Relative balance of the cost and benefit associated with carnivory in the tropical Utricularia foliosa

Investment by bladderwort (Utricularia foliosa) in carnivory, in terms of total C and N of bladders per leaf, was estimated in places with different nutrient concentrations from the Yahuarcaca Creek in the Colombian Amazon. The aims were to determine whether nutrient limiting conditions stimulate the investment in carnivory, and the relative balance between C and N invested in carnivory versus C and N obtained from prey. There were no significant differences either for phosphate (PO₄³⁻) concentration or for ammonia (NH₄⁺) concentration among five sampling areas, along approximately 5 km long stretch of the creek, with a pooled mean ± S.D. of 0.19 ± 0.06 and 8.6 ± 3.0 μM, respectively. However, there were significant differences in the nitrate (NO₃⁻) concentration ranging from 0.6 to 2.5 μM. Total C and N of bladders per leaf increased with decreasing NO₃⁻. This corroborates the hypotheses that the carnivorous plant U. foliosa optimises its investment in carnivory according to nutrient availability in the water, and that N is a limiting factor that stimulates the investment in carnivory. The numbers of prey per bladder were also higher under NO₃⁻ limitation, thus enhancing the input of nutrients toward the plant through the bladders. The ratio of total C of prey captured/total C invested in bladders was always lower than 1. However, the efficiency of N was higher since when NO₃⁻ concentration was lower than 1 μM, the ratio of total N of prey captured/total N invested in bladders ranged between 0.97 and 1.67.     

Effects of zooplankton and conductivity on tropical Utricularia foliosa investment in carnivory

Investment by bladderwort (Utricularia foliosa) in carnivory was estimated in lakes from the Colombian and Brazilian Amazon with different dissolved mineral nutrients and prey availability. As zooplankton abundance in the lake decreased, an increase in the number of bladders per leaf and in the mean bladder size was observed. However, this investment increment in carnivory diminished as the overall availability of dissolved ions in the lake increased. Our results show that carnivorous plants U. foliosa optimise their investment in carnivory, changing bladder number and bladder size according to zooplankton abundance and conductivity.     

Ecological energetics of Chaoborus in a tropical lake

Summary Ecological energetics of Chaoborus brasiliensis from Lake Valencia, Venezuela, were studied between February 1979 and February 1980. Direct measurements were made of the respiration rate, assimilation efficiency, and growth rate of all 4 larval instars and of the pupae. For the larval stages, respiration increased as the 0.67 power of body mass. Respiration rates of the larvae, when corrected for body size and temperature, were extraordinarily low by comparison with the rates for most aquatic insects. The respiration rates of pupae were 3 times as high as those of larvae the same size. Assimilation rates increased significantly with body size for the larvae and differed slightly but significantly among food types. Assimilation efficiencies fell within the expected range for carnivores. The growth efficiencies were exceptionally high for instars II-IV by comparison with other small aquatic organisms. High growth efficiency for Chaoborus brasiliensis, and possibly for Chaoborus generally, is explained by a very low maintenance cost and may be a significant explanation for the wide distribution and high degree of ecological success in this primary carnivore of plankton communities.     

Costs of carnivory in the common bladderwort,Utricularia macrorhiza

Summary Carnivorous plants are usually restricted to nutrient-poor environments, suggesting that there is a cost to caputuring animals that is offset by the benefits of carnivory only under unusual circumstances. One such cost could involve a reduced photosynthetic capacity associated with the growth and maintenance of prey-capture organs. This hypothesis is tested using the common bladderwort, Utricularia macrohiza, which bears numerous distinct prey-capture bladders. Measurements of the photosynthetic and respiration rates of leaves and bladders were incorporated into growth models to estimate the growth rates of plants with and without bladders. Comparisons were made in three lakes which differed in nutrient status and in which plants exhibited marked differences in their densities of prey-capture bladders. Overall, photosynthetic rates for leaves were approximately twice those for bladders while respiration rates did not differ significantly between tissues. Calculations incorporating these values indicate that plants producing both bladders and leaves would grow to as little as 21% or as much as 83% of plants that produced leaves alone. Comparisons among lakes led to the rejection of the hypothesis that plants from some lakes are able to produce more bladders per leaf because bladders differ in their photosynthetic productivity.     

