scholarly journals Benthic Cyanobacterial Diversity and Antagonistic Interactions in Abrolhos Bank: Allelopathy, Susceptibility to Herbivory, and Toxicity

2022 ◽  
Vol 8 ◽  
Author(s):  
Felipe de Vargas Ribeiro ◽  
Taiara Aguiar Caires ◽  
Marcela Alvarenga de Almeida Simões ◽  
Paulo Iiboshi Hargreaves ◽  
Livia Bonetti Villela ◽  
...  
Keyword(s):  
Southeastern Brazil ◽  
Allelopathic Effect ◽  
Benthic Organisms ◽  
Cascading Effects ◽  
Cyanobacteria Blooms ◽  
Cyanobacterial Species ◽  
Rdna Sequencing ◽  
Brine Shrimps ◽  
Cyanobacterial Diversity ◽  
Antagonistic Interactions

Benthic cyanobacterial mats (BCMs) are conspicuous components of coral reef communities, where they play key ecological roles as primary producers among others. BCMs often bloom and might outcompete neighboring benthic organisms, including reef-building corals. We investigated the cyanobacterial species composition of three BCMs morphotypes from the marginal reef complex of Abrolhos Bank (Southeastern Brazil). Also, we assessed their allelopathic effects on coral zooxanthellae, their susceptibility to herbivory by fish, and their toxicity to brine shrimp nauplii. Morphology and 16S rDNA sequencing unveiled the cyanobacteria Moorena bouillonii, Okeania erythroflocculosa, Adonisia turfae, Leptolyngbya sp., and Halomicronema sp. as components of BCMs from Abrolhos. BCMs cell-free filtrates and extracts exerted an allelopathic effect by reducing the growth of the ex hospite Symbiodinium sp. in culture. BCMs-only treatments remained untouched in field susceptibility assays in contrast to macroalgae only and mixed BCMs-macroalgae treatments that had the macroalgae fully removed by reef fish. Crude aqueous extracts from BCMs were toxic to brine shrimps in acute assays. Besides unveiling the diversity of BCMs consortia in Abrolhos, our results cast some light on their allelopathy, antiherbivory, and toxicity properties. These antagonistic interactions might promote adverse cascading effects during benthic cyanobacteria blooms and in gradual shifts to BCMs-dominated states.

scholarly journals New morphological data and molecular diagnostic of Henneguya friderici (Myxozoa: Myxobolidae), a parasite of Leporinus friderici (Osteichthyes: Anostomidae) from southeastern Brazil

2017 ◽  
Vol 26 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Letícia Poblete Vidal ◽  
José Luis Luque
Keyword(s):  
Body Length ◽  
18S Rdna ◽  
Genetic Similarity ◽  
Morphological Data ◽  
Southeastern Brazil ◽  
Molecular Diagnostic ◽  
Similarity Analysis ◽  
Rdna Sequencing ◽  
The Family ◽  
Gill Filaments

Abstract The myxozoan Henneguya friderici is a parasite of the gills, intestine, kidney and liver of Leporinus friderici, a characiform fish belonging to the family Anostomidae. Forty-two specimens of L. friderici that had been caught in the Mogi Guaçú River, state of São Paulo, were studied. Elongated white plasmodia were found in the gill filaments of 10 host specimens (24%). The mature spores had an ellipsoidal body with polar capsules of equal size and caudal length greater than body length. This study also described 18S rDNA sequencing of H. friderici infecting the gill filaments. This produced a sequence of 1050 bp that demonstrated significant genetic differences with previously described species of Henneguya. Similarity analysis using sequences from species that clustered closest to those produced by this study showed that the species with greatest genetic similarity to H. friderici was H. leporinicola, with 94% similarity.

scholarly journals Feeding habits of whitemouth croaker Micropogonias furnieri (Perciformes: Sciaenidae) in Caraguatatuba Bay, southeastern Brazil

2015 ◽  
Vol 63 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Márcia Regina Denadai ◽  
Flávia Borges Santos ◽  
Eduardo Bessa ◽  
Wellington Silva Fernandez ◽  
Camila Luvisaro ◽  
...  
Keyword(s):  
Organic Matter ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Southeastern Brazil ◽  
Opportunistic Behavior ◽  
Large Bank ◽  
Benthic Organisms ◽  
Southern Area ◽  
Varied Diet ◽  
Micropogonias Furnieri

