Bioaccumulative Characteristics of Polybrominated Diphenyl Ethers in Channel Catfish and Fish Feeds from China

PBDEs are widely used brominated flame retardant, which are increasingly reported in the environment. Concentrations of thirteen PBDEs in a large number of channel catfish and fish feeds collected from Hubei province of China were investigated in this study. A fast isotopic dilution GC-MS method was firstly developed to simultaneously determine thirteen PBDEs in channel catfish and fish feeds in this study, and especially for the first time PBDEs in fish feeds. Pressurized liquid extraction and multi-layer silica gel column chromatography cleanup were used, some important steps and crucial parameters were modified and intensified compared with other literatures, and GC and MS conditions were optimized. The limits of quantitation values of 0.25 - 5 μg·kg-1 wet weight in channel catfish were calculated for PBDEs;so did 1 - 20 μg·kg-1 wet weight in fish feeds. In addition, good repeatability and accuracy of the whole method were achieved. The established methods were therefore suitable for the simultaneous determinations of thirteen PBDEs in these samples at trace contamination levels. Using the established methods, PBDEs emerged in 10 of 180 channel catfish and 13 of 115 fish feeds, and the dominant PBDEs homologues were PBDE-28, PBDE-47, PBDE-100, PBDE-99, PBDE-154, PBDE-153 and PBDE-183. The detection rates of seven PBDEs congeners were in turn respectively 1.74%, 7.83%, 4.35%, 5.22%, 3.48%, 2.61% and 2.61% in fish feeds, and detection rates of seven PBDEs congeners were in turn respectively 1.11%, 3.89%, 2.22%, 1.67%, 1.11%, 1.11% and 1.11% in channel catfish. There was significant correlation in PBDEs between matching channel catfish and fish feeds (R2 = 0.742, P < 0.001, n = 30), suggesting that fish feeds contaminated with PBDEs possibly resulted in PBDEs residual in channel catfish through biological transfer.

From oral structure to molecular evidence:new insights into the evolutionary phylogeny of the ciliate order Sessilida(Protista,Ciliophora),with the establishment of two new families and new contributions to the poorly studied family Vaginicolidae

Ciliated protists represent one of the most primitive and diverse lineages of eukaryotes,with nuclear dimorphism,a distinctive sexual process(conjugation),and extensive genome rearrangements.Among divergent ciliate lineages,the peritrich order Sessilida includes members with a colonial lifestyle,which may hint to an independent evolutionary attempt for multicellularity,although they are still single-celled organisms.To date,the evolution and phylogeny of this group are still far from clear,in part due to the paucity of molecular and/or morphological data for many taxa.In this study,we extend taxon sampling of a loricate group of sessilids by obtaining 69 new r DNA(SSU r DNA,ITS1-5.8S rDNA-ITS2,and LSU r DNA)sequences from 20 wellcharacterized representative species and analyze the phylogenetic relationships within Sessilida.The main findings are:(i)the genera Rhabdostyla and Campanella each represents a unique taxon at family level,supporting the establishment of two new families,i.e.,Rhabdostylidae n.fam.and Campanellidae n.fam.,respectively,the former being sister to a morphologically heterogeneous clade comprising Astylozoidae and several incertae sedis species and the latter occupying the basal position within the Sessilida clade;(ii)the structure of infundibular polykinety 3 is likely to be a phylogenetically informative character for resolving evolutionary relationships among sessilids;(iii)differences between sparsely and the densely arranged silverline systems could be a suprageneric taxonomic character;(iv)the monophyly of Vaginicolidae is confirmed,which is consistent with its specialized morphology,i.e.,the possession of a typical peritrich lorica which might be an apomorphy for this group;(v)within Vaginicolidae,the monotypic Cothurniopsis sensu Stokes,1893 is a synonym of Cothurnia Ehrenberg,1831,and a new combination is created,i.e.,Cothurnia valvata nov.comb.;(vi)Vaginicola sensu lato comprises at least two distinctly divergent clades,one affiliated with Thuricola and the other with a systematically puzzling clade represented by Vaginicola tincta.

