bluuebunny/crossref_metadata_2025 huggingface dataset:
Work Group Organisation
Authors: Daniels Barrie
Published: April 2005

Considers the micro‐level structure of organizations, particularly
the design of structures for sub‐units and individual jobs. Examines the
problem at the following levels: the individual worker, the work group,
and the organization, adhering to principles for the design of
individual jobs. Surmises that the quality of working life is a
composite of the attributes of the work groups, and that the
organizational structure is only fully complete when each employee′s
role is defined to a detailed level.
Disintegration – The Slow Birth of a Fad
Authors: Ramsay John
Published: April 2005

Considers the phenomenon of contracting out non‐essential services
as a process of “disintegration”, in contrast to the fashion
for integration and growth in the 1960s. Argues that the identification
of core functions is problematic, undermining the concept of
disintegration. Concludes that current cost reduction techniques is
symptomatic of a brutal attitude to those functions which fail the
purchase enquiry test.
How do cohabiting couples with children spend their money?
Authors: DeLeire Thomas , Kalil Ariel
Published: April 2005

Increasing rates of cohabitation in the United States raise important questions about how cohabitation fits in with the definition of family. Answers to this question depend in part upon the extent to which cohabitors’ behavior differs from that of other family types. Using data from the Consumer Expenditure Survey, we compare the expenditure patterns of cohabiting‐parent (n = 1,804), married‐parent (n = 33,159), divorced single‐parent (n = 7,641), and never‐married single‐parent (n = 2,893) families. We find that cohabiting‐parent families, compared to married‐parent families, spend a greater amount on 2 adult goods (alcohol and tobacco) and a smaller amount on education. Cohabiting‐parent families also differ in their spending patterns from divorced single‐parent families and from never‐married single‐parent families. Overall, our results show that cohabiting‐parent families allocate their budgets differently than do other families.
Premarital cohabitation and marital disruption among white, black, and Mexican American women
Authors: Phillips Julie A. , Sweeney Megan M.
Published: April 2005

We use data from the 1995 National Survey of Family Growth (N = 4,547) to investigate racial and ethnic differences in risk factors for marital disruption, with a particular emphasis on premarital cohabitation. We find that the nature and strength of the estimated effects of several risk factors for disruption differ across groups. In particular, premarital cohabitation is positively associated with subsequent marital disruption among non‐Hispanic White women but not among non‐Hispanic Black or Mexican American women. Little of the observed gaps between groups in levels of disruption, however, appears to be attributable to differences in premarital cohabitation. In addition to improving our understanding of marital disruption, this research contributes to a growing literature emphasizing heterogeneity across groups in the meaning and function of cohabitation.
The economic consequences of the dissolution of cohabiting unions
Authors: Avellar Sarah , Smock Pamela J.
Published: April 2005

Although the economic effects of divorce have been well studied, a similar exploration of cohabitation has not been conducted. For this analysis, we use a sample from the National Longitudinal Survey of Youth (N = 2,372) documenting changes in economic well‐being at the end of a cohabiting relationship and comparing these results to a sample of divorced respondents. After dissolution, formerly cohabiting men's economic standing declines moderately, whereas formerly cohabiting women's declines much more precipitously, leaving a substantial proportion of women in poverty. This effect is particularly pronounced for African American and Hispanic women. Though the end of the relationship does reinforce gender stratification, it is also an “equalizer” between married and cohabiting women, leaving them in strikingly similar economic positions.
Family roles and work values: Processes of selection and change
Authors: Kirkpatrick Johnson Monica
Published: April 2005

This study focuses on whether marriage and parenthood influence work values after taking into account the influence of work values on family formation. In a recent panel of young adults (N= 709), stronger extrinsic and weaker intrinsic work values during adolescence predicted marriage and parenthood 9 years out of high school. Controlling these relationships, wives, but not husbands, came to attach less importance to extrinsic rewards, and both husbands and wives attached less importance to intrinsic rewards, compared to single men and women. Fathers came to place greater importance on extrinsic rewards than men who had not become parents. The effect of motherhood on extrinsic values depended upon marital status, with positive effects only evident among single mothers. The findings are discussed in terms of their implications for models of work‐family relationships and understanding the meaning of contemporary family roles, especially motherhood and fatherhood.
Instability in patchworks of child care when moving from welfare to work
Authors: Scott Ellen K. , London Andrew S. , Hurst Allison
Published: April 2005

We use longitudinal, qualitative interview data collected from 38 initially welfare‐reliant women in Cleveland, Ohio to examine the factors driving instability in child‐care arrangements when women transitioned from welfare to work. Grounded theory analysis revealed that decisions about care were circumscribed by scarce social and economic resources, women went to extraordinary lengths to patch together arrangements that typically involved multiple providers, relative care was central to patchworks of care, and patchworks of child care were often highly unstable. These complex arrangements and their instability were influenced by mothers’ desires to find the most suitable arrangements for their children within resource and job constraints, dissatisfaction with providers, difficulties accessing subsidies, and changes in provider availability. Findings suggest that policymakers must consider instability in patchworks of multiple child‐care providers as they consider alternatives for meeting low‐wage working women's and children's needs for safe, affordable, accessible, and enriching nonmaternal child care.
Retirement and marital decision making: Effects on retirement satisfaction
Authors: Szinovacz Maximiliane E. , Davey Adam
Published: April 2005

