How to contend with paraphyly in the taxonomy of the delphinine cetaceans?

Molecular phylogenetic analyses conducted over the past 15 yr have consistently had difficulties resolving relationships among the cetacean species in the subfamily Delphininae. In addition, paraphyly of the genera Tursiops and Stenella in these molecular phylogenies has been a recurrent problem since the first appearance of such a phylogeny in 1999, suggesting that these genera do not accurately reflect the evolutionary relationships of the species they contain. Morphological analyses have not resolved the issues. The genera in Delphininae originated in the 19th Century on questionable morphological grounds. The species were nearly all originally described in the genus Delphinus of Linnaeus. Recent molecular phylogenies based on various mitochondrial and nuclear DNA markers have suggested a wide range of possible relationships among these taxa, and several authors have suggested synonymizing all the taxa (Lagenodelphis, Stenella, Sousa, and Tursiops) under Delphinus. Until molecular and/or morphological analyses adequately sort out relationships in this very recently radiated group, one possible solution indeed would be to merge all the delphinine genera with Delphinus. Implications of such a move and alternatives are discussed.

Editor's Note: Papers from past Norris Award winners have primarily been a revised or reduced version of the actual presentation given as a plenary talk at the biennial conference. Dr. Perrin requested being allowed to take a topic from his presentation and expand on it to present a set of ideas in the form of an essay that could pass the rigors of the peer‐review process. As a result, this Norris Award paper has undergone peer‐review and has taken longer than usual for a Norris Award paper to appear in the journal following its presentation at the biennial conference. It also has co‐authors, with varying opinions on the issues discussed in the essay, to cover appropriately and more thoroughly those components of the paper that required additional expertise. I believe this approach has produced an excellent, thought‐provoking essay and is an approach that should be available to future Norris Award winners if they so choose to take it. Since this essay is meant to elicit dialogue, comments are welcome and will be considered for publication in Letters to the Editor.

     

Trichobaris weevils distinguish amongst toxic host plants by sensing volatiles that do not affect larval performance

Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host‐selection behaviours are often consistent with the preference–performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically relevant interactions. Here, we examined the host‐selection behaviours of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field and glasshouse experiments with transgenic host plants specifically altered in different components of their secondary metabolism. Adult females of both species strongly preferred to feed on D. wrightii rather than on N. attenuata leaves, but T. mucorea preferred to oviposit on N. attenuata, while T. compacta oviposited only on D. wrightii. These oviposition behaviours increased offspring performance: T. compacta larvae only survived in D. wrightii stems and T. mucorea larvae survived better in N. attenuata than in D. wrightii stems. Choice assays with nicotine‐free, JA‐impaired, and sesquiterpene‐over‐produced isogenic N. attenuata plants revealed that although half of the T. compacta larvae survived in nicotine‐free N. attenuata lines, nicotine did not influence the oviposition behaviours of both the nicotine‐adapted and nicotine‐sensitive species. JA‐induced sesquiterpene volatiles are key compounds influencing T. mucorea females’ oviposition choices, but these sesquiterpenes had no effect on larval performance. We conclude that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions.     

Extensive Interspecific Gene Flow Shaped Complex Evolutionary History and Underestimated Species Diversity in Rapidly Radiated Dolphins

Recently diverged taxa are often characterized by high rates of hybridization, which can complicate phylogenetic reconstruction. For this reason, the phylogenetic relationships and evolutionary history of dolphins are still not very well resolved; the question of whether the genera Tursiops and Stenella are monophyletic is especially controversial. Here, we performed re-sequencing of six dolphin genomes and combined them with eight previously published dolphin SRA datasets and six whole-genome datasets to investigate the phylogenetic relationships of dolphins and test the monophyly hypothesis of Tursiops and Stenella. Phylogenetic reconstruction with the maximum likelihood and Bayesian methods of concatenated loci, as well as with coalescence analyses of sliding window trees, produced a concordant and well-supported tree. Our studies support the non-monophyletic status of Tursiops and Stenella because the species referred these genera do not form exclusive monophyletic clades. This suggests that the current taxonomy of both genera might not reflect their evolutionary history and may underestimate their diversity. A four-taxon D-statistic (ABBA-BABA) test, five-taxon D_FOIL test, and tree-based PhyloNet analyses all showed extensive gene flow across dolphin species, which could explain the instability in resolving phylogenetic relationship of oceanic dolphins with different and limited markers. This study could be a good case to demonstrate how genomic data can reveal complex speciation and phylogeny in rapidly radiating animal groups.

