bluuebunny/crossref_metadata_2025 huggingface dataset:
Contributions of an alley cropping system and arbuscular mycorrhizal fungi to maize productivity under cassava intercrop in the derived savannah zone
Authors: OYETUNJI O. J. , OSONUBI O. , EKANAYAKE I. J.
Published: August 2003

Alley cropping is a prototype agro-forestry system practiced in many parts of the humid tropics. It is one of the established, promising and sustainable low-input soil management ventures. An improved understanding of the eco-physiological relationships between the arable and perennials in this system could contribute to solving issues of sustainability for nutrient use and system productivity. Field experiments were conducted in Alabata and Ajibode, located in the derived savannah zone of Nigeria, to evaluate the comparative effects of an alley cropping system, arbuscular mycorrhizal fungi inoculation and cassava intercropping on maize yield. These on-farms trials (research managed and farmer managed) were conducted in the 1993/94 and 1995/96 growing seasons, in Rhodic Kandiustalf soil type with low nutrients. Each trial was a split-plot factorial arranged in randomized complete blocks with three replications. Biomass productions of maize and cassava tuber yield were determined. The results obtained at Alabata indicated that the maize plants were heavily infected with AM fungi whether inoculated or not. The hedgerow trees did not have a significant effect on maize yield. The increase in yield brought about by the alley cropping system was generally less than 15%, except in one farm where increases of 34·6 and 46·5% were recorded in AM-inoculated and non-inoculated plots respectively. The introduced AM fungi did not significantly enhance maize yield at Alabata; the percentage increase was not more than 24%. This trend was also observed at Ajibode. Cassava tuber yield was found to be suppressed by the alley cropping system irrespective of the cultivar. The decrease in yield ranged from 2·6 to 150·8%. However, inoculation of the cassava with exotic AM fungi brought about an enhancement of its tuber production. The increase ranged from 20·7 to 189·8% depending on the treatment combination. It is therefore necessary to encourage adoption of the improved alley cropping system integrated with mycorrhizal technology.
Effectiveness of the water-insoluble component of triple superphosphate for yield and phosphorus uptake by plants
Authors: JOHNSTON A. E. , RICHARDS I. R.
Published: August 2003

The water-insoluble phosphorus (P) component (‘residue source’) was separated from four commercial triple superphosphate (TSP) products and its agronomic effectiveness evaluated. Two of the TSP products were sourced from the USA and two from the UK. Effectiveness was measured using a pot trial technique with ryegrass as the test crop. The residue sources were evaluated on 13 soils varying in key properties: readily plant-available P, texture, pH and organic matter content. Four of the soils were from Germany, one from Spain, five from the UK and three from France. Grass dry-matter yield and P offtake were measured at every cut on every soil. For both of these variables, significant responses to applied P were obtained on all soils. Mono-calcium phosphate (MCP) was used as the comparative P source and effectiveness of the residue sources was estimated relative to that of MCP. Using dry-matter data, the residue sources were 44–87% as effective as MCP; P offtake data provided corresponding estimates of 35–79%. Both methods of estimation indicated the same ranking of residue sources in terms of relative effectiveness, those derived from USA products being more effective than those derived from UK products. The ranking was the same for all soils. The effectiveness of the residue sources relative to that of MCP appeared little affected by measured soil properties: texture, pH, available P or organic carbon content. The results indicate there is little difference in agronomic effectiveness of TSP products with water solubility greater than 85%.
Assessment of observer performance in a subjective scoring system: visual classification of the gait of cows
Authors: ENGEL B. , BRUIN G. , ANDRE G. , BUIST W.
Published: August 2003

As with any measurement procedure, the performance of a subjective classification procedure must be evaluated. Observers have to be trained and their performance has to be assessed, preferably on a regular basis, to guarantee sufficient consistency and accuracy of classification results. The current paper is a study of observer performance where observers were asked to classify the gait of cows from video recordings. Gait was classified in nine ordered categories (ranging from 1=normal gait to 9=severely abnormal gait) and also as a continuous fraction by putting a mark on a paper strip (the left end corresponding to 0=normal gait and the right end to 1=severely abnormal gait). The use of statistical models and methodology for analysis of these visual scores is demonstrated and discussed. Observers were assessed by comparing their classification results with the results of an expert. Models and methodology take proper account of typical features of the data, i.e. the fact that data are discrete scores or continuous scores with an upper and lower bound, the variance heterogeneity and non-linearity of model terms that arises from this, and the dependence between repeated classifications of videos of the same cow. Results of the analyses are summarized in simple tables and plots. These are useful tools to indicate possible flaws in judgement of an observer, that may be corrected by further training. When a high standard is developed, which usually takes the form of the opinion of one or more experts, this methodology can be applied prior to any experiment where responses are ordered subjective scores.
The impact of controlled breeding on milk production in pastoral goats in northern Kenya: an application of polynomial growth curve fitting
Authors: HARY I.
Published: August 2003

The paper investigates the effect of controlled seasonal breeding on milk production in a herd of Small East African (SEA) goats. Polynomial growth curve models were fitted to both daily and cumulative milk yield data obtained from an experiment conducted over a period of 4 years (1984–88) under simulated pastoral herd management in Isiolo District, northern Kenya. The experimental treatment consisted of six different mating seasons per year, which were replicated three times over the course of the experiment.

