle fibres of the trunk showed marked separation in fish fed every third day just prior to settlement. Low feeding regimes also caused reductions in growth, increases in larval duration and reductions in size at metamorphosis. Gut epithelium cell height was also influenced by fish standard length and age. This study suggests that gut epithelium cell height is a useful index for an examination of the importance of starvation of larvae in tropical waters; however, size and age standardization is required prior to comparisons of wild caught fish through time or with laboratory samples.
Dynamic changes in prey choice by stickleback during simultaneous encounter with large prey
Authors: Gill A. B. , Hart P. J. B.
Published: April 2005

When a three‐spined sticklebackGasterosteus aculeatusencountered prey simultaneously the probability of hanging and the median pursuit time were greater than when prey were encountered sequentially. During simultaneous prey encounter fish did not choose to attack the more profitable prey but instead the nearer prey was handled first except when the difference between the two prey sizes was large. No difference was found in the level of total energetic intake by the fish regardless of prey size pairing. Fish that handled and ate the first prey of a pair in <5 s attacked the second prey with a high probability of success, demonstrating an opportunistic feeding strategy. Importantly however, the fish did not choose to maximize long term energy intake rate by eating both prey, but rather short‐term considerations over the course of feeding took precedence. With an empty stomach, the probability of a fish eating (Peat) the first prey handled was high regardless of prey size. As stomach fullness increased, thePeatthe first prey handled decreased if it was the larger prey. Hence, the fish were unselective when the stomach was empty but thereafter there was a shift in preference towards the smaller prey. The decision of which prey to attack and eat appeared to be based on short‐term energy considerations and the level of stomach fullness. This study demonstrates that feeding on a short‐term scale is a crucial factor to take account of when analysing fish feeding during simultaneous prey encounter.
Absence of a seasonal cycle in the sonic neuromuscular system of the oyster toadfish
Authors: Johnson M. S. , Waybright T. D. , Matt D.W. , Feher J. J. , Fine M. L.
Published: April 2005

No seasonal pattern was found in total swimbladder weight, sonic muscle weight, or spinal sonic motor nucleus neuron soma size of the oyster toadfish Opsanus tau, indicating that additional nonsteroidal factors are also involved in the development of the toadfish sonic neuromuscular system.
The growth rate of eel in tributaries of the lower River Severn, England, and its relationship with stock size
Authors: Aprahamian M. W.
Published: April 2005

The growth rate of 1980 eel Anguilla anguilla from 15 sites in the Severn system varied between 16·4 and 27·9 mm year‐1, density from 0·12 to 1·14 m‐2 and biomass from 2·56 to 25·24 g m‐2. There was no significant relationship between growth rate and density or biomass (P > 0·05).
The role of the pectoral fins in body trim of sharks
Authors: Fish F. E. , Shannahan L. D.
Published: April 2005

In a large aquarium the leopard shark Triakis semifasciata, sand tiger shark Odontaspis taurus, sandbar shark Carcharhinus plumbeus, and spiny dogfish Squalus acanthias cruised steadily at 0·1‐0·7 body lengths s‐1. Relative to the trajectory of the shark, the pectoral fins were maintained at a positive angle of ttack regardless of vertical direction. For level swimming the mean angle of attack for the pectoral fin was 11±1·7, 10·1±1·3°, 9·3±1·3°, and 15·0±0·0 for T. semifasciata, C. plumbeus, O. taurus, and S. acanthias, respectively. The long axis of the body was canted at an angle of attack for T. semifasciata and S. acanthias, but trim was maintained during level swimming for C. plumbeus and O. taurus. Hydrodynamic analysis of the body and fin design of T. semifasciata indicated that the pectoral fins could develop suffcient pitching moment to maintain depth and keep the body in trim. Demonstration of positive angles of attack support the hypothesis that lift is generated in the anterior body to counterbalance the lift produced by the heterocercal tail.
Isolation of twenty low stutter di‐ and tetranucleotide microsatellites for population analyses of walleye pollock and other gadoids
Authors: O'Reilly P. T. , Canino M. F. , Bailey K. M. , Bentzen P.
Published: April 2005

