scholarly journals Microalgal pigments and their relation with phytoplankton carbon biomass on the northeastern Mediterranean Sea shore, with special emphasis on nanophytoplankton

2019 ◽  
Author(s):  
Merve Konucu ◽  
Elif Eker-Develi ◽  
Hasan Örek ◽  
Şehmuz Başduvar
Keyword(s):  
Environmental Factors ◽  
Mediterranean Sea ◽  
Community Composition ◽  
Coastal Waters ◽  
Phytoplankton Community ◽  
Group Contribution ◽  
Carbon Biomass ◽  
Diatom Abundance ◽  
Accessory Pigment ◽  
First Time

Summary Marker pigments are used as a proxy for biomass of distinct phytoplankton classes in different oceanic regions. However, sometimes disagreements are observed between microscopy and accessory-pigment based approaches in distinct regions mainly due to changing environmental factors governing diversity and structure of community composition. In this study, concordance between microscopy and HPLC-CHEMTAX methods were investigated first time in coastal waters of Erdemli, Turkey, in the Levantin Basin of the northeastern Mediterranean Sea by weekly intervals during 2015-2016. According to our results, marker pigment of diatoms, fucoxanthin, which was the most prominent pigment in the study area during most of the year, was a better indicator of diatom abundance than diatom carbon biomass. CHEMTAX derived values of diatom chlorophyll a (Chl a) were not in concert with either abundance or carbon biomass of this group. Contribution of dinoflagellates and cryptophytes to the phytoplankton community was underestimated with pigment based approach. Accessory pigment of cyanophytes, zeaxanthin, was also an important pigment in the samples. Biomass of haptophytes seemed to be overestimated by HPLC-CHEMTAX analysis. In contrast to diatoms, CHEMTAX derived chlorophyll a values of cryptophytes were correlated with abundance of this group but not with alloxanthin. Inclusion of live counts of nanoplanktic cryptophytes, haptophytes and prasinophytes provided a better correlation between microscopy and pigment based results. According to CHEMTAX analysis, nanoplankton and picoplankton constituted ∼55% of Chl a in the region.

scholarly journals Are Bacterio- and Phytoplankton Community Compositions Related in Lakes Differing in Their Cyanobacteria Contribution and Physico-Chemical Properties?

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 855
Author(s):  
Mikołaj Kokociński ◽  
Dariusz Dziga ◽  
Adam Antosiak ◽  
Janne Soininen
Keyword(s):  
Environmental Factors ◽  
Community Composition ◽  
Phytoplankton Community ◽  
Heterotrophic Bacteria ◽  
Bacterial Community Composition ◽  
Physical Factors ◽  
Research Attention ◽  
Phytoplankton Community Composition ◽  
The Impact ◽  
Bacteria Communities

Bacterioplankton community composition has become the center of research attention in recent years. Bacteria associated with toxic cyanobacteria blooms have attracted considerable interest. However, little is known about the environmental factors driving the bacteria community, including the impact of invasive cyanobacteria. Therefore, our aim has been to determine the relationships between heterotrophic bacteria and phytoplankton community composition across 24 Polish lakes with different contributions of cyanobacteria including the invasive species Raphidiopsis raciborskii. This analysis revealed that cyanobacteria were present in 16 lakes, while R. raciborskii occurred in 14 lakes. Our results show that bacteria communities differed between lakes dominated by cyanobacteria and lakes with minor contributions of cyanobacteria but did not differ between lakes with R. raciborskii and other lakes. Physical factors, including water and Secchi depth, were the major drivers of bacteria and phytoplankton community composition. However, in lakes dominated by cyanobacteria, bacterial community composition was also influenced by biotic factors such as the amount of R. raciborskii, chlorophyll-a and total phytoplankton biomass. Thus, our study provides novel evidence on the influence of environmental factors and R. raciborskii on lake bacteria communities.

scholarly journals First record of Octopus vulgaris (Cuvier, 1797) (Octopodidae) in the Iraqi coastal waters, NW Arabian Gulf

2021 ◽  
Vol 13 (3) ◽  
pp. 1048-1051
Author(s):  
Anwar M.J. Al-Maliky ◽  
Khaled Kh. Al-Khafaji ◽  
Tariq H. Al-Maliky
Keyword(s):  
Environmental Factors ◽  
Coastal Waters ◽  
Persian Gulf ◽  
Arabian Gulf ◽  
First Record ◽  
Morphological Features ◽  
The Other ◽  
Octopus Vulgaris ◽  
The World ◽  
First Time

The present study identifies one species of the genus Octopus in the order: Octopoda (Cephalopoda: Mollusca), recorded forthe first time in the Iraqi coastal waters and Arabian-Persian Gulf. The study extended from January 2019 to December of thesame year. The Octopus specimens were seasonally obtained from the fishing trawlers operating in the Iraqi coastal waters inthe South of Al- Fao District, Basrah- Iraq, NW Arabian Gulf. The Octopus was identified as O. vulgaris in Iraqi coastal watersdepending on morphological features. The habitats of living specimens are briefly described. Some observations were reported on the occurrence of this species and the measurement of some environmental factors. The species was identified up to spe-cies level using standard literature. This species looks similar morphologically to the species which is already identified from the other areas around the world. The present study records significant expansion in the distribution range of this species.