Milk yields in the first 2 weeks of lactation were negatively affected (<400 g/day) when kidding took place between June and September, whereas maximum initial yields of about 450 to 550 g/day were achieved at the onset and during the long rainy season. Multiple peaks in milk yield curves were observed when a rainy season occurred after about the first half of the lactation period. In terms of total amount of milk produced until 28 weeks of lactation, the production system could benefit from the introduction of a restricted breeding management allowing does to be bred in the period from June to November, with total milk yields being estimated at approximately 60 kg of milk. Maximum milk production until weaning can be expected to be achieved by does mated between October and January (between 46 and 48 kg of milk). The present experiment has revealed that mating just prior to or during the long rainy season leads to low milk yields until weaning and significantly increases the incidence of early kid deaths.

It is concluded that evaluating milk production in goat herds exposed to strong seasonal changes in forage supply is perhaps best carried out in terms of cumulative milk yields, instead of average daily yields, which are subject to large fluctuations. Furthermore, under these conditions fitting polynomial growth curves to longitudinal milk yield data using the general linear mixed model appears to be more appropriate than the estimation of non-linear algebraic lactation curves.
Effects of cold exposure and time relative to feeding on glucose metabolism of sheep using a glucose clamp approach
Authors: TAKEBAYASHI A. , SANO H. , FUJITA T. , AMBO K.
Published: August 2003

An experiment combining a hyperinsulinaemic euglycaemic clamp approach and an isotope dilution method determined the effects of cold exposure and time relative to feeding on blood glucose metabolism in four sheep. The sheep, fed 20 g/kg body-weight (BW) of lucerne hay cubes and 5 g/kg BW of maize-based concentrates once daily, were exposed in turn to a thermoneutral environment (20 °C) and a cold environment (0 °C) for 20 days. The combined experiments were performed at four different times relative to feeding, i.e. 3 to 2 h, 2 to 1 h and 1 to 0 h before, and 1 to 2 h after the initiation of feeding for the basal periods, and 1 to 0 h before, and 0 to 1 h, 1 to 2 h and 3 to 4 h after the initiation of feeding for the glucose clamp periods in both environments. [U-13C]Glucose was continuously infused for 6 h after a priming injection. Insulin was continuously infused at 6·0 mU/kg BW per min for 2 h, which corresponded to the last 2 h of the [U-13C]glucose infusion. Blood glucose concentrations were maintained euglycaemic during the insulin infusion by concomitant variable glucose infusion. Blood glucose turnover rate (GTR) during the basal period was enhanced by cold exposure (P=0·01) and feeding (P=0·04). Blood GTR increased (P<0·01) with the glucose clamp. During the glucose clamp, blood GTR and glucose infusion rate (GIR) were greater (P=0·003 and P=0·001, respectively) during cold exposure than in the thermoneutral environment. Time relative to feeding influenced (P=0·003) the GIR, whereas changes in blood GTR and endogenous glucose production rate were not significant. No significant cold×feeding interaction was observed in these variables. It was suggested that, in sheep, glucose metabolism was enhanced by cold exposure and the glucose clamp. It was probable that blood glucose metabolism during the glucose clamp was influenced by cold exposure and feeding, but the combined effect of cold exposure and feeding was not significant.
Effects of Crotalaria and Sesbania aculeata green manures and N fertilizer on soil fertility and the productivity of sugarcane
Authors: BOKHTIAR S. M. , GAFUR M. A. , RAHMAN A. B. M. M.
Published: August 2003

The effects of green manuring with dhaincha (Sesbania aculeata) and sunhemp (Crotalaria juncea) in combination with four levels of urea-N (0, 75, 150 and 225 kg N/ha) on the productivity of a subsequent sugarcane (Saccharum officinarum) crop and the fertility of the soil were examined. C. juncea contributed more nitrogen to the soils when ploughed down than S. aculeata (56·7 v. 40·0 kg N/ha). The green manures and the supplemented urea-N increased cane yield by 2 to 26% and 26 to 57%, respectively. The organic matter, total N, available P and S of the soil was only slightly increased by the incorporation of green manures.
Dietary effects on the composition of pig slurry and on the plant utilization of pig slurry nitrogen
Authors: SØRENSEN P. , FERNÁNDEZ J. A.
Published: August 2003

The composition of animal manure is influenced by the diet fed. Efforts are made to decrease nitrogen emission from pig production by optimizing diet composition. This normally results in a lower proportion of N excreted in urine relative to faeces, and may also influence the turnover and utilization of manure N after field application. The effects of pig feed composition on the excretion of urinary and faecal N, on the dynamics of manure N in soil and on the potential utilization of manure N in the field was studied. Growing pigs and sows were fed 12 different diets with variable contents of fibre and protein (with or without synthetic amino acids). Slurries consisting of a mixture of faeces and urine were stored according to common agricultural practice in Northern Europe. The plant availability of N in the resultant slurries originating from animals fed known diets was tested in small field plots with barley, under conditions with minimal N losses. Separate plots were fertilized with increasing amounts of mineral N. Nitrogen uptake in barley was determined and the utilization of slurry N was compared with that of mineral fertilizer N. The net release of mineral N and C from the slurries in soil was also measured in a parallel incubation study.

