LSU rDNA Sequences Research Articles

Morphology, ultrastructure and molecular phylogeny of cyst-producing Caladoa arcachonensis gen. et sp. nov. (Peridiniales, Dinophyceae) from France and Indonesia

ABSTRACTThe dinoflagellate order Peridiniales encompasses several well circumscribed families. However, the family level of some genera, such as Bysmatrum and Vulcanodinium, has remained elusive for many years. Four Peridinium-like strains were established from the Atlantic coast of France and North Sulawesi, Indonesia through cyst germination or isolation of single cells. The cyst-theca relationship was established on specimens from the French Atlantic. Their morphologies were examined using light, scanning and transmission electron microscopy. The cells were characterized by a much larger epitheca relative to the hypotheca, a large anterior sulcal (Sa) plate deeply intruding the epitheca and a small first anterior intercalary plate. The plate formula was identified as Po, cp, X, 4′, 3a, 7′′, 6C, 5S, 5′′′, 2′′′′, shared by Apocalathium, Chimonodinium, Fusiperidinium and Scrippsiella of the family Thoracosphaeraceae but the configuration of Sa plate and anterior intercalary plates is different. Transmission electron microscopy showed that the eyespot was located within a chloroplast comprising two rows of lipid globules and thus belongs to type A. All four strains were classified within a new genus Caladoa as C. arcachonensis gen. et sp. nov. Small subunit ribosomal DNA (SSU rDNA), partial large subunit ribosomal DNA (LSU rDNA) and internal transcribed spacer ribosomal DNA (ITS rDNA) sequences were obtained from all strains. Genetic distance based on ITS rDNA sequences between French and Indonesian strains reached 0.17, suggesting cryptic speciation in C. arcachonensis. The maximum likelihood and Bayesian inference analysis based on concatenated data from SSU and LSU rDNA sequences revealed that Caladoa is monophyletic and closest to Bysmatrum. Our results supported that Caladoa and Bysmatrum are members of the order Peridiniales but their family level remains to be determined. Our results also support that Vulcanodinium is closest to the family Peridiniaceae.

Discovery of a New Clade Nested Within the Genus Alexandrium (Dinophyceae): Morpho-molecular Characterization of Centrodinium punctatum (Cleve) F.J.R. Taylor

Investigation of phytoplankton from East China Sea of the Pacific Ocean, offshore Réunion Island of the Indian Ocean, and the French Atlantic coast revealed a species of poorly known armored fusiform dinoflagellate. To clarify this species, morphology and phylogeny based on mitochondrial and nuclear protein gene sequence (Cox1, Cob and Hsp90) concatenated with the SSU, ITS region and LSU rDNA sequences were analysed. Epifluorescence and scanning electron microscopy observations revealed that the nucleus of the specimen was elongated, sausage-shaped and located equatorially on the left lateral side of the cell, and that the plate formula is Po, 3', 1a, 6″, 6C, 8S, 5‴, 1p, 2'‴. These morphological features indicate that the species can be assigned to Centrodinium punctatum. Interestingly, the phylogenetic analyses placed this species within the Alexandrium clade, with Alexandrium affine being its closest relative. This indicates that genus Alexandrium is not monophyletic. The most similar morphological traits between C. punctatum and Alexandrium species were the shape of apical pore plate and the arrangement of the sulcal plates. However, since there are significant morphological differences between C. punctatum and Alexandrium species, further studies are needed to clarify the relation between the morphology and molecular phylogeny of other Centrodinium-related fusiform species.

Phylogeny and a new species of the genus Arachnomyces (Arachnomycetaceae)

A slow growing, asexual fungus that produces numerous arthroconidia was isolated during a mycobiota survey of pig farm soil in China. Phenotypic characteristics and phylogenetic analysis based on ITS and LSU rDNA sequences showed that it is a new species in the genus Arachnomyces, and the name Arachnomyces jinanicus was introduced. A. pilosus and A. scleroticus are new combinations for Chrysosporium pilosum and Onychocola sclerotica (=Malbranchia scleroticus) respectively. Currently, 11 species are accepted in Arachnomyces and an overview with type information and reference sequence data is given. The phylogenetic relationships of species within the genus are discussed, and a dichotomous key for distinguishing all reported Arachnomyces species is provided.

