scholarly journals Inter-annual ciliate distribution variation within the late stratification oxycline in a monomictic lake, Lake Alchichica (Mexico)

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Ximena Sánchez Medina ◽  
Miroslav Macek ◽  
Fernando Bautista-Reyes ◽  
Andrea Perz ◽  
Patricia Bonilla Lemus ◽  
...  
Keyword(s):  
Species Composition ◽  
Water Column ◽  
Heterotrophic Bacteria ◽  
Life Cycles ◽  
Species Level ◽  
Epifluorescence Microscopy ◽  
Strictly Anaerobic ◽  
Coarse Filter ◽  
Lake Alchichica ◽  
Community Budget

<p>noxia, and ciliates might play a very important role in the plankton community budget there. We analysed changes in the composition and biomass of the ciliate assemblage and other microbial loop components throughout the oxycline just at the end of stratification in a warm-monomictic lake, Lake Alchichica, Mexico (four samplings: 2006-2008, 2010); the results were compared with those obtained from another lake from the region, La Preciosa, sampled in 2010. Bacteria, autotrophic picoplankton (APP) and flagellates were analysed using epifluorescence microscopy. Ciliates were evaluated either in DAPI stained samples (looking for pigmented organelles and/or ingested phototrophs) or in quantitative protargol stain (QPS) permanent preparations, where they were identified at the genus or species level. The end of the stratification period in Lake Alchichica was characterized by almost uniform heterotrophic picoplankton (HPP) numbers (10<sup>6</sup> cells mL<sup>-1</sup>) throughout the water column. Meanwhile, APP showed epilimnetic and/or metalimnetic maxima of 10<sup>5</sup> cells mL<sup>-1</sup> followed by an order of magnitude drop in the hypolimnion. A very important peak (10<sup>5</sup> cells mL<sup>-1</sup>) of the autotrophic or mixotrophic flagellate <em>Pyramimonas</em> sp. was observed repeatedly above and within the oxycline of Lake Alchichica. Ciliate biomass maxima were found around the oxycline and in the above-bottom layer. The top of the oxycline was dominated by <em>Euplotes</em> spp. and <em>Spirostomum teres</em> fine- to coarse-filter feeders (feeding upon APP, nanodiatoms and algae). Raptorial haptorids (in particular, <em>Phialina </em>sp.) were the second most important group, generally occupying the layer below euplotids, followed by <em>Holophrya</em> and <em>Prorodon</em> facultative anaerobic prostomes. Sometimes, strictly anaerobic <em>Caenomorpha</em> sp. was found to be important in the anoxic hypolimnion. Minute picoplankton feeding species (both APP and heterotrophic bacteria feeders) were important throughout the water column: in the epilimnion, vorticellids (2006-2008) or scuticociliates (2010) dominated. Typically, the scuticociliate maximum was located in the oxycline and/or above the bottom. Some microaerophilic species were isolated; thus, their identification could be carried out. However, the apparent polymorphic ciliate life cycles were not described completely, and the species composition was only estimated: two dominant species (SC 1 – <em>Cristigera</em>-like and SC 2 – <em>Cyclidim</em>-like) covered nearly the total scuticociliate biomass. Strictly anaerobic scuticociliates were not isolated but observed in the deepest layers of the lake (bacteria symbiotic <em>Isocyclidium globosum</em> and <em>Cristigera </em>sp.). Significant statistical relation within the ciliate distribution and environmental variables was not confirmed due to unique species composition in the respective years. However, general trends in the distribution of ciliates on a species level were observed. Scuticociliates, including two important tentatively identified species, did not present unambiguous ecological position, and the study of their live cycle should be the next step in investigations.</p>

MICROBES PARAMETERS OF WATER QUALITY FOR AQUACULTURE ON PARI ISLAND WATERS

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lies Indah Sutiknowati
Keyword(s):  
Pathogenic Bacteria ◽  
Heterotrophic Bacteria ◽  
Total Coliform ◽  
Total Cell ◽  
Epifluorescence Microscopy ◽  
Coliform Bacteria ◽  
Total Density ◽  
Shellfish Aquaculture ◽  
Microbiological Parameters ◽  
Phosphate Nitrate