     

Huia caspica gen. & comb. nov., a dinoflagellate species that recently crossed the marine‐freshwater boundary

The dinoflagellate subfamily Diplopsalidoideae encompasses 11 genera whose plate patterns show a large diversity. In a recently published molecular phylogeny (Liu et al. 2015) some of these genera (e.g. Diplopsalis, Diplopelta) are polyphyletic, suggesting that further subdivision of these genera is needed. Here we established the cyst‐theca relationship of Diplopsalis caspica by incubating cysts collected from the East China Sea. Cells of D. caspica display a plate formula of Po, X, 3′, 1a, 6″, 3c+t, ?4s, 5″′, 1″″, characterized by a small, parallelogrammic anterior intercalary plate (1a) located in the middle of the dorsal part of the epitheca. The cysts are spherical and smooth‐walled with a theropylic archeopyle. In addition, we obtained four large subunit ribosomal DNA (LSU rDNA) sequences from the germinated motile cells by single‐cell polymerase chain reaction. Strains of D. caspica from the marine environment of the East China Sea differ at 0–2 positions of LSU rDNA sequences from that of lacustrine strains from NE China. In the molecular phylogeny, D. caspica was close to Lebouraia pusilla but distant from D. lenticula, the type species of Diplopsalis. Our results support the systematic importance of plate 1a, and therefore D. caspica was transferred to a new genus, Huia. The conservative LSU rDNA sequences in H. caspica suggest that the marine‐freshwater transition occurred recently.     

A molecular evaluation of the Liagoraceae sensu lato (Nemaliales,Rhodophyta) in Bermuda including Liagora nesophila sp. nov. and Yamadaella grassyi sp. nov.

We have undertaken a comprehensive, molecular‐assisted alpha‐taxonomic examination of the rhodophyte family Liagoraceae sensu lato, a group that has not previously been targeted for molecular studies in the western Atlantic. Sequence data from three molecular markers indicate that in Bermuda alone there are 10 species in nine different genera. These include the addition of three genera to the flora — Hommersandiophycus, Trichogloeopsis, and Yamadaella. Liagora pectinata, a species with a type locality in Bermuda, is phylogenetically allied with Indo‐Pacific species of Hommersandiophycus, and the species historically reported as L. ceranoides for the islands is morphologically and genetically distinct from that taxon, and is herein described as L. nesophila sp. nov. Molecular sequence data have also uncovered the Indo‐Pacific L. mannarensis in Bermuda, a long‐distance new western Atlantic record. DNA sequences of Trichogloeopsis pedicellata from the type locality (Bahamas) match with local specimens demonstrating its presence in Bermuda. We described Yamadaella grassyi sp. nov. from Bermuda, a species phylogenetically and morphologically distinct from the generitype, Y. caenomyce of the Indo‐Pacific. Our data also indicated a single species each of Ganonema, Gloiocallis, Helminthocladia, Titanophycus, and Trichogloea in the flora.     

Multi‐locus phylogeny of African pipits and longclaws (Aves: Motacillidae) highlights taxonomic inconsistencies

The globally distributed avian family Motacillidae consists of five to seven genera (Anthus, Dendronanthus, Tmetothylacus, Macronyx and Motacilla, and depending on the taxonomy followed, Amaurocichla and Madanga) and 66–68 recognized species, of which 32 species in four genera occur in sub‐Saharan Africa. The taxonomy of the Motacillidae has been contentious, with variable numbers of genera, species and subspecies proposed and some studies suggesting greater taxonomic diversity than currently recognized (five genera and 67 species). Using one nuclear (Mb) and two mitochondrial (cyt b and CO1) gene regions amplified from DNA extracted from contemporary and museum specimens, we investigated the taxonomic status of 56 of the currently recognized motacillid species and present the most taxonomically complete and expanded phylogeny of this family to date. Our results suggest that the family comprises six clades broadly reflecting continental distributions: sub‐Saharan Africa (two clades), the New World (one clade), Palaearctic (one clade), a widespread large‐bodied Anthus clade, and a sixth widespread genus, Motacilla. Within the Afrotropical region, our phylogeny further supports recognition of Wood Pipit Anthus nyassae as a valid species, and the treatment of Long‐tailed Pipit Anthus longicaudatus and Kimberley Pipit Anthus pseudosimilis as junior subjective synonyms of Buffy Pipit Anthus vaalensis and African Pipit Anthus cinnamomeus, respectively. As the disjunct populations of Long‐billed Pipit Anthus similis in southern and East Africa are genetically distinct and geographically separated, we propose a specific status for the southern African population under the earliest available name, Nicholson's Pipit Anthus nicholsoni. Further, as our analyses indicate that Yellow‐breasted Pipit Anthus chloris and Golden Pipit Tmetothylacus tenellus are both nested within the Macronyx longclaws, we propose transferring these species to the latter genus.     