Hermatomyces trangensis sp. nov., a new dematiaceous hyphomycete (Hermatomycetaceae, Pleosporales) on sugar palm in Thailand

A new species of a hyphomycetous fungus, Hermatomyces trangensis, was collected during an investigation of the diversity of palm fungi in Na Yong district, Trang province, Southern Thailand, and is introduced in this paper based on morphological and molecular evidence. The fungus is characterized by the production of only one type of conidia, globose or subglobose in front view, broadly ellipsoidal or oblong in lateral view, with dark brown to black central cells and subhyaline to pale brown peripheral cells and sporulation in culture. Phylogenetic analyses of combined SSU rDNA, LSU rDNA, ITS rDNA, TEF1 and RPB2 sequence data using maximum parsimony, maximum likelihood and Bayesian inference approaches placed the fungus within a strongly supported clade with other Hermatomyces species within the family Hermatomycetaceae (Pleosporales, Dothideomycetes). Morphologically, it is similar to other taxa with only one type of conidia such as H. sphaericus, H. sphaericoides and H. verrucosus but molecular data clearly support H. trangensis as distinct from those species.

Cryptic diversity of small‐sized species of Phalacroma (Dinophysales, Dinophyceae) from Denmark Strait (Eastern Arctic Greenland)

SUMMARY Phalacroma currently comprises 69 species of mostly marine heterotrophic dinophysoids. With a round cell body and short sulcal and cingular lists, Phalacroma spp. have a simple morphology compared to other dinophysoid genera. Therefore, species identification is not always a trivial matter. A few Arctic species have been described and, with the exception of Ph. rotundatum, they are not only infrequently recorded but also occur in low cell abundances. Here, we studied a Lugol fixed sample from Denmark Strait. From this sample 13 cells with a Phalacroma‐like morphology were isolated under a stereo microscope, photo documented, and used for single‐cell PCR determination of nuclear‐encoded LSU rDNA sequences. The sequences fell in three groups defined by their ribotype. A single ribotype sequence representing each group was added to an alignment containing a diverse assemblage of dinophysoids and analyzed using Bayesian analysis and maximum likelihood. Based on comparative light microscopy one of the ribotypes (ribotype 1) was similar but not identical to Ph. ruudi and ribotype 2 could not be matched to a known species of Phalacroma. In the phylogeny both clustered with other species of Phalacroma including the type species. The morphology of ribotype 3 was similar but not identical to Ph. braarudii. In the phylogeny ribotype 3 clustered outside the core group of Phalacroma species. Hence, ribotype 3 was designated ‘Phalacroma’ sp. 3 and has to be described as a new genus pending additional data. This study has revealed the existence of cryptic species diversity within the Phalacroma morphotype boundary. Two additional Phalacroma species (Ph. apicatum and Ph. cf. argus) also clustered outside Phalacroma sensu stricto further emphasizing the presence of cryptic species within the genus. Future studies with a polyphasic approach are needed to better address the taxonomy of Phalacroma and Phalacroma‐like dinophysoids.

Molecular and morphological characterisation of Cryptaphelenchus baujardi n. sp. (Nematoda: Ektaphelenchinae), a new species based on two populations from Iran

SummaryCryptaphelenchus baujardin. sp. is described and illustrated based on two populations from Golestan province, northern Iran. The new species is characterised by female and male body length of 224 (190-261) and 215 (195-229)μm, respectively, offset cephalic region with a shallow constriction, delicate stylet 6.6 (6.0-7.0)μm long, four incisures in the lateral field, presence of a rudimentary post-uterine sac in the female gonoduct, elongate-conoid female tail ending in an acute to finely rounded terminus, male tail conical, male with seven caudal papillae and delicate spicules. The new species shows a strong resemblance toC. varicaudatusandC. iranicus, but has a sclerotised mass near the tip of the spicule and an indistinct spermatheca. Phylogenetic analyses based on both partial SSU and LSU rDNA sequences confirm its status as a new taxon.