The objective of this research was to evaluate waters quality in Pari island waters for aquaculture purpose based on bacteriological information conducted in Mei and September 2011. Microbiological parameters analyzed were total density of bacteria for coliforms, E.coli, pathogenic, heterotrophic, halotoleran, phosphate-nitrate-ammonia breaker, and total cells. Method to analyze coliform bacteria was filtration, identification of pathogenic bacteria using biochemical test, density analises for heterotrophic bacteria, analises for phosphate-nitrate-ammonia breaker bacteria using pour plate, and total cell using Acridine Orange Epifluorescence Microscopy. Results showed that the abundance of total coliform cell was about 1000-7000 colony forming unit (cfu)/100 ml. The abundance of heterotrophic, halotolerant, phosphate-nitrate-ammonia bacteria in seawater was (3.6-4.3)x105 cfu/ml, (1.1-1.3)x105 cfu/ml, (0.5-3.44)x103cfu/ml; and (3.6-6.7)x105 cfu/ml, (1.6-2.7)x105 cfu/ml, (0.6-5.22)x103 cfu/ml in sediment, respectively. The total cell of bacteria was (0.05-2.1)x107cells/ml. The dog-conch (Strombus turturella) and blood-clamps (Anadara granosa) can survive in Pari Island and there was a significant increase in sea grass litter with growth average of 0.67 mm/day and 0.90 mm/day. During snails and clamps growth, there were found several genus of pathogenic bacteria such as Salmonella, Vibrio, Aeromonas, Pseudomonas, Citrobacter, Proteus, Shigella, Hafnia, and Yersinia. The results showed that Pari island waters was suitable for developing shellfish aquaculture dog conch and blood clamps. Keywords: bacteria, parameter, shellfish, aquaculture.

scholarly journals Evaluation of culturable, nitrifying, ammonium-oxidizing, and metabolically active bacteria in shrimp farm effluents of Kino Bay, Sonora, México

2012 ◽  
Vol 64 (3) ◽  
pp. 895-909 ◽  
Author(s):  
Nolberta Huerta-Aldaz ◽  
M.A. López-Torres ◽  
J.E. Valdez-Holguín ◽  
R.H. Barraza-Guardado
Keyword(s):  
Heterotrophic Bacteria ◽  
Natural Populations ◽  
Control Site ◽  
Epifluorescence Microscopy ◽  
Nitrifying Bacteria ◽  
Production Cycle ◽  
Mean Values ◽  
Discharge Area ◽  
Shrimp Farm ◽  
Active Bacteria

Bacteria from shrimp farm effluents in Kino Bay, Sonora, M?xico were evaluated during the 2008 production cycle. The culturable bacterial populations considered were viable heterotrophic bacteria (VHB) and Vibrio-like bacteria (VLB). In addition, total bacteria (TB), metabolically active bacteria (MAB), nitrifying bacteria (NB), and ammonium-oxidizing bacteria (AOB) were quantified by epifluorescence microscopy. Three sampling sites were established in the influence area of drain and one control site far from the discharge area. Average concentrations of VHB and VLB were 103 and 102 CFU mL-1, respectively. The TB ranged from 107 to 109 cells mL-1. The mean values of Mrelated to TB counts in the affected area were higher throughout the culture cycle compared to the control site, ranging from 1.09 to 27.35%. These results indicate that effluents modify the natural loads of bacteria in the discharge area, which could affect natural populations and the microbial balance of the area.

Historical Changes in Large River Fish Assemblages of the Americas

2005 ◽  
Keyword(s):  
Species Composition ◽  
Human Population ◽  
Fish Assemblages ◽  
Pacific Salmon ◽  
Large River ◽  
Life Cycles ◽  
Fish Assemblage Structure ◽  
River Region ◽  
Major Industry ◽  
Mackenzie River

<em>Abstract.</em>—The Mackenzie River is the second longest river in North America and drains 1.8 × 10<sup>6</sup> km<sup>2</sup>. of Arctic and sub-Arctic Canada. Thirty-eight fish species have been recorded in the lower Mackenzie River. These species represent a unique mixture of fishes from the Beringian and Agassisian refugia. Many of the species important for subsistence and commercial fisheries in the lower Mackenzie River have complex life cycles and undertake long migrations to spawn, rear, and overwinter. The lower Mackenzie River is a relatively pristine environment with no dams or major industry, a low human population, and species only lightly harvested. This explains why the species composition is relatively stable. However, recently, the effects of climate change may be starting to influence the species composition in terms of greater frequency of rare species such as Pacific salmon. Moreover, a major gas pipeline proposed for the lower Mackenzie River region will probably disturb the fish assemblage structure.

