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| | 1. |
2009 Jun 17 |
Risk-sensitive mating decisions in a visually compromised environment.
Wong BB, Järvenpää M, Lindström K
Biol. Lett. 2009 Jun 17; [Epub ahead of print]
Abstract
Reproductive activities are often conspicuous and can increase the risk of predation. Evidence suggests that individuals are capable of responding to predators in a risk-sensitive manner. However, most studies tend to consider only the predator-mediated responses of males and females in isolation and with little regard to differences in local environmental conditions. Here, we experimentally investigate the effects of environmental visibility (turbidity) and predation risk on reproductive decisions in the sand goby, Pomatoschistus minutus, when exposed to a visually oriented predator, the European perch, Perca fluviatilis. We found that gobies were more reluctant to spawn in the predator's presence, although larger males spawned sooner than smaller males. Interestingly, latency to spawning was unaffected by the visual environment, suggesting that gobies may be relying on non-visual cues under turbid conditions.
[Pubmed: 19535368]
| | 2. |
2000 Feb |
β-Cyanoalanine Production by Marine Bacteria on Cyanide-Free Medium and Its Specific Inhibitory Activity toward Cyanobacteria
Yoshikawa, Adachi, Nishijima, Takadera, Tamaki, Harada, Mochida, Sano
Appl Environ Microbiol 2000 Feb;66(2):718-722.
Abstract
In screening the culture broth of marine bacteria collected at Yap (Micronesia), Palau (Belau), and Okinawa (the southwest islands of Japan) for antimicroalgal activity, 37 out of 2,594 bacterial isolates tested were found to produce anticyanobacterial substances against Oscillatoria amphibia NIES-361. One strain, C-979, identified as a Vibrio sp., was selected and cultured in 2.4 liters of marine broth 2216 to identify the bioactive compound produced by the strain. The purified very hydrophilic compound (16.4 mg) was determined to be β-cyano-l-alanine (l-CNAla) by instrumental analyses and the application of the advanced Marfey method. l-CNAla did not inhibit the growth of bacteria, yeast, or eukaryotic microalgae, but some cyanobacteria were found to be sensitive to l-CNAla at a concentration of 0.4 to 25 μg/ml. The effect of l-CNAla on some other environmental organisms, including invertebrates and a macroalgae, is discussed. CNAla production in marine broth was examined by thin-layer chromatography for the 37 bacterial isolates which produced an anticyanobacterial substance. The broth of 36 of these strains contained CNAla, suggesting the wide distribution of CNAla production by marine bacteria. This is the first report on bacteria that produce CNAla without a supply of the cyanide ion in the medium.
[Pubmed: 10653741]
| | 3. |
2002 Mar |
Collodictyon triciliatum and Diphylleia rotans (=Aulacomonas submarina) form a new family of flagellates (Collodictyonidae) with tubular mitochondrial cristae that is phylogenetically distant from other flagellate groups.
Brugerolle G, Bricheux G, Philippe H, Coffea G
Protist. 2002 Mar;153(1):59-70.
Abstract
Comparative electron microscopic studies of Collodictyon triciliatum and Diphylleia rotans (=Aulacomonas submarina) showed that they share a distinctive flagellar transitional zone and a very similar flagellar apparatus. In both species, the basic couple of basal bodies and flagella #1 and #2 are connected to the dorsal and ventral roots, respectively. Collodictyon triciliatum has two additional basal bodies and flagella, #3 and #4, situated on each side of the basic couple, each of which also bears a dorsal root. The horseshoe-shaped arrangement of dictyosomes, mitochondria with tubular cristae and the deep ventral groove are very similar to those of Diphylleia rotans. These two genera have very specific features and are placed in a new family, Collodictyonidae, distinct from other eukaryotic groups. Electron microscopic observation of mitotic telophase in Diphylleia rotans revealed two chromosomal masses, surrounded by the nuclear envelope, within the dividing parental nucleus, as in the telophase stage of the heliozoan Actinophrys and the helioflagellate Dimorpha. Spindle microtubules arise from several MTOCs outside the nucleus, and several microtubules penetrate within the dividing nucleus, via pores at the poles. This semi-open type of orthomitosis is reminiscent of that of actinophryids. The SSU rDNA sequence of Diphylleia rotans was compared with that of all the eukaryotic groups that have a slow-evolving rDNA. Diphylleia did not strongly assemble with any group and emerged in a very poorly resolved part of the eukaryotic phylogenetic tree.
