Interactions between Psilocybe fasciata and its companion fungus Acremonium strictum

Interactions between Psilocybe fasciata and its companion fungus Acremonium strictum were analysed. The conidia of A. strictum were observed on stipe, flesh and gill of P. fasciata, which suggested that A. strictum is the fungicolous fungi or mycophilic fungi of P. fasciata. The microscopic observations of the interacting hyphae of P. fasciata and A. strictum in dual culture and the negligible activities of chitinase and β-1,3-glucanase in inducing or non-inducing media of the pure and mixed cultures of the two fungi indicated that A. strictum is not the mycoparasite of P. fasciata. In addition, the co-existence, no pigmentation and dew formation in dual culture of both fungi were observed, which implied that the interference competition between the two fungi is weak. The activities of cellobiase, filter paper enzyme, endoglucanase and xylanase of pure and mixed cultures of P. fasciata and A. strictum were the same or similar, which may allow the co-existence of the two fungi. As a consequence of coevolution, the relationship between P. fasciata and A. strictum is commensalism: A. strictum showed no clear benefit to P. fasciata; however, P. fasciata may shelter A. strictum by its psychoactive tryptamines and may be helpful to conidium dispersal of A. strictum. The relationship between P. fasciata and A. strictum is different from that of A. strictum and other fungi.     

The ecology of Belizean mangrove-root fouling communities: patterns of epibiont distribution and abundance,and effects on root growth

The aerial prop roots of the neotropical red mangrove,Rhizophora mangle L., begin growing well above highest high water (HHW) and often extend well below lowest low water (LLW) before rooting in the benthic substratum. In Belize, Central America, prop roots growing below LLW are colonized by diverse assemblages of organisms, including macroalgae, hydrozoans, ascidians, sponges, anemones, hard corals, and isopod crustaceans. Mangroves, root-fouling epibionts, root herbivores, and benthic predators engage in complex interactions that are major determinants of mangrove growth and production. Species richness of root epibionts increases with distance from the mainland and with proximity to the barrier reef. Species richness decreases with variability in water temperature and salinity. Ascidians and sponges transplanted from Lark Cay into the coastal Placencia Lagoon failed to survive, but anemones from Lark Cay survived in Placencia Lagoon. Reciprocal transplants survived off-shore. The gastropod predator,Melongena melongena L., present only in mainland estuaries, reduced local barnacle abundance and epibiont species richness in Placencia Lagoon. Isopod species richness also increases with distance from shore, but the number of roots bored by these species decreases. These isopods can reduce root relative growth rate (RGR_root) by 55%. On off-shore cays, sponges and ascidians ameliorate negative effects of isopods. In mainland estuaries where epibionts are less common, isopod damage to roots is more severe. Experimental studies in mangrove swamps throughout the world would clarify the importance of plant-animal interactions in these widespread tropical ecosystems.     

Seasonal changes and population dynamics of the ctenophore Mnemiopsis leidyi after its first year of invasion in the Kiel Fjord, Western Baltic Sea

We analyzed the seasonal variations of the ctenophore Mnemiopsis leidyi weekly collected since its first record in the western Baltic Sea in October 2006. The distribution pattern together with the seasonal dynamics and population outbreaks in late summer 2007 indicate recent successfully establishment of M. leidyi in this area. Seasonal changes showed two periods of high reproductive activity characterized by a population structure dominated by small size classes, followed by an increase of larger ones. These results further revealed that the bulk of the population remains in deep layers during the periods of low population density, whereas it appeared situated in upper layers during the proliferation of the species. We further emphasized the strength of the population outbreaks, which can reach abundances >10-fold higher in time periods shorter than a week. The predatory impact this species may have in pelagic ecosystems warns on the importance of its recent range of expansion.     