The coralline genera Sporolithon and Heydrichia (Sporolithales,Rhodophyta) clarified by sequencing type material of their generitypes and other species

Interspecific systematics in the red algal order Sporolithales remains problematic. To re‐evaluate its species, DNA analyses were performed on historical type material and recently collected specimens assigned to the two genera Sporolithon and Heydrichia. Partial rbcL sequences from the lectotype specimens of Sporolithon ptychoides (the generitype species) and Sporolithon molle, both from El Tor, Egypt, are exact matches to field‐collected topotype specimens. Sporolithon crassum and Sporolithon erythraeum also have the same type locality; material of the former appears to no longer exist, and we were unable to PCR amplify DNA from the latter. A new species, Sporolithon eltorensis, is described from the same type locality. We have not found any morpho‐anatomical characters that distinguish these three species. No sequenced specimens reported as S. ptychoides from other parts of the world represent this species, and likely reports of S. ptychoides and S. molle based on morpho‐anatomy are incorrect. A partial rbcL sequence from the holotype of Sporolithon dimotum indicates it is not a synonym of S. ptychoides, and data from the holotype of S. episporum confirm its specific recognition. DNA sequences from topotype material of Heydrichia woelkerlingii, the generitype species, and isotype material of Heydrichia cerasina confirm that these are distinct species; the taxon reported to be H. woelkerlingii from New Zealand is likely an undescribed species. Type specimens of all other Sporolithon and Heydrichia species need to be sequenced to confirm that they are distinct species; morpho‐anatomical studies have proved inadequate for this task.     

PHYLOGENETIC RELATIONSHIPS AMONG THE DELPHINID CETACEANS BASED ON FULL CYTOCHROME B SEQUENCES

Complete cytochrome b gene sequences from all but one species of delphinid plus four outgroups were analyzed using parsimony, maximum likelihood, and neighbor-joining methods. The results indicate the need for systematic revision of the family; a provisional classification is presented and compared to previous studies. Among the suggested revisions are removal of Orcinus from the Globicephalinae, placement of Grampus within the Globicephalinae, removal of all Lagenorhynchus spp. from the Delphininae, and placement of Sousa in the Delphininae. The genus Lagenorhynchus is found to be polyphyletic. L. albirostris (type species for the genus) and L. acutus are not closely related to each other or to nominal congeners. L. acutus is therefore assigned to the genus Leucopleurus. The remaining four Lagenorhynchus species are closely related to Lissodelphis and Cephalorbynchus and are placed in the genus Sagmatias. These three genera constitute the revised Lissodelphininae. Within the Delphininae, a well-supported clade includes the two species of Delphinus, Stenella clymene, S. frontalis, S. coeruleoalba, and the aduncus form of Tursiops truncatus. Accepting the monophyly of this group renders the genera Stenella and Tursiops polyphyletic. Apart from this finding, phylogenetic resolution within the Delphininae was poor, so comprehensive taxonomic revision of this group awaits further study.     

The ‘Oxycythereis’ problem: taxonomy and palaeobiogeography of deep‐sea ostracod genera Pennyella and Rugocythereis

Systematic revision of the globally distributed deep‐sea ostracod genera Pennyella Neale, 1974 and Rugocythereis Dingle, Lord and Boomer, 1990, which have been considered to correspond, at least partially, to nomen nudum but widely used genus name ‘Oxycythereis,’ was conducted to reduce taxonomic uncertainty of these important components of the Modern and fossil deep‐sea ostracod community. Approximately 100 specimens from 18 species were examined, ranging in age from the Cretaceous to the present day. Nine new species are described: Pennyella rexi, Pennyella sanfordae, Pennyella liowae, Pennyella schellenbergi, Pennyella majorani, Pennyella iani, Pennyella ayressi, Rugocythereis melonis and Rugocythereis zarikiani. Emended generic concepts of Pennyella and Rugocythereis are proposed, and the palaeobiogeographical distributions of these two genera are discussed.     