Evolution of carnivory in Lentibulariaceae and the Lamiales

As a basis for analysing the evolution of the carnivorous syndrome in Lentibulariaceae (Lamiales), phylogenetic reconstructions were conducted based on coding and non-coding chloroplast DNA (matK gene and flanking trnK intron sequences, totalling about 2.4 kb). A dense taxon sampling including all other major lineages of Lamiales was needed since the closest relatives of Lentibulariaceae and the position of "proto-carnivores" were unknown. Tree inference using maximum parsimony, maximum likelihood, and Bayesian approaches resulted in fully congruent topologies within Lentibulariaceae, whereas relationships among the different lineages of Lamiales were only congruent between likelihood and Bayesian optimizations. Lentibulariaceae and their three genera (Pinguicula, Genlisea, and Utricularia) are monophyletic, with Pinguicula being sister to a Genlisea-Utricularia clade. Likelihood and Bayesian trees converge on Bignoniaceae as sister to Lentibulariaceae, albeit lacking good support. The "proto-carnivores" (Byblidaceae, Martyniaceae) are found in different positions among other Lamiales but not as sister to the carnivorous Lentibulariaceae, which is also supported by Khishino-Hasegawa tests. This implies that carnivory and its preliminary stages ("proto-carnivores") independently evolved more than once among Lamiales. Ancestral states of structural characters connected to the carnivorous syndrome are reconstructed using the molecular tree, and a hypothesis on the evolutionary pathway of the carnivorous syndrome in Lentibulariaceae is presented. Extreme DNA mutational rates found in Utricularia and Genlisea are shown to correspond to their unusual nutritional specialization, thereby hinting at a marked degree of carnivory in these two genera.     

不同作物田烟粉虱发生的时空动态

2008～2009年连续2年系统调查了番茄、茄子、棉花、大豆、玉米等寄主植物上烟粉虱种群发生的时间与空间动态。结果表明：不同寄主植物上的烟粉虱成虫及其伪蛹数量有显著性差异,其密度大小依次为：茄子>棉花>番茄>大豆>玉米。其中,在玉米上除了发现极少量的成虫逗留外,没有发现烟粉虱的卵及若虫。在发生的时间序列上,烟粉虱成虫及伪蛹的数量呈现为先逐渐上升后又下降的变化过程,发生高峰期集中在8月5日到8月31日,9月初以后烟粉虱数量慢慢减少。在空间分布上,表现为烟粉虱成虫喜食寄主的上部叶片。统计分析显示,寄主对烟粉虱成虫和伪蛹的数量的影响极显著,而年份对其数量的影响没有显著差异。由此得出的烟粉虱发生和达到高峰的时间,可为烟粉虱预测预报和区域性综合治理提供重要理论依据。     

Venus flytrap biomechanics: Forces in the Dionaea muscipula trap

Biomechanics of morphing structures in the Venus flytrap has attracted the attention of scientists during the last 140 years. The trap closes in a tenth of a second if a prey touches a trigger hair twice. The driving force of the closing process is most likely due to the elastic curvature energy stored and locked in the leaves, which is caused by a pressure differential between the upper and lower layers of the leaf. The trap strikes, holds and compresses the prey. We have developed new methods for measuring all these forces involved in the hunting cycle. We made precise calibration of the piezoelectric sensor and performed direct measurements of the average impact force of the trap closing using a high speed video camera for the determination of time constants. The new equation for the average impact force was derived. The impact average force between rims of two lobes in the Venus flytrap was found equal to 149 mN and the corresponding pressure between the rims was about 41 kPa. Direct measurements of the constriction force in the trap of Dionaea muscipula was performed during gelatin digestion. This force increases in the process of digestion from zero to 450 mN with maximal constriction pressure created by the lobes reaching to 9 kPa. The insects and different small prey have little chance to escape after the snap of the trap. The prey would need to overpower the “escaping” force which is very strong and can reach up to 4 N.     

Trap gland morphology and its systematic implications in Taiwan Utricularia (Lentibulariaceae)

The highly specialized trap glands of carnivorous plant are responsible for the digestion and absorption of the prey; however, there are few studies on their systematics and evolution. In this study, the gland morphology of six carnivorous plant species of the genus Utricularia (Lentibulariaceae) in Taiwan, including U. aurea Lour., U. australis R. Br., U. bifida L., U. caerulea L., U. gibba L. and U. striatula Sm., was examined with a scanning electron microscope. The glands on both the outer and inner surfaces of the traps were examined. We found that the external glands had little diagnostic value, but the internal glands could be used in the identification of Taiwan species. Evolutionary trends of gland characteristics are discussed, analyzing morphology of the internal glands, based on previous work. A new hypothesis for the evolution of internal gland structure in Utricularia is also proposed.     