The mineral fertilizer equivalent of pig slurry N was 72–100% and significantly influenced by feed fibre composition, but not significantly influenced by the protein content. There was a significant positive correlation between enzyme-digestible organic matter in the pig diet (measurement used for feed evaluation) and the plant availability of pig slurry N (R2=0·90). The ammonium content of stored pig slurry could not be used for prediction of the N availability since the net mineralization of pig slurry N was variable, but there was a significant negative correlation between the pig slurry C/N ratio and the plant availability of slurry N (R2=0·86).

Increased dietary concentration of fermentable structural carbohydrates (e.g. by including sugar beet pulp in the diet) reduces the excretion of N in urine without affecting the availability of slurry total N, whereas an increased concentration of dietary fibre with a low fermentability (straw) results in less urinary N, but also a lower plant availability of slurry N.
Association of linseed characters and its variability in different environments
Authors: ADUGNA W. , LABUSCHAGNE M. T.
Published: August 2003

Associations of characters were studied in linseed using data of 60 accessions evaluated in a randomized complete block design with three replications under glasshouse and field conditions during 2000 and 2001. The main objectives were to determine the magnitude of correlations between yield and its components under variable environments, and identify stable and major yield attributes that could support further improvements of linseed productivity. The degree of character association varied considerably across years and locations, due mainly to climatic factors (e.g. temperature, moisture levels, etc.) and disease incidences. However, seed yield per plot was significantly (P<0·01) and positively associated with seed yield per plant, 1000 seed weight and bolls per plant across environments. These three yield attributes were also strongly and positively correlated with plant height, branches per plant, days to flowering and maturity. Oil yield was significantly and positively associated with polyunsaturated (linoleic and linolenic) fatty acids, whereas it was negatively correlated with saturated (palmitic and stearic) fatty acids. Oil yield also had a weak positive relation with monounsaturated oleic acid. The quality of linseed oil, which is dependent on the levels of these fatty acids, can be influenced by the correlated responses of these variables in reaction to different environmental factors. Thus, knowledge on the causes and effects of these correlated responses are necessary to undertake sound and effective selection programmes.
Effect of two opposing changes in photoperiod upon age at first egg in layer-hybrid pullets
Authors: LEWIS P. D. , MORRIS T. R. , PERRY G. C.
Published: August 2003

An experiment was designed to test the response of growing pullets to two changes in photoperiod (an increase from 8 to 14 h followed 5 weeks later by the reverse change, or a decrease from 14 to 8 h followed by an increase). The first change was made either at 35 days or at 56 days of age, to test the influence of age on the responses observed. Control groups were kept on constant 8-h and constant 14-h photoperiods and the responses to appropriate single changes were also tested. Mean age at first egg varied from 111 days for birds given a single increment at 56 days to 166 days for pullets given an increase in photoperiod at 35 days followed by a reduction at 70 days. Responses to the single changes confirmed earlier reports that sensitivity to change in photoperiod varies with age in a manner that is quantitatively predictable. Responses to the double changes could be explained by postulating that the initial change altered the ‘physiological age’ of the bird to an extent that was also quantitatively predictable. An early increase in photoperiod advances sexual development and makes the bird more sensitive to a subsequent decrease than would be expected by reference to its chronological age. An early decrease in photoperiod delays sexual development, which can have the effect of making the bird more or less sensitive to a subsequent increase since, in layer-strain pullets, sensitivity to an increment in photoperiod normally increases up to about 9 weeks of age but decreases thereafter. Mean age at first egg predicted using these concepts was very highly correlated with observed age at first egg. The results provide a rational basis for constructing a model to predict age at first egg for any combination of increases and decreases in photoperiod applied to growing pullets.
Influences of cultivar, cultivation year and fertilizer rate on amount of protein groups and amount and size distribution of mono- and polymeric proteins in wheat
Authors: JOHANSSON E. , PRIETO-LINDE M. L. , SVENSSON G. , JÖNSSON J. Ö.
Published: August 2003

Influences of cultivar and environment, i.e. cultivation year and fertilizer rate, on amount of protein groups and amount and size distribution of mono- and polymeric proteins, were investigated in four sets of wheat (Triticum aestivum L.). The cultivars were chosen in order to obtain a high range of variation in protein concentration and gluten strength. Environmental influences on protein concentration and gluten strength were investigated, as well as relations between variation in protein concentration and gluten strength and variation in protein groups and amount and size distribution of mono- and polymeric proteins.