Biofilm characterization of several wastewater treatment plants with rotating biological contactors in Madrid (Spain)

1998 ◽  
Vol 37 (4-5) ◽  
pp. 215-218 ◽  
Author(s):  
B. Pérez-Uz ◽  
C. Franco ◽  
M. Martín-Cereceda ◽  
L. Arregui ◽  
I. Campos ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Species Composition ◽  
Wastewater Treatment Plants ◽  
Species Level ◽  
Plant Performance ◽  
Ciliate Species ◽  
Level Ii ◽  
Rotating Biological Contactors ◽  
One Year

Ciliate communities were studied in the biofilms of three plants with rotating biological contactors (RBCs) over the period of one year. The aims of this study were: (i) to characterize ciliates to species level; (ii) to determine their abundance and spatial variation through the biological system; and (iii) to relate the spatial segregation and richness of ciliate species to plant performance. A number of species ranging from 33 to 67 were identified at the different plants. The overall best represented groups were peritrichs followed by scuticociliates (Las Matas), cyrtophorids (Boadilla) or hypotrichs (Camarma). Comparison of RBCs and activated sludge communities indicated that even though both were mainly constituted by peritrichs, differences in groups and species composition were observed.

scholarly journals Decreased Snow Cover Stimulates Under-Ice Primary Producers but Impairs Methanotrophic Capacity

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Sarahi L. Garcia ◽  
Anna J. Szekely ◽  
Christoffer Bergvall ◽  
Martha Schattenhofer ◽  
Sari Peura
Keyword(s):  
Climate Change ◽  
Snow Cover ◽  
Water Column ◽  
Relative Abundance ◽  
Heterotrophic Bacteria ◽  
Methane Emissions ◽  
Boreal Lakes ◽  
Climate Change Scenarios ◽  
Primary Producers ◽  
Microbial Composition

ABSTRACT Climate change scenarios anticipate decreased spring snow cover in boreal and subarctic regions. Forest lakes are abundant in these regions and substantial contributors of methane emissions. To investigate the effect of reduced snow cover, we experimentally removed snow from an anoxic frozen lake. We observed that the removal of snow increased light penetration through the ice, increasing water temperature and modifying microbial composition in the different depths. Chlorophyll a and b concentrations increased in the upper water column, suggesting activation of algal primary producers. At the same time, Chlorobiaceae, one of the key photosynthetic bacterial families in anoxic lakes, shifted to lower depths. Moreover, a decrease in the relative abundance of methanotrophs within the bacterial family Methylococcaceae was detected, concurrent with an increase in methane concentration in the water column. These results indicate that decreased snow cover impacts both primary production and methane production and/or consumption, which may ultimately lead to increased methane emissions after spring ice off. IMPORTANCE Small lakes are an important source of greenhouse gases in the boreal zone. These lakes are severely impacted by the winter season, when ice and snow cover obstruct gas exchange between the lake and the atmosphere and diminish light availability in the water column. Currently, climate change is resulting in reduced spring snow cover. A short-term removal of the snow from the ice stimulated algal primary producers and subsequently heterotrophic bacteria. Concurrently, the relative abundance of methanotrophic bacteria decreased and methane concentrations increased. Our results increase the general knowledge of microbial life under ice and, specifically, the understanding of the potential impact of climate change on boreal lakes.