Tuberlatum coatsi gen. n., sp. n. (Alveolata, Perkinsozoa), a New Parasitoid with Short Germ Tubes Infecting Marine Dinoflagellates

Perkinsozoa is an exclusively parasitic group within the alveolates and infections have been reported from various organisms, including marine shellfish, marine dinoflagellates, freshwater cryptophytes, and tadpoles. Despite its high abundance and great genetic diversity revealed by recent environmental rDNA sequencing studies, Perkinsozoa biodiversity remains poorly understood. During the intensive samplings in Korean coastal waters during June 2017, a new parasitoid of dinoflagellates was detected and was successfully established in culture. The new parasitoid was most characterized by the presence of two to four dome-shaped, short germ tubes in the sporangium. The opened germ tubes were biconvex lens-shaped in the top view and were characterized by numerous wrinkles around their openings. Phylogenetic analyses based on the concatenated SSU and LSU rDNA sequences revealed that the new parasitoid was included in the family Parviluciferaceae, in which all members were comprised of two separate clades, one containing Parvilucifera species (P. infectans, P. corolla, and P. rostrata), and the other containing Dinovorax pyriformis, Snorkelia spp., and the new parasitoid from this study. Based on morphological, ultrastructural, and molecular data, we propose to erect a new genus and species, Tuberlatum coatsi gen. n., sp. n., from the new parasitoid found in this study. Further, we examined and discussed the validity of some diagnostic characteristics reported for parasitoids in the family Parviluciferaceae at both the genus and species levels.

Light capture and pigment diversity in marine and freshwater cryptophytes.

Phenotypic traits associated with light capture andphylogenetic relationships were characterized in 34 strains of diversely pigmented marine and freshwater cryptophytes. Nuclear SSU and partial LSU rDNA sequence data from 33 of these strains plus an additional 66 strains produced aconcatenated rooted maximum likelihood tree that classified the strains into 7 distinct clades. Molecular and phenotypic datatogether support: (i) the reclassification of Cryptomonas irregularis NIES 698 tothe genus Rhodomonas, (ii) revision of phycobiliprotein (PBP) diversity within the genus Hemiselmis to include cryptophyte phycocyanin (Cr-PC) 569, (iii) the inclusion of previously unidentified strain CCMP 2293 into the genus Falcomonas, even though it contains cryptophyte phycoerythrin 545 (Cr-PE 545), and (iv) the inclusion of previously unidentified strain CCMP 3175, which contains Cr-PE 545, in aclade with PC-containing Chroomonas species. Adiscriminant analysis-based model of group membership correctly predicted 70.6% of the clades using three traits: PBP concentration · cell-1 , the wavelength of PBP maximal absorption, and habitat. Non-PBP pigments (alloxanthin, chl-a, chl-c2 , α-carotene) did not contribute significantly to group classification, indicating the potential plasticity of these pigments and the evolutionary conservation of the PBPs. Pigment data showed evidence of trade-offs in investments in PBPs vs. chlorophylls (a +c2 ).