Effects of light and microcrustacean prey on growth and investment in carnivory in Utricularia vulgaris

SUMMARY 1. In a 5-week enclosure experiment, we studied the effects of light (ambient light, low light) and prey availability (no prey, prey added) on growth and investment in carnivory in Utricularia vulgaris .
2. Investment in carnivory, measured as the proportion of biomass allocated to bladders, was strongly affected by our manipulations of light intensity and prey density. In the treatment with high prey density the light reduction decreased the investment in bladders from 25% to zero. The effect of prey density on investment in bladders was negative. Because prey addition increased the concentration of nutrients, especially phosphorus, we propose that the effect of the prey treatment on investment reflected altered nutrient concentrations.
3. Availability of prey increased growth and apical biomass of Utricularia . As Utricularia had very few bladders in some treatments we suggest that the effect was due to a combination of live prey trapped and increased nutrient availability from dead prey.
4. Abundance of periphyton on Utricularia and on the enclosure walls was highest in the treatments with high prey density where nutrient concentrations were highest. Thus we interpret the response of periphyton as primarily reflecting nutrient availability.     

The significance of carnivory for the fitness of Drosera in its natural habitat

Summary The effects on Drosera intermedia and D. rotundifolia of supplementary feeding with Drosophila melanogaster were studied in plants growing in their natural habitat. The artificial food supply was within the natural range of prey quantity. In both species supplementary feeding led to significantly higher dry weights of summer and winter plant, more leaves, more flowers, more seeds, and a larger trapping area. The dry weight of plants increased much more than the dry weight of prey added, indicating a fertilizing effect. Thus, animal food supply is an important limiting factor in the field. The essential component of the prey is probably its mineral content. There were significant differences between the two species of sundew. In D. rotundifolia the effect of feeding on dry weight was smaller and plants nerver showed axillary budding. However the effect on the percentage of blooming plants was more than twice as strong as in D. intermedia. Considering only the prey actually absorbed per unit of plant biomass, both species show about the same fertilizing effect. The number of fruits per unit of biomass was about twice as large in D. rotundifolia as in D. intermedia. The reasons for these differences are discussed in the light of niche segregation with respect to habitat and range of prey.     

Predation risk and the structure of freshwater zooplankton communities

Summary Many predators inflict substantial mortality on their prey. The prey respond to these selective pressures with changes in their spatial and temporal overlap with the predator (density risk responses), or with changes in their vulnerability to the predator (prey vulnerability responses). Here we develop a simple predation model that permits quantification of the basic response types of the prey in nature. We then test the hypothesis that prey response will be proportional to the intensity of the predation mortality relative to all other sources of mortality and decreased natality acting on the prey. A significant regression relationship is obtained for the prey vulnerability response but not for any of the density risk responses. The individual response values and regression statistics are used to interpret the relative importance of the different response types and to assess the predator's influence on prey community structure.Supported by Lehigh University Environmental Studies Center     

Temporal and spatial variation in an Australian tropical rainforest

Abstract This study describes the floristics and structure of a 0.95‐ha lowland tropical rainforest plot at the Australian Canopy Crane Research Facility at Cape Tribulation, Queensland. Five years of post‐cyclonic change in forest floristics and structure following the passage of Tropical Cyclone ‘Rona’ in February 1999 are examined. Local and regional variation in tropical rainforest is examined in comparison with other lowland plots established nearby and mid‐elevation plots located elsewhere in north Queensland at Eungella, Paluma and the Atherton Tablelands. These plots are placed in a broader Australasian context along with lowland rainforest plots at Baitabag and Oomsis, Papua New Guinea. The 2005 survey found 680 stems of 82 species ≥10 cm d.b.h. on the crane plot, an increase of 30.3% in stems and 16.4% of species in the 5 years since the previous survey. The most abundant families were Meliaceae, Euphorbiaceae, Lauraceae, Myrtaceae and Apocynaceae and the most abundant species were Cleistanthus myrianthus, Alstonia scholaris, Myristica insipida, Normanbya normanbyi and Rockinghamia angustifolia. Temporal floristic and structural variation suggests that the crane site remains in an active stage of post‐cyclonic recovery. Local spatial variability in floristics and structure at Cape Tribulation exceeded the variation exhibited by a single plot over a period of 5 years, despite the impact of Cyclone Rona. This finding suggests a high degree of temporal stability within this stand of rainforest despite frequent catastrophic disturbances. The rainforests of Cape Tribulation constitute a relatively unique floristic community when observed in an Australasian context. Variation in rainforest community composition across the region shows the importance of biogeographical connections, the impacts of local topography, environmental conditions and disturbance history.     

