Antimicrobial activities of Eusteralis deccanensis and E. quadrifolia essential oils

Antimicrobial activity of the essential oils of Eusteralis deccanensis and E. quadrifolia were investigated on Bacillus subtilis, B. megaterium, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Rhizopus oryzae, Aspergillus niger and Colletotrichum musae. Both the oils possess growth inhibitory activity against most of the microorganisms tested.     

Ultrastructural,biochemical, and immunological characterization of two populations of the mytilid mussel <Emphasis Type="Italic">Bathymodiolus</Emphasis><Emphasis Type="Italic">azoricus</Emphasis> from the Mid-Atlantic Ridge: evidence for a dual symbiosis

A recently described species of mytilid mussel, Bathymodiolus azoricus Von Cosel et al., 1999, was observed to be the dominant organism at the hydrothermal vents off the Azores, at both the Lucky Strike and Menez Gwen sites. Evidence suggests this species of Bathymodiolus represents yet another example of the intriguing dual symbiosis known in three other species of deep-sea mytilid mussels. Transmission electron micrographs (TEM) show the majority of gill bacteriocytes in mussels sampled from both populations to contain two distinct symbiont morphotypes. One morphotype is characterized by large size (mean diameter, 1.25 µm), coccoid shape, and stacked intracytoplasmic membranes that are consistent with the morphology of type I methanotrophs. The second morphotype is smaller (mean diameter, 0.35 µm) and was observed in coccoid or rod shapes. Immunoblots revealed the presence of ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) and methanol dehydrogenase (MeDH) in both populations of mussels. Activities of these enzymes, as well as sulfate adenylyl transferase (ATP sulfurylase) and adenylyl sulfate reductase (APS reductase), were detected in gill extracts. The activities measured for the two populations were highly variable, though the population sampled from Lucky Strike showed higher RubisCO activity. Stable carbon isotope values (Lucky Strike, '¹³C=-32.6ǂ.3‰; Menez Gwen, '¹³C=-22.8ǂ.4‰) are in the range of previously reported stable carbon isotope measurements for mytilid mussels hosting a dual symbiosis. Collectively, these results provide evidence for the activity of both sulfur-oxidizing and methane-oxidizing metabolic pathways in B. azoricus. Furthermore, evidence for a greater dependence on methanotrophy in the Menez Gwen mussel population is offered by analysis of cell counts from TEMs. Higher methanotroph numbers, and putatively activity, in this population of mussels are further supported by published geochemical data indicating higher methane concentrations in the vent fluids at Menez Gwen. This finding suggests that environmental conditions may regulate a balance between the physiological activities of different symbiont populations associated with these mussels. The existence of a dual symbiosis could thus confer greater environmental tolerance and increased niche space to the mytilid host in the stochastic hydrothermal vent habitat.     

Evolutionary relationships of Southern Ocean Octopodidae (Cephalopoda: Octopoda) and a new diagnosis of <Emphasis Type="Italic">Pareledone</Emphasis>

The phylogenetic relationships of eight species of incirrate octopodid from western Antarctica were investigated using molecular sequence data from the mitochondrial 16s ribosomal RNA gene. The genus Pareledone, which is endemic to the Antarctic, was found to be polyphyletic. On the basis of this and previous morphological studies, it is suggested that species that are morphologically similar to Pareledone polymorpha should be removed from the genus. This simplifies the diagnosis of Pareledone: a new diagnosis is given. The subfamilies Eledoninae and Graneledoninae were also found to be polyphyletic. The applicability of using the presence of an ink sac as a taxonomic character to define the subfamilies is discussed. Loss of an ink sac is almost certainly an adaptation to depth and use of this character has produced an artificial classification with no evolutionary significance. As the other two subfamilies, Octopodinae and Bathypolypodinae, are also separated by this character, it is probable that all the subfamilies of the Octopodidae are polyphyletic. The use of subfamilies should therefore be discontinued until our understanding of the evolution of the family Octopodidae increases.     