This study explores how partner's employment and preretirement decision‐making structures affect retirement satisfaction, using pooled data from Waves 1 to 4 of the Health and Retirement Surveys. Based on resource theory, the analyses indicate that retired husbands are least satisfied if their wives remain employed and had more say in decisions prior to the husband's retirement. Retired wives are least satisfied if their husbands remain employed and had more say in decisions prior to the wife's retirement. These results suggest that retirement transitions undermine married retirees’ satisfaction if they enhance the other partner's influence in the relationship. More research should address linkages between work and family realms during transitions such as retirement and explore the negotiation processes surrounding such transitions.
The timing of entry into fatherhood in young, at‐risk men
Authors: Pears Katherine C. , Pierce Susan L. , Kim Hyoun K. , Capaldi Deborah M. , Owen Lee D.
Published: April 2005

Timing of first fatherhood was examined in a sample of 206 at‐risk, predominantly White men, followed prospectively for 17 years. An event history analysis was used to test a model wherein antisocial behavior, the contextual and familial factors that may contribute to the development of antisocial behavior, and common correlates of such behavior, including academic failure, substance use, and early initiation of sexual behaviors, lead both directly and indirectly to an early transition to fatherhood. Having a mother who was younger at first birth, low family socioeconomic status, poor academic skills, failure to use condoms, and being in a cohabitating or marital relationship predicted entry into fatherhood. Implications of the findings for prevention of and intervention with early fathering are discussed.
Testosterone, marital quality, and role overload
Authors: Booth Alan , Johnson David R. , Granger Douglas A.
Published: April 2005

In a sample of established working‐ and middle‐class families with school‐aged children (N= 307 wives and 307 husbands), neither husbands’ nor wives’ testosterone showed a direct connection with marital quality. In contrast, the association between husbands’ testosterone and positive and negative marital quality (as evaluated by both spouses) was conditional on husbands’ role overload. When perceptions of role overload were elevated, higher testosterone levels were associated with lower levels of marital quality. When perceptions of role overload were low, higher testosterone was linked to greater marital quality. The study supports the biosocial model such that, depending on perceptions of the social context, testosterone enables positive behavior in some instances and negative behavior in others.
The Role of Diminutives in the Acquisition of Russian Gender: Can Elements of Child‐Directed Speech Aid in Learning Morphology?
Authors: Kempe Vera , Brooks Patricia J.
Published: April 2005

This study investigated second‐language (L2) learning to gain a better understanding of learning mechanisms that also operate in child first‐language (L1) learners. The research was inspired by research on the beneficial effects of child‐directed speech (CDS). We tried to examine whether such benefits can be observed in the domain of inflectional morphology in adult L2 learners. Specifically, we investigated whether one typical feature of CDS, diminutivization, can facilitate learning of Russian gender. Diminutives (i.e., the translational equivalent of doggy, birdie, etc.) are a pervasive feature of Russian CDS. Olmsted (1994) suggested that the frequent use of diminutives in Russian CDS may facilitate the child's acquisition of grammatical gender because it eliminates nontransparent morphophonological marking. To examine the effect of diminutives on gender learning directly, adult native speakers of English were taught a variety of Russian nouns, with half of the participants trained on diminutive nouns and half on the nondiminutive base forms. Over 4 sessions, participants learned to use color adjectives to name the color of the objects depicting the nouns. In Russian, adjectives have to agree in gender with the nouns they modify; correct adjective agreement was used as a measure of gender learning. The diminutive training group demonstrated better learning of noun gender and better generalization to novel word forms and novel nouns, thus confirming the beneficial effects of diminutives on gender learning. The observed diminutive benefit for gender agreement has subsequently been demonstrated in Russian children (Kempe, Brooks, Mironova, & Fedorova, 2003), both for familiar and, in even more pronounced ways, for novel nouns, thus confirming the generalizability of the results to L1 learners. In light of these later findings, the present study underscores the importance of complementary research in L1 and L2 learning so that important questions about the nature of L1 acquisition may be answered by means of controlled manipulation of the language input in L2 learning.
Can fish survive by filter‐feeding on microparticles? Energy balance in tilapia grazing on algal suspensions
Authors: Dempster P. , Baird D. J. , Beveridge M. C. M.
Published: April 2005

Data on dietary preferences, filter‐feeding mechanisms and ingestion rates of algae by tilapias are outlined and discussed. Quantitative data on algal ingestion by filter‐feeding are incorporated into a bioenergetic model, demonstrating that under most conditions tilapias are unable to fulfil basic maintenance requirements and hence lose weight. It is concluded that the apparently high volumes of algae ingested by tilapias must be achieved by other means, by particulate feeding on aggregations of algae in the water column or flocculent surface scums of cyanobacteria or by grazing on periphytic mats.
The effect of light exposure on buoyancy of halibut eggs
Authors: Mangor‐Jensen A. , Waiwood K. G.
Published: April 2005