The significance of carnivory for the fitness of Drosera in its natural habitat

Summary A field study of two carnivorous plant species, Drosera intermedia and D. rotundifolia, was carried out in a small silting-up bog in Southern Bavaria (FR Germany). Various parameters of undisturbed individuals of both species were measured for a period of two years and subjected to a partial correlation analysis. The importance of prey as a limiting factor for various fitness parameters was confirmed for both species. Other factors may occasionally also be limiting, e.g. assimilation area and water supply. Benefits obtained from the prey are partly transferred to the next year via the winter bud. The importance of the relative demonstrated: Plants of D. rotundifolia showed higher fitness values in higher positions, those of D. intermedia in lower positions. Growth characteristics of both species tended to influence the height of their own position in a corresponding direction: D. intermedia downwards and D. rotundifolia upwards. In both species negative effects of intraspecific neighbourhood were evident, whereas interspecific effects were not detectable. Plants of D. intermedia tend to influence their neighbourhood situation by changing their position by rhizome-like stem growth. In D. intermedia the decision to reproduce by seeds or axillary buds seems to be made at least partially already in the year before. D. rotundifolia was only observed reproducing by seeds. In spite of different catching characteristics (plant shape, plant size, microhabitats, prey spectra), the general catching success, measured as prey biomass per plant biomass, was equal in both species of sundew. This agrees with earlier findings that in this bog both species have the same biomass per ground area.     

Temporal and spatial complexity of maternal thermoregulation in tropical pythons

Parental care is a widespread adaptation that evolved independently in a broad range of taxa. Although the dynamics by which two parents meet the developmental needs of offspring are well studied in birds, we lack understanding about the temporal and spatial complexity of parental care in taxa exhibiting female-only care, the predominant mode of parental care. Thus, we examined the behavioral and physiological mechanisms by which female water pythons Liasis fuscus meet a widespread developmental need (thermoregulation) in a natural setting. Although female L. fuscus were not facultatively thermogenic, they did use behaviors on multiple spatial scales (e.g., shifts in egg-brooding postures and surface activity patterns) to balance the thermal needs of their offspring throughout reproduction (gravidity and egg brooding). Maternal behaviors in L. fuscus varied by stage within reproduction and were mediated by interindividual variation in body size and fecundity. Female pythons with relatively larger clutch sizes were cooler during egg brooding, suggesting a trade-off between reproductive quantity (size of clutch) and quality (developmental temperature). In nature, caregiving parents of all taxa must navigate both extrinsic factors (temporal and spatial complexity) and intrinsic factors (body size and fecundity) to meet the needs of their offspring. Our study used a comprehensive approach that can be used as a general template for future research examining the dynamics by which parents meet other developmental needs (e.g., predation risk or energy balance).     

Temporal and spatial windows delimit activation of the outer ring of wingless in the Drosophila wing

Extracellular signalling molecules play many roles in the development of higher organisms. They are used reiteratively in different tissues and stages, but the response of the receiving cells is controlled in a context dependent manner. The pattern of expression of the signalling molecule Wingless/WNT in Drosophila is extraordinarily complex. We have studied the mechanism that controls its expression and function in the outer ring of the Drosophila wing hinge. Our findings indicate that wingless expression is controlled by a dual mechanism: its initial activation requires the product of zinc finger homeodomain 2 and is subsequently repressed by the product of the gene complex elbow/no ocelli. This tight regulation restricts the activation of wingless temporally and spatially. Later in development, wingless expression is maintained by an autoregulatory loop that involves the product of homothorax. We have analyzed the phenotype of a wingless allelic combination that specifically removes the outer ring, and our results show that Wingless is required to promote local proliferation of the wing base cells. Thus, cell proliferation in the proximal-distal axis is controlled by the sequential activation of wingless in the inner ring and the outer ring at different stages of development.     