Fourteen tetra‐ and six dinucleotide microsatellites, which exhibit minimal stuttering following amplification via PCR were developed from walleye pollock Theragra chalcogramma. Most of these loci were isolated from a library enriched for tetranucleotide microsatellites by hybridization of genomic DNA to (gata)7 oligonucleotides bound to streptavidin‐coated paramagnetic beads. The average heterozygosity of these loci is ∼80%, and ranges from 53–95%. Mendelian inheritance was confirmed in five families, each consisting of a minimum of 10 or more offspring. Primer sets for all 20 loci were also evaluated in Arctic cod Boreogadus saida, Pacific cod Gadus macrocephalus, Pacific tomcod Microgadus proximus, sa.ron cod Eleginus gracilis, Pacific hake Merluccius productus, Atlantic cod Gadus morhua, haddock Melanogrammus aeglefinus, blue whiting Micromesistius poutassou, and European hake Merluccius merluccius. In each of these species, 3–19 primer sets amplified variable microsatellite loci. These loci, which exhibit little stutter and moderate to high variability, should be useful population markers in pollock and other gadoid fishes.
Egg surface structure of three clingfish species, using scanning electron microscopy
Authors: Breining T. , Britz R.
Published: April 2005

The three eastern Atlantic gobiesocid species Lepadogaster lepadogaster, Apletodon dentatus and Diplecogaster bimaculata share an attachment apparatus consisting of numerous bifurcating filaments that originate at the animal egg pole and are embedded in a mucous layer. The thickness of the mucous layer and zona radiata, and the structure and size of the micropyle vary among the three species. Because of lack of information about egg structure in paracanthopterygians and percomorphs with adhesive demersal eggs, the phylogenetic significance of this character complex remains unclear.
Analysis of the factors related with mate choice and reproductive success in male three‐spined sticklebacks
Authors: Cubillos E. R. , Guderley H. E.
Published: April 2005

Territorial three‐spined sticklebacks moved 5·3 times as far as non‐territorial males in 2 min (P< 0·001) and spent 11·1 times longer in aggression in the pools (P< 0·001). Territorial males had slightly higher condition factors than non‐territorial males. Condition factor was correlated positively with the gonad mass (P< 0·006), carotenoid concentration (P< 0·006) and the activity of CS in the axial muscle (P< 0·05) and lactate dehydrogenase (LDH) in pectoral muscle (P< 0·003). The male traits best correlated positively with female mate choice were courtship effort (P< 0·001), coloration (P< 0·003) and initial condition (P< 0·025). Courtship behaviour was related to intestine mass (P< 0·018), axial (P< 0·028) and pectoral muscle citrate synthase (CS) activity (P< 0·047); coloration was related to gonad mass (P< 0·037). These muscle enzymes may be involved in ATP generation for sustained activities or in recuperation between bouts of burst activity. Females that choose to mate with assiduously courting males which bear higher CS levels may be choosing individuals that show honestly their good condition and capacity to accomplish reproductive tasks.
Fecundity of Baltic cod: temporal and spatial variation
Authors: Kraus G. , Müller A. , Trella K. , Köuster F. W.
Published: April 2005

Potential and relative potential fecundity of 701 cod Gadus morhua caught in the Bornholm Basin (ICES Sub‐division 25) during 1987–1996 and 106 from the Gdansk Deep (ICES Sub‐division 26) in 1995 and 1996 varied significantly between years but neither between different spawning grounds nor between different sampling months within one spawning season. Growth and water temperature are factors identified to influence the mean relative fecundity explaining 66% of the variance between years.
Thermal dependence of swimming endurance in juvenile brown trout
Authors: Ojanguren A. F. , Brañta F.
Published: April 2005

The maximum swimming stamina of hatchery reared juvenile brown troutSalmo trutta, swimming against a fixed‐velocity water flow of 36·6 cm s‐1(6·97Ls‐1), was achieved at 16·1° C, and a 90% performance level occurred over a breadth of 7·7° C (12·2–19·9° C). The wide range of temperatures at which swimming performance is close to the maximal capacity could be a consequence of the implications for survival of this function.
Temporal abundance patterns and growth of juvenile herring and sprat from the Thames estuary 1977–1992
Authors: Power M. , Attrill M. J. , Thomas R. M.
Published: April 2005

Most herring Clupea harengus and sprat Sprattus sprattus sampled from West Thurrock power station intake screens, middle Thames estuary, between 1977 and 1992 were age‐0 and followed regular patterns of seasonal occurrence. Juvenile herring entered the estuary in July, peaked in abundance November to March, and then declined. Juvenile sprat first appeared in September and peaked in abundance in January. Neither species was abundant in summer samples. While in the estuary, herring and sprat increased in length an average of 4·0 and 0·33 cm respectively. Abundance of both species was significantly affected by temperature, temporal trend, shoaling behaviour and seasonal variables, and of herring by suspended solids. Interactions between environmental variates did not influence the abundance of either species. As estuarine clupeids were influenced by a complex set of events within and outside the estuary, estuarine monitoring studies alone will not be sufficient for understanding the changes in estuarine fish communities resulting from future human activity.
Fitness‐related effects of growth investment in brown trout under field and hatchery conditions
Authors: Johnsson J. I. , Jöusson E. , Petersson E. , Jäurvi T. , Bjöurnsson B. Th.
Published: April 2005