Effects of light‐exposure on eggs of the Atlantic halibut (Hippoglossus hippoglossus) were investigated. Egg buoyancy, yolk sac osmolality and perivitelline space (PVS) in light and dark‐exposed eggs were followed during 3–12 days after fertilization. In light‐exposed eggs, the density increased to a maximum at day 6 while the density in dark exposed eggs significantly decreased between day 4 and 10. There was no significant difference between treatments at day 12. The pattern of yolk osmolality reflected these changes in density. Embryonic volume, calculated from estimates of total volume and PVS, was found to decrease rapidly at days 3–4 after fertilization in the light exposed group, whereas the control group during the same period showed no change. After this period, the embryonic volume showed a parallel decrease in both groups. The increased egg density is caused by both the loss of water from the embryonic compartment and by increased yolk osmolality. These results are discussed in relation to changes in vertical distribution in both natural and culture systems.
Phylogenetic relationships between 21 species of three tilapiine genera Tilapia, Sarotherodon and Oreochromis using allozyme data
Authors: Pouyaud Laurent , Agnèse Jean‐François
Published: April 2005

With the aim of detecting speciation events in Tilapia sensu lato, 24 enzyme loci were studied in eleven species of the genus Tilapia, four species fo the genus Sarotherodon, five species fo the genus Oreochromis and five other species belonging to similar genera (Pelmatochromis, Chilochromis, Tylochromis, Hemichromis and Chromidotilapia). The phylogenetic trees obtained show a clustering of species (except for Sarotherodon melanotheron) according to their genera, i.e. Tilapia, Sarotherodon or Orechromis, which confirms the systematics adopted by Trewavas. The phylogenetic trees obtained by rooting with species belonging to similar genera confirm the hypothesis that mouthbrooders (Sarotherodon and Oreochromis) have a single origin, i.e. egg layers (Tilapia), and negate the hypothesis of multiple speciation of Peters and Berns.
Tolerance of Pomacanthus imperator to hypoosmotic salinities: changes in body composition and hepatic enzyme activities
Authors: Woo N. Y. S. , Chung K. C.
Published: April 2005

Emperor angel fish Pomacanthus imperator were acclimated to various salinities (33, 22, 15, 10 and 7%) for 1 month and changes in serum chemistry, body composition and liver enzyme activities were monitored. No mortality was observed in fish adapted throughout the salinity range of 7–33% and the limit of survival was around 5%. Serum Na+; and Cl – exhibited a stepwise decrease as the salinity was reduced from 33–7% but no concomitant tissue hydration could be observed. Branchial Na‐K‐ATPase activity was generally higher in hypoosmotic (7–15%) than in hyperosmotic salinities (22–33%o). Serum concentrations of glucose, lipid, α‐amino acids and protein as well as the haematocrit value were all elevated in the salinity range of 15–22%. Serum cortisol was markedly lower but serum thyroxine was significantly elevated at 15–22%. Fish adapted to 15–22% had higher hepatosomatic indices, liver glycogen and muscle lipid contents and hepatic glucose‐6‐phosphate dehydrogenase activity. These data indicate that Pomacanthus imperator is a‘ physiologically euryhaline’ species and metabolism in isoosmotic salinities has been fundamentally re‐organized to favour carbohydrate and lipid retention.
A non‐destructive morphometric technique for estimation of body and mesenteric lipid in Arctic charr: a case study of its application
Authors: Adams C. E. , Huntingford F. A. , Jobling M.
Published: April 2005

Weight and eight linear measurements were made on Arctic charr from the domesticated Hammerfest strain from Norway and offspring of wild charr of a pelagic morph from Loch Rannoch, Scotland. Guts and mesenteries were removed from the Hammerfest charr only, and the amount of lipid in both carcass and mesenteries measured by Soxhlet extraction. Lipid was extracted from the whole body of the Loch Rannoch charr. Multiple regression analysis was used to derive morphometric predictors of total lipid for the Hammerfest charr and percentage body lipid for the Loch Rannoch charr, the regressions explaining 83 and 59% of variance respectively. For the Hammerfest charr, multiple regression also provided a reliable predictor of mesenteric fat, accounting for 65% of its variance. Hammerfest charr that exhibited high aggression rates had 53% more whole body lipid and 100% more mesenteric fat than those with low aggression rates, using direct measures of lipid levels. Indirect, morphometrically‐derived measures of lipid levels gave almost identical results. It is concluded that morphometric techniques can provide estimates of both whole body and mesenteric lipid in studies requiring repeated measures on the same individuals.
Application of a fry (0+;) abundance index, based on semi‐quantitative electrofishing, to predict Atlantic salmon smolt runs in the River Bush, Northern Ireland
Authors: Crozier W. W. , Kennedy G. J. A.
Published: April 2005

An abundance index for 0+ Atlantic salmon was based on semi‐quantitative electrofishing estimates at 137 sites in typical juvenile habitat throughout the River Bush (N. Ireland). 0 + abundance was linearly related to total smolt numbers migrating through a downstream trap in subsequent years (r2= 0.716, P<0.001), suggesting a high degree of predictive ability. This predictive ability decreased as smolt age increased, suggesting influence of density‐independent mortality. Potential application of the technique to estimate smolt production from rivers having no trapping facilities is discussed, together with sources of variability potentially affecting estimates.
The growth of young pike in small Finnish lakes with different acidity‐related water properties and fish species composition
Authors: Raitaniemi J.
Published: April 2005

Pike growth was generally slower in small Finnish lakes than has been reported from large lakes or brackish coastal waters. Growth was unrelated to pH, alkalinity, COD, or conductivity of the water, but length of 1–2‐year‐old pike correlated positively with water colour (i.e. humic content), nitrogen content, and phosphorus content. These water properties also correlated with each other. Growth of 1–2‐year‐old pike was negatively correlated with lake area in lakes smaller than 20 ha.