Seasonal and spatial shifts in copepod diets within tropical estuaries measured by fatty acid profiles

Fatty acids are the main components of lipids and are necessary for the production and permeability of cell membranes, playing an essential role in the physiological responses of organisms. The biochemical composition of zooplankton might be used as bio-indicators of the trophic status of aquatic ecosystems. Aiming to fill the gap of knowledge in tropical estuaries, the main aim of this study was to test if the fatty acid profiles can reveal spatial and temporal shifts in the diet of copepods and therefore can be used as indicators of the trophic status of estuarine systems. We investigated the fatty acids composition of copepod species and their possible food sources along the salinity gradient of two tropical estuaries (Paraíba do Norte and Mamanguape estuaries, northeastern Brazil), during the rainy and dry seasons. We found clear seasonal differences regarding fatty acids composition and concentration in copepods, with maximal concentrations and diversity of total fatty acids during the rainy season. The copepods species were mainly carnivorous in the dry season and omnivorous in the rainy season and, in both estuaries, the diet of most copepods was dependent on food availability. The fatty acid profiles suggest that, in general, feeding patterns of zooplankton change spatially and temporally, reflecting the shifts in their food sources abundance (i.e., dominance among diatoms and flagellates, terrestrial detritus and small animals). We observed a residual proportion of terrestrial detritus and green algae in the diets and these items were only present in the dry season. Furthermore, the food sources in the Paraiba do Norte estuary, a system with high levels of anthropogenic disturbance, showed lower feeding quality, with lower essential fatty acids concentrations. Our study showed that fatty acid profiles can be used as ecological indicator to assess seasonal and spatial shifts in the trophic ecology of copepods in tropical estuaries and to distinguish systems with different levels of human impact in a fast and accurate way.     

Temporal and spatial metabolic rate variation in the Antarctic springtail Gomphiocephalus hodgsoni

Spatial and temporal environmental variation in terrestrial Antarctic ecosystems are known to impact species strongly at a local scale, but the ways in which organisms respond (e.g. physiologically, behaviourally) to such variation are poorly understood. Further, very few studies have attempted to assess inter-annual variability of such responses.Building on previous work demonstrating intra-seasonal variation in standard metabolic rate in the springtail Gomphiocephalushodgsoni, we investigated variation in metabolic activity of G. hodgsoni across two austral summer periods at Cape Bird, Ross Island. We also examined the influence of spatial variation by comparing metabolic rates of G. hodgsoni at Cape Bird with those from two other isolated continental locations within Victoria Land (Garwood and Taylor Valleys).We found significant differences between metabolic rates across the 2 years of measurement at Cape Bird. In addition, standard metabolic rates of G. hodgsoni obtained from Garwood and Taylor Valleys were significantly higher than those at Cape Bird where habitats are comparable, but environmental characteristics differ (e.g. microclimatic temperatures are higher).We discuss potential underlying causes of these metabolic rate variation patterns, including those related to differences among individuals (e.g. physiological and genetic differences), locations (e.g. habitat quality and microclimatic regime differences) and populations (e.g. acclimation differences among G. hodgsoni populations in the form of metabolic cold adaptation (MCA)).     

First observations of predation by New Zealand Greenshell mussels (Perna canaliculus) on zooplankton