GC-EAG-analysis of volatiles from Brussels sprouts plants damaged by two species of Pieris caterpillars: olfactory receptive range of a specialist and a generalist parasitoid wasp species

Summary. Feeding by Pieris brassicae or P. rapae caterpillars on Brussels sprouts plants induces the emission of synomones that attract natural enemies of the caterpillars, Cotesia glomerata, a generalist parasitoid, and C. rubecula, a specialist on P. rapae. Previous research on this tritrophic system has identified a large number of volatiles in the headspace of herbivore-damaged Brussels sprouts plants, and this paper addresses the question which of these volatiles are perceived by the two parasitoid species. Headspace odors from both P. brassicae- and P. rapae-damaged Brussels sprouts plants were analyzed by coupled gas chromatography electro- antennogram (GC-EAG) detection. Twenty volatiles evoked consistent EAG reactions in the antennae of both species and nineteen of these volatiles could be identified with GC-MS. One component that could not be identified due to its low concentration, evoked EAG responses in antennae of C. rubecula only. Possible consequences for searching behavior of the two parasitoid species are discussed.     

Morphology of<Emphasis Type="Italic"> Ecklonia radiata</Emphasis> (Phaeophyta: Laminarales) along its geographic distribution in south-western Australia and Australasia

Ecklonia radiata (C. Ag.) J. Agardh is a common macroalga on reefs in the warm-temperate parts of the southern hemisphere. It is a dominant habitat-former and as such has a strong structuring effect on associated algal assemblages. Morphological variation in E. radiata potentially affects its interactions with the surroundings and contributes to confusion about its taxonomy. We quantified the magnitude of morphological variation in fully developed E. radiata sporophytes across Australasia and tested the hypotheses that E. radiata has different morphology at different locations and that the degree of morphological difference depends on spatial distances among locations. A total of 11 morphological characters were sampled from 11 locations along the Australian coastline from Kalbarri in Western Australia to Sydney in New South Wales as well as from Doubtful Sound, New Zealand. Most morphological characters varied considerably from one location to another. For example, the average (±SE) thallus length was 135.2±12.5 cm in Kalbarri and only 69.7±5.5 cm in Sydney. There were no consistent spatial patterns of variation among individual morphological characters, and, generally, variations among individual characters were poorly correlated (-0.5< R<0.5). This suggests that individual morphological characters develop independently of each other in response to processes operating at different spatial scales. Multivariate measures of morphology were found to be different among some locations and similar among others (-0.37=Clarke's  R=1), but there was no correlation (Spearman's R=0.08) between morphological similarity and distance between locations. Consequently, our results do not support clinal variation in E. radiata morphology. Rather, they suggest the presence of discrete morphologically different populations, in which the morphology at any one location reflects multiple forcing factors operating on different morphological characters at different spatial scales.     

Damage to Cauliflower Coral by Monofilament Fishing Lines in Hawaii

Abstract:  Many fishing methods and gear types used in coral reefs cause physical damage to the reef substratum. Only recently have monofilament fishing lines been recognized as a cause of coral damage and death. We assessed the extent of damage caused by monofilament fishing lines to the cauliflower coral (  Pocillopora meandrina ) colonies in fished and adjacent unfished zones at seven sites in the main Hawaiian islands. We examined coral colonies for the presence or absence of fishing line and for the degree of damage (dead, no live coral surface; damaged, some dead coral surface; or intact, no dead coral surface) in nine 25-m² grids. The mean proportion of colonies entangled with fishing lines in fished zones ranged from 0.18 to 0.44. The mean proportion of dead or damaged colonies was higher in fished than adjacent unfished zones, and there was a positive linear relationship between the proportion of colonies entangled with fishing lines and the proportion of dead or damaged colonies. These results indicate that monofilament fishing lines have a negative impact on the health and survival of P. meandrina colonies. Because tourism and related recreational fishing activities are expanding rapidly in many tropical states and nations, we recommend that the degrading effects of fishing lines on corals be considered in the design and management of tourism development.     