Morphological and molecular examination of the ciliate family Lagynusidae(Protista,Ciliophora,Prostomatea)with descriptions of two new genera and two new species from China

Ciliates in the class Prostomatea play an important role in the global microbial loop due to their signifcant abundances and broad feeding strategies at the foundation of food webs.Despite their importance in ecosystems,the taxonomy and systematics of this group of ciliates has long been poorly understood,with this being especially true for members of the family Lagynusidae.Here we examine four lagynusids collected from sandy beaches in China,using silver-staining and 18S rRNA gene sequencing techniques.These investigations revealed two new genera and two new species and provided details for two little known forms:Penardella marina gen.nov.,sp.nov.,Apolagynus cucumis(as reported by Penard.Études sur les infusoires d’eau douce.Georg and Cie,Genève,1922)gen.nov.,comb.nov.,Lagynus minutus sp.nov.,and Lagynus elegans(Engelmann in Z Wiss Zool 11:347-393,1862)Quennerstedt(Acta Univ Lund 4:1-48,1867).Penardella gen.nov.can be morphologically distinguished by having more than three dikinetidal perioral kineties.Apolagynus gen.nov.difers from the closely related genus Lagynus in the absence of a conspicuous neck-like region.The ciliature of Apolagynus cucumis is revealed here for the frst time,which demonstrates the classifcation of this species within Lagynusidae.Furthermore,Apolagynus binucleatus(Jiang et al.,2021)comb.nov.is established according to the new fnding.The results of our phylogenetic analyses based on the 18S rRNA gene support the establishment of two new genera and indicate that Lagynusidae is monophyletic,which further strengthens its valid taxonomic status.

Redescription of five tintinnine ciliates (Alveolata: Ciliophora: Oligotrichea) from coastal waters of Qingdao, China

Tintinnine ciliates are widely distributed around the world and are characterized by the possession of a lorica that is highly diverse in structure and morphology.In the present study,five tintinni nes,namely Tintinnopsis cf.radix,T.evert a Kofoid and Campbell,1929,T.mulctrella Kofoid and Campbell,1929,Eutintinnus inflatus Marshall,1969,and Favella ehrenbergii(Claparede and Lachmann,1858)Jorgensen,1924,were collected from coastal waters of Qingdao,China.Three are newly recorded from China,i.e.,T.evert a,T.mulctrella,and E.inflatus.The morphology of the lorica and cell proper of all five species are described and compared with original and subsequent descriptions.The morphology in vivo of the lorica and cell proper of all five species are described and compared with original and subsequent descriptions.In addition,the ciliary patterns of F.ehrenbergii and T.cf.radix are revealed based on protargol-stained specimens.

Integrative studies on the taxonomy and molecular phylogeny of four new Pleuronema species(Protozoa,Ciliophora,Scuticociliatia)

The ciliate genus Pleuronema comprises approximately 30 nominal species and has been reported in freshwater,brackish water,and marine habitats.Nevertheless,recent studies have indicated that there might be a large undiscovered species diversity.In the present work,four new Pleuronema species,namely P.foissneri sp.nov.,P.parasmalli sp.nov.,P.parasalmastra sp.nov.,and P.paraorientale sp.nov.,collected from Shenzhen,southern China,was investigated using taxonomic methods.The diagnosis,description,comparisons with morphologically related species and detailed morphometric data are supplied for each.The small subunit ribosomal RNA(SSU rRNA)gene of the four new species is sequenced and their molecular phylogeny is analyzed.The SSU rRNA gene tree shows that Pleuronema is polyphyletic comprising several separate clades.All four new species cluster consistently with P.orientale KF206429,P.puytoraci KF840520 and P.setigerum FJ848874 within the core Pleuronematidae+Peniculistomatidae clade.Phylogenies of Pleuronematidae-related taxa are also discussed.

Phylogeny of the anaerobic ciliate genus Sonderia(Protista:Ciliophora:Plagiopylea),including the description of three novel species and a brief revision of the genus

Anaerobic protists in general,and ciliates in particular,are important components of anoxic or hypoxic environments,however,their diversity remains underestimated.Sonderia is a poorly studied genus that is distributed worldwide and is commonly found in anaerobic environments.In the present study,the taxonomy and phylogeny of three new species,namely Sonderia aposinuata sp.nov.,Sonderia paramacrochilus sp.nov.and Sonderia steini sp.nov.,collected from China,were investigated based on microscopic observations and SSU rRNA gene sequencing methods.Sonderia aposinuata sp.nov.is diagnosed mainly by having a relatively large body size,a crescent-shaped oral opening,numerous slender extrusomes,one suture on the ventral side and two on the dorsal side,and a buccal cavity that occupies the anterior third of the cell.Sonderia paramacrochilus sp.nov.closely resembles S.macrochilus but differs mainly by its oral opening being located closer to the anterior cell margin and its spindle-shaped extrusomes.Sonderia steini sp.nov.is a freshwater species that can be recognized by its shallow buccal cavity,sparsely distributed rod-shaped extrusomes,and having 68–79 monokinetidal somatic kineties that form sutures on both sides of the body.Phylogenetic analyses based on small subunit ribosomal RNA(SSU rRNA)gene sequence data support the monophyly of the family Sonderiidae,however,Sonderia is paraphyletic.The genus Sonderia is briefly revised and a key to the identification of species belonging to this genus is supplied.