Observations made overseas of predation by blue mussels and zebra mussels on mesozooplankton (>200 μm) have raised concern within New Zealand that the Greenshell mussel, Perna canaliculus, which is cultured in large tonnages throughout hundreds of marine farms within the New Zealand coastal zone, could exert ecologically detrimental effects by preying on zooplankton. We conducted experiments at Clova Bay, Pelorus Sound in May 2002 to determine the rates that P. canaliculus ingests prey, up to and including the mesozooplankton size range. Single mussels from farms were incubated with seawater enriched with zooplankton (>60 μm) in gently circulated 15-l pails. Depletion of chlorophyll-a (chl-a), ciliate microzooplankton, and nauplii, copepodites, and adults of copepods was determined over 5 h, relative to controls with no mussels. Two experiments were made over consecutive days. Gut contents of these experimental mussels, and of mussels examined soon after collection from a farm, were described.Gut contents of experimental and of freshly collected mussels (standard shell length ∼90 mm) had numerous copepod parts, whole copepods and larval bivalves present. Experimental mussels cleared chl-a and ciliates from 59- to 137-l individual⁻¹ day⁻¹, respectively, averaged across the two experiments. Faster ciliate than chl-a clearance was probably caused by the high proportion (56%) of phytoplankton below the retention size for P. canaliculus (ca. 5 μm) and by faster ciliate grazing in controls than treatments. The average clearance rates of adult, copepodite, and naupliar copepod stages by mussels were 20, 31, and 49 l individual⁻¹ day⁻¹, respectively. The clearance rates of each copepod stage were not significantly different between the two experiments. Clearance of nauplii was significantly greater than of adults and copepodites, while adult and copepodite clearance rates were nearly significantly different. The mean lengths of the adult, copepodite, and naupliar copepods were 430, 265, and 165 μm, respectively. The decreasing clearance rates with increasing size and development of prey (from ciliates, through naupliar, copepodite to adult copepods), suggested that prey escape ability, related to body size and/or morphology, affected capture rates. Mussel faecal samples indicated complete digestion of the gut contents. Pseudofaecal samples showed very low rejection rates of mesozooplankton by mussels. The results are considered in context of current biophysical modelling studies of impacts of large mussel farms in New Zealand. Designs of future experiments to improve accuracy of estimates of mesozooplankton clearance rates by P. canaliculus are considered.     

The Stratiotes aloides L. stand as a habitat in oxbow lake Bużysko

The impact of Stratiotes aloides L. (water soldier) on the accumulation and concentration of nitrogen and phosphorus, seston concentrations and provision a habitat for planktonic crustaceans was studied in a Polish oxbow lake during 2002–2004. The Stratiotes stand and the open water differed in the concentrations of mineral nitrogen and chlorophyll a. Stratiotes accumulated significantly more nitrogen in spring. The lower TN:TP ratio, concentrations of mineral nitrogen and chlorophyll a in stands of the water soldier may suggest nitrogen limitation in the littoral of the oxbow lake. The decrease of phytoplankton biomass in the Stratiotes stands may also result from shading and/or allelopathy. The plants did not reduce seston concentrations in the littoral but did affect the abundance and diversity of planktonic and bentho-planktonic crustaceans and probably provided a daytime refuge for Ceriodaphnia and older stages of Cyclopoida but not for Daphnia.     

Predation-driven dynamics of zooplankton and phytoplankton communities in a whole-lake experiment

Summary 1. Species compositions of zooplankton and phytoplankton were followed in Tuesday Lake before and after experimental manipulation of its fish populations (addition of piscivorous largemouth bass, removal of planktivorous minnows). Plankton dynamics were compared to those of adjacent, unmanipulated Paul Lake, where piscivorous fish have been dominant historically. 2. Indices of similarity for the zooplankton communities in the two lakes in 1984 prior to the manipulation were low; however, following the manipulation in spring, 1985, similarity of the zooplankton in the two lakes rose considerably and remained high throughout 1986. This was the result of an increase in Tuesday Lake of previously rare large-bodied cladocerans (Daphnia pulex, Holopedium gibberum) which were the dominants in Paul Lake, and the disappearance in Tuesday Lake of the dominant small-bodied copepod Tropocyclops prasinus, a minor component of the Paul Lake zooplankton. These observations are consistent with prior observations of the effects of size-selective predation on zooplankton communities. 3. Phytoplankton communities also responded strongly to the manipulation, with similarity indices for the two lakes rising from low levels in 1984 to high levels of similarity in 1985 and 1986, reflecting the decrease of formerly dominant Tuesday Lake taxa which were unimportant in Paul Lake and the appearance or increase in Tuesday Lake of several taxa characteristic of the Paul Lake phytoplankton assemblage. these results clearly show that food web structure can have pronounced effects on community composition at all levels of the food web, and that, just as zooplankton communities are structured by sizeselective predation, phytoplankton communities are structured by herbivory. These observations may provide some insight into factors governing the complex distributions of phytoplankton species among various lakes.A contribution from the University of Notre Dame Environmental Research Center, funded by NSF grants BSR-83-08918 and BSR-86-06271