[Pubmed: 12022276]
| | 4. |
2004 Nov 22 |
Water turbidity by algal blooms causes mating system breakdown in a shallow-water fish, the sand goby Pomatoschistus minutus.
Järvenpää M, Lindström K
Proc. Biol. Sci. 2004 Nov 22;271(1555):2361-5.
Abstract
Eutrophication as a result of human activity has resulted in increased algal blooms and turbidity in aquatic environments. We investigated experimentally the effect of algal turbidity on the mating system and sexual selection in the sand goby, Pomatoschistus minutus (Pallas), a marine fish with a resource-defence mating system and paternal care. Owing to male-male competition and female choice, large males can monopolize multiple mates, while some males do not achieve mating at all. We show that the number of eggs laid was the same in both turbid and clear tanks but that mating success was more evenly distributed among males in turbid than in clear water. The opportunity for sexual selection was lower in turbid conditions. In turbid conditions mating success was less skewed towards large males. Our results suggest that increased turbidity can change mating systems and decrease the opportunity for sexual selection as well as selection intensity.
[Pubmed: 15556888]
| | 5. |
2001 Mar 15 |
Effects of toxic and non-toxic cyanobacteria on grazing, zooplanktivory and survival of the mysid shrimp Mysis mixta.
Engström J, Viherluoto M, Viitasalo M
J. Exp. Mar. Biol. Ecol. 2001 Mar 15;257(2):269-280.
Abstract
We measured the effect of toxic and non-toxic cyanobacteria strains on grazing, predation rates and survival of the mysid shrimp Mysis mixta by means of laboratory experiments. Juvenile and adult M. mixta fed most actively on the non-toxic strains Aphanizomenon flos-aquae and Nodularia sphaerocarpa as on high quality food, the green flagellate Brachiomonas submarina, whereas grazing on the toxic N. spumigena was significantly lower than on the other strains. The mysids showed normal functional responses; decreasing clearance rates at increasing concentrations of cyanobacteria. In a separate predation experiment, the feeding rates on copepods declined in the presence of aggregated non-toxic cyanobacteria. However, we could not demonstrate increased mortality in a 7-week experiment where mysids were exposed to high concentrations of toxic N. spumigena
[Pubmed: 11245880]
| | 6. |
2011 Jul 21 |
Ecosystem Resilience and Threshold Response in the Galápagos Coastal Zone
Seddon, Froyd, Leng, Milne, Willis
PLoS One 2011 Jul 21;6(7). published online before print
Abstract
The Intergovernmental Panel on Climate Change (IPCC) provides a conservative estimate on rates of sea-level rise of 3.8 mm yr−1 at the end of the 21st century, which may have a detrimental effect on ecologically important mangrove ecosystems. Understanding factors influencing the long-term resilience of these communities is critical but poorly understood. We investigate ecological resilience in a coastal mangrove community from the Galápagos Islands over the last 2700 years using three research questions: What are the ‘fast and slow’ processes operating in the coastal zone? Is there evidence for a threshold response? How can the past inform us about the resilience of the modern system?
[Pubmed: 21811594]
| | 7. |
1986 Oct |
The Role of Glycerol and Inorganic Ions in Osmoregulatory Responses of the Euryhaline Flagellate Chlamydomonas pulsatilla Wollenweber 1
Ahmad, Hellebust
Plant Physiol 1986 Oct;82(2):406-410.