Epidemiology and identification of two species of Chilodonella affecting farmed fishes in China

The genus Chilodonella includes free-living ciliated protozoa as well as pathogenic species for freshwater fish, with Chilodonella hexasticha and Chilodonella piscicola being the most important ones. These parasites cause outbreaks with high mortalities among farmed freshwater fishes with great economic losses. There are few reports of these species in China, and their identification has been based mostly on their morphological characteristics. In the present work, the parasites causing five outbreaks occurring in China between 2014 and 2017 have been identified by morphological and genetic analysis. We provide the first records of Ctenopharingodon idella and Siniperca chuatsi as hosts of C. hexasticha, and of Procypris rabaudi and Schizothorax wangchiachii as hosts of C. piscicola. There are no differences in the gross pathological findings produced by C. hexasticha and C. piscicola, consisting in desquamation and necrosis of epithelial cells in the skin and gills and in severe fusion of gill lamellae. However, both species differ in their geographic distribution: C. piscicola was found in farms located at altitudes over 1500 m above sea level and with a water temperature ≤18 °C, while C. hexasticha was found in farms located at altitudes under 50 m above sea level and with a water temperature ≥21 °C. Present results confirm that C. hexasticha and C. piscicola are two different species that can be differenced by their morphology; however, their biological variability may lead to erroneous identifications and the diagnosis should be preferably based in genetic analysis including nuclear LSU rDNA and mitochondrial SSU rDNA sequences.

Gonyaulax whaseongensis sp. nov. (Gonyaulacales, Dinophyceae), a new phototrophic species from Korean coastal waters.

The planktonic phototrophic dinoflagellate Gonyaulax whaseongensis sp. nov., isolated from coastal waters of western Korea, was described from living and fixed cells under light and scanning electron microscopy, and its rDNA was sequenced. Gonyaulax whaseongensis had a plate formula of 2pr, 4', 6'', 6c, 6''', 1p, and 1'''' with S-type ventral organization like the other species in the genus. However, this dinoflagellate had a narrow cingulum (ca. 2.6μm), small displacement of the cingulum, slight overhang and steep angle between the ends of the cingulum, quadrangular sixth precingular plate, reticulated cell surface without longitudinal lines or ridges, and two unequal antapical spines, together which distinguish this from all other reported Gonyaulax species. In addition, the SSU and LSU rDNA sequences were 8%-12% and 11%-24%, respectively, different from those of Gonyaulax polygramma, Gonyaulax spinifera, Gonyaulax fragilis, Gonyaulax membranacea, and Gonyaulax digitale, the putatively closest related species in the phylogenetic analysis.

The morphological and phylogenetic characterization for the dinoflagellate Margalefidinium fulvescens (=Cochlodinium fulvescens) isolated from the Jiaozhou Bay, China

The dinoflagellate genus Margalefidinium has been split from Cochlodinium as a new genus recently and Margalefidinium fulvescens is one of the five Margalefidinium species. Margalefidinium fulvescens is toxic and has been reported from the coastal waters of USA, Canada, Mexico, China, Japan, Indonesia, Korea, Pakistan and Spain. Here we provide the morphological and phylogenetic characterization for an isolate of it from the Jiaozhou Bay, Qingdao, China. Our results showed that the vegetative cells were subspherical to ellipsoidal, 34-60 m in length, and 19-41 m in width. Both single cell forms and colonies in chains of 2, 4, or 8 cells were observed in cultures, but chain forms with 2 or 4 cells were observed more often in the field samples. The cingulum was rather deep, encircling the cell approximately twice, but the sulcus was rather narrow, surrounding the cell about one turn. The nucleus was spherical and located at the central epicone. The chloroplasts were granular, brownish, and scattered peripherally. An orange pigmented body also appeared in the epicone. The apical groove appeared vase-like as previously described. Under epi-fluorescence microscopy, a pumpkin-like structure was clearly observed, in which cells were embedded. Cells were observed to exit from the structure, which led us to a hypothesis that the structure may provide cells a shelter to avoid predation or to respond to other stresses. The phylogenetic analyses based on partial LSU rDNA sequences indicated that M. fulvescens from the Jiaozhou Bay was grouped with M. fulvescens populations from other origins and closely related to the clade of M. polykrikoides. Our morphological observations and phylogenetic analyses together confirmed the presence of M. fulvescens in China and our monitoring has also observed the species dominant in the dinoflagellate community of the Jiaozhou Bay in the early autumn of 2015, which alerted us to continually monitor this bloom-forming species in the region.

Phylogenetic relationships of the family Gryporhynchidae (Cestoda: Cyclophyllidea) inferred through SSU and LSU rDNA sequences.

Tapeworms of the family Gryporhynchidae are endoparasites of fish-eating birds distributed worldwide. Currently the family contains 16 genera classified on the basis of the morphology of the rostellar apparatus, rostellar hooks and strobilar anatomy. However, the phylogenetic relationships among the genera are still unknown. In this study, sequences of the near complete 18S (SSU) and 28S (LSU) from rDNA of 13 species of gryporhynchids (adult specimens) representing eight genera (Cyclustera, Dendrouterina, Glossocercus, Gryporhynchidae gen. sp., Neovalipora, Paradilepis, Parvitaenia, Valipora) and one species of metacestode from fish (Neovalipora) were generated. Additionally, sequences of metacestodes of the genera Amirthalingamia, Neogryporhynchus, Paradilepis, Parvitaenia and Valipora from Africa recently added to the GenBank database were analysed. Phylogenetic relationships were inferred using maximum-likelihood (ML) and Bayesian inference of each (SSU and LSU) dataset. The phylogenetic analyses indicated that the family Gryporhynchidae is a well-supported monophyletic group within the Cyclophyllidea. The trees inferred with SSU and LSU datasets had similar topologies and suggested that the genera Glossocercus (two species sequenced) and Paradilepis (four spp.) are monophyletic. In contrast, Dendrouterina, Parvitaenia and Valipora are paraphyletic, suggesting that the species composition of these genera should be critically reviewed. Interestingly, species of the genera that use the same groups of definitive hosts such as herons (Ardeidae), cormorants (Phalacrocoracidae) and ibis (Threskiornithidae) are together in the phylogenetic tree, even though they differ markedly from each other in some morphological characters, especially shape and size of rostellar hooks.

Morphology, ultrastructure, and molecular phylogeny of Wangodinium sinense gen. et sp. nov. (Gymnodiniales, Dinophyceae) and revisiting of Gymnodinium dorsalisulcum and Gymnodinium impudicum.

The genus Gymnodinium includes many morphologically similar species, but molecular phylogenies show that it is polyphyletic. Eight strains of Gymnodinium impudicum, Gymnodinium dorsalisulcum and a novel Gymnodinium-like species from Chinese and Malaysian waters and the Mediterranean Sea were established. All of these strains were examined with light microscopy, scanning electron microscopy and transmission electron microscopy. SSU, LSU and internal transcribed spacers rDNA sequences were obtained. A new genus, Wangodinium, was erected to incorporate strains with a loop-shaped apical structure complex (ASC) comprising two rows of amphiesmal vesicles, here referred to as a new type of ASC. The chloroplasts of Wangodinium sinense are enveloped by two membranes. Pigment analysis shows that peridinin is the main accessory pigment in W.sinense. Wangodinium differs from other genera mainly in its unique ASC, and additionally differs from Gymnodinium in the absence of nuclear chambers, and from Lepidodinium in the absence of Chl b and nuclear chambers. New morphological information was provided for G.dorsalisulcum and G.impudicum, e.g., a short sulcal intrusion in G.dorsalisulcum; nuclear chambers in G.impudicum and G.dorsalisulcum; and a chloroplast enveloped by two membranes in G.impudicum. Molecular phylogeny was inferred using maximum likelihood and Bayesian inference with independent SSU and LSU rDNA sequences. Our results support the classification of Wangodinium within the Gymnodiniales sensu stricto clade and it is close to Lepidodinium. Our results also support the close relationship among G.dorsalisulcum, G.impudicum, and Barrufeta. Further research is needed to assign these Gymnodinium species to Barrufeta or to erect new genera.

