Factors influencing taxonomic composition and abundance of macrozoobenthos in extralittoral zone of shallow eutrophic lakes

AbstractThe thickness and duration of ice cover are strongly influenced by global warming. The aim of this study was to determine chemical (organic carbon, total nitrogen and phosphorus concentrations) and biological (nanoflagellates, ciliates, phytoplankton, rotifers, crustaceans) parameters under the ice cover in three eutrophic lakes (Masurian Lake District, Poland), differing in their morphometry and fisheries management. All the studied groups of organisms showed high variability over a short time. Taxonomic composition of planktonic communities, except for rotifers and phytoplankton, was similar in all lakes. Nanoflagellates were dominated by autotrophic forms, while ciliates were primarily composed of small oligotrichs and prostomatids. Nano-sized diatoms and mixotrophic cryptophytes were the most important components of phytoplankton and they formed an under-ice bloom in one lake only. Rotifers were mainly represented by

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Relationship between marine epilithic diatoms and environmental variables in oligotrophic bay, NE Mediterranean

Mediterranean Marine Science ◽

10.12681/mms.14151 ◽

2018 ◽

pp. 223 ◽

Cited By ~ 2

Author(s):

DUBRAVKA HAFNER ◽

ANA CAR ◽

NENAD JASPRICA ◽

TATJANA KAPETANOVIĆ ◽

IRIS DUPČIĆ RADIĆ

Keyword(s):

Taxonomic Composition ◽

Diatom Community ◽

Silicate Concentration ◽

Factors Influencing ◽

Composition And Structure ◽

Infraspecific Taxa ◽

Monthly Distribution ◽

Ne Mediterranean ◽

The Difference ◽

Epilithic Diatom

The taxonomic composition and structure of a marine epilithic diatom community were sampled from the bottom of the two sites at monthly intervals from January to December 2011 in the small semi-enclosed oligotrophic Neum Bay in Bosnia and Herzegovina (Middle Adriatic). Altogether, 264 diatom taxa (species and infraspecific taxa) within 69 genera were identified. Among them, 149 and 203 taxa occurred in samples from the shallow (0.5 m depth) and deep (8 m depth) sites, respectively. The monthly distribution of most of the diatoms was irregular and high numbers of sporadic taxa were found. SIMPER analysis indicated that the difference between shallow and deep sites could be largely attributed to the frequently recorded diatom taxa and those with high percentage abundances. They were Halamphora coffeiformis, Caloneis excentrica, Cocconeis scutellum var. scutellum, Licmophora flabellata, Licmophora gracilis, Licmophora sp., Navicula abunda, Rhabdonema adriaticum, and Striatella unipunctata. Canonical Correspondence Analysis (CCA) showed that temperature, oxygen saturation (O2/O2′), silicate concentration (SiO4), and salinity were the most important factors influencing diatom community structure in the bay.

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Zooplankton community structure of Volzhsko-Kamsky National Nature Reserve

Proceedings of the Zoological Institute RAS ◽

10.31610/trudyzin/2016.320.3.294 ◽

2016 ◽

Vol 320 (3) ◽

pp. 294-303

Author(s):

O.Y. Derevenskaya ◽

E.N. Unkovskaya

Keyword(s):

Water Quality ◽

Community Structure ◽

Nature Reserve ◽

Zooplankton Community ◽

Water Quality Assessment ◽

Taxonomic Composition ◽

Eutrophic Lakes ◽

Middle Volga Region ◽

Zooplankton Community Structure ◽

Taxonomic Groups

Long-term studies had been held on the lakes of the Volga-Kama State Natural Reserve (Russia). The aim of our research was to study the biodiversity of planktonic rotifers and crustaceans, zooplankton community structure characteristics and also water quality assessment with bioindication methods. 137 species of zooplankton were identified in our research. In all lakes rotifers were presented by highest number of species. The lowest number ofspecies was found for copepods. In general, the species composition of zooplankton is typical for eutrophic lakes of Middle Volga region. The species most commonly found in lakes are indicators of eutrophic waters. We also analyzed and compared the structure of zooplankton communities and taxonomic composition in different types of nature reserve lakes. It was shown that changing the relationship between taxonomic groups of zooplankton and increase of rotifers in the community is also a sign of eutrophication. According to the abundance rotifers dominated in most lakes. Drastic changes in quantitative indicators of zooplankton during the growing season, due to an increase in the abundance of one of the species were typical of eutrophic lakes of the reserve. Studies have shown that in meso-eutrophic and eutrophic lakes the indicators that reflect the structure of the zooplankton community are the most informative for the assessment of the water quality. Lakes Raifskoe and Ilinskoe were the least polluted, and characterized by the structure of communities of mesotrophic type. The rest of the lakes are more prone to eutrophication processes and community structure of zooplankton corresponds to eutrophic lakes type.

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Factors influencing adhesive bonding at the bone/implant interface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130201 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1114-1115

Author(s):

Julie A. Martini ◽

Robert H. Doremus

Keyword(s):

Electron Microscopy ◽

Adhesive Bonding ◽

Microscopy Study ◽

Electron Microscopy Study ◽

Bone Implant ◽

Factors Influencing ◽

Lr White ◽

Transmission Electron ◽

New Zealand White Rabbits ◽

Scanning Electron

Tracy and Doremus have demonstrated chemical bonding between bone and hydroxylapatite with transmission electron microscopy. Now researchers ponder how to improve upon this bond in turn improving the life expectancy and biocompatibility of implantable orthopedic devices.This report focuses on a study of the- chemical influences on the interfacial integrity and strength. Pure hydroxylapatite (HAP), magnesium doped HAP, strontium doped HAP, bioglass and medical grade titanium cylinders were implanted into the tibial cortices of New Zealand white rabbits. After 12 weeks, the implants were retrieved for a scanning electron microscopy study coupled with energy dispersive spectroscopy.Following sacrifice and careful retrieval, the samples were dehydrated through a graduated series starting with 50% ethanol and continuing through 60, 70, 80, 90, 95, and 100% ethanol over a period of two days. The samples were embedded in LR White. Again a graduated series was used with solutions of 50, 75 and 100% LR White diluted in ethanol.

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Factors Influencing Electrophysiologic Responsivity in Normal Adults

Journal of Speech and Hearing Research ◽

10.1044/jshr.0804.323 ◽

1965 ◽

Vol 8 (4) ◽

pp. 323-347

Author(s):

Robert Goldstein ◽

Benjamin RosenblÜt

Keyword(s):

Conditioned Stimulus ◽

White Light ◽

Pure Tone ◽

Alpha Rhythm ◽

White Women ◽

White Men ◽

Inverse Relation ◽

Factors Influencing ◽

Electrodermal Responses ◽

Normal Adults

Electrodermal and electroencephalic responsivity to sound and to light was studied in 96 normal-hearing adults in three separate sessions. The subjects were subdivided into equal groups of white men, white women, colored men, and colored women. A 1 000 cps pure tone was the conditioned stimulus in two sessions and white light was used in a third session. Heat was the unconditioned stimulus in all sessions. Previously, an inverse relation had been found in white men between the prominence of alpha rhythm in the EEG and the ease with which electrodermal responses could be elicited. This relation did not hold true for white women. The main purpose of the present study was to answer the following questions: (1) are the previous findings on white subjects applicable to colored subjects? (2) are subjects who are most (or least) responsive electrophysiologically on one day equally responsive (or unresponsive) on another day? and (3) are subjects who are most (or least) responsive to sound equally responsive (or unresponsive) to light? In general, each question was answered affirmatively. Other factors influencing responsivity were also studied.

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