The results showed that cultivar and environmental influences giving rise to variation in protein concentration also gave rise to variation in most of the investigated protein components. Protein concentration was significantly positively correlated to the total amounts of glutenins and gliadins and amounts of most mono- and polymeric proteins. However, the correlation with the amount of gliadins and sodium dodecyl sulphate (SDS)-soluble mono- and polymeric proteins were often higher than the correlation to the glutenins and the SDS-insoluble mono- and polymeric proteins. Cultivar influences giving rise to variation in gluten strength were found to influence the relation between SDS-soluble and -insoluble polymeric proteins, leading to a significant positive correlation between the gluten strength and the percentage of total unextractable polymeric protein (TUPP) in the total polymeric protein and large unextractable polymeric protein (LUPP) in the total large polymeric protein. Environmental variation in gluten strength was found to be significantly positively correlated to SDS-insoluble proteins and negatively correlated to SDS-soluble proteins. This also led to a significant positive correlation with the percentage of LUPP and/or TUPP.
Cluster and canonical variate analyses in multilocation trials of linseed
Authors: ADUGNA W. , LABUSCHAGNE M. T.
Published: August 2003

Multivariate cluster and canonical variate analyses were undertaken for 10 genotypes of linseed (Linum usitatissimum L.) that were tested in a four-times replicated randomized block design across 18 environments (six localities by 3 years) of Ethiopia. The main aims of this study were to determine the similarities and differences of the genotypes and their testing environments, and to compare applicability of the two statistical methods. Cluster analysis grouped the genotypes into five classes in accordance with their original sources. The six locations and 18 environments were stratified into four and seven clusters, respectively. Three sites (Bekoji, Kulumsa and Sinana) were separately stratified, while three other ones (Holetta, Asasa and Adet) showed closer similarity. Canonical variate analysis indicated that ‘D33C’ and ‘D24C’ were distinguished from the other genotypes by their high oil contents. ‘N10D’ and ‘Norlin’ had closer values and were thus preferred for their good seed yield and earliness. Days to flowering and maturity, oil contents and lodging per cent played major roles in discriminating the genotypes. Comparison of the two methods showed clearer differentiation by cluster analysis than canonical variate analysis. Canonical variate analysis also contributed information on how each variable discriminated the genotypes and their test environments. Thus, both methods complement each other in providing useful information for more efficient variety development programmes.
Breeding white clover for increased ability to compete with associated grasses
Authors: ANNICCHIARICO P.
Published: August 2003

Greater white clover (Trifolium repens L.) competitive ability can increase the forage quantity and quality of clover-grass mixed stand (MS) cropping. The present work assessed the relationship of clover competitive ability with morphophysiological traits, and the efficiency of direct and indirect selection procedures for increasing clover dry matter (DM) yield in MS. Some 165 large-leaved clover genotypes representative of Italian Ladino germplasm and 13 clover genotypes from an elite small-leaved population were clonally evaluated for one year in pure stand (PS) and in MS environment with Italian ryegrass (Lolium multiflorum Lam.) and tall fescue (Festuca arundinacea Schreb.) that reproduced the level of interspecific interference met by the clover over a multi-year crop cycle. Results for all genotypes and their subsets indicated that the level of leaf size variation among tested genotypes can affect the results. Wider variation decreased the relative importance of clover genotype×evaluation environment interaction, because competitive ability was mainly correlated with traits (longer petiole; larger leaflet) contributing to scale foraging in MS and yielding ability in PS. Competitive ability tended to be more closely associated with other traits (high stolon density; plasticity of petiole elongation) contributing to foraging ability, i.e. the ability to make fine-scale exploitation of light and nutrients in MS, within germplasm of similar leaf size. Leaf size variation also affected the relative efficiency of selection procedures estimated from expected responses to clonal selection. Results for all entries indicated direct selection in MS as 23% more efficient than selection in PS based on a selection index including three traits associated with competitive ability (petiole length; stolon density; leaflet size) which, in turn, was predicted to be 16% more effective than selection in PS based on DM yield. The advantage in relative efficiency of direct selection was almost doubled when considering only large-leaved germplasm. In a second experiment, evaluating 16 clover half-sib progenies of elite large-leaved parents for 2 years in PS and in MS with Italian ryegrass, tall fescue and cocksfoot (Dactylis glomerata L.), direct selection was estimated to be over three-fold and 68% more effective than indirect selection in PS based on DM yield and the selection index, respectively, based on expected responses to genotypic selection. The selection index may improve the efficiency of preliminary, PS-based clonal selection. Further evaluation of elite genotypes and/or their polycross progenies in MS is recommended for final selection.
Fiscal Straitjacket: The Politics of Macroeconomic Reform in Brazil, 1995–2002
Authors: SAMUELS DAVID
Published: August 2003

Brazil's President Fernando Henrique Cardoso will be remembered for his administration's accomplishments as well as the problems his government left unresolved. On the one hand, fiscal policy represents one of Cardoso's success stories: the Plano Real curbed inflation, established economic stability, and enabled the central government to rein in subnational governments' out-of-control spending patterns, which had been a key source of macroeconomic instability. However, the question remains whether Brazil can truly escape from the political and economic consequences of past fiscal profligacy. Despite many successes, Cardoso's own policies have created additional obstacles that future administrations will necessarily confront, in particular a dramatic increase in Brazil's internal debt. Observers of Brazil should count both sides of the accounting ledger when evaluating the Cardoso administration. Much has been gained, but the costs of those gains must be recognised and the impact of those gains on the range of policy choice available to future administrations understood. This article explores the factors that contributed to Brazil's macroeconomic difficulties prior to 1995, and then explores how the Plano Real provided the Cardoso administration with leverage to constrain the capacity of subnational actors to affect Brazil's economy. Subsequently, however, the paper describes how the Cardoso administration's policies have created Brazil's current ‘fiscal straitjacket’, and concludes by discussing how Cardoso's policies will constrain future administrations.
The Politics of Public Health: Smallpox in Chile
Authors: SATER WILLIAM F.
Published: August 2003