In lakes with a strong roach population or without ruffe the 0 group pike grew faster than in lakes without roach or with ruffe. The growth of pike aged 1–4 years in two very acid and practically fishless lakes did not differ clearly from the rest of the lakes, although the pike were forced to forage for abundant acid resistant invertebrates like dragonfly nymphs (Odonata) or Asellus aquatlcus.

The results of this work support earlier studies where the growth rate above all depends on water temperature and food availability. Acidity was not shown to affect the growth rate of pike.
Fine structure and function of the gut epithelium of pike eel larvae
Authors: Otake T. , Hirokawai J. , Fujimoto H. , Imaizumi K.
Published: April 2005

The development of the alimentary canal of pike eel, Muraenesox cinereus, that were hatched and reared in the laboratory, was examined. The larvae did not feed on zooplankton or phytoplankton and survived for 10 days. Histological and histochemical investigations showed that the alimentary canal was morphologically and functionally differentiated in 3 days after hatching and before exhaustion of the yolk. The foregut was not functional in absorption. The midgut absorptive cell was characterized by a well‐developed lamellar membranous structure in the basal portion of the cytoplasm. Na1‐K1 ATPase activity was demonstrated on the lamellar membrane of the structure. It suggests that water and solute transport is quite active in the midgut epithelium. Orally administered HRP (horseradish peroxidase) was ingested and intracellularly digested in the hindgut absorptive cells. Some of the HRP was transported, without complete digestion, into tissue spaces under the epithelium. Evidence suggests that pike eel larvae possibly utilize dissolved organic matter, including soluble macromolecules, as their nutrition sources.
Observations on skin colour changes in juvenile lumpsuckers
Authors: Davenport J. , Bradshaw C.
Published: April 2005

This study reports on an experimental investigation of colour change in young lumpsuckers Cyclopterus lumpus, employing Munsell colour charts to quantify skin hue, colour value and chroma. Juvenile lumpsuckers can live pelagically close to the sea surface, or can attach to floating seaweed and debris with their suckers. When swimming they adopt a cryptic default light green coloration, with the dorsum being darker than the belly (countershading). This default colour is also seen in complete darkness. When attached to objects they take a colour stimulus from below and to the sides and change colour. They can achieve good colour matches (noticeable in 3 min; complete within 15 min) with substrata that are green‐yellow in colour, especially the brown alga Ascophyllum nodosum. Colour matching is largely dependent upon changes in colour value (i.e. lightness/darkness) produced by melanin dispersal or concentration in the melanophores. Thus, on artificial backgrounds outside the range of achievable hue matching, they still achieve good matchings of colour value. Slight hue changes were recorded (probably reflecting interaction of basic skin colour with melanin dispersal state), but chroma (brightness) variations were negligible. Lumpsucker colour depends upon light intensity, allowing sustained colour matching as weed illumination changes.
Uptake of tritiated thymidine in muscle of juvenile carp
Authors: Akster H. A. , Koumans J. T. M. , Cuelenaere J. , Osse J. W. M.
Published: April 2005

In juvenile carp (4.5–6 cm s.l.) labelled myosatellite cell nuclei are found 24 h after injection of tritiated thymidine, but labelled myonuclei after 48 h, indicating that fish myonuclei do not proliferate but originate from undifferentiated myogenic cells. The time pattern accords with the estimated cell‐cycle time of adult myogenic cells of carp.
Copulation, spawning and parental care in captive ocean pout
Authors: Yao Zuxu , Crim L. W.
Published: April 2005

The ocean pout copulates through direct genital contact for internal fertilization. A complete spawning event consists of copulation, oviposition, and the female displaying parental care by wiping and wrapping herself around the eggs.
Sea trout as a carrier of infectious salmon anaemia virus
Authors: Nylund A. , Jakobsen P.
Published: April 2005

Sea trout did not develop symptoms or gross clinical signs of infectious salmon anaemia (ISA) when injected with ascites from salmon, but ISA virus was propagated and haematocrit values dropped. The virus was transmitted from trout to salmon.
Pseudodactylogyrus anguillae on Anguilla rostrata in Nova Scotia: an endemic or an introduction?
Authors: Cone D. K. , Marcogliese D. J.
Published: April 2005

This first report of Pseudodactylogyrus anguillae from North America supports the idea that this monogenean is a natural parasite of American and European eels and not an introduced Asian species.
Evaluating the use of spawning success to estimate reproductive success in a Caribbean reef fish
Authors: Cole K. S. , Sadovy Y.
Published: April 2005

Observations on egg batch production by known female Stegastes partitus and the fates of those egg batches within the nests of known males revealed that spawning success was not a reliable predictor of hatching success and, hence, reproductive success because of high egg batch mortality. Moreover, while numbers of eggs per batch increased with increasing female length, both inter‐ and intra‐individual variation in batch size was considerable, demonstrating that spawning events cannot be considered equivalent. These two findings indicate that spawning success cannot be assumed to provide a direct quantitative substitute for a measure of reproductive success in this benthic spawning reef fish.
Intraseasonal characterization of glass eel migration in the River Tiber: space and time dynamics
Authors: Ciccotti E. , Ricci T. , Scardi M. , Fresi E. , Cataudella S.
Published: April 2005