DNA sequencing,anatomy, and calcification patterns support a monophyletic,subarctic, carbonate reef‐forming Clathromorphum (Hapalidiaceae,Corallinales, Rhodophyta)

For the first time, morpho‐anatomical characters that were congruent with DNA sequence data were used to characterize several genera in Hapalidiaceae—the major eco‐engineers of Subarctic carbonate ecosystems. DNA sequencing of three genes (SSU, rbcL, ribulose‐1, 5‐bisphosphate carboxylase/oxygenase large subunit gene and psbA, photosystem II D1 protein gene), along with patterns of cell division, cell elongation, and calcification supported a monophyletic Clathromorphum. Two characters were diagnostic for this genus: (i) cell division, elongation, and primary calcification occurred only in intercalary meristematic cells and in a narrow vertical band (1–2 μm wide) resulting in a “meristem split” and (ii) a secondary calcification of interfilament crystals was also produced. Neopolyporolithon was resurrected for N. reclinatum, the generitype, and Clathromorphum loculosum was transferred to this genus. Like Clathromorphum, cell division, elongation, and calcification occurred only in intercalary meristematic cells, but in a wider vertical band (over 10–20 μm), and a “meristem split” was absent. Callilithophytum gen. nov. was proposed to accommodate Clathromorphum parcum, the obligate epiphyte of the northeast Pacific endemic geniculate coralline, Calliarthron. Diagnostic for this genus were epithallial cells terminating all cell filaments (no dorsi‐ventrality was present), and a distinct “foot” was embedded in the host. Leptophytum, based on its generitype, L. laeve, was shown to be a distinct genus more closely related to Clathromorphum than to Phymatolithon. All names of treated species were applied unequivocally by linking partial rbcL sequences from holotype, isotype, or epitype specimens with field‐collected material. Variation in rbcL and psbA sequences suggested that multiple species may be passing under each currently recognized species of Clathromorphum and Neopolyporolithon.     

Variation in cranial morphology of bottlenose dolphins (genus Tursiops) off South Africa

Taxonomy plays an important role in conservation biology. Despite the variety of methods used to differentiate units, some groups, such as Delphinidae within the Cetacea have proven difficult to untangle. This study aimed to shed light on morphological variation of the genus Tursiops in South African waters using geometric morphometrics and to distinguish morphological groups and variation in these groups. A total of 241 crania of Tursiops spp. were analyzed using a suite of 2‐dimensional landmarks defined on photographs of the specimens. Results revealed two distinct morphological groups, with the smaller cluster comprised mainly of specimens from the cold temperate region off the west coast and the larger cluster comprised of specimens mainly from the warm temperate and subtropical regions off the south and east coast, respectively. We suggest that these groups correspond to different species of Tursiops, but this result requires further support. These groups were treated as separate entities and sexual dimorphism and geographic variation were assessed within each group. While sexual dimorphism and geographic variation were not significant within Cluster D1 and V1, they were significant within Clusters D2 and V2. The few Cluster 1 specimens found in the warm temperate and subtropical regions, relative to the number of Cluster 2 specimens, could be an indication of an offshore distribution for this group in these regions. Alternatively, the smaller cluster may also be indicative of a potentially small population size.     

Application of multigene phylogenetics and site‐stripping to resolve intraordinal relationships in the Rhodymeniales (Rhodophyta)

Previous molecular assessments of the red algal order Rhodymeniales have confirmed its monophyly and distinguished the six currently recognized families (viz. Champiaceae, Faucheaceae, Fryeellaceae, Hymenocladiaceae, Lomentariaceae, and Rhodymeniaceae); however, relationships among most of these families have remained unresolved possibly as a result of substitution saturation at deeper phylogenetic nodes. The objective of the current study was to improve rhodymenialean systematics by increasing taxonomic representation and using a more robust multigene dataset of mitochondrial (COB, COI/COI‐5P), nuclear (LSU, EF2) and plastid markers (psbA, rbcL). Additionally, we aimed to prevent phylogenetic inference problems associated with substitution saturation (particularly at the interfamilial nodes) by removing fast‐evolving sites and analyzing a series of progressively more conservative alignments. The Rhodymeniales was resolved as two major lineages: (i) the Fryeellaceae as sister to the Faucheaceae and Lomentariaceae; and (ii) the Rhodymeniaceae allied to the Champiaceae and Hymenocladiaceae. Support at the interfamilial nodes was highest when 20% of variable sites were removed. Inclusion of Binghamiopsis, Chamaebotrys, and Minium, which were absent in previous phylogenetic investigations, established their phylogenetic affinities while assