EFFECT OF TEMPERATURE ON GERMINATION OF RHIZOCLONIUM RIPARIUM (SIPHONOCLADALES,CHLOROPHYTA) AKINETES AND ZOOSPORES1

The temperature requirements for germination by reproductive initials of Rhizoclonium riparium (Roth) Harv., a filamentous green alga, were investigated in laboratory culture. Akinetes and zoospores were produced by exposing aging cultures to high temperatures (40°C). Germination proceeded rapidly and followed a typical bell-shaped response curve, with germination optima between 15 and 20°C. These findings follow the trend found in related algae, i.e. reproductive initials are produced under stressful conditions.     

Body size as an indicator of parasitoid quality in male and female Anagyrus kamali (Hymenoptera: Encyrtidae)

The parasitoid Anagyrus kamali Moursi was recently introduced into the Caribbean as a biological control agent against the hibiscus mealybug, Maconellicoccus hirsutus Green. In the laboratory, parasitoid size, as measured by left hind tibia length, was positively correlated with several indicators of the parasitoid's fitness: longevity, mating preference, fecundity, reproductive longevity, progeny emergence and sex-ratio. When fed ad libidum with honey drops, large male parasitoids lived significantly longer (29.1 +/- 6.5 days) than small ones (18.4 +/- 5.7 days). Large females also lived significantly longer (35.4 +/- 10 days) than small females (27.9 +/- 9.6 days). Females showed no significant mating preference between large and small males. Lifetime fecundity was positively correlated with the size of adult females and ranged from 37 +/- 21 eggs for small females to 96 +/- 43 eggs for large ones. The reproductive longevity, daily oviposition rate, and number of progeny were also higher among large parasitoids. The sex ratio of progeny from small female parasitoids was higher (0.76 +/- 0.24) than that of large individuals (0.47 +/- 0.18).     

Carrageenans from Cystocarpic and Sterile Plants of Chondrus Pinnulatus (Gigartinaceae, Rhodophyta) Collected from the Russian Pacific Coast

The chemical structure, gel properties and biological activity of the carrageenans isolated from cystocarpic and sterile plants of Chondrus pinnulatus were investigated. The total carrageenan content of the sterile plant was observed to be twice that of the cystocarpic plants. According to data obtained by ¹³C-NMR and FT IR, the gelling polysaccharides from cystocarpic and sterile plants of C. pinulatus have similar structures and were identified as κ/ι-carrageenans. The difference between these polysaccharides was in the ratio of the κ- and ι-segments, with a predominant content of κ-segments in cystocarpic plants (80%). Moreover, KCl-insoluble fractions possibly contain hetero-disperse μ/ν precursor: amounts of this in the polysaccharide from sterile plants were more than that extracted from the cystocarpic plants. The KCl-soluble fractions (non gelling) were λ-carrageenans with another carrageenan type that had a low amount of 3,6-anhydrogalactose. Carrageenans from cystocarpic stages showed good gelling properties, whereas those from sterile plants formed a very weak gel. Structural differences and molecular weight of carrageenans obviously determine the biological activity of the polysaccharides. Non gelling-carrageenans from both types of ιt C. pinnulatus plants showed high macrophage-phosphatase activity and κ/ι-carrageenan from cystocarpic plant possessed a potent anti-coagulant activity, which was extremely strong in a low concentration of 100 μg ml⁻¹.     

Reproductive activity of Coelomera lanio (Coleoptera: Chrysomelidae)

The Cecropia spp. (Cecropiaceae) trees are attacked by several insects; among them, Coelomera lanio (Dalman) (Coleoptera: Chrysomelidae). The reproductive behavior of C. lanio was studied under laboratory conditions (12 hour photoperiod, 24.1 +/- 0.1 degrees C and mean relative humidity 67.7 +/- 0.6%), in Vi?osa, Minas Gerais, Brazil. The insects were reared in cages and in Petri dishes and fed leaves of Cecropia pachystachya Trec. Reproductive activity began 5.8 +/- 0.2 days after adult emergence and mean copulation time was 2.5 +/- 0.1 min. The female began oviposition only after 25.7 +/- 0.7 days. Each female laid a mean of 4.7 +/- 0.4 times (range 1-9). The mean number of eggs per oviposition and female was 129.2 +/- 2.4 and 587.4 +/- 92.1 respectively, and the time between egg-layings averaged 16.3 +/- 0.8 days.     

