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Abstract: Sensors based on in vivo measurements of photosynthetic pigments fluorescence enable real-time phytoplankton monitoring with high spatial and temporal resolution. A combination of chlorophyll a (CHL) and phycocyanin (PC) fluorescence sensors was used for phytoplankton quantification and differentiation in two small water bodies, Koseze Pond and pond in Hotinja vas. The high correlation of CHL and PC fluorescence signals with biovolume was confirmed during the two-year monitoring in anatural pond environment in spite of a seasonal succession of the phytoplankton. Additionally, disturbances of the sensors were investigated. Water bodies containing predominantly algae yielded false positive signals of the PC sensor, which reached up to 1% of the intensity of the CHL signal. Similarly, underestimated counts of cyanobacteria measured with CHL fluorescence sensor can be adjusted using PC fluorescence sensor.
Keywords: small water bodies, algae, cyanobacteria, fluorescence sensors, biovolume
Published in DiRROS: 01.08.2024; Views: 260; Downloads: 177
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Abstract: Many non-native algal species are found in waters all over the world. Many terms are used to describe such organisms that have expanded their distribution. However, a unified model or concept remains to be defined, as how biological ‘invasions’ are seen depends on the perspective. Understanding invasive organisms is important for biodiversity, science policy and water management. During monitoring sampling at Slivniško Lake (Slovenia) in 2016, the curved diatom Aulacoseira ambigua f. japonica Tuji & D.M. Williams was identified. This species originates from Japan, from where it was described more than 100 years ago. The chronology of the published distributions of A. ambigua f. japonica defines its spread from Japan to Asia, then to western Russia and South Africa, and now to central Europe. This study provides further evidence that A. ambigua f. japonica has become established in Europe (Slovenia), as supported by light microscopy and scanning electron microscopy. To the best of our knowledge, this is the first qualitative and quantitative description of A. ambigua f. japonica in Europe. It has been suggested that the shape of these algal colonies is significant for the interpretation of ecological information, and indeed, also in the present case, spiral colonies were found in this eutrophic water body. Although curved cells and colonies can also be interpreted as (sub)populations or morphological variants, only detailed molecular studies can reveal if these also have taxonomic significance.
Keywords: algae, introduced species, invasive species, scanning electron microscopy
Published in DiRROS: 01.08.2024; Views: 329; Downloads: 229
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Abstract: To develop novel crop breeding strategies, it is crucial to understand the mechanisms underlying the interaction between plants and their pathogens. Network modeling represents a powerful tool that can unravel properties of complex biological systems. In this study, we aimed to use network modeling to better understand immune signaling in potato (Solanum tuberosum). For this, we first built on a reliable Arabidopsis (Arabidopsis thaliana) immune signaling model, extending it with the information from diverse publicly available resources. Next, we translated the resulting prior knowledge network (20,012 nodes and 70,091 connections) to potato and superimposed it with an ensemble network inferred from time-resolved transcriptomics data for potato. We used different network modeling approaches to generate specific hypotheses of potato immune signaling mechanisms. An interesting finding was the identification of a string of molecular events illuminating the ethylene pathway modulation of the salicylic acid pathway through Nonexpressor of PR Genes1 gene expression. Functional validations confirmed this modulation, thus supporting the potential of our integrative network modeling approach for unraveling molecular mechanisms in complex systems. In addition, this approach can ultimately result in improved breeding strategies for potato and other sensitive crops.
Keywords: network modelling, potato, molecular biology
Published in DiRROS: 01.08.2024; Views: 278; Downloads: 233
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Abstract: Two obligate cave-dwelling species of cyclopoid copepods (Copepoda, Cyclopoida) were discovered inside caves in central Thailand. Siamcyclops cavernicolus gen. et sp. nov. was recognised as a member of a new genus. It resembles Bryocyclops jankowskajae Monchenko, 1972 from Uzbekistan (part of the former USSR). It differs from it by (1) lack of pointed triangular prominences on the intercoxal sclerite of the fourth swimming leg, (2) mandibular palp with three setae, (3) spine and setal formulae of swimming legs 3.3.3.2 and 5.5.5.5, respectively, and (4) specific shape of spermatophore. Metacyclops thailandicus sp. nov. resembles M. cushae Reid, 1991 from Louisiana (USA). It differs from it by (1) distal segment of the endopod of the fourth swimming leg with one apical spine, (2) the fifth swimming legs with one broad segment, (3) the spine formula of the distal segment of the exopod of the swimming legs 3.4.3.3, and (4) well developed anal operculum reaching articulation with caudal rami. Detailed descriptions of the habitats of the new species and up-to-date keys to the genera and subgenera of the Bryocyclops and Microcyclops groups are provided, along with an updated list of obligate groundwater species of Copepoda in Southeast Asia.
Keywords: Siamcyclops cavernicolus gen. et sp. nov., Metacyclops thailandicus sp. nov., stygobionts, groundwater environment, epikarstic drip
Published in DiRROS: 01.08.2024; Views: 232; Downloads: 251
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Abstract: Artificial reefs (ARs) are man-made structures used with the aim of improving fisheries and increasing natural production of biological resources. In 2006 an AR made of three types of modules was sunk near an underwater sewage outfall. The objectives of the project were: (a) to use the AR to restock some target species of commercial interest and (b) to promote biodiversity in selected areas. The epibenthic macrofauna that had settled on this AR was annually monitored for five years (2007-2011) using non-destructive photographic methods. A total of 88 taxa from 8 phyla were identified, with a predominance of Porifera, Mollusca and Ascidiacea. Among the types of modules used to construct the AR, polyethylene panel nets were functional for bivalve settlement in the first year, whereas concrete structures seemed to perform best in promoting biodiversity in terms of species richness in the long term. Nevertheless, the 5-year monitoring period was too short to speculate on the stability or homeostasis of communities settled on the AR in terms of ecological succession.
Keywords: artificial reefs, macrozoobenthos, Adriatic Sea, photographic monitoring, marine biology, hydrobiology
Published in DiRROS: 01.08.2024; Views: 532; Downloads: 262
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