Distribution Patterns of Isomorphic Cold-Water Dinoflagellates (Scrippsiella/Woloszynskia Complex) Causing ‘red tides’ in the Baltic Sea

During the latest years medium-sized (15–30 μm), single-celled dinoflagellates have been reported to form blooms in the northern Baltic Proper and the Gulf of Finland in winter and spring. Recent studies (Kremp et al., 2003. Proceedings of the 7th International conference of Modern and Fossil Dinoflagellates, September 21–25, Nagasaki, Japan, 66 pp.) indicate that those blooms are caused by two isomorphic species – Scrippsiella hangoei (Schiller) Larsen, and a new species, tentatively belonging to the genus Woloszynskia. Until now there has been no report on how widely distributed these phytoplankton species are in the Baltic Sea. In this study, the occurrence of Scrippsiella/Woloszynskia complex in the entire Baltic Sea was investigated, by using monitoring data from 1997 to 2003. The species occurred in a salinity range from 2 to 8 PSU. Highest concentrations were observed at salinity 4.5–6.5 PSU. Maximum cell densities of Scrippsiella/Woloszynskia complex in the water column were mainly obtained in April or in the beginning of May by the water temperature <3 °C prior to stratification was formed. In the central Gulf of Finland, the second maximum was found in 1999 and 2002 by the temperature >6 °C. Bloom formations in the Baltic Proper and in the Gulf of Finland may not only be explained by optimum temperature and salinity, but also with other factors e.g. high nutrient concentrations and good seeding conditions from the sediments.     

Factors influencing the occurrence of males in natural populations of Synchaeta spp.

Changes in the temporal abundance of females and males of Synchaeta spp. were followed for one year (1983) at two stations in the brackish northern Baltic proper. Males were found only when the abundance of females was increasing and the phytoplankton biomass was dominated by large diatoms.     

Distribution and population characteristics of the alien talitrid amphipod Orchestia cavimana in relation to environmental conditions in the Northeastern Baltic Sea

The talitrid amphipods were found for the first time in the Northeastern Baltic Sea in 1999. Orchestia cavimana inhabited damp wracks cast up on shore within a 200 m area of Saaremaa Island. In the following year, the species expanded its range to a few kilometres. In 2002, six additional locations of O. cavimana were found in Saaremaa Island and two locations in the Northwestern part of Estonia. Abundances and biomasses were highest in the first year of the invasion. In the following years, the values stabilized on remarkably lower levels. Population characteristics of the species varied significantly between locations. The average biomass and abundance were 9 g dw m⁻² and 1975 ind m⁻², respectively. Wrack biomass and interaction between wrack biomass and exposure were the best predictors of the abundances and biomasses of O. cavimana. Humidity explained additional variability in biomasses. The size structure of the population of O. cavimana was mostly related to humidity and wrack biomass. The Southern coast of the Baltic Sea may be regarded as the initial donor region for the Estonian populations of O. cavimana. The vector of this invasion is most likely related to the natural dispersal of the drifting algae but human activities as a transport vector can not be excluded. The incredible speed of the invasion of O. cavimana and its high biomasses indicate that the species will very likely extend its distribution along the coast of the Northeastern Baltic Sea in the following years.     

Biodeposition in a juvenile mussel bed of the east Frisian Wadden Sea (Southern North Sea)

Seasonal trends of biodeposition and animal coverage in backbarrier beds of the musselMytilus edulis in the East Frisian Wadden Sea were documented and quantified to assess the effects of physical disturbance by storms and to develop a conceptual model for the interpretation of biodeposits in the stratigraphic record. Accretion and erosion of biogenic muds (faeces and pseudofaeces) were quantified by repeated precision levelling of a 12 m² test area. Animal coverage was documented by vertical photography prior to each levelling survey. Levelling and photography were conducted from a bridge and rail system to avoid physical disturbance by trampling. Four surveys, covering a period of different weather conditions, showed variable mean accretion/erosion rates of biodeposits ranging from +0.56 mm d⁻¹ (accretion) to −1.34 mm d⁻¹ (erosion) and areal coverage of mussels ranging from 39.1% to 0%. A pronounced seasonal trend in the biodepositional pattern was observed. Mean accretion rates were high (>0.5 mm d⁻¹) during the summer season, whereas in the winter season net deposition decreased to zero or showed erosional trends. Longterm sediment budgets are thus composed of highly variable mean annual rates which, in turn, comprise highly variable seasonal and even monthly rates, depending on the local weather pattern. This forms the basis for a conceptual model, in terms of which the stratigraphic record of fossil biodeposits can be meaningfully interpreted.     

Phytoplankton vertical distributions and composition in Baltic Sea cyanobacterial blooms

We studied the vertical structure of the phytoplankton community in two toxic cyanobacterial blooms in the offshore Baltic Sea. In 1994, vertically separated potentially toxic, diazotrophic and mixotrophic species (belonging to Cyanophyceae, Dinophyceae and Prymnesiophyceae) dominated. In 1997, picocyanobacteria, mainly in colonies, made up 40–50% of the total phytoplankton carbon biomass in the top 20 m both day and night. Colony-forming species of picocyanobacteria seem to be occasionally important and hitherto underestimated in the Baltic Sea.We found species-specific depth distribution patterns. Nodularia spumigena and Anabaena spp. were observed mainly above 10 m depth, while Aphanizomenon sp. was mostly found deeper, especially at night. Dinophysis norvegica was only abundant near the seasonal pycnocline and showed very limited diurnal migration. Other flagellates, including small Cryptophyceae and 10 identified Chrysochromulina species, occurred down to 40 m depth. Their vertical migration may help to retrieve nutrients from below the summer pycnocline.We conclude that considerable differences in dominating functional groups may occur between years/bloom stages, and that the vertical distribution pattern of many species is recurring at similar environmental conditions, suggesting species-specific niche-separation.     

Are marine planktonic invertebrates food limited? The case of Mysis mixta (Crustacea,Mysidacea) in the Baltic Sea

Summary Linear regression analysis of field data from a coastal area of the Baltic Sea indicated that growth of the zooplanktivorous Mysis mixta was food limited. No statistically significant effects of temperature on growth were detected.     

Stylochus tauricus,a predator of the barnacle Balanus improvisus in the Black Sea

The flatworm Stylochus tauricus Jacubova has been found associated with the barnacle Balanus improvisus Darwin, on which it feeds. The predation rate (the number of barnacles eaten by one polyclad in a month) ranges between 5–10. Inside the empty shells of B. improvisus some egg-plates of S. tauricus were observed. Pelagic Götte's larvae aged 2–3 days possess 4 lobes while those aged 7–8 days have 5 lobes. Flatworms can prey on the young of another species Balanus eburneus Gould, whereas predation on the mussels Mytilus galloprovincialis Lam. is rare. There is a direct correlation between predator abundance and prey ingested.     

Seasonal variability in the individual carbon content of the calanoid copepod Acartia bifilosa from the northern Baltic Sea

The seasonal variation in the carbon content of the calanoid copepod Acartia bifilosa was studied in the northern Baltic Sea. Monthly length-weight relationships were followed from November 1990 to October 1991 by analysing the organic carbon content of individuals, using a high temperature combustion method. The monthly length (L) on carbon (C) regressions of copepodites were best described by power functions (C = aL^b), where 75% to 88% of the variation could be explained by length. Nauplii length explained less of their carbon content (63–71 %). The carbon content per length was highest in summer when the nutritional situation was good and temperature at its highest. However, the carbon-length regressions differed significantly between months, except in winter, when two subsequent months had similar regressions. The results pointed out the importance of seasonal variation as well as the risk of making errors if biomass estimates based on length on carbon regressions are used. Carbon analysis should, if possible, be done on every sample or should at least be tested as to whether the regressions are consistent with the study material before estimations are calculated.     

First record of the occurrence of "gill disease" in Mytilus edulis trossulus from the Gulf of Gdańsk (Baltic Sea, Poland)

We are presenting the first report of the occurrence of "gill disease" in Mytilus edulis trossulus from the southern Baltic Sea, Gulf of Gdańsk (Poland). The disease preliminary diagnosis was based on the presence of white and yellow "spots" causing deep indentations in the gills with degeneration, destruction and necrosis of gill filaments. Average prevalence of gill erosion in the blue mussels population was 15.8%. According to other authors, gill erosion may affect over 80% of the bivalve population resulting in mortality rates of up to 40%. The origin of the gill erosion remains unknown, but viruses are most likely involved in the etiology of these pathological conditions. The disease as such may indicate a decrease in the immunological resistance of organisms to infections and inflammations directly or indirectly caused by harmful factors in the ambient environment. Furthermore, the occurrence of numerous pathologies in bivalves is a particular problem in the Gulf of Gdańsk being a low biodiversity ecosystem. Pathologies reduce bilvalves' reproduction ability, worsen their physiological condition and increase their mortality rate. Those factors may also pose a significant ecological danger and lead to negative alterations of the ecosystem.     

Dinophysis norvegica (Dinophyceae), more a predator than a producer?

Several studies have proved that some Dinophysis species are capable of ingesting particulate organic matter besides of being photosynthetic, a form of nutrition termed mixotrophy. Phagotrophy may be an important aspect of the life history of the genus Dinophysis and the key to understand its ecology. We used modern techniques coupling flow cytometry and acidotropic probes to detect and score food vacuolated Dinophysis norvegica cells in natural samples. In addition, feeding experiments were conduced under controlled conditions to observe if D. norvegica would grow feeding on the cryptophyte Teleaulax amphioxeia. The results of the field observations showed a frequency of phagotrophy between 25 and 71% in a natural D. norvegica population from the Baltic Sea, which is higher than previous reports (1–20%). Although molecular methods have proved that the kleptoplastids of the D. norvegica from the Baltic Sea are from T. amphioxeia, the laboratory experiments showed that the presence of T. amphioxeia in the cultures did not enhance the survival rate of D. norvegica neither in phototrophic nor in heterotrophic conditions. We suggest that the D. norvegica Kleptoplats are obtained through a heterotrophic or mixotrophic protist, which have been feeding on cryptophytes, as it has recently been shown for Dinophysis acuminata. Our main conclusion is that D. norvegica, and probably all other species from the genus Dinophysis, is mainly phagotrophic and feeds on a larger prey than T. amphioxeia. Autotrophy through kleptoplastidy would be a secondary feature used as a complementary or short-term survival strategy.     

The root-nodule symbiosis between Sarothamnus scoparius L. and its microsymbionts

When nitrogen fixing root nodules are formed, Sarothamnus scoparius (broom) is inoculated with its microsymbionts. Nodules studied under light and electron microscopy exhibited typical indeterminate nodule histology with apical, persistent meristem, age gradient of nodule tissues, and open vascular bundles, and also with some particular features such as: the presence of mitotic activity in the infected meristematic cells, lack of infection threads, distribution of bacteria by process of host cell division, and occurrence of a large bacteroid zone only with infected cells. The results of cross-inoculation tests have shown a broad host range for S. scoparius microsymbionts including not only the native host but also species such as: Lupinus luteus, Ornithopus sativa, Lotus corniculatus, Genista tinctoria, Chamaecitisus ratisbonensis, Macroptilium atropurpureum, and Phaseolus vulgaris. In addition, our data established a close symbiotic relationship of S. scoparius nodulators to Bradyrhizobium sp. (Lupinus) by comparison of the partial sequence of nodC gene of the strain CYT7, specific for the broom, to those from Bradyrhizobium sp. (Lupinus) strain D1 and others available in the public databases.     

Toxicity and isolation of the cyanobacterium Nodularia spumigena from the southern Baltic Sea in 1986

Three water bloom samples were collected in August 1986 from the southern Baltic Sea. Acute toxicity of the samples was determined by mouse bioassay and the toxins were further studied by HPLC. The bloom samples contained equal amounts of cyanobacteria Nodularia spumigena and Aphanizomenon flos-aquae and were hepatotoxic. Two hepatotoxic Nodularia spumigena strains were isolated from the samples. The isolates produce a toxic peak indistinguishable from the bloom material in the HPLC analysis. The toxicity of the fractions was verified by mouse bioassay. Thus the toxicity of the bloom samples was in all likelihood caused by Nodularia spumigena.     

Population of <Emphasis Type="Italic">Aphanizomenon</Emphasis> from the Gulf of Gdańsk (Southern Baltic Sea): differences in phenotypic and genotypic characteristics

In this study, one of the major bloom-forming cyanobacteria in the Gulf of Gdańsk (Southern Baltic Sea), Aphanizomenon Morren ex Bornet et Flahaut has been characterized using a polyphasic approach by comparing phenotypic and molecular characteristics. The phenotypic analysis dealt with cell and filament morphology as well as ultrastructure. The molecular phylogenetic analyses were based on sequences of the 16S rRNA gene and the adjacent intergenic transcribed spacer (ITS). We have found the Aphanizomenon population from the Gulf of Gdańsk to be significantly different in ultrastructure, morphology from freshwater A. flos-aquae and according to the traditional approach; it could be assigned to different taxonomic units. However, genetic relationship with regard to sequences of the 16S rRNA gene, showed an high overall sequence identity (97.5–99%) to freshwater isolates. Similarly, ITS sequence identity among populations from the Baltic Sea and different freshwater isolates was as high as 90.3–97.7% suggesting one and the same species. Handling editor: D. Hamilton An erratum to this article can be found at     

Prorocentrum minimum (Dinophyceae) in the Baltic Sea: morphology, occurrence—a review

The potentially toxic dinoflagellate Prorocentrum minimum (Pavillard) Schiller has successfully established in the Baltic Sea in the last two decades. A review of the invasion history is presented as well as new data on the spatial and inter-annual variability of this species and its relation to salinity, temperature, and nutrient concentrations. A short literature review of the morphological characters of the Baltic P. minimum is also included.From 1993 to 2002, P. minimum was a regular component of the summer and autumn plankton flora of the Baltic Sea proper and the Gulf of Finland. Its abundance varied considerably inter-annually and did not show any clear trends during the period. Abundance of P. minimum was significantly higher in the nutrient-enriched Bay of Mecklenburg (German coast) and the southern Baltic proper than in the central and northern Baltic proper and the Gulf of Finland, where its abundance was mostly sparse. In coastal waters P. minimum occasionally reached densities of several million cells per litre and dominated phytoplankton biomass (>90%).Abundance of the Baltic P. minimum was generally not related to salinity or temperature. It could be a dominant species at both high and low salinity (over 15 and 4.8 PSU), and its temperature range was broad (from 2.7 to 26.4 °C). However, dense populations usually occurred from July to October at temperatures above 10 °C.Further, there appears to be a positive correlation between the success of P. minimum in the Baltic Sea and high concentrations of total phosphorus and nitrogen.This tolerant and morphologically variable dinoflagellate seems to be a morphospecies without subtaxa, which can expand its range in the Baltic Sea, especially in nutrient-rich coastal waters.     