Beset by a variety of diseases, numerous public health measures were advocated in late-nineteenth century Chile. Among these was the call for mandatory vaccination. Although the state supported programmes to encourage vaccination, these were voluntary. In the early 1880s, however, some legislators argued that compulsory vaccination would substantially reduce the death rate. Surprisingly, the legislature rejected this proposal. Claiming that the vaccination legislation would enhance the power of the executive branch, the congressmen soundly rejected an apolitical proposal designed to improve public health.
Simón Bolívar and the Spectre of Pardocracia: José Padilla in Post-Independence Cartagena
Authors: HELG ALINE
Published: August 2003

This article examines the tensions between the Gran Colombian republican constitution of 1821 and Simón Bolívar's fear of a mulatto takeover. It focuses on Cartagena in the 1820s, where the mulatto general José Padilla challenged the socio-racial hierarchy and accepted notions of equality of the city, heading a three-day coup in 1828 against Bolívar's attempt to impose a new authoritarian constitution. Padilla failed to rally the mostly African-derived population of Cartagena behind the republican views of Francisco de Paula Santander and was promptly executed. Using the protagonists' correspondence, manifestos, criminal investigations, consular reports and censuses, the article analyses the factors in the city's demography, political leadership and culture, and in the composition of its military forces, that explain Padilla's failure. It highlights the role played by race and by Bolívar's views of mulattos in the process.
Tax Reforms and Tax Compliance: The Divergent Paths of Chile and Argentina
Authors: BERGMAN MARCELO S.
Published: August 2003

This article compares the effects of tax reform on tax compliance in Argentina and Chile. After constructing three different comparative indexes of tax compliance, it proposes a comprehensive approach, which includes political, economic and sociological explanations to address the different behaviour of taxpayers in each country. It concludes that Chile was able to enhance better tax compliance because it has implemented a permanent, stable and rational policy that allowed for the development of an effective tax administration – a process never fully accomplished in Argentina. Tax reforms may enhance better compliance only after they reverse the entrenched evasion strategies of the taxpayers.
Implicit Costs of Empire: Bureaucratic Corruption in Nineteenth-Century Cuba
Authors: QUIROZ ALFONSO W.
Published: August 2003

Cycles of bureaucratic corruption in nineteenth-century Cuba evolved according to institutional conditions shaped by interest groups, financial needs, imperatives of colonial governance, and internal conflicts and war. Corrupt gain inimical to general public interest was not a consequence of cultural constants, but of unreconstructed institutional flaws and weaknesses. The risks of engaging in bureaucratic corruption diminished under the systematic condoning of administrative faults, collusive allowance of illegal slave trafficking, and a code of illegal rewards expected by loyalist officials opposing colonial reform. Despite some few anti-corruption initiatives, the prosecution and punishment of corrupt officials was lax. The implicit, yet significant, financial, institutional and political costs of corruption contributed to the demise of Spanish imperial dominion over Cuba and left a damaging burden and legacy for Cuban civil society.
The Insertion of Rural Areas into Global Markets: A Comparison of Garment Production in Yucatán and La Laguna, Mexico
Authors: VAN DOOREN ROBINE , ZÁRATE-HOYOS GERMÁN A.
Published: August 2003

This article examines the recent trends in extending the global garment production process to the rural areas of the Laguna region and the Yucatán Peninsula in Mexico. As these remote regions are incorporated into global markets, several similar patterns and rationale are found behind the policies followed by state governments to attract these types of enterprises. The implications for regional economic development are also discussed.
Heat, salt and tracer transport in the Plymouth Sound coastal region: a 3-D modelling study
Authors: Siddorn J.R. , Allen J.I. , Uncles R.J.
Published: August 2003

A 3-D hydrodynamic model of the circulation, salinity and temperature within the embayment of Plymouth Sound, UK and its surrounding English Channel waters has been implemented. Thorough validation of the model shows that the main hydrographic features of the region, as characterized by these variables, are reproduced. The general flow characteristics, and the resultant distribution of freshwater from the main riverine source (the River Tamar), are described. The potential fate of contaminant releases within Plymouth Sound is investigated. Whitsand Bay, located south-west of Plymouth Sound, is shown to be a likely recipient for a proportion of these contaminants, irrespective of where in the Sound the release occurs, and as such is considered to be vulnerable to pollution events originating there.
Comparison of near seabed currents at two locations in the Porcupine Sea Bight—implications for benthic fauna
Authors: White Martin
Published: August 2003

Recent measurements of benthic currents, within the depth range where the highest abundance of the hexactinellid sponge Pheronema carpenteri are found, have been made and compared to historical data for the northern Porcupine Sea Bight region where no Pheronema have been recorded. Bottom currents at a location where Pheronema have not been recorded are much higher than a location where the sponges have previously been sampled. The measurements provide some evidence to support the hypothesis that the sponges favour a location adjacent to regions where enhanced bottom tidal currents are found, but currents experienced by the sponges themselves are much reduced.
Species distribution and habitat exploitation of fauna associated with kelp (Laminaria Hyperborea) along the Norwegian Coast
Authors: Christie Hartvig , Jørgensen Nina Mari , Norderhaug Kjell Magnus , Waage-Nielsen Elisabeth
Published: August 2003