Effects of shell lesions on survival, growth, condition and reproduction in the New Zealand blackfoot abalone Haliotis iris

The pathogenicity of shell lesions in Haliotis iris Martyn was examined in a laboratory experiment in which 73 apparently healthy and 106 lesion-bearing abalone were maintained for up to 12 mo. The abalone were collected from the wild and kept in cages (1 ind. cage(-1)) for 4, 8 or 12 mo, at which times estimates of survival, growth, condition and reproductive capacity were made for each of 3 groups: 'healthy' (n = 73), 'mildly affected' (n = 61) and 'severely affected' (n = 32). Unaffected abalone showed a 2.7% mortality (n = 73) compared to 7.5% (n = 93) in lesion-bearing individuals over the entire experiment. Growth rates were significantly decreased in mildly and severely affected abalone: the relative von Bertalanffy growth coefficient (K), calculated over 12 mo, was -0.176 for unaffected, -0.079 for mildly affected and -0.048 for severely affected individuals. The asymptotic length (L(infinity)) was calculated to be 131.5 mm for unaffected, 142.1 mm for mildly affected and 150.3 mm for severely affected abalone. Significantly (p < 0.05) lower condition indices and decreased reproductive capacity (p > 0.05) were obtained for the severely affected group compared to unaffected abalone. These trends were consistent over the course of the experiment.     

Diet composition influences the fitness of the herbivorous crab Grapsus albolineatus

The tropical rocky shore crab Grapsus albolineatus feeds primarily on filamentous algae but eats animal matter whenever it is available. During the summer the crab's diet switches to encrusting algae due to a die-off of filamentous algae. As a result of the switch the nutrients in the diet of the crab vary seasonally and may influence the fitness of the crab. Maintenance, growth, reproductive performance and nutrient storage of crabs were examined under four dietary regimes of increasing nutritional value ranging from low organic to high protein content. The nutritional quality of these diets significantly affected crab survival and moulting. Crabs fed on the nutritionally superior diet of algae and meat exhibited enhanced growth, higher levels of energy in the reproductive organs and stored more energy in the hepatopancreas than did individuals on the shore and crabs fed only on algal diets in the laboratory. Filamentous algae were a better food source than other algae, resulting in fewer deaths and superior levels of maintenance and growth. Growth and maintenance can occur on a pure algal diet, but reproductive performance and nutrient storage require some degree of added nutrients in the form of animal matter in the diet. Crabs fed coralline or foliose algae had higher mortality and fewer successful moults than crabs fed the other two diets. The fitness of G. albolineatus appears to be limited by the amount of extra nutrients obtained from animal matter. The opportunistic consumption of animal material in the form of carrion, or of animals associated with dietary algae, could be a key factor in the reproductive success of this crab.     

Carrageenans solubilize asymmetric acetylcholinesterase from nicotinic cholinergic synapses

1. Acetylcholinesterase (AChE) catalyzes the hydrolysis of acetylcholine at cholinergic synapses in both vertebrate and invertebrates organisms. 2. The asymmetric synaptic AChE is attached to the extracellular matrix (ECM) of the neuromuscular junction through heparin sulphate proteoglycans (HSPGs). 3. It has been shown previously that heparin-like glycosaminoglycans (GAGs) can solubilize this enzyme from the cholinergic synapses. 4. The present paper describes the solubilization of asymmetric AChE by different marine macroalgal polysaccharides, called carrageenans. 5. Important differences were found among all the carrageenans tested; they released 15-50% of the total AChE activity normally solubilized by heparin. 6. Carrageenans extracted from tetrasporic stages of Iridaea ciliata and I. membranacea were always better extracting agents than those from the cystocarpic stages of these algae, suggesting that lambda-like carrageenans are involved. 7. This hypothesis was confirmed by extracting AChE with purified carrageenans.     

Termite colony ontogeny: supplemental data in the long-term assessment of reproductive lifespan, female neotenic production and colony size in Reticulitermes flavipes (Isoptera: Rhinotermitidae)

Reticulitermes flavipes (Kollar) colonies established by field-collected alates were reared in the laboratory for 11 years. Weights of members of each caste and full-colony censuses were performed regularly; the most recent 2003-2004 data are reported. Colonies averaged 11623.5 +/- 910 individuals, and with the exception of primary queens from one genetic lineage, mean weights for all castes had increased since 2001. Female replacement reproductives, or neotenics, developed to replace dead queens in clusters of either few, large individuals or many, small individuals. Regardless of cluster size, female neotenics comprised more reproductive biomass per colony than primary queens. The number and size of female neotenics was independent of colony size or time elapsed since a founding queen's death.     

Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta,Rhodymeniales) en Méditerranée

Abstract

Presence of Rhodymenia delicatula P.J.L. Dangeard in the Mediterranean. - The presence of Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta, Rhodymeniales) in the southern Thyrrhenian sea is reported. Both cystocarpic and tetrasporic individuals have been collected. Anatomical features of the reproductive structures, as well as the position of these on the thallus allowed the identification of this species formerly known for the Atlantic coasts of Morocco and British Isles.     

Interlaboratory comparison of the 32P-postlabelling assay for aromatic DNA adducts in white blood cells of iron foundry workers

Analysis by nuclease P1-enhanced 32P-postlabelling assay of DNA isolated from the white blood cells of 53 iron foundry workers was carried out independently in 3 laboratories, and the presence of aromatic DNA adducts was detected. The mean adduct levels in foundry workers varied from 9.2 +/- 23 (laboratory 3) and 12 +/- 10 (laboratory 2) to 26 +/- 43 (laboratory 1) and for the controls from 1.7 +/- 0.7 (laboratory 3) to 3.1 +/- 1.7 (laboratory 1) adducts per 10(8) nucleotides. No effect of smoking was observed in the present study. Each laboratory observed large interindividual variations of adduct levels. Good correlations were found between the results of the 32P-postlabelling assays carried out in the 3 laboratories; the correlation coefficients between laboratories 1 and 2, 1 and 3, and 2 and 3 were 0.61, 0.62, and 0.45, respectively, all being statistically highly significant (p less than 0.01). This interlaboratory comparison of the 32P-postlabelling method indicates the reproducibility of the method and its applicability in occupational exposure monitoring.     

不同培养条件下差巴嘎蒿种子萌发与幼苗生长特征

差巴嘎蒿是科尔沁沙地流动、半流动沙丘的主要物种之一.本试验设置室内自然条件培养、培养箱中恒温全光(24 h光照)培养、恒温光暗交替(12 h光照)培养和恒温全暗(0 h光照)培养4种处理,研究不同温度和光照对差巴嘎蒿种子萌发及幼苗生长的影响.结果表明： 室内自然光照和温度条件下差巴嘎蒿种子的萌发率(66.6%)和萌发指数(19.1%)均明显低于恒温箱培养,恒温箱的3个处理中,全暗条件下的种子发芽率(70.2%)低于全光(73.4%)和光暗交替(73.4%)培养,但差异不显著,全光条件下的萌发指数为28.2%,显著低于全暗(31.4%)和光暗交替(30.8%)培养;光照条件对幼苗生长的影响明显,在种子萌发过程中,胚根的生长出现全光促进、全暗抑制的现象,胚芽长度为全暗(2.81 cm)和光暗交替(1.51 cm)条件下高于全光(1.21 cm)培养和实验室自然条件(1.27 cm)培养.环境温度可能是限制差巴嘎蒿种子萌发的主要因素,而光照是影响差巴嘎蒿幼苗生长发育的重要因子.     

Biomass variation and reproductive phenology of Gracilaria gracilis in a Patagonian natural bed (Chubut, Argentina)

The biomass variation and the reproduction of the natural Gracilaria gracilis bed in Bahía Bustamante (Patagonia, Argentina) were analyzed for 2 years, with the aim of determining the present situation of the population for an updated status overview; establishing the relevant features of the temporal variation in both biomass and reproductive states in relation to environmental factors, epiphytes and associated algae; and assessing carpospore availability for future spore-culture development. Field measurements and sampling were performed monthly between March 2006 and February 2008. In both years, G. gracilis biomass presented marked seasonal variations, with a minimum in winter and a maximum in late spring and in summer. During both years, coexistence of the three life-cycle phases was found, with dominance of tetrasporophytes. Two data sets from individuals originated from sexual reproduction (tetraspores and carpospores) and from asexual reproduction by thallus fragmentation were analyzed separately. In the fragmentation fraction, tetrasporophyte frequencies remained higher than those for gametophytes. However, in the spore-originated fraction, a generation ratio close to 0.5 was observed. Female gametophytes bearing cystocarps were always present, with a maximum in summer and autumn. Biological data were related to environmental factors by means of canonical correspondence analysis (CCA). The first year was characterized by higher biomass values of G. gracilis and Undaria pinnatifida, lower epiphytism, larger Gracilaria thalli and greater proportion of mature tetrasporophytes and gametophytes. The second year was characterized by a high proportion of Gracilaria vegetative thalli and high epiphyte density. The best time to obtain spores from cystocarpic thalli would be in summer and early autumn.     