Glass eel (Anguilla anguilla) upstream migration was studied in the River Tiber estuary to obtain a better understanding of spatial and temporal migration dynamics within the season of ascent. Using data from glass eel fisheries, time series analysis of daily catches per unit of effort revealed a fortnightly cycle that can be related to invasion waves possibly corresponding to tidal currents. The amplitude of these waves appeared to correspond to the tidal area of the estuary. Furthermore, glass eels apparently had a delay in this area before resuming upstream migration.
The mating system of Xyrichthys novacula: sperm economy and fertilization success
Authors: Marconato A. , And V. Tessari , Marin G.
Published: April 2005

We determined the fertilization rates achieved by males of the polygynous wrasse Xyrichtys novacula in the northern Mediterranean sea, by collecting all sperms and eggs released in individual spawns from three adjacent male territories that encompassed different numbers of female home ranges. Two males with territories including four and six females respectively, released similar average numbers of sperm/spawn, whereas a male holding at the same time two territories with six females each, released significantly fewer sperm/spawn. Although fertilization rates decreased with absolute numbers of sperm released, the male with the largest harem achieved the highest total daily number of fertilized eggs, as a result of the high number of females in his territory. These results demonstrate a strategy of a male's sperm economy that is in conflict with the female's interests.
Parasites, aggression and dominance in male upland bullies
Authors: Hamilton W. J. , Poulin R.
Published: April 2005

The effects of the digenean trematode parasite Telogaster opisthorchis on aggression and competitive ability in male upland bullies (Gobiomorphus breviceps) were examined using mirror‐image stimulation (MIS) techniques and dyadic contests for nest sites between pairs of males. Parasite load had no significant effect on male aggression or success in dyadic contests, nor was aggression a predictor of the likely winner of these contests. The results are discussed with relation to the role of parasites in male‐male competition and to possible problems in using MIS techniques for studies on dominance and aggression in fish.
Ingestion of suspended bacteria by fish: a modified approach
Authors: Matěna J. , ŠImek K. , Fernando C. H.
Published: April 2005

The ingestion of suspended bacteria by common carp larvae and juvenile tilapias was quantified by counting of fluorescently labelled bacteria (FLB) in guts of experimental fish under an epifluorescence microscope.
Rates at which post‐larval prawns are digested by a small predatory fish and the implications for predation studies
Authors: Haywood M. D. E.
Published: April 2005

Juvenile Monocanthus chinensis digested most of the flesh of post‐larval Penaeus monodon within 60 min, and most exoskeletal components within 180 min. Rapid cooling of predator samples should improve estimates of consumption of young prawns.
Allopaternal care in the redlip blenny
Authors: Santos R. S.
Published: April 2005

Territorial male Ophioblennius atlanticus atlanticus were found to switch to experimentally deserted nests of other males and adopt their fry. This alloparental care appears to aid in
Role of feeding and prey distribution of summer and southern flounder in selection of estuarine nursery habitats
Authors: Burke J. S.
Published: April 2005

Diets of metamorphosing larvae and early juvenile summer and southern flounder were examined during the settlement period when their distributions overlapped and during a subsequent period when the two flounders were found in different habitats. Prey abundance on tidal flats was examined along an upstream transect. Though initially similar, diets of the two species diverged prior to the development of a segregated distribution. These diet differences reflected those found in the diets of the two species following segregation. Southern flounder ate more active epifaunal prey: mysids, amphipods and calanoid copepods and appeared to be an ambush predator. The summer flounder ate primarily infauna: polychaetes, and invertebrate parts and appeared to be an active forager. Distribution of prey within the study area suggested that mysid gradients may influence movement of southern flounder to nursery grounds. The coupling of biotic and abiotic gradients are probably important in creating nursery areas and guiding fishes to species specific habitat types.
The visual cells of the corsula mullet
Authors: Narayanan K. , Khan A. A.
Published: April 2005

The eye of Rhinomugil corsula has a duplex retina differentiated into dorsal and ventral halves, with the ventral retina 116·4 μm thicker than the dorsal retina. The rods of the ventral retina are relatively longer, with longer outer segments. The nuclei of the outer nuclear layer of the dorsal and ventral halves are in four and six to seven rows respectively. The rod outer segment bears a single incision. The mitochondria of cone and rod inner segments has a vitreal‐scleral gradient. Single and double cones are present in both halves, with triple cones in the dorsal half only. The outer segments of double cones are equal and united. The single cones have two connecting cilia. The cone cells are arranged in a square mosaic with four double cones and five single cones to each unit in the dorsal half, and in a rhombic pattern in the ventral half.
Sex differentiation in the European eel: histological analysis of the effects of sex steroids on the gonad
Authors: Colombo G. , Grandi G.
Published: April 2005

The effects of sex steroids on sex differentiation in the European eel were studied. The steroids, 17α‐methyltestosterone (MT) and 17α‐ethynylestradiol (EE), were given in the diet to 6–8 cm elvers and to 15–18 cm and 22–25 cm yellow eels. In our rearing conditions a very large percentage of the untreated eels developed as males. No masculinizing effect of MT could be demonstrated. The EE, administered at a dose of 10 mg kg‐1 of diet to 6–8 cm elvers and 15–18 cm eels, induced ovarian differentiation in about 90 and 65% of eels respectively, while in the control <5% of females was recorded. In 22–25 cm yellow eels a moderated feminizing effect was observed.