Abstract This study examined the feeding habits of Micropogonias furnieri in Caraguatatuba Bay. Samples were collected monthly between May 2003 and October 2004 by trawling in two areas (southern and northern parts of the bay). The fish were measured and their stomach contents identified. The abundance was compared between areas and among months. M. furnieri was more abundant in the southern area and in the spring of 2003. The population was dominated by small immature individuals. This species had a varied diet, feeding on crustaceans, bivalve siphons, and polychaetes. The ingestion of bivalve siphons may be an opportunistic behavior, due to the presence of a large bank of the bivalve Tivela mactroides in the study area. The high proportion of unidentified organic matter in the stomach corroborates published reports that this species eats continuously and has rapid digestion. These results demonstrate that M. furnieri can be considered a carnivore, with a preference for benthic organisms.

Nephrococcus serbicus, a new coccoid cyanobacterial species from Božana Cave, Serbia

Phytotaxa ◽  
2016 ◽  
Vol 289 (2) ◽  
pp. 135
Author(s):  
SLAĐANA POPOVIĆ ◽  
GORDANA SUBAKOV SIMIĆ ◽  
ALEKSANDRA KORAĆ ◽  
IGOR GOLIĆ ◽  
JIŘÍ KOMÁREK
Keyword(s):  
New Species ◽  
Relative Humidity ◽  
Light Intensity ◽  
Morphological Characteristics ◽  
First Record ◽  
Confocal Laser ◽  
Inorganic Matter ◽  
Cyanobacterial Species ◽  
Cyanobacterial Diversity ◽  
A New Species

During the investigation of cyanobacterial diversity in Božana Cave, which is situated in a limestone region in western Serbia, a new species of cyanobacterium belonging to the genus Nephrococcus was found. So far, there are only three records of the genus Nephrococcus in the whole world (recorded in China and Nepal), which was reviewed and is presented in this study. Detailed morphology of the examined cyanobacterium was documented by digital photography and drawings using light and confocal laser microscopy. Ecology (temperature, relative humidity and light intensity) and biofilm parameters (chlorophyll-a, the water content and the content of organic/inorganic matter in the biofilm) were also measured, and the associated taxa described. Detailed morphological characteristics that indicated the differences between this species from those already known, allowed us to describe this cyanobacterium as a new species, Nephrococcus serbicus. This is the first record of the genus Nephrococcus in the territory of Europe.

How diverse are coccoid cyanobacteria? A case study of terrestrial habitats from the Atlantic Rainforest (São Paulo, Brazil)

Phytotaxa ◽  
2014 ◽  
Vol 178 (2) ◽  
pp. 61 ◽  
Author(s):  
WATSON ARANTES GAMA-JR ◽  
Haywood Dail Laughinghouse IV ◽  
Célia Leite Sant'Anna
Keyword(s):  
Sao Paulo ◽  
Atlantic Rainforest ◽  
Southeastern Brazil ◽  
São Paulo ◽  
Generic Level ◽  
Paulo State ◽  
Terrestrial Habitats ◽  
High Species Richness ◽  
Cyanobacterial Diversity

The present study analyzed 267 samples of terrestrial habitats from different fragmented areas of the Atlantic Rainforest located in São Paulo State (southeastern Brazil), finding 61 taxa of coccoid cyanobacteria, 21 of which we were only capable of identifying at the generic level. The samples were examined using light microscopy and populations were morphometrically separated and taxonomically identified. Among the identified taxa, we propose the elevation of Chroococcus turgidus var. subviolaceus to Chroococcus subviolaceus comb. et stat. nov. Due to the high species richness found, we assume that the Atlantic Rainforest is a ‘hotspot’ of coccoid cyanobacterial diversity and should be better studied, in addition to other tropical ecosystems and terrestrial habitats, which have been shown to be suitable places for cyanobacterial diversity establishment.