SEASONAL GROWTH,BIOMASS, AND REPRODUCTIVE BEHAVIOR OF THREE SPECIES OF RED ALGAE IN GODAVARI ESTUARY,INDIA1

Growth and different phases in the life histories of Bos-trychia tenella (Vohl.) J. Ag., Caloglossa leprieurii (Mont.) J. Ag., and Catenella impudica (Mont.) J. Ag. were estimated for 23 months from January 1986 to December 1987 in the Gautami Godavari estuary of lndia. Seasonal data on hydrographical conditions, biomass, and plant length were collected from three stations in this estuary. Biomass was minimum in August and September and maximum in January and February, as was frond length of tetrasporic and vegetative plants. Temperatures of 24°–27°C and salinities of 5–20 ppt coincided with optimal growth for all three algae. In all three species, tetrasporophytes were present in all months of the year without any seasonal periodicity, and nearly 50% of the plants were tetrasporophytes. The gametophytes of B. tenella and C. leprieurii and cystocarpic plants of C. impudica occurred from October to May, with greatest abundance in January. The abundance of spermatangial and cystocarpic plants in the populations of B. tenella and C. leprieurii ranged from 3 to 15%. Spermatangial plants of Catenella impudica could not be identified, and the abundance of cystocarpic plants was very low.     

入侵植物小花山桃草种群构件生物量结构及种子萌发特征

通过野外设置样方调查和室内萌发试验,研究小花山桃草种群各构件生物量的结构特征和它们之间的关系模型、繁殖分配以及种子萌发特点。结果表明:(1)小花山桃草根、茎、叶、花(果)序生物量与植株高度之间以及各构件生物量之间均呈正相关关系,可用幂函数模型或线性函数模型较好地表达;(2)各构件生物量在个体生物量中所占的比率表现为茎>花序>叶>根;(3)小花山桃草的繁殖投入和繁殖分配都随植株个体的增大而增加;(4)小花山桃草个体大小和繁殖投入之间为线性关系,而个体大小和繁殖分配之间为幂函数关系;(5)小花山桃草存在一个较小的繁殖阈值(0.6043g);(6)小花山桃草种子在有光照(12h)和黑暗条件下发芽率均可达到85%以上;未经贮藏的种子不萌发,低温沙藏(1～2℃)和室温干藏(14～32℃)一个半月种子萌发率分别可达92.5%和79%;低温沙藏时种子即可发芽,且发芽率可达61%。在研究地区,小花山桃草几乎整个生长季都可萌发,甚至初冬还有幼苗产生。小花山桃草构件生物量结构和繁殖分配特征、种子萌发特点等都有助于其入侵能力的提高,是其成功入侵我国的重要原因。     

背角无齿蚌对浮游藻类的滤食选择性与滤水率研究

以滇池及其附近水体中分布的背角无齿蚌为研究对象,分析其滤水速率及相关的影响因素,研究其食物组成和滤食浮游藻类的选择性,并初步估算其自然种群的滤水能力和控制浮游藻类的潜力.结果表明,背角无齿蚌的滤水率有一定的日变化,傍晚时较高;滤水率与水体中的悬浮物质含量密切相关,随着悬浮物质浓度增加而减少;滤水率与蚌的个体大小有关,体重增加,滤水率下降.对比水体中与蚌消化道内浮游藻类所占的百分比,发现其对浮游藻类的滤食没有显著的选择性.自然水体中背角无齿蚌的滤水能力很低.     

The role of the secondary attachment disc in the vegetative propagation of Chondracanthus chamissoi (Gigartinales; Rhodophyta)

The reattachment and vegetative growth of tetrasporophytic and cystocarpic fronds of Chondracanthus chamissoi by means of secondary attachment discs was evaluated in vitro. Our results show that both the reattachment of fronds and sprouting of new shoots from secondary attachment discs, occurred in both life cycle phases. We did not observe statistical differences between cystocarpic and tetrasporophytic fronds, which have a similar ability to reattach and produce new shoots. Reattachment was observed after 5 d and reached 54 ± 9% (mean ± S.D.). The new shoots started sprouting 20 d after reattachment, with a growth rate of 5 ± 1% d⁻¹ (mean ± DS). Our results show that the formation of secondary attachment discs is not only an effective form of reattachment for drifting fronds but also an important strategy to generate new individuals.     

