Changes of bacterioplankton apparent species richness in two ornamental fish aquaria

Abstract

We analysed the 16S rRNA gene diversity within the bacterioplankton community in the water column of the ornamental fish Pterophyllum scalare and Archocentrus nigrofasciatus aquaria during a 60-day growth experiment in order to detect any dominant bacterial species and their possible association with the rearing organisms. The basic physical and chemical parameters remained stable but the bacterial community at 0, 30 and 60 days showed marked differences in bacterial cell abundance and diversity. We found high species richness but no dominant phylotypes were detected. Only few of the phylotypes were found in more than one time point per treatment and always with low relative abundance. The majority of the common phylotypes belonged to the Proteobacteria phylum and were closely related to Acinetobacter junii, Pseudomonas sp., Nevskia ramosa, Vogesella perlucida, Chitinomonas taiwanensis, Acidovorax sp., Pelomonas saccharophila and the rest belonged to the α-Proteobacteria, Bacteroidetes, Actinobacteria, candidate division OP11 and one unaffiliated group. Several of these phylotypes were closely related to known taxa including Sphingopyxis chilensis, Flexibacter aurantiacus subsp. excathedrus and Mycobacterium sp. Despite the high phylogenetic diversity most of the inferred ecophysiological roles of the found phylotypes are related to nitrogen metabolism, a key process for fish aquaria.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-66) contains supplementary material, which is available to authorized users.

‘Candidatus Megaira polyxenophila’ gen. nov., sp. nov.: Considerations on Evolutionary History, Host Range and Shift of Early Divergent Rickettsiae

“…The Candidatus Megaira polyxenophyla subclade is composed of the four newly characterized sequences and the previously published sequences of the symbionts of D. oligothrix BOD9 [28], Carteria cerasiformis , and Pleodorina japonica [10]. It additionally contains seven sequences derived from the screenings of microbial communities: EF520417 from an acid-impacted lake [51], FJ612282 from lake Dongping [52], AF523878 from forested wetland [53], DQ223223 from subsurface water of the Kalahari Shield [54], JX105713 from bacterioplankton in an ornamental fish aquarium [55], JF828749 from waste water [56], and JN869203 from water of lake Taihu [57]. Candidatus Megaira subclade B comprises seven sequences, six sequences of eukaryotic-associated bacteria: FJ203077, associated with Montastraea faveolata [58], DQ395479 and DQ395439, associated with a deep-sea octacoral [59], HE648945-47 associated with Bryopsis sp.…”

An Experimental Brackish Aquaponic System Using Juvenile Gilthead Sea Bream (Sparus aurata) and Rock Samphire (Crithmum maritimum)

“…Data were tested for normality and homogeneity with Kolmogorov-Smirnov and Levene's tests, respectively. Independent t-tests were considered statistically significant at p < 0.05 [31]. Statistical analyses were carried out using the software package IBM SPSS Statistics V22.…”

“…Furthermore, total organic carbon (TOC) and total nitrogen (TN) were analysed using a Shimadzu TOC analyser (TOC-VCSH) coupled with a chemilumine scence detector (TNM-1 TN unit), thus creating a simultaneous analysis system. TOC analysis was performed using the Combustion-Infrared method [31]. The principle of this method is that a microportion of the sample is injected into a heated reaction chamber packed with an oxidative catalyst, which in our case was Pt/Al 2 O 3 .…”

Diversity and Universality of Endosymbiotic Rickettsia in the Fish Parasite Ichthyophthirius multifiliis

“…Members of the subclade Ca. Megaira polyxenophila were identified in both marine and freshwater ciliates ( Vannini et al, 2005 ), in green algae ( Kawafune et al, 2012 ), in lake water from the US ( Percent et al, 2008 ) and China, in subsurface water from South Africa, and in aquaria in Greece ( Vlahos et al, 2013 ). The other two subclades, Ca.…”