The affiliation of Hexasterias problematica and Halodinium verrucatum sp. nov. to ciliate cysts based on molecular phylogeny and cyst wall composition

Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens indicates a carbohydrate-based composition of the cyst wall with evidence for nitrogen-containing functional groups. A similar composition is recorded for tintinnid loricae, which further supports the placement of Hexasterias and Halodinium as ciliate cysts, and the composition is consistent with the heterotrophic nature of ciliates. The morphologically similar species Radiosperma corbiferum has a comparable composition, suggesting a similar ciliate affinity and indicating the utility of micro-FTIR in understanding acritarch affinity. Hexasterias problematica typically occurs in coastal waters from temperate to arctic regions. Halodinium verrucatum sp. nov. is observed in temperate estuarine sediments in the northern hemisphere.

Stilbocrea walteri sp. nov., an unusual species of Bionectriaceae

The new species Stilbocrea walteri is described and illustrated from Quercus ilex collected in Portugal. Phylogenetic analyses of LSU rDNA, rpb1, rpb2 and tef1 sequence matrices place S. walteri in the Bionectriaceae, Hypocreales, within a clade of specimens morphologically identified as Stilbocrea macrostoma, the generic type of Stilbocrea. Stilbocrea walteri differs from S. macrostoma in dark olive green to blackish ascomata basally immersed in a stroma, KOH+ and LA+ ascomata and the lack of a stilbella-like asexual morph on natural substrate and pure culture. A simple phialidic asexual morph is formed in pure culture. To enable a morphological comparison, Stilbocrea macrostoma is illustrated.

Zenkevitchiidae fam. nov. (Crustacea: Gammaroidea), with description of new subterranean amphipods from extremely deep cave habitats

ABSTRACTPrevious phylogenetic analysis based on combined mitochondrial and nuclear gene sequences detected paraphyly of the Typhlogammaridae. To test this hypothesis a portion of large subunit (LSU-rDNA) gene sequences were obtained for typhlogammarid species from Caucasus. The Bayesian approach to LSU-rDNA sequences provided evidence for an independent origin of the Dinaric and Caucasus ‘typhlogammarid’ clades. A new family, Zenkevitchiidae fam. nov., is proposed to reconcile the observed phylogeny with the concept of monophyly. Using light microscopy, two mouthpart morphotypes of the Zenkevitchiidae fam. nov. species with quite different setae are identified. Taking into account these two morphotypes, a new classification is proposed – Adaugammarus revazi comb. nov., and Adaugammarus sandroruffoi comb. nov. Additionally, two new stygobiont zenkevitchiid amphipod species – Adaugammarus kasiani sp. nov. and Kruberia relicta sp. nov. – are described from Krubera Cave in Abkhazia. A distribution map and an identification key for the Zenkevitchiidae fam. nov. species of Transcaucasia are provided.http://zoobank.org/urn:lsid:zoobank.org:pub:90177B0C-BED0-4601-8CFC-3F774B22065C

Phragmidium species parasitizing species of Rosaceae in Tibet, China, with descriptions of three new species

Phragmidum spp. are rust fungi that are serious pathogens of plants in the Rosaceae. We characterized 15 Phragmidium species from Tibet, including 12 previously described and 3 new species. All the taxa, including the three new species (Ph. chayuensis, Ph. cibanum, Ph. zangdongii) are described and illustrated based on morphological characteristics. These taxa have multi-celled teliospores with firm pedicels. Phragmidium chayuensis is characterized by (5)7–9-celled teliospores with short papillae. Phragmidium cibanum is characterized by smooth teliospores that are distinctly constricted at the septa. Phragmidium zangdongii is characterized by large uredinia and 11–13-celled teliospores. Five types of urediniospore-surface structures were identified based on the gross shape of ornamentations and their distribution on the urediniospore wall. Molecular sequence data from the LSU rDNA analysis showed that the new taxa formed distinct clades independent from previously recorded species represented by LSU rDNA sequence data. The phylogenetic tree indicated that Phragmidium species are highly host specific.