The mortality of brown troutSalmo truttaover winter in a near‐natural stream was not significantly increased by growth hormone (GH) treatment, but lipid reserves were lower in GH‐treated fish. As GH‐treated trout grew faster than controls, GH appears to promote growth at the expense of investment in maintenance. However, the growth promoting effect of GH was much more pronounced in the hatchery than in the stream, suggesting that the pay‐off associated with increased growth investment is higher under hatchery conditions with unrestricted food supply than in wild, where food availability is limited.
Asymmetry, reproductive success and parasitism ofPomatoschistus micropsin a French lagoon
Authors: Sasal P. , Pampoulie C.
Published: April 2005

There was an allometry between length of nesting malePomatoschistus micropsand the size of the nest. There was also a positive relationship between parasite load and pectoral fin asymmetry. There was no marked relationship between the number of eggs in the nest and parasitism or level of asymmetry. These results are discussed in terms of energy allocation and fish reproductive success.
Cold shocks: a stressor for common carp
Authors: Tanck M. W. T. , Booms G. H. R. , Eding E. H. , Bonga S. E. Wendellar , Komen J.
Published: April 2005

The stress response of common carp Cyprinus carpio was studied by evaluating plasma cortisol, glucose and lactate after single or multiple rapid temperature drops (ΔT: 7, 9 or 11° C). All three amplitudes used induced a significant rise in plasma cortisol levels. Peaks occurred within 20 min after onset of the cold shock. No stress‐related secondary metabolic changes were observed in any of the experiments described: plasma glucose levels remained unaffected and plasma lactate levels dropped. Carp of 60 days old showed a significant stress response, although plasma cortisol levels were lower than those observed in carp of 120 days. Furthermore, fish that had experienced multiple cold shocks showed an overall lower cortisol response than fish experiencing a single cold shock, indicating that habituation to this stressor occurred.
Digestion rate, gut passage time and absorption efficiency in the Antarctic spiny plunderfish
Authors: Boyce S. J. , Murray A. W. A. , Peck L. S.
Published: April 2005

The absolute gut evacuation rate (GER) (g day−1) of Harpagifer antarcticus increased with increasing ration mass, fish mass only influenced the absolute GER at a daily ration level of 0·3% wet fish mass (approximately a maintenance ration). The relative GER (% of meal fed day−1) was also affected differently by fish and ration mass depending on the relative ration level being fed; at rations of 0·7% wet fish mass or above the relative GER decreased with increasing fish or ration mass (in such a way that the absolute GER remained constant and unaffected by fish mass). At maintenance (0·3% wet fish mass) rations the relative GER was not affected by fish size or ration mass. Thus, there appears to be a ration threshold above which the digestion physiology alters. Mass‐specific GER (% g fish−1 day−1) decreased with increasing fish mass. Within a set relative ration level (% wet fish mass) an increase in fish mass decreased the mass‐specific GER. At a fixed ration mass, an increase in fish mass (i.e. a reduction in the ration expressed as % fish mass) resulted in a decrease in mass‐specific GER. Gut evaluation time (GET) decreased and absorption efficiency (A) increased with increasing absolute GER. The effect of ration and fish mass on the absolute and relative GER followed the same pattern irrespective of the diet, however the A and GER (% day−1 and g day−1) were higher and the GET shorter when the fish were fed shelled krill rather than amphipods.
Sibling cannibalism in dorada under experimental conditions.
Authors: Baras E. , Maxi M. Y. J. , Ndao M. , Mélard C.
Published: April 2005

Cannibalism among embryos and larvae ofBrycon moorei(Characidae) occurs during daytime and night‐time, and persists under permanent darkness. Embryos and larvae of dorada‐provisioned with formulated feed over the first week of exogenous feeding did not survive, except for those exerting cannibalism. When offered alternative fish prey [embryos ofProchilodus magdalenae(0·5–0·8 mg) andOreochromis niloticus(9–10 mg)], 1‐day‐old embryos of dorada preferred preying on these, thereby reducing early cannibalism. However, this promoted depensatory growth and more intense cannibalism later in the larval stage. Dorada provisioned withArtemianauplii in excess showed more homogeneous growth and higher survival, most cannibalistic acts being restricted to the first 24 h of exogenous feeding, just after oral teeth were fully developed (21 h after hatching). Provisioning dorada withArtemianauplii a few hours before their oral teeth were fully developed reduced early cannibalism from 41 to 15%. High proportions of deformed fish caused higher mortality, both directly and indirectly, as they promoted early cannibalism, depensatory growth and more intense cannibalism among larvae. The initial sorting of embryos, based on their occupation of the water column improved survival significantly during the first week of exogenous feeding, up to 52% in progenies containing <10% of deformed fish. Size‐grading of larvae and young juveniles over the next 2 weeks reduced cannibalism to 2·6 and 1·9% day−, in the first and second weeks, respectively. These results indicate that cannibalism in dorada can be mitigated efficiently through appropriate rearing procedures, and open promising perspectives for the intensive culture of this fast‐growing tropical species.
Effects of graded hypoxia on Atlantic salmon infected with amoebic gill disease
Authors: Powell M. D. , Fisk D. , Nowak B. F.
Published: April 2005

