Specificity of diatom communities attached on the carapace of the European pond turtle (Emys orbicularis)

Periphytic diatoms growing on aquatic turtle carapaces provide an interesting example of biofouling on an animal substrate. This study dealt with the question of the specificity of epizoic diatom communities for the case of the European pond turtle (Emys orbicularis) and across five water bodies in South-Eastern France. 375 diatom taxa have been identified on the European pond turtle carapace. The results showed that the epizoic communities of the five sites were significantly different from each other. The epizoic diatom communities could be clearly distinguished from epilithic and epiphytic communities only in two out of five sites. The differences in composition at the two sites resulted from the greater abundance of some species and life forms. However, the characteristic pattern of diatom communities on the carapaces was not the same at the two sites. It therefore appeared that the European pond turtle’s carapace did not harbour specific diatom communities and can rather be considered a neutral substrate.

Periphytic diatoms in the presence of a cyanobacterial bloom: A case study of the Vrutci Reservoir in Serbia

Despite their unique ecology and implications for ecological assessment, diatoms in lentic ecosystems are still insufficiently studied in both scientific research and operational monitoring. In particular, the ecology of periphytic diatoms relative to the global expansion of cyanobacterial blooms in lakes has not been described at all. This study aims to describe the diversity and dynamics of a periphytic diatom community in the Vrutci Reservoir during Planktothrix rubescens bloom, and to evaluate the adequacy of standard diatom index implementation in lentic ecosystems relative to the diatom index adapted for lakes ? the Trophic Diatom Index for Lakes (TDIL). The study was conducted in the Vrutci Reservoir in western Serbia. Periphyton was developed on an artificial glass substrate during the summer of 2015, following a depth gradient of a stratified water column. Diatom diversity and abundance, as well as diatom indices were estimated. Discounting the cyanobacterial bloom, 79 taxa of diatoms were recorded and among them the species Aneumastus stroesei as the first representative of the entire genus Aneumastus ever to be detected in Serbia. Diatom distribution along the depth gradient was clearly associated with shifts in environmental conditions. TDIL showed an advantage over standard diatom indices in terms of stability during experimental period and uniformity along the depth gradient, indicating the necessity for further testing of this index performance in lakes, and consequently local water-quality legislation update.

Komposisi Diatom (Bacillariophyceae) Perifitik pada Substrat Kaca di Sungai Kapuas Kecil Kota Pontianak Kalimantan Barat

Periphytic diatom (Bacillariophyceae) is diatom that lives attach on a substrate and it was dependent on the environmental conditions in an aquatic ecosystem. This study was aimed to determine the composition of periphytic diatom (Bacillariphyceae) on glass substrate and the condition of physical chemical water in Kapuas Kecil River. This study was conducted from September to December 2017. The sampling stations were chosen by purposive random sampling method and divided into four stations. At each station in the river were installed 5 baskets each with 5 glass slides. Samples were collected from three baskets with sampling intervals on day 2, 5, 10, 15, and 20. The result shows that the composition of periphytic diatoms (Bacillariophyceae) in Kapuas Kecil River consists of 29 genera from 2 orders (Pennales and Centrales) and 12 families. The most commonly genera found of periphytic diatom were Eunotia, Gomphonema, Frustulia and Nitzschia.

Periphytic diatoms (Bacillariophyta) in streams from three Conservation Units of central Brazil: Pinnularia Ehrenberg

ABSTRACT This study aimed to survey the genus Pinnularia Ehrenberg (Bacillariophyta) in five preserved streams located in three conservation units (Brasília National Park, Chapada dos Veadeiros National Park and Terra Ronca State Park). Periphyton was collected in different substrata during the dry and rainy seasons (years 2012 to 2013), totalizing 25 sample units. Altogether, 23 taxa were identified, being P. subanglica, P. angustivalva and P. butantanum the most frequent. Pebble and sand were the richest substrates, with nine taxa each. Among the 23 taxa reported, 13 are cited for the first time for the central Brazil: P. angusta var. angusta, P. angustivalva, P. butantanum, P. divergens var. biconstricta, P. divergens var. mesoleptiformis, P. gibba var. subundulata, P. paulensis, P. persudetica var. persudetica, P. subgibba var. angustarea, P. subgibba var. capitada, P. superpaulensis, P. viridiformis var. minor and P. undula var. undula.

Periphytic Diatoms in the Polluted Linggi (sensu stricto) and Kundor Rivers, Negeri Sembilan, Malaysia

The investigation in this paper aimed to describe periphytic diatom assemblage, species composition and distribution in tropical polluted Linggi (sensu stricto or s.s.) and Kundor rivers in Negeri Sembilan, Malaysia. Regardless of ecological and environmental conditions, diatoms were the numerically dominant flora among periphytic algae collected monthly over a period of 13 months at nine stations in the Linggi (s.s.) and Kundor rivers. The freshwater periphytic diatom samples were collected mainly using artificial substrates and supplemented with natural substrates. The periphytic diatoms thus collected from both natural and artificial substrates comprised 86 taxa (82 pennate and 4 centric forms) belonging to 21 genera. Of the 86 species, 71 species were found colonized in artificial substrates while the remaining 15 species were recorded exclusively on natural substrates. On the whole, the most common diatoms in both rivers combined were Eunotia vanheurckii, Gomphonema parvulum, Nitzschia palea, Pinnularia braunii, Navicula cryptocephala, Achnanthes saxonica, Achnanthes minutissima and Pinnularia microstauron. The most abundant species were E. vanheurckii, N. palea, A. saxonica, G. parvulum and A. minutissima.