Fauna associated with the common kelp along the Norwegian coast, Laminaria hyperborea, was sampled at four sites covering 1000 km of coastline. Exploitation of the kelp habitat by the fauna, and the ways in which habitat size and seasonal variations affect the kelp fauna community were analysed. The study focused on mobile macrofauna, of which 238 species were found on 56 kelps sampled, with an average density of almost 8000 individuals per kelp. Amphipods and gastropods were the most diverse and abundant fauna groups. The species composition was different on the lamina, stipe (with epiphytic algae) and holdfast. A similar pattern of epiphyte- and holdfast-fauna composition was found for all regions. Lowest diversity and abundance were found on the lamina, and highest diversity in the holdfast. Highest abundance was found on the stipe in summer, but there were large variations between sites and seasons, from a few individuals to more than 80 000 animals per stipe. Neither seasonal changes nor variation in habitat volume affected the number of species significantly, but abundance was significantly related to season and habitat volume. These variations were most pronounced for stipe fauna. Laminaria hyperborea offers a heterogeneous habitat exploited by a diverse and abundant invertebrate community, its abundance depending on local and regional variations in kelp size.
Effects of wave exposure on the proportion of gametophytes and tetrasporophytes of Mazzaella oregona (Rhodophyta: Gigartinales) from Pacific Canada
Authors: Mudge Benita , Scrosati Ricardo
Published: August 2003

The proportion of life history phases in red seaweeds is an important descriptor of population structure. This paper describes the relative abundance of gametophytes and tetrasporophytes of Mazzaella oregona (Rhodophyta: Gigartinales; formerly M. heterocarpa), focusing particularly on the effects of wave exposure on the proportion of both life history phases. In two different rocky points in Barkley Sound (Pacific Canada), gametophytes were, in proportion to tetrasporophytes, relatively more abundant under low wave exposure than under high wave exposure in July 2002, during the period of highest abundance for this species. The inverse relationship between the G:T ratio and the degree of wave exposure also occurs for local M. splendens, but not for local M. parksii. Differences in frond size and population density between these three sympatric species are related to the effects of wave exposure on their G:T ratio.
The effect of wave exposure on the foraminifera of Gelidium pristoides
Authors: Toefy R. , McMillan I.K. , Gibbons M.J.
Published: August 2003

The foraminifera of Gelidium pristoides were examined on exposed and sheltered shores around False Bay, South Africa, during the summer and winter of 1998/1999. Twenty-five species were recognized, seven are potentially new. Multivariate statistics indicated that the assemblages on plants from exposed shores were distinct from those on sheltered shores, and two species of foraminifera were confined to exposed shores. Plant size and the quantity of trapped sediment were positively correlated, and plants on exposed shores were significantly bigger than those on sheltered shores. Plant size and sediment weight were linked to assemblage diversity and abundance; assemblages on exposed shores were generally more diverse and abundant than those of sheltered shores. Different species dominated on the two shore types, and larger foraminifera tended to be more common on exposed shores.
First record of Caulerpa racemosa (Caulerpales: Chlorophyta) in the Adriatic Sea
Authors: Žuljević Ante , Antolić Boris , Onofri Vlado
Published: August 2003

The present short note reports the first occurrence of the Caulerpa racemosa ‘invasive variety’ in the Adriatic sea.
Recovery of substrates and macro-benthos after fishing trials with a new Portuguese clam dredge
Authors: Gaspar M.B. , Santos M.N. , Leitão F. , Chícharo L. , Chícharo A. , Monteiro C.C.
Published: August 2003

The effect of dredging on bottom structure was assessed, to estimate the damage inflicted on the benthic macrofauna left on the dredge path and to evaluate aggregations of scavengers within the track. Sediment suspended during dredging rapidly resettled both on sand and sandy-mud bottoms. Dredge tracks were deeper on sandy-mud sediments and persisted longer than in sandy sediments. The disappearance of tracks in both sediment types depended both on current strength and wave action. Damage and mortality induced by dredging on the macrobenthic animals left on the dredge path was relatively low. Post-fishing SCUBA diver observations showed that damaged animals left on the dredge path rapidly attracted scavengers, mainly Ophiura albida. Immediately after the tow ophiuroids reached densities eight times greater in the track region than in the background. However, they dispersed again rapidly because only few damaged fauna were available on the dredge tracks. Undamaged or slightly damaged shellfish started to rebury immediately after escaping from the dredge.
Changes in benthic community structure due to clam dredging on the Algarve coast and the importance of seasonal analysis
Authors: Alves Filipe , Chícharo Luís , Nogueira António , Regala João
Published: August 2003