DESCRIPTION OF MUCOR PERNAMBUCOENSIS (MUCORALES, MUCOROMYCOTA), A NEW SPECIES ISOLATED FROM THE BRAZILIAN UPLAND RAINFOREST

The Mucor genus mostly comprises saprobe specimens which are commonly isolated from herbivore dung, fruit and soil. Morphologically, Mucor specimens produce simple or branched sporangiophores without basal rhizoids and non-apophysate sporangia. During a survey of Mucorales in soil from an upland rainforest area in Pernambuco, Brazil, one specimen of Mucor was isolated and characterized based on morphological, physiological and molecular data (ITS1-5.8S-ITS2 and LSU rDNA sequences). The specimen is characterized by producing strongly sympodially branched sporangiophores and sporangiospores which can contain one or more granules at each end. The columellae are frequently globose or obovoid, some ovoid or cylindrical with a truncate base, rarely piriform. It grew better at 25ºC, with no development at 35ºC. Based on the evidence of the analyzed datasets, a new species of Mucor is proposed.

An annotated list and molecular data on larvae of gryporhynchid tapeworms (Cestoda: Cyclophyllidea) from freshwater fishes in Africa.

An annotated list of larvae (metacestodes) of gryporhynchid tapeworms (Cestoda: Cyclophyllidea) from freshwater fishes in Africa is provided with numerous new host and geographical records. Newly collected materials from Burundi, Democratic Republic of the Congo, Kenya, Madagascar, Namibia, Senegal, South Africa, Sudan and Zimbabwe practically double the total number of species reported from African fish so far. We confirm the occurrence of 16 species (five unidentified to the species level and most likely representing new taxa) belonging to the genera Amirthalingamia Bray, 1974 (1 species), Cyclustera Fuhrmann, 1901 (2 species), Dendrouterina Fuhrmann, 1912 (1 species), Neogryporhynchus Baer & Bona, 1960 (1 species), Paradilepis Hsü, 1935 (4 species), Parvitaenia Burt, 1940 (5 species), and Valipora Linton, 1927 (2 species). Additionally, metacestodes of four unidentified species of Paradilepis and Parvitaenia are reported from fish for the first time. Rostellar hooks of all species are illustrated and their measurements are provided together with a host-parasite list. The molecular phylogenetic analysis based on partial LSU rDNA sequences offers the first insight into the internal phylogenetic relationships within the family. Together with the morphological observations, the present study provides a taxonomic baseline for future studies on this largely neglected, but widely distributed and relatively frequent, group of parasites of African fishes, including economically important cichlids like tilapias and cyprinids.

First Ultrastructural and Molecular Phylogenetic Evidence from the Blastogregarines, an Early Branching Lineage of Plesiomorphic Apicomplexa

Blastogregarines are poorly studied parasites of polychaetes superficially resembling gregarines, but lacking syzygy and gametocyst stages in the life cycle. Furthermore, their permanent multinuclearity and gametogenesis by means of budding considerably distinguish them from other parasitic Apicomplexa such as coccidians and hematozoans. The affiliation of blastogregarines has been uncertain: different authors considered them highly modified gregarines, an intermediate apicomplexan lineage between gregarines and coccidians, or an isolated group of eukaryotes altogether. Here, we report the ultrastructure of two blastogregarine species, Siedleckia nematoides and Chattonaria mesnili, and provide the first molecular data on their phylogeny based on SSU, 5.8S, and LSU rDNA sequences. Morphological analysis reveals that blastogregarines possess both gregarine and coccidian features. Several traits shared with archigregarines likely represent the ancestral states of the corresponding cell structures for parasitic apicomplexans: a distinctive tegument structure and myzocytotic feeding with a well-developed apical complex. Unlike gregarines but similar to coccidians however, the nuclei of male blastogregarine gametes are associated with two kinetosomes. Molecular phylogenetic analyses reveal that blastogregarines are an independent, early diverging lineage of apicomplexans. Overall, the morphological and molecular evidence congruently suggests that blastogregarines represent a separate class of Apicomplexa.