Larval behaviour and choice of settlement site: Correlation with environmental distribution pattern in an erect bryozoan

Summary This paper concerns the preferred environmental conditions for settlement and metamorphosis of larvae of the erect, rigidly calcified cheilostome bryozoanSchizotheca serratimargo and compares the settlement preferences with in situ distribution of adult colonies. A review of bryozoan larval behaviour and responses to environmental parameters is given in order better to understand larval settlement and metamorphosis in this species. Release of larvae ofS. serratimargo (Hincks) was induced so that each travelled down a path with a limited set of microenvironments in which it could choose to settle. Four different flow velocities, three different depths below the water surface, two different light intensities, three different orientations of plexiglas surfaces, and subdivision of distance of travel into three segments, yielded 216 microenvironments. 466 larvae successfully settled and metamorphosed within the experimental chamber. They metamorphosed in significantly higher numbers in microenvironments with low flow velocity, in the shallowest of the three possible depths, in darker areas, and on nonoverhanging surfaces with little or no sediment. The most important stimulus for settlement was darkness, especially where there was a strong gradient in light intensity.S. serratimargo grows as erect bilaminate bushes on protected flanks of boulders, in small caves, and just within the entrances of larger caves at depths of 5–30 m, as well as on hard debris on open muddy sand floors at 30–35 m depth in the Adriatic and Mediterranean Seas. The experimentally-determined settlement patterns suggest that recruitment is more important than post-settlement interactions or exposure to physical damage in determining local distribution of the species.     

Pollination niche overlap between a parasitic plant and its host

Niche theory predicts that species which share resources should evolve strategies to minimise competition for those resources, or the less competitive species would be extirpated. Some plant species are constrained to co-occur, for example parasitic plants and their hosts, and may overlap in their pollination niche if they flower at the same time and attract the same pollinators. Using field observations and experiments between 1996 and 2006, we tested a series of hypotheses regarding pollination niche overlap between a specialist parasitic plant Orobanche elatior (Orobanchaceae) and its host Centaurea scabiosa (Asteraceae). These species flower more or less at the same time, with some year-to-year variation. The host is pollinated by a diverse range of insects, which vary in their effectiveness, whilst the parasite is pollinated by a single species of bumblebee, Bombus pascuorum, which is also an effective pollinator of the host plant. The two species therefore have partially overlapping pollination niches. These niches are not finely subdivided by differential pollen placement, or by diurnal segregation of the niches. We therefore found no evidence of character displacement within the pollination niches of these species, possibly because pollinators are not a limiting resource for these plants. Direct observation of pollinator movements, coupled with experimental manipulations of host plant inflorescence density, showed that Bombus pascuorum only rarely moves between inflorescences of the host and the parasite and therefore the presence of one plant is unlikely to be facilitating pollination in the other. This is the first detailed examination of pollination niche overlap in a plant parasite system and we suggest avenues for future research in relation to pollination and other shared interactions between parasitic plants and their hosts.     

Effects of Cyanobacteria on Survival and Reproduction of the Littoral Crustacean Gammarus zaddachi (Amphipoda)

Toxic cyanobacteria can have harmful or fatal impacts on aquatic organisms. In the archipelagos of the northern Baltic Sea, the open sea blooms often drift into littoral areas, where they decompose and release toxins and other chemical compounds in the water. However, the effects of cyanobacteria on the littoral organisms have not previously been investigated. We studied the effects of three cyanobacteria species (toxic Nodularia spumigena, non-toxic N. sphaerocarpa and non-toxic Aphanizomenon flos-aquae) and purified dissolved nodularin (produced by N. spumigena) on a common littoral amphipod Gammarus zaddachi. Nodularin was transferred to eggs, juveniles and adults of G. zaddachi, but no significant negative effects of dissolved nodularin were detected on adults, eggs or juveniles. However, survival of adults decreased by the exposure to toxic N. spumigena cells. The egg hatching rate and juvenile survival were not affected when exposed to the three cyanobacteria species. In contrast, a weak decrease in the egg production and an increased abortion of embryos from the brood pouch of females was observed, the later indicating a failure in parental care. Further, a decrease in grazing rate on the filamentous green alga Enteromorpha intestinalis was observed. The results suggest that toxic cyanobacteria blooms are not extremely fatal, but may have, in high concentrations, negative effects on the adult survival, fecundity, and feeding behaviour of gammarids inhabiting the littoral zone.