Patterns in community structure of meiofauna and macrofauna in relation to Portuguese clam dredging were compared during a 2-y-period off Lagos and Vilamoura, south Portugal. SCUBA divers randomly sampled corer and quadrat samples before and immediately after simulating commercial dredge fishery. Univariate measures (abundance, number of taxa, evenness, diversity and biomass) and multivariate analyses (Cluster, MDS and SIMPER) revealed changes in the meio- and macro-benthic community structure caused by dredge disturbance (short-term effects), with a general decrease in all measures. Macrofauna were found to be more sensitive to dredge disturbance, and aggressive predatory behaviour was observed after disturbance in the continuously dredged area. Nevertheless, higher significant natural changes were found between seasonal periods, indicating that dredging may only cause a small-scale and short-term impact.
Limited mid-water scavenging of trawl discards
Authors: Erzini Karim , Monteiro Pedro , Araújo Artur , Castro Margarida
Published: August 2003

The consumption or scavenging of fish in the water column at depths from 75 to 275 m in Algarve (southern Portugal) trawl fishing grounds was evaluated. Longlines were used to suspend baits throughout the water column while electric fishing reels were used to simulate sinking discards. Eighteen species were caught, with higher catch rates near the surface than near the bottom. However, scavenging rates were generally highest near the bottom and lowest in the middle of the water column. At depths less than 100 m the majority or all the fish were scavenged throughout the water column, while at depths greater than 200 m most of the fish were untouched after periods of time greater than would be required for them to sink to the bottom. Since other studies have shown that most small fish discards are scavenged at the surface by sea birds and most of the discarded species that sink are either too large or not attractive to pelagic predators, these results suggest that mid-water scavenging of trawl discards in deep water is relatively unimportant.
New records of marine invertebrates from São Tomé Island (Gulf of Guinea)
Authors: Wirtz Peter
Published: August 2003

The anthozoan Actinostella flosculifera, the polychaete Lygdamis wirtzi, the decapods Gnathophyllum americanum and Periclimenes platalea, the phoronid Phoronis australis, the holothurian Euapta lappa, and the asteroid Goniaster tesselatus are recorded from São Tomé Island for the first time. The marine zoogeography of the area is briefly discussed, with special emphasis on the high proportion of amphi-Atlantic species.
Ecological features of Syllidae (Polychaeta) from shallow-water benthic environments of the Aegean Sea, eastern Mediterranean
Authors: Ertan Çinar Melih
Published: August 2003

Ecological features of Syllidae inhabiting shallow-water benthic habitats of the Aegean Sea were analysed by utilizing some univariate and multivariate statistical methods. A total of 121 benthic materials collected in a variety of substrata and depths (0–76 m) contained 90 syllid species belonging to the four subfamilies Autolytinae, Exogoninae, Eusyllinae and Syllinae. Among the subfamilies, Syllinae were characterized by a high number of species and Exogoninae by a high number of individuals. Although dominant species varied according to substrata, the two species, Grubeosyllis clavata and Syllis prolifera, accounted for up to 51% of the total syllid populations in the area. Among the biotopes sampled, Posidonia oceanica seems to be particularly suitable for the settlement of syllid species, whereas bare sand and mud harbour only a few species, mainly Exogoninae. The cluster- and ordination analyses detected species associations on soft and hard substrata, and suggested that syllid assemblages are strongly affected by the habitat structure. Species compositions associated with algae appear to be related to complexity of the algae, so that the ones with relatively small thalli, such as Padina pavonica and Halopteris spp., constituted a group with a high similarity-index value. Samples of Posidonia oceanica collected at different stations showed a high consistency in terms of syllid assemblages.
Revision of Spinosphaera and establishment of the new genus Hutchingsiella (Polychaeta: Terebellidae: Terebellinae)
Authors: Londoño-Mesa Mario H.
Published: August 2003

Spinosphaera is a Terebellinae genus with three species described from the Pacific Ocean, S. pacifica from Japan, S. oculata from California, and the doubtful S. cowarrie from Western Australia. The genus is presently unknown in the Grand Caribbean region. Spinosphaera is characterized by the absence of branchiae, by the great number of notopodia, and the presence of a special type of notochaetae, called ‘Spinosphaera-chaeta’. These chaetae have three different regions: distal denticulate blade, neck separating the former from a middle swollen spinous region, and a proximal smooth or bilimbate region; two sizes are present. The genus is redefined, with redescription of all species currently known. Three new species are described here, two from the Mexican Caribbean coast, S. hutchingsae and S. carrerai, and one from California, S. harrisae. A taxonomic key to identify all species is given. Hutchingsiella gen. nov. is proposed for S. cowarrie; it differs from Spinosphaera in having notochaeta from segment 5 and neurochaetae from segment 6, and for lacking Spinosphaera chaeta.
Articulatia, a new genus of Terebellinae (Polychaeta: Terebellidae) living in Brazilian corals
Authors: de M. Nogueira João M. , Hutchings Pat A. , Amaral A. Cecília Z.
Published: August 2003