Planktonic and Benthic Bacteriovorous Protozoa at Eleven Stations in Puget Sound and Adjacent Pacific Ocean

1969 ◽  
Vol 26 (2) ◽  
pp. 299-304 ◽  
Author(s):  
Bruce Lighthart
Keyword(s):  
Pacific Ocean ◽  
Water Column ◽  
Deep Sea ◽  
Heterotrophic Bacteria ◽  
Puget Sound ◽  
Ecological Role ◽  
Population Densities ◽  
Sediment Samples

Bacteriovorous Protozoa and heterotrophic bacteria quantitatively cultured from 31 samples collected at eight stations in Puget Sound and three in the adjacent Pacific Ocean (one station being 1520 m deep) ranges from undetectable to approximately 1000 Protozoa per ml and 5–80,000 bacteria/ml. Flagellates in the genera Bodo, Oikomonas, Monas, Rynchomonas, and Actinomonas were the most prevalent forms cultured. One ciliate and several sarcodinoids were also grown. The regression of predatory Protozoa on prey bacteria in sediment samples was calculated to be 580 bacteria for every bacteriovorous protozoan. Population densities of both bacteriovorous Protozoa and heterotrophic bacteria in the samples decreased from sediment to the water column, and from shore seaward. The ecological role of bacteriovorous Protozoa in the shallow and deep sea is discussed.

Potential for nitrogen fixation in the rhizosphere and habitat of natural stands of the wild rice Zizania aquatica

1979 ◽  
Vol 57 (11) ◽  
pp. 1285-1291 ◽  
Author(s):  
M. T. Ogan
Keyword(s):  
Nitrogen Fixation ◽  
Water Column ◽  
Acetylene Reduction ◽  
Wild Rice ◽  
Heterotrophic Bacteria ◽  
Nitrogenase Activity ◽  
Early Summer ◽  
Zizania Aquatica ◽  
Natural Stands ◽  
Root Surfaces

The potential for nitrogen fixation in the rhizosphere and habitat of natural stands of Zizania aquatica (L) was studied by the acetylene reduction method. The data obtained suggested that this potential exists in the water column, the rhizosphere soil of the wild rice habitat, and on the root surfaces of the plants.In situ determination of rates of nitrogen fixation in the water column showed low but significant levels only in late spring – early summer and the rate was thought to be dependent on the presence of the blue-green algae Aphanizomenon. Laboratory experimental evidence showed that acetylene reduction by rhizosphere surface soil was attributable to Oscillatoria species while bacteria were more active in the subsurface soil and on the root surfaces. The bacteria-mediated nitrogenase activity was often preceded by a long lag period. The heterotrophic bacteria involved were enumerated, isolated, and characterised and they belong to the genera Azotobacter and Clostridium. Algal components of blooms occurring within the stands of Zizania at various times were identified.

Host-based formation of fauna of lung helminths, its biological and taxonomic classification

2016 ◽  
Vol 3 (3) ◽  
pp. 345-369 ◽  
Author(s):  
Демиаскевич ◽  
A. Demiaszkiewiz ◽  
Мовсесян ◽  
S. Movsesyan ◽  
ПанайотоваПенчева ◽  
...  
Keyword(s):  
Species Composition ◽  
Family Life ◽  
Life Cycles ◽  
Land Snails ◽  
Taxonomic Classification ◽  
Intermediate Hosts ◽  
The Third ◽  
Object Of Study ◽  
Biological Group

Object of study: Studies of lung helminths from various groups were performed. Elaboration of biological and taxonomic classification of these species has been proposed. Materials and methods: 16 species from families Cervidae, Bovidae, Leporidae and humans were studied for lung helminths in Russia (South and central), Armenia, Bulgaria, Poland. The helminths found were studied using a scope of traditional and elaborated helminthological methods. Results and discussion: In lungs of mammals studied 23 helminth species have been found including 1 of Taeniidae (Echinococcus granulosus), 4 of Dictyocaulidae and 18 of Protostrongylidae. We have divided species composition of these lung helminths into three biological groups. The first biological group included nematodes from Dictyocaulidae family. Life cycles of those helminths are monoxenous (they are geohelminths). The second group includes helminths from family Protostrongylidae. Their life cycles include intermediate hosts — land snails and so they are dixenous (biohelminths). The third group includes an agent of a quite dangerous zoonosis — Echinococcus granulosis larvae. These cestodes also develop per dixenous type, but their intermediate hosts are vertebrates with definitive hosts also vertebrate, mostly carnivores. Taxonomic classification for family Protostrongylidae haelminths is also proposed.