Atlantic salmon Salmo salar with amoebic gill disease (AGD) were exposed to a graded hypoxia (135–40 mmHg water PO2) and blood samples analysed for respiratory gases and pH at 119, 79·5 and 40 mmHg water PO2. There were no differences in the rate of oxygen uptake between infected and control fish. However, arterial PO2, and pH were significantly lower in the infected fish whereas PCO2 was significantly higher in infected fish compared with controls prior to hypoxia and at 119 mmHg water PO2. At 79·5 and 40 mmHg water PO2 saturation, there were no significant differences in blood PO2 or pH although blood PCO2 was elevated in AGD affected fish at 50% hypoxia (79·5 mmHg water PO2). The elevated levels of PCO2 in fish affected by AGD resulted in a persistent respiratory acidosis even during hypoxic challenge. These data suggest that even though the fish were severely affected by AGD, the presence of AGD while impairing gas transfer under normoxic conditions, did not contribute to respiratory failure during hypoxia.
Effects of diet supplementation with carp ovary on gonad differentiation and growth of the European eel
Authors: Grandi G. , Poerio F. , Colombo G. , Chicca M.
Published: April 2005

Treating elvers of European eel Anguilla anguilla with mature carp ovary for 3–6 months during early growth induced female differentiation in 51·6–66·7% of treated animals compared with c. 5% in controls. The treatment also induced differentiation of ovaries in eels <13 cm LT and a higher number of Syrski organs with ambisexual characters, and was most effective when administered at an early growth stage. The results could be attributed to the natural steroid content of the carp ovary. The total weight of treated animals at the end of the farm experiment was 84·7% higher than controls. The specific growth rate for weight was significantly higher in female yellow eels than in males, for both control and treated groups. The enhanced growth was related to induced feminization. A diet supplementation with mature carp ovary could be a good approach to control of sex differentiation and growth in eels.
The effect of progressive hypoxia on swimming activity and schooling in Atlantic herring
Authors: Domenici P. , Steffensen J. F. , Batty R. S.
Published: April 2005

Schools of herring exposed to progressive hypoxia show a peak in velocity during severe hypoxia, at 15–34% oxygen saturation, followed by a decrease in swimming speed until school disruption occurred. The observed increase in swimming speed during severe hypoxia reveals a graded response, since the lower the fish's swimming speed prior to severe hypoxia (U95−50, the speed at oxygen saturations between 95 and 50%), the greater the relative increase in swimming speed. The oxygen saturations at which both peak velocity and school disruption occurred were lower for fish with lowest U95−50, suggesting that the fish with the slowest speed U95−50 reach their critical PO2 (at which there is respiratory distress) last, i.e. at lower oxygen saturation. At a functional level, it is suggested that herring encountering hypoxia increase their speed in order to find more favourable conditions, and the magnitude of this increase is modulated by their respiratory distress. It is also hypothesised that the observed increase in speed may be related to an increase in the rate of position shifting within the school. Since the oxygen saturation at which the response to hypoxia occurs and the magnitude of the response are related to the fish's preferred speed prior to severe hypoxia, it is suggested that such a preferred speed should be measured in experiments testing the effect of hypoxia on fish behaviour.
Comparative feeding ecology of sympatric Solea solea and S. senegalensis, within the nursery areas of the Tagus estuary, Portugal
Authors: Cabral H. N.
Published: April 2005

Among the stomach contents of 609 individuals of Solea solea and 1104 of S. senegalensis the main food items of S. solea were Corophium spp. and Hediste diversicolor, and of S. senegalensis were Corophium spp., H. diversicolor and Scrobicularia plana. For both species, the importance of larger prey items in the diet, namely H. diversicolor and Crangon crangon, increased with fish size. Feeding activity of S. solea and S. senegalensis increased in spring and summer. Short‐term variations were particularly related to the tidal cycle and the two species fed in intertidal areas. Dietary dierences between the two nursery areas reflected prey availability mainly. Although intra‐ and interspecific length classes overlapped in diet, potential interspecific competition was probably minimized by a dierential habitat use pattern.