Histological analysis of the gonads of treated eels showed that sex steroids affect the gonadal structure. The androgen stimulates hypertrophy of compact connective tissue, early differentiation of Leydig cells, Sertoli cells and early formation of the spermatic duct. Oestrogen inhibits the differentiation of these structural components and stimulates the differentiation of follicular cells and an ovarian structure.

The involvement of gonadal structural components is discussed in relation to the effect of steroid treatment and to the peculiarities of sex differentiation in the European eel.
Observations on the depth distribution pattern of the small‐spotted catshark in the North Aegean Sea
Authors: ĎOnghia G. , Matarrese A. , Tursi A. , Sion L.
Published: April 2005

Aspects of Scyliorhinus canicula distribution in the North Aegean Sea are reported. Data were collected during four seasonal trawl surveys carried out in 1991. The pattern of vertical distribution of the individuals did not exhibit any sexual segregation. In contrast to Springer's hypothesis, juveniles and adults were found together on the bathyal bottoms.
Organogenesis of the liver in sea bream
Authors: Guyot E. , Diaz J. P. , Connes R.
Published: April 2005

Development of the liver in sea bream, Sparus aurata, was studied using light and electron microscopy from hatching to the age of 23 days. Histochemical reactions were used to monitor changes in lipids and glycogen during this period. During the strictly endotrophic prelarval phase from hatching until mouth‐opening, the primordial liver formed by budding on the gut wall and became organized in contact with the vitelline vesicle. The initially undifferentiated cells rapidly polarized and became pyramidal in outline with their apical extremities terminating in cavities corresponding to the future bile canaliculi. Sinusoids formed centripetally. Glycogen was stored in the cytoplasm of differentiating hepatocytes. At the beginning of the larval stage the hepatocytes multiplied, bile canaliculi were completed and the sinusoids acquired their final form. Glycogen reserves decreased strongly as bile secretion started. The end of the endo‐extrophic period was marked by distinct recovery of glycogen storage, synthesis of numerous lipoproteins and discharge into the sinusoids.
Contrasts in algal food processing among five herbivorous coral‐reef fishes
Authors: Polunin N. V. C. , Harmelin‐Vivien M. , Galzin R.
Published: April 2005

There were significant differences among five sympatric herbivorous reef fish species in their ranking of seven food‐processing characters. Between them Zebrasoma scopas and Stegastes nigricans had the lowest bite rates, longest filling times, lowest defaecation activities and slowest gut turnover. Acanthurus nigrofuscus and Scarus sordidus were similar in having the fastest filling times, and high bite rates, gut‐contents masses, gut turnover and defaecation activities. Ctenochaetus striatus was intermediate between those species pairs in five out of seven characters. Rich algal diets of S. nigricans and Z. scopas were contrasted with the carbonate intake of S. sordidus. The food‐processing pattern of C. striatus was related to the siliceous content of a diatom diet. Food‐processing characteristics of A. nigrofuscus were attributed to a diet which is readily absorbed and/or is of high nutritional quality.
Gradual transfer to sea water of rainbow trout: effects on liver carbohydrate metabolism
Authors: Soengas J. L. , And M. Aldegunde , Andrés M. D.
Published: April 2005

The levels of glycogen and glucose, as well as of the activities of several key enzymes of glycogenolysis, glycolysis, gluconeogenesis and the pentose phosphate shunt were assessed in livers of small (97 g) and large (166 g) rainbow trout Oncorhynchus mykiss during gradual transfer to sea water (salinities of 0, 9, 18 and 28%). Plasma glucose and protein levels were also evaluated. Liver carbohydrate metabolism changed during gradual adaptation of rainbow trout to sea water. Glucose increased with salinity in livers of both sizes of animals, as did glycogenolysis and gluconeogenesis, but this latter only in large animals, and glycolytic rates in small animals. The different responses in metabolic parameters between sizes of animals may reflect a higher stress of the small animals and/or a better adaptation of large animals to increased salinities, in a way similar to that previously suggested by other authors after evaluation of non‐metabolic parameters. The changes observed at 28% can also be the result of reduced food consumption.
Fine structure and motility of spermatozoa and composition of the seminal plasma in the perch
Authors: Lahnsteiner F. , Berger B. , Weismann T. , Patzner R.
Published: April 2005