Abstract
The green euryhaline flagellate Chlamydomonas pulsatilla Wollenweber, isolated from a coastal marine environment, was grown exponentially over the salinity range of 10 to 200% artificial seawater (ASW). The cellular volume and aqueous space of the alga, measured by [14C] mannitol and 3H2O tracer analyses of centrifuged cell pellets, ranged between 2.3 and 3.1 picoliters and between 1.5 and 2.1 picoliters, respectively. The nonaqueous space determined in those analyses (28-35%) was consistent with the cell composition of the alga. The glycerol content of the alga increased almost linearly with increasing salinity; its contribution to intracellular osmolality at 200% ASW was about 57%. The contribution of amino acids and soluble carbohydrates to the cell osmotic balance was small. Intracellular ion concentrations determined by analyzing centrifuged cell pellets of known [14C]mannitol space by atomic absorption spectrophotometry, and by neutron activation analyses of washed cells were similar. At 10% ASW, potassium and magnesium were the major cations, and chloride and phosphate were the major anions. The sodium and chloride content of the alga increased with increasing salinity; at 200% ASW the intracellular concentration of both sodium and chloride was about 400 millimolar. The intracellular osmolality (πint) matched closely the external osmolality (πext) over the entire salinity range except at 10% ASW where πint exceeded πext by 120 to 270 milliosmoles per kilogram H2O.
[Pubmed: 16665042]
| | 8. |
2011 Nov 24 |
Additions and corrections to the check list of the Noctuoidea (Insecta, Lepidoptera) of North America north of Mexico
Lafontaine, Schmidt
Zookeys 2011 Nov 24;(149):145-161. published online before print
Abstract
A total of 115 additions and corrections are listed and discussed for the check list of the Noctuoidea of North America north of Mexico published in 2010. Thirty-two of these are changes in authorship and/or date of publication or spelling. Taxonomic changes are 33 new or revised synonymies, three new combinations, and six revisions in status from synonymy to valid species.
[Pubmed: 22207802]
| | 9. |
2011 Dec 16 |
Cyanotoxins: Bioaccumulation and Effects on Aquatic Animals
Ferrão-Filho, Kozlowsky-Suzuki
Mar Drugs 2011 Dec 16;9(12):2729-2772. published online before print
Abstract
Cyanobacteria are photosynthetic prokaryotes with wide geographic distribution that can produce secondary metabolites named cyanotoxins. These toxins can be classified into three main types according to their mechanism of action in vertebrates: hepatotoxins, dermatotoxins and neurotoxins. Many studies on the effects of cyanobacteria and their toxins over a wide range of aquatic organisms, including invertebrates and vertebrates, have reported acute effects (e.g., reduction in survivorship, feeding inhibition, paralysis), chronic effects (e.g., reduction in growth and fecundity), biochemical alterations (e.g., activity of phosphatases, GST, AChE, proteases), and behavioral alterations. Research has also focused on the potential for bioaccumulation and transferring of these toxins through the food chain. Although the herbivorous zooplankton is hypothesized as the main target of cyanotoxins, there is not unquestionable evidence of the deleterious effects of cyanobacteria and their toxins on these organisms. Also, the low toxin burden in secondary consumers points towards biodilution of microcystins in the food web as the predominant process. In this broad review we discuss important issues on bioaccumulation and the effects of cyanotoxins, with emphasis on microcystins, as well as drawbacks and future needs in this field of research.
[Pubmed: 22363248]
| | 10. |
2012 Mar 14 |
A comparison of TO-PRO-1 iodide and 5-CFDA-AM staining methods for assessing viability of planktonic algae with epifluorescence microscopy.
Gorokhova E, Mattsson L, Sundström AM
J Microbiol Methods. 2012 Mar 14; [Epub ahead of print]
Abstract
Two fluorescent dyes, TO-PRO-1 iodide and 5-CFDA-AM, were evaluated for LIVE/DEAD assessment of unicellular marine algae Brachiomonas submarina and Tetraselmis suecica. Epifluorescence microscopy was used to estimate cell viability in predetermined mixtures of viable and non-viable algal cells and validated using microplate growth assay as reference measurements. On average, 5-CFDA-AM underestimated live cell abundance by ~25% compared with viability estimated by the growth assay, whereas TO-PRO-1 iodide provided accurate viability estimates. Furthermore, viability estimates based on staining with TO-PRO-1 iodide were not affected by a storage period of up to one month in -80°C, making the assay a good candidate for routine assessment of phytoplankton populations in field and laboratory studies.
[Pubmed: 22446098]
| | 11. |
2005 Apr 25 |
Marine toxicity assessment of imidazolium ionic liquids: acute effects on the Baltic algae Oocystis submarina and Cyclotella meneghiniana.