scholarly journals Effects of temperature and phytoplankton community composition on subitaneous and resting egg production rates of Acartia omorii in Tokyo Bay

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ayumi Tsunashima ◽  
Hiroshi Itoh ◽  
Toshiya Katano
Keyword(s):  
Water Temperature ◽  
Community Composition ◽  
Egg Production ◽  
Phytoplankton Community ◽  
Tokyo Bay ◽  
Production Rates ◽  
Phytoplankton Community Composition ◽  
Carbon Biomass ◽  
Effects Of Temperature ◽  
Second Peak

AbstractTo clarify the effects of temperature and phytoplankton community composition on Acartia omorii (Copepoda: Calanoida) egg production, its abundance and egg production rates were investigated from 2016 to 2018 in Tokyo Bay, Japan. Abundance was high from March to May (> 3.0 × 104 individuals m−3) and low or undetected from late June to December (≤ 0.4 × 104 individuals m−3). In 2018, most eggs were subitaneous until April; diapause eggs appeared in May when the water temperature exceeded 20 °C. The weight-specific egg production rate (SEPR, Cegg Cfemale−1 day−1) had two peaks. In the first peak in January, > 90% of eggs were subitaneous; in contrast, in the second peak in May, 60% of eggs were unhatched, including diapause eggs. The first peak of subitaneous eggs may contribute to planktonic population development from March to May. In contrast the second peak of diapause eggs probably enhances their recurrence in the next winter. Multiple regression analysis revealed that subitaneous SEPR showed a negative response, whereas diapause SEPR showed a positive response to temperature. Subitaneous SEPR positively correlated with the proportion of small diatoms in phytoplankton carbon biomass, whereas unhatched SEPR positively correlated with the proportion of inedible preys in large diatoms and dinoflagellates. Edible diatoms may induce subitaneous egg production, whereas low-food availability may induce diapause egg production. These results suggest that phytoplankton composition and water temperature have strong impacts on the dynamics of A. omorii via egg production.

A checklist of parasitic helminths reported from sixty-five species of marine fish from Turkey including two new records of monogeneans

Zootaxa ◽  
2005 ◽  
Vol 1063 (1) ◽  
pp. 33 ◽  
Author(s):  
AHMET ÖKTENER
Keyword(s):  
Mediterranean Sea ◽  
Marine Fish ◽  
Coastal Waters ◽  
New Records ◽  
Sea Of Marmara ◽  
Parasitic Helminths ◽  
The Mediterranean ◽  
First Time ◽  
Belone Belone

This study provides a checklist of 114 parasitic helminths (87 Platyhelminthes; 16 Nemathelminthes; 9 Acanthocephala; 2 Annelida) reported from 65 marine fish collected from Turkey since 1931, including locations where fish were collected. Two species of microcotylids (Monogenea): Pyragraphorus pyragraphorus (Mac Callum and Mac Callum, 1913) on garrick, Trachynotus ovatus (Linnaeus, 1758) (Carangidae), from the Mediterranean Sea and Axine belones Abildgaard, 1794 on garfish, Belone belone (Linnaeus,1761) (Belonidae), from the Sea of Marmara are reported for the first time in Turkish coastal waters.

scholarly journals Abiotic environmental factors override phytoplankton succession in shaping both free-living and attached bacterial communities in a highland lake

AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Huan Wang ◽  
Rong Zhu ◽  
Xiaolin Zhang ◽  
Yun Li ◽  
Leyi Ni ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Bacterial Community ◽  
Species Composition ◽  
Community Composition ◽  
Bacterial Communities ◽  
Phytoplankton Community ◽  
Bacterial Community Composition ◽  
Free Living ◽  
The Impact ◽  
Abiotic Environmental Factors

Abstract Bacterial communities are an important part of biological diversity and biogeochemical cycling in aquatic ecosystems. In this study, the relationship amongst the phytoplankton species composition and abiotic environmental factors on seasonal changes in the community composition of free-living and attached bacteria in Lake Erhai were studied. Using Illumina high-throughput sequencing, we found that the impact of environmental factors on both the free-living and attached bacterial community composition was greater than that of the phytoplankton community, amongst which total phosphorus, Secchi disk, water temperature, dissolved oxygen and conductivity strongly influenced bacterial community composition. Microcystis blooms associated with subdominant Psephonema occurred during the summer and autumn, and Fragilaria, Melosira and Mougeotia were found at high densities in the other seasons. Only small numbers of algal species-specific bacteria, including Xanthomonadaceae (Proteobacteria) and Alcaligenaceae (Betaproteobacteria), were tightly coupled to Microcystis and Psephonema during Microcystis blooms. Redundancy analysis showed that although the composition of the bacterial communities was controlled by species composition mediated by changes in phytoplankton communities and abiotic environmental factors, the impact of the abiotic environment on both free-living and attached bacterial community compositions were greater than the impact of the phytoplankton community. These results suggest that the species composition of both free-living and attached bacterial communities are affected by abiotic environmental factors, even when under strong control by biotic factors, particularly dominant genera of Microcystis and Psephonema during algal blooms.

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