Intestinal helminth parasites of the ray Raja naevus in British waters

1977 ◽  
Vol 51 (1) ◽  
pp. 11-21 ◽  
Author(s):  
A. H. McVicar
Keyword(s):  
Species Composition ◽  
Significant Variation ◽  
Nematode Species ◽  
Life Cycles ◽  
Helminth Fauna ◽  
Intestinal Helminth ◽  
Helminth Parasites ◽  
Geographical Differences ◽  
Host Sex ◽  
Host Diet

ABSTRACTFive cestode, one monogenean, and two nematode species comprised the “normal” intestinal helminth fauna of Raja naevus in British waters. An additional two nematodes, a digenean, an acanthocephalan and a crustacean recorded are considered to be accidental infections. Geographical differences in the species composition and level of infection are noted and discussed. Short descriptions of the tetraphyllidean cestode Echeneibothrium sp. and the nematode Capillaria sp. are given, but the species, although probably both new, are left unnamed. The intensity of cestode infections show two patterns associated with host length and these are discussed in relation to variations in host diet. Speculations are made on the cestode life cycles. Only Echeneibothrium sp. numbers showed any significant variation associated with host sex.

scholarly journals Interactions between Sponges and the Water Column:  Nutrient Utilisation and Feeding by New Zealand  Subtidal Sponges

2021 ◽  
Author(s):  
◽  
Alejandra Perea-Blázquez
Keyword(s):  
New Zealand ◽  
Water Column ◽  
Heterotrophic Bacteria ◽  
Marine Ecosystems ◽  
Sponge Species ◽  
Suspension Feeders ◽  
Functional Roles ◽  
Nutrient Utilisation ◽  
Wide Range ◽  
Micro Organisms

<p>Sponges are an important component of New Zealand subtidal communities and play many key functional roles in marine ecosystems, including competition for space, facilitating primary production, nutrient cycling, bioerosion, and interactions with the water column. Sponges are involved in the bidirectional movement of detritus, nutrients, micro-organisms and planktonic particles both to and from the benthos to the pelagic ecosystem, thereby affecting pelagic processes. As suspension-feeders, sponges are capable of filtering large volumes of water, and they depend on food that is suspended in the water column, meaning that their interaction with the water column is likely to be very important. The main goal of my research was to investigate the interactions between sponges and the water column and how this varies in relation to sponge characteristics, nutrient fluxes, seasonality and food supply. I studied the diet composition of 10 sponge species that are abundant and widely distributed along the south coast of Wellington, New Zealand. I found that the diet of the sponge species analysed comprised three types of picoplanktonic organisms: heterotrophic bacteria, Prochlorococcus, and Synechococcus. These micro-organisms (picoplankton) that sponges feed on are vital for benthic food webs because they are involved in the transformation and cycling process of dissolved inorganic nutrients before they become available to other marine organisms. The results from this thesis demonstrated that different sponge species have different retention efficiencies for different types of picoplankton and I propose that this suggests intra-phyletic food particle niche partitioning among sponges. While these findings support the partitioning of food resources between different co-existing sponge species, they also suggest that partitioning may not be essential for co-existence, as some species had similar retention efficiencies implying an overlap in resource use. By measuring rates of carbon assimilation in the form of planktonic food particles, combined with data on a number of characteristics of the sponge species analysed, I found that sponge assemblages play a key role in the transfer of energy from the water column to the benthos. The results from this thesis indicate that there is a wide range of food concentrations in the rocky reefs where the study species are living, over which retention rate, nutrient utilisation and carbon consumption varied temporally. This emphasises the importance of understanding temporal variation in productivity, and suggests that such variations are likely to have important implications for suspension-feeders. By integrating the feeding results with estimations of oxygen consumption rates, and the amount of carbon obtained from the different micro-organisms found in the water column, preliminary carbon budgets were created. These budgets were used to quantify the capacity of carbon obtained via heterotrophic suspension-feeding to support sponge metabolism, as well as infer the potential for this carbon to support other processes such as sponge growth and reproduction. Overall, this project was the first to consider the functional roles of sponges in New Zealand marine ecosystems and provided useful information on their ecological and biological importance. The large amounts of carbon that sponges transfer from the water column to the benthos, in conjunction with the other findings of my thesis, increase our understanding of the ecology of temperate sponges.</p>

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