Effects of two paralytic shellfish toxin producing dinoflagellates on the pelagic harpacticoid copepod Euterpina acutifrons

The effects of two paralytic shellfish toxin (PST) producing dinoflagellates, Alexandrium minutum Halim (high and low toxin strains) and Gymnodinium catenatum Graham, on the pelagic harpacticoid copepod Euterpina acutifrons Dana were tested in a series of experiments run from October 1994 to May 1995. In small volumes (350 ml), both strains of A. minutum (300 to 350 cells ml^-1), and G. catenatum (175 cells ml^-1), strongly reduced naupliar activity (about 30 and 17% were inactive after 24 h, respectively). Activity is here defined as movement. In medium volumes (6 litre), 40% of nauplii incubated with the high toxin strain of A. minutum (1000 cells ml^-1) and 8% of nauplii incubated with cell-free filtrate of the same culture were inactive after 24 h; these values increased to 50 and 30% respectively after 3 d. In large volumes (20 litre), adult copepods incubated with A. minutum (1000 and 10000 cells ml^-1) for 5 d revealed only trace levels of PSP-toxins (paralytic shellfish poisoning) in the extracts analysed by HPLC. With both strains of A. minutum (1000 and 10000 cells ml^-1), 10 to 15% of the copepods were inactive after 1 to 2 d. It is suggested that E. acutifrons avoids feeding on the dinoflagellates after tasting a few cells, but that the dinoflagellates may exude toxins or other substances that affect the copepods. The inactivating effect of the toxic dinoflagellates on the nauplii was more rapid and stronger than on adult copepods, although strong inactivation and death were also observed in adults with time (up to 80% were inactive after 5 d of incubation with A. minutum). Still, in our experiments a considerable proportion of adult females incubated with the toxic dinoflagellates remained active and were able to produce viable eggs for several days.     

Intertidal distribution,population dynamics and production of the amphipod Uhlorchestia spartinophila in a Georgia,USA, salt marsh

The talitrid amphipod Uhlorchestia spartinophila Bousfield and Heard occurs in close association with the smooth cordgrass Spartina alterniflora Loisel in salt marshes along the U.S. Atlantic coast. In order to assess its potential as a prey resource for secondary consumers, we followed the population and production dynamics of this amphipod from 3 November 1990 to 2 October 1991 in a salt marsh on Sapelo Island, Georgia. Semimonthly samples were taken along an intertidal transect, which extended from a vegetated creekbank levee landward 140 m to a site near the upland edge of the marsh. Amphipod densities ranged from 9 to 826 indm^-2 and were greatest in the levee and high marsh habitats at opposite ends of the transect. The highest densities occurred in March to May and the lowest in November and December. Specific growth rates, which ranged from 0.001 to 0.024 mm mm^-1 d^-1 length and 0.003 to 0.068 mg mg^-1 d^-1 AFDW (ash-free dry weight), were least in winter and decreased with increasing amphipod size. Although some reproduction occurred year-round, most of the population's reproductive output was from January to May, when adults had the greatest size-specific mass. Sex ratio usually favored females, which were larger than males. Minimum adult female size was 5.4 mm total length (TL). Broods included from 1 to 28 eggs or young and increased with increasing body size, averaging 7.4 young for an average-size female of 7.6 mm TL. Annual production, which ranged from 0.769 to 1.444 g AFDW m^-2, was least in the low marsh and greatest in the levee habitat. Production:biomass ratios were 15.4 to 17.3 in different habitats. Such high turnover rates, together with the population's broad intertidal distribution, suggest a greater contribution to trophic dynamics than is implied by the relatively low standing stock biomass of U. spartinophila in this marsh system.     

Synthetischer Crandallit

Crandallite (Ca,Sr) Al₃ (PO₄)₂ (OH)₅ · H₂O crystallizes in the alunitecrystal lattice. Because of its open structure, the cations Ca²⁺, Sr²⁺, and Al³⁺ can be replaced by various elements depending on their diadochial properties; the element entering into the crystal network thus becomes immobilized. Artificial amorphous crandallite has been shown to eliminate the heavy metal ions: Pb²⁺>>Cu²⁺>Hg²⁺>>Cd²⁺ from contamined water in the presence of lateritic phosphates. Pb²⁺ could be removed nearly quantitatively in all cases.