Quantification of viable endospores from a Greenland ice core

Endospores (i.e., bacterial spores) embedded in polar ices present an opportunity to investigate the most durable form of life in an ideal medium for maintaining long-term viability. However, little is known about the endospore distribution and viability in polar ices. We have determined germinable endospore concentrations of bacterial spores capable of germination in a Greenland ice core (GISP2 94 m, ID# G2-271) using two complementary endospore viability assays (EVA), recently developed in our laboratory. These assays are based on bulk spectroscopic analysis (i.e., spectroEVA), and direct microscopic enumeration (i.e., microEVA) of ice core concentrates. Both assays detect dipicolinic acid (DPA) release during l-alanine induced germination via terbium ion (Tb3+)-DPA luminescence. Using spectroEVA, the germinable and total bacterial spore concentrations were found to be 295+/-19 spores mL(-1) and 369+/-36 spores mL(-1), respectively, (i.e., 80% of the endospores were capable of germination). Using microEVA, the germinating endospore concentration was found to be 27+/-2 spores mL(-1). The total cell concentration, as determined by DAPI stain fluorescence microscopy, was 7.0 x 10(3)+/-6.7 x 10(2) cells mL(-1). Culturing attempts yielded 2 CFU mL(-1) (4 degrees C). We conclude that endospores capable of germination in the GISP2 ice cores are readily determined using novel endospore viability assays.     

Seroprevalence of six reproductive pathogens in European wild boar (Sus scrofa) from Spain: the effect on wild boar female reproductive performance

We studied the seroprevalence of six reproductive pathogens in Spanish hunter-harvested wild boar females. The sample was representative of the hunting harvest in the studied hunting estates. Mean antibody prevalences were: 60.6+/-0.06% for Aujeszky's disease virus (ADV), 56.6+/-0.09% for porcine parvovirus (PPV), 51.8+/-0.06% for porcine circovirus type 2 (PCV2), 29.7+/-0.09% for Brucella spp. and 36.3+/-0.1% for Toxoplasma gondii. We did not detect antibodies against porcine reproductive and respiratory syndrome virus (PRRSv). ADV seroprevalence was associated with PPV and PCV2 seroprevalence in Spanish wild boar females. Ovulation rate in the studied wild boar females was 4.41+/-0.16 (n=120), mean litter size was 3.91+/-0.16 (n=82) and the partial resorption index 0.92+/-0.17 (n=66). Ovulation rate and litter size were statistically associated with age. T. gondii seroprevalence was negatively related to ovulation rate and partial resorption index. Wild boars from managed fenced estates had antibodies against more pathogens than wild boars from open estates. Potential relations between management of wild boar populations and exposure of individuals to different reproductive pathogens are discussed.     

Germination inhibitory constituents from Erigeron annuus

(5-Butyl-3-oxo-2,3-dihydrofuran-2-yl)-acetic acid was isolated from the flowers of Erigeron annuus as one of four germination inhibitory constituents. Its structure was determined by analysis of MS and NMR spectroscopic data. Three known compounds, 3-hydroxy-pyran-4-one, 4-hydroxycinnamic acid, and 3,4-dihydroxycinnamic acid methyl ester were also identified as active constituents. These compounds showed 50% inhibitory effects (IC(50)) on the germination of lettuce seed at concentrations of 2.13+/-0.03, 12.85+/-0.56, 4.97+/-0.24, and 4.87+/-0.25 mM, respectively. 4-Hydroxybenzoic acid was used as a positive control, displaying an IC(50) value of 4.02+/-0.39 mM.     

Genetic Adaptation to Captivity and Inbreeding Depression in Small Laboratory Populations of Drosophila Melanogaster

The rate of adaptation to a competitive laboratory environment and the associated inbreeding depression in measures of reproductive fitness have been observed in populations of Drosophila melanogaster with mean effective breeding size of the order of 50 individuals. Two large wild-derived populations and a long-established laboratory cage population were used as base stocks, from which subpopulations were extracted and slowly inbred under crowded conditions over a period of 210 generations. Comparisons have been made of the competitive ability and reproductive fitness of these subpopulations, the panmictic populations produced from them by hybridization and random mating and the wild- or cage-base populations from which they were derived. After an average of ~180 generations in the laboratory, the wild-derived panmictic populations exceeded the resampled natural populations by 75% in fitness under competitive conditions. The cage-derived panmictic population, after a total of 17 years in the laboratory, showed a 90% superiority in competitive ability over the corresponding wild population. In the inbred lines derived from the wild-base stocks, the average rate of adaptation was estimated to be 0.33 +/- 0.06% per generation. However, the gain in competitive ability was more than offset by inbreeding depression at an initial rate of ~2% per generation. The effects of both adaptation and inbreeding on reproductive ability in a noncompetitive environment were found to be minor by comparison. The maintenance of captive populations under noncompetitive conditions can therefore be expected to minimize adaptive changes due to natural selection in the changed environment.