Gut content microbiota of introduced bigheaded carps ( Hypophthalmichthys spp.) inhabiting the largest shallow lake in Central Europe

Abstract

Studying the microbiota in the alimentary tract of bigheaded carps (Hypophthalmichthys spp.) gained special interest recently, as these types of investigations on non-native fish species may lead to a better understanding of their ecological role and feeding habits in an invaded habitat. For microbiological examinations, bigheaded carp gut contents and water column samples from Lake Balaton (Hungary) were collected from spring to autumn in 2013.Denaturing Gradient Gel Electrophoresis (DGGE) and pyrosequencing of the 16S rRNA gene were performed to reveal the composition. According to the DGGE patterns, bacterial communities of water samples separated clearly from that of the intestines. Moreover, the bacterial communities in the foreguts and hindguts were also strikingly dissimilar. Based on pyrosequencing, both foregut and hindgut samples were predominated by the fermentative genus Cetobacterium (Fusobacteria). The presence of some phytoplankton taxa and the high relative abundance of cellulose-degrading bacteria in the guts suggest that intestinal microbes may have an important role in digesting algae and making them utilizable for bigheaded carps that lack cellulase enzyme. In turn, the complete absence of typical heterotrophic freshwater bacteria in all studied sections of the intestines indicated that bacterioplankton probably has a negligible role in the nutrition of bigheaded carps.

Gut Bacterial Communities in Geographically Distant Populations of Farmed Sea Bream (Sparus aurata) and Sea Bass (Dicentrarchus labrax)

“…In this study, core OTUs refer to the ones found in each individual midgut sample. The effect of the surrounding water was not studied since it is expected to be insignificant for the GITM diversity as shown previously [ 20 , 21 , 22 , 23 ]. A single water sampling on the same day of the midgut sampling of the investigated fish individuals, would not be so informative due to the following two factors: 1) marine bacterioplankton is characterized by strong variation in short (e.g., [ 24 , 25 ]) and longer [ 26 , 27 , 28 , 29 ] time scales, and 2) the life cycle of farmed S. aurata and D. labrax spans over several months.…”

Comparative study of gut microbiota in wild and captive Malaysian Mahseer (Tor tambroides)

“…Anaerobic Cetobacterium spp. promotes decomposition of consumed organic debris, phytoplankton, or zooplankton (Borsodi et al., ). This species was also common in intestinal tracts of goldfish, common carp, grass carp, ayu, tilapia, zebrafish, rainbow trout, channel catfish, largemouth bass, and bluegill (Adeoye et al., ; Etyemez & Balcázar, ; Larsen, Mohammed, & Arias, ; Roeselers et al., ; Tsuchiya, Sakata, & Sugita, ; Van Kessel et al., ).…”

Comparison of planktonic and reed biofilm bacteria in different riverine water bodies of river Danube

“…The results of this study are also in accordance with a long‐term study on the seasonal patterns of free‐living bacteria of the mesoeutrophic Lake Tiefwaren (Germany) where high abundance of the lineage “ Candidatus Planktophila limnetica” was retrieved by DGGE method (Rösel, Allgaier, & Grossart, ). In another study, season independent presence of DGGE band sequences closely related to Candidatus Planktophila limnetica was detected in the water of Lake Balaton (Hungary), and the high abundance of this lineage was verified by pyrosequencing (Borsodi et al, ). Due to the lack of a pure culture, the ecological role of these freshwater Actinobacteria has not been clarified yet (Jezbera et al, ).…”