The fine structure and motility of spermatozoa and the composition of the seminal plasma of the perch Perca fluviatilis are investigated by electron microscopy, computer assisted cell motility analysis (CMA) and biochemical methods. The spermatozoon is asymmetrical as the flagellum inserts mediolateral on the nucleus. It lacks an acrosome, has an ovoid head and a small midpiece with one mitochondrion. Sperm motility–initiated in distilled water (10° C)–is characterized as follows: 85·0 ± 2·7% of the spermatozoa are motile, the main swimming type (10 ± 1 s after motility initiation) is the linear motion (61·4 ± 24·4%) and the average swimming velocity is 122·4 ± 21·9 μm s–1. When motility is initiated with NaCl, glucose or sucrose solutions of 100 mosmol kg–1 the percentage of motile spermatozoa and the swimming types are similar as in water, but the swimming velocity (174·0 ± 22·3 μm s–1) is significantly higher. Motility is inhibited by high osmolality of the diluent: when increasing the osmolality of the saline solutions to 350 mosmol kg–1 sperm motility is totally suppressed while potassium (10–40 mmol 1–1) does not affect motility parameters. pH optimum for sperm motility is between pH 7·0 and 8·5. The seminal fluid contains 124·01 ± 21·68 mmol 1–1 sodium, 10·22 ± 1·11 mmol 1–1 potassium and 0·72 ± 0·26 mmol 1–1 calcium. pH is 8·25 ± 0·09, and osmolality 283·90 ± 37·19 mosmol kg–1. The following organic components were determined: monosaccharides (glucose 63 ± 19 μmol 1–1, fructose 54 ± 28 μmol 1–1, galactose 59 ± 25 μmol 1–1), lipids (cholesterol 5·51 ± 6·42 μmol 1–1, triglycerides 72 ± l00 μmol l–1, cholesteryloleate 15–150 μmol 1–1, phosphatidylcholine 26 · 31 μmol 1–1, glycolipids 1–10 mg 100 m1–1), lactate 108 ± 99 μmol 1–1, hydroxybutyrate 102 ± 99 nmol 1–1, choline 59 ± 159 μmol 1–1, protein 344·75 ± 59·06 mg 100m1–1, enzymes (β‐d‐glucuronidase l.4 ± 0.7 μmol h–1 100 ml–1, protease (caseolytic activity) 1·0 ± 0·6 μmol h–1 100 ml–1, alkaline phosphatase 2520·0 ± 861·0 μmol h–1 100 ml–1, acid phosphatase 44.0 ± 16.0 μmol h–1 100 ml–1, glucose‐6‐phosphate dehydrogenase 38·9 ± 86·9 μmol h–1 100 ml–1, lactate dehydrogenase 134·4 ± 69·6 μmol h–1 100 ml–1, butyrylcholine esterase 0·014 ± 0·010 μmol h–1 100 ml–1, adenosine triphosphatase 562·8 ± 665·4 μmol h –1 100 ml–1).
The annual ovarian cycle and the influence of pollution on vitellogenesis in the flounder, Pleuronectes flesus
Authors: Janssen P. A. H. , Lambert J. G. D. , Goos H. J. Th.
Published: April 2005

A study of the annual ovarian cycle of the flounder, Pleuronectes flesus, was made, describing the different stages of germ cell maturation and the different phases of ovarian development. The development of oocytes in the flounder is a group synchronous process with two distinct generations of primary growth phase oocytes. One group becomes vitellogenic at the end of the summer while the other group does not surpass the primary growth phase. Oogonia, as well as seven stages of oocyte development and post‐ovulatory follicles were distinguished. The occurrence of these oocyte stages was used to define the different phases of ovarian development. Previtellogenesis and vitellogenesis were each divided into two subphases: the perinucleolus and cortical alveoli phase, and early and advanced vitellogenesis, respectively. These phases were followed by final maturation, ovulation, spawning and a post‐spawning phase. The GSI increased rapidly during vitellogenesis, to a maximum value of about 35 just before spawning, at the end of the winter, when the animals had migrated to the North Sea spawning grounds. After spawning the GSI dropped to 1.5. Fish that had lived in a polluted environment exhibited premature vitellogenesis, resulting in a high number of oocytes in yolk granule stage. This study on the effects of pollution indicates the importance of the description of the normal annual cycle of the ovary as a control in toxicological studies.
The effect of hunger and cestode parasitism on the shoaling decisions of small freshwater fish
Authors: Arber B , Huntingford F. A. , Crompton D. W. T.
Published: April 2005

Individual minnows Phoxinus phoxinus and three‐spined sticklebacks Gasterosteus aculeatus were provided with a mutually exclusive choice between joining a shoal of conspecifics and foraging alone in a maze. The shoaling decisions and foraging behaviour of individual fish were studied when the fish were satiated and after 24‐ and 48‐h periods of food deprivation. Hunger level was found to have a significant effect on shoaling behaviour. When satiated, fish of both species spent a greater proportion of time within one body length of the shoal and spent less time out of visual contact with the shoal than after periods of food deprivation. The effect of the cestode parasite Schistocephalus solidus on the shoaling behaviour of stickleback hosts was complex. When satiated, infected fish spent less time than uninfected fish within one body length of the shoal, preferring to remain outside the shoal, yet within visual contact, although when food deprived there was no difference in the proportion of time spent by infected and uninfected fish close to the shoal. The possible ecological significance of this change in behaviour is discussed with reference to the manipulation hypothesis of host‐parasite interactions.
Induction of nest building and spawning in Hoplosternum littorale
Authors: Ramnarine I. W.
Published: April 2005

Sexually mature neotropical armoured catfish, Hoplosternum littorale were induced to build nests and spawn by reducing the conductivity of the water. Simulation of rain and increasing water level without a reduction in conductivity had no effect.
Feline cutaneous toxoplasmosis: a case report
Authors: ANFRAY PASCAL , BONETTI CRISTINA , FABBRINI FABRIZIO , MAGNINO SIMONE , MANCIANTI FRANCESCA , ABRAMO FRANCESCA
Published: April 2005