A new genus of terebellid polychaetes is described, from material collected from living colonies of a stony coral (Mussismilia hispida) in the State of São Paulo, south-eastern Brazil. Articulatia is characterized by possessing notopodia from segment 5, neuropodia from segment 5 or 6 with double rows of uncini from segment 7 until near pygidium. Up to segment ten, notopodia with bilimbate capillaries; from segment 11 onwards two types of notochaetae are present, articulated chaetae, due to a deep cut at the sulcus of the third tooth, as well as capillary chaetae, both types with serrated blades. The presence of deep-cut chaetae is unique among all previously described terebellomorph polychaetes. This new genus is compared with other terebelline genera, and the phylogenetic analysis previously performed for the group is rerun, in order to determine the position of Articulatia within the subfamily. The type species of the new genus, A. aberrans, is also new to science and herein described.
A temporarily planktonic terebellid polychaete
Authors: Westheide Wilfried
Published: August 2003

Mass swarming of a basically sessile terebellid polychaete was observed in the free water column off the south-west coast of Madagascar. Specimens are described and tentatively identified as Loimiamedusa (Savigny, 1818). Swimming behaviour is documented and the phenomenon is discussed as a flight reaction to an environmental disturbance event.
Records and distribution of Syscenus infelix in the deep Mediterranean (Crustacea: Isopoda: Aegidae)
Authors: Kensley Brian , Cartes Joan E.
Published: August 2003

The parasitic isopod Syscenusinfelix is recorded from the Mediterranean, based on 19 specimens from a depth range of 375–2071 m. The first ovigerous female of the species is also recorded. Patterns of possible parasitism were suggested based on the depth distribution of S. infelix, and their possible host macrourid fish below 900 m depth in the Catalano-Balearic basin.
First record of Kentrocapros rosapinto (Tetraodontiformes: Ostraciidae) from Vema Seamount (south-east Atlantic)
Authors: Armesto A. , Bañón R. , Garabana D. , Durán P.
Published: August 2003

The capture of a specimen of Kentrocapros rosapinto at Vema Seamount in the south-east Atlantic Ocean is reported as the first record of this species in the Atlantic Ocean. This species was previously known only from the western Indian Ocean.
Influence of estuarine zonation on exploited shrimp populations in a Mexican biosphere reserve: a feature for management and conservation
Authors: Pérez-Castañeda Roberto , Defeo Omar
Published: August 2003

The influence of estuarine zonation in a coastal lagoon on the population variability of exploited penaeid shrimps Farfantepenaeus aztecus, F. brasiliensis, F. duorarum and F. notialis (Crustacea: Decapoda) at the ‘Ría Celestún’ Biosphere Reserve, Mexico, was evaluated. Monthly samples of shrimp and environmental factors were taken throughout 1997 and 1998 in three zones (seaward, middle, inner) of Celestún lagoon. Salinity and aquatic vegetation biomass exhibited a clear spatial heterogeneity of habitat. A total of 20,757 shrimps were collected mainly at the seaward zone, which registered the highest salinity and aquatic vegetation biomass. This revealed the critical contribution of the seaward zone as the most suitable habitat for shrimp populations, mainly for recruits. Results support the implementation of spatially-explicit management strategies, such as the closure of the seaward zone for fishing activities. The significant relationship between the recruits and the subsequent abundance of shrimp in the lagoon also support this operational measure.
Dikwa andresi, a new amphipod crustacean (Dikwidae) from the Scotia Arc
Authors: Lörz Anne-Nina , Coleman Charles Oliver
Published: August 2003

The new amphipod crustacean species Dikwa andresi from the Scotia Arc is described in detail. This is the first record of the family Dikwidae in the Southern Ocean. The white species was caught in water depth of 270–290 metres during the Antarctic autumn, living on the red hydrocoral (Hydrozoa) Errinopsis reticulum. It has a carinate pereon and pleon, no eyes and the head is telescoped into the first pereon segment. The first gnathopod is propodochelate, the second gnathopod is simple. The only known species of the family is Dikwa acrania from southern Africa. The new species mainly differs from D. acrania in having dorsal processes on all pereonites and the first coxa being twice as long as the second. An intraspecific variation of the shape of the telson was observed.
Biological aspects of Mithraculus forceps (Brachyura: Mithracidae) from Anchieta Island, Ubatuba, Brazil
Authors: Mantelatto Fernando L.M. , Faria Fabiola C.R. , Garcia Renata B.
Published: August 2003

The population structure of Mithraculus forceps sampled monthly on Anchieta Island from January 1999 to December 2000 was studied. A total of 68 individuals were collected by SCUBA diving. The population presented normal and unimodal distribution, and the total sex ratio was 1·4:1·0 in favour of males. Ovigerous females were captured during all seasons. The pattern observed for the M. forceps population in Anchieta Island indicated the strategy favoured by environmental characteristics of the island and by coexistence with other decapod crustaceans in the studied area.
Parasitic copepods in the sea hare Dolabrifera brazieri (Gastropoda: Opisthobranchia: Anaspidea)
Authors: Clarke Cathryn L. , Klussmann-Kolb Annette
Published: August 2003

The parasitic copepod, Alimeda orientalis, is recorded from the gill of the sea hare, Dolabrifera brazieri (Gastropoda: Opisthobranchia: Anaspidea). Ten specimens of D. brazieri from a population on the coast of New South Wales, Australia were examined for the incidence of parasitism. Histological techniques and scanning electron microscopy were utilized to determine the feeding mode of A. orientalis and its effect on the host. Alimeda orientalis is a tissue feeder on the gill tissue, and damage caused by feeding and attachment is minimal.