Allelopathic effect of cumin (Cuminum cyminum L.) on seed germination of three weeds

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
A Soleymanifard ◽  
R Naseri ◽  
A Mirzaei ◽  
H Naserirad
Keyword(s):  
Seed Germination ◽  
Allelopathic Effect ◽  
Cuminum Cyminum

Cascading effects of fishing on Galapagos rocky reef communities

2007 ◽  
Vol 343 ◽  
pp. 77-85 ◽  
Author(s):  
JI Sonnenholzner ◽  
LB Ladah ◽  
KD Lafferty
Keyword(s):  
Rocky Reef ◽  
Cascading Effects ◽  
Reef Communities

Modeling cetacean habitat use in an urban coastal area in southeastern Brazil

2020 ◽  
Vol 642 ◽  
pp. 227-240
Author(s):  
L Lodi ◽  
R Tardin ◽  
G Maricato
Keyword(s):  
Habitat Use ◽  
Protected Areas ◽  
Linear Models ◽  
Anthropogenic Activities ◽  
Buffer Zone ◽  
Humpback Whales ◽  
Southeastern Brazil ◽  
Major Influence ◽  
Cetacean Species ◽  
Few Data

Most studies of cetacean habitat use do not consider the influence of anthropogenic activities. We investigated the influence of environmental and anthropogenic variables on habitat use by humpback Megaptera novaeangliae and Bryde’s whales Balaenoptera brydei off the coast of the Brazilian city of Rio de Janeiro. Although there are 2 marine protected areas (MPAs) in this area, few data are available on cetacean habitat use or on the overlap of different cetacean species within these MPAs. Our aim was to evaluate the effectiveness of the MPAs and propose a buffer zone to better protect the biodiversity of the study area. We conducted systematic surveys and developed spatial eigenvector generalized linear models to characterize habitat use by the species in the study area. Habitat use by humpback whales was influenced only by depth, whereas for Bryde’s whales there was the additional influence of anthropogenic variables. For Bryde’s whales, which use the area for feeding, sea surface temperature and the distance to anchorages had a major influence on habitat use. We also showed that neither of the MPAs in the study area adequately protects the hotspots of either whale species. Most of the humpback whale grid cells with high sighting predictions were located within 2 km of the MPAs, while areas of high sighting prediction of Bryde’s whales were located up to 5 km from the MPAs, closer to beaches. Our findings provide important insights for the delimitation of protected areas and zoning of the MPAs.

Changes in the Population Density of Pathogenic Microorganisms in Response to the Allelopathic Effect of Thypha Latifolia

2014 ◽  
Vol 1 (1) ◽  
pp. 31-36 ◽  
Author(s):  
O. Zhukorskiy ◽  
O. Gulay ◽  
V. Gulay ◽  
N. Tkachuk
Keyword(s):  
Cell Density ◽  
Allelopathic Effect ◽  
Pathogenic Microorganisms ◽  
Sterile Water ◽  
Erysipelothrix Rhusiopathiae ◽  
Pathogenic Leptospira ◽  
Favorable Conditions ◽  
And Control ◽  
The Impact ◽  
Control Samples

Aim. To determine the response of the populations of Erysipelothrix rhusiopathiae and Leptospira interrogans pathogenic microorganisms to the impact of broadleaf cattail (Thypha latifolia) root diffusates. Methods. Aqueous solutions of T. latifolia root diffusates were sterilized by vacuum fi ltration through the fi lters with 0.2-micron pore diameter. The experimental samples contained cattail secretions, sterile water, and cultures of E. rhusiopathiae or L. interrogans. The same amount of sterile water, as in the experimental samples, was used for the purpose of control, and the same quantity of microbial cultures was added in it. After exposure, the density of cells in the experimental and control samples was determined. Results. Root diffusates of T. latifolia caused an increase in cell density in the populations of E. rhusiopathiae throughout the whole range of the studied dilutions (1:10–1:10000). In the populations of the 6 studied serological variants of L. interrogans spirochetes (pomona, grippotyphosa, copenhageni, kabura, tarassovi, canicola), the action of broadleaf cattail root diffusates caused the decrease in cell density. A stimulatory effect was marked in the experimental samples of the pollonica serological variant of leptospira. Conclusions. The populations of E. rhusiopathiae and L. interrogans pathogenic microorganisms respond to the allelopathic effect of Thypha latifolia by changing the cell density. The obtained results provide the background to assume that broadleaf cattail thickets create favorable conditions for the existence of E. rhusiopathiae pathogen bacteria. The reduced cell density of L. interrogans in the experimental samples compared to the control samples observed under the infl uence of T. latifolia root diffusates suggests that reservoirs with broadleaf cattail thickets are marked by the unfavorable conditions for the existence of pathogenic leptospira (except L. pollonica).

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