Abstract A 9‐year‐old female, domestic short hair cat was presented with sudden onset of polyuria/polydipsia, and hundreds of cutaneous nodules. Prior to referral, the cat had had four skin nodules that were treated with steroids. The four skin nodules then multiplied to form more than 100 ulcerated and nonulcerated nodules located all over the trunk. Clinical evaluation revealed hypothermia and respiratory distress. Cytology from both skin nodules and bronchoalveolar lavage showed macrophages and small organisms whose shape and size were indicative ofToxoplasmaspp., or similar organisms. Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) serology results were negative. The cat was seropositive forToxoplasma(IgG 1 : 640) andNeospora(1 : 80) infections. The cat died soon after referral. Necropsy revealed pyothorax, necrotic/purulent pneumonia, haemorrhagic spots on kidneys and mesentery. Histopathology from skin nodules showed diffuse, deep necrotic dermatitis/panniculitis, vasculitis and disseminated free and grouped protozoa. The parasites were found in lungs, spleen, kidneys and liver. Immunohistochemistry on skin tissue with anti‐Toxoplasma gondiiandNeospora caninumantibodies gave positive results with both. Electron microscopy showed single and grouped tachyzoites with morphological features ofT. gondii, often within macrophages. Samples of cutaneous nodules and bronchoalveolar fluid were examined by a polymerase chain reaction (PCR) assay for detecting apicomplexa coccidia. PCR results were consistent only withT. gondiiinfection. Therefore, immunohistochemistry positivity forN. caninumwas considered a cross‐reaction and a diagnosis of cutaneous and visceral toxoplasmosis was made.
Long‐term use of cyclosporine in the treatment of canine atopic dermatitis
Authors: RADOWICZ STACEY N. , POWER HELEN T.
Published: April 2005

Abstract This retrospective study of 51 dogs with atopic dermatitis (AD) treated with cyclosporine (CsA) for a minimum of 6 months assessed the frequency of dosing and the need for continual treatment to control clinical signs. The study evaluated both medical records and information supplied by the owners in the form of written questionnaires and telephone follow‐up. Laboratory parameters, possible adverse effects and owner satisfaction were assessed. The dose of CsA was 5 mg/kg orally per day and dogs received CsA for 6–30 months. At the conclusion of the study period, 28 dogs (55%) needed ongoing CsA to control clinical signs of AD: 8 (15%) received CsA 2–3 days per week, 10 (20%) 4–5 days per week, and 10 (20%) daily. CsA was discontinued in 23 dogs (45%) after 6–24 months due to either a limited response (22%) or after achieving a clinical response (24%). The results suggest that some dogs with AD treated with CsA may not require daily or even ongoing treatment to control clinical signs. Laboratory abnormalities were detected in 13 dogs (25%) during their CsA treatment. Two dogs developed oral growths and three developed hirsuitism. Forty owners (78%) reported no adverse events in their dogs during the treatment period. Thirty‐six owners (71%) were satisfied with CsA as treatment for their atopic dog.
Immunoglobulin E‐bearing cells and mast cells in skin biopsies of horses with urticaria
Authors: RÜFENACHT SILVIA , MARTI ELIANE , VON TSCHARNER CLAUDIA , DOHERR MARCUS G. , FORSTER URSULA , WELLE MONIKA , ROOSJE PETRA J.
Published: April 2005

Abstract The pathogenesis of equine urticaria is not well understood. In man, urticaria has been associated with immunological and nonimmunological mechanisms leading to the release of various mediators by mast cells. Skin biopsies of 32 horses with a history of urticaria were stained with toluidine blue, a double‐labelling method for chymase and tryptase, and immunohistochemistry for immunoglobulin (Ig)E. These horses were compared with horses with pemphigus foliaceus, insect bite hypersensitivity and control horses with healthy skin. Neither formalin fixation time nor biopsy site influenced the staining methods. No chymase‐positive cells were found. In all groups of horses, cells staining with toluidine blue and for tryptase and IgE were found in the epidermis and hair follicle papilla and significantly more positively staining cells were observed in the subepidermal dermis compared with the deep dermis. Horses with urticaria had significantly more IgE‐bearing cells in the subepidermal dermis than control horses. However, horses with urticaria had significantly fewer toluidine‐blue‐stained mast cells in both subepidermal and deep dermis compared with the insect bite hypersensitivity and pemphigus foliaceus groups. This study suggests that IgE‐mediated reactions play a role in the pathogenesis of urticaria.
Acral mutilation and analgesia in 13 French spaniels
Authors: PARADIS MANON , JAHAM CAROLINE DE , PAGE NADIA , SAUVE FREDERIC , HELIE PIERRE
Published: April 2005

Abstract  Acral mutilation and analgesia (AMA) is reported in 13 French spaniels in Canada. This newly recognized disorder shares striking similarities in clinical features and biopsy findings to the other acral mutilation syndromes or hereditary sensory neuropathies reported in German short‐haired pointer dogs, English pointer dogs and English springer spaniels. Clinical signs are first noted between 3.5 and 12 months of age. Affected dogs lick, bite and severely self‐mutilate their distal extremities resulting in ulcers with secondary bacterial infection. Auto‐amputation of claws, digits and footpads occurs in severe cases. Single or multiple feet can be affected. Affected dogs walked on their severely mutilated feet without evidence of pain, lameness, or ataxia. The majority of the dogs were euthanized within days to months of diagnosis.