Latała A, Stepnowski P, Nedzi M, Mrozik W
Aquat. Toxicol. 2005 Jun 1;73(1):91-8. Epub 2005 Apr 25.
Abstract
Interest in ionic liquids for their potential in different chemical processes is increasing, as they are claimed to be environmentally benign and are very good non-volatile solvents for a wide range of applications. With regard to their physical and chemical characteristics, the properties of ionic liquids can be modified over a wide range because the cation's fine structure and the anion's identity can be altered. Since millions of ion combinations are possible it is of the highest importance to outline rational guidelines to develop technologically suitable but also environmentally harmless ionic liquids. This paper presents the results of a preliminary assessment of the toxicity of selected imidazolium ionic liquids towards marine algae. The selection of chemical entities was based on the t-SAR approach (thinking in terms of structure-activity relationships) focusing on the length (C(2)<R1<C(6)) or type (aliphatic-aromatic) of the side chain whereas head group (imidazolium) remained the same. The acute effect of ionic liquids was measured using the green alga Oocystis submarina and the diatom Cyclotella meneghiniana inhabiting the southern Baltic Sea. Standard algal testing procedures revealed significant differences in the responses of the two species. O. submarina appeared to acclimatize to the lower concentrations used: after ca. 5 days their ability to grow recovered, and initial densities were eventually restored. In the case of C. meneghiniana, growth in batch cultures was effectively inhibited throughout the experiment regardless of the ionic liquid concentration applied. Additionally, it was found that at higher salinities, the toxicity of 1-butyl- and 1-hexyl-3-methylimidazolium entities towards O. submarina was significantly lower than at low salinities.
[Pubmed: 15892995]
| | 12. |
1965 Apr |
THE EFFECT OF RADIATIONS ON REPLICATION IN BRACHIOMONAS SUBMARINA BOHLIN.
DUCOFF HS, BUTLER BD, GEFFON EJ
Radiat. Res. 1965 Apr;24:563-71.
[Pubmed: 14275316]
| | 13. |
1964 Nov |
X-RAY SURVIVAL STUDIES ON THE ALGA BRACHIOMONAS SUBMARINA BOHLIN.
DUCOFF HS, BUTLER BD, GEFFON EJ
Radiat. Res. 1964 Nov;23:446-53.
[Pubmed: 14229118]
| | 14. |
1998 Mar 9 |
A Novel 95-kD Protein Is Located in a Linker between Cytoplasmic Microtubules and Basal Bodies in a Green Flagellate and Forms Striated Filaments In Vitro
Geimer, Clees, Melkonian, Lechtreck
J Cell Biol 1998 Mar 9;140(5):1149-1158.
Abstract
The flagellar basal apparatus comprises the basal bodies and the attached fibrous structures, which together form the organizing center for the cytoskeleton in many flagellated cells. Basal apparatus were isolated from the naked green flagellate Spermatozopsis similis and shown to be composed of several dozens of different polypeptides including a protein band of 95 kD. Screening of a cDNA library of S. similis with a polyclonal antibody raised against the 95-kD band resulted in a full-length clone coding for a novel protein of 834 amino acids (90.3 kD). Sequence analysis identified nonhelical NH2- and COOH-terminal domains flanking a central domain of ∼650 residues, which was predicted to form a series of coiled-coils interrupted by short spacer segments. Immunogold labeling using a polyclonal antibody raised against the bacterially expressed 95-kD protein exclusively decorated the striated, wedge-shaped fibers, termed sinister fibers (sf-fibers), attached to the basal bodies of S. similis. Striated fibers with a periodicity of 98 nm were assembled in vitro from the purified protein expressed from the cloned cDNA indicating that the 95-kD protein could be a major component of the sf-fibers. This structure interconnects specific triplets of the basal bodies with the microtubular bundles that emerge from the basal apparatus. The sf-fibers and similar structures, e.g., basal feet or satellites, described in various eukaryotes including vertebrates, may be representative for cytoskeletal elements involved in positioning of basal bodies/centrioles with respect to cytoskeletal microtubules and vice versa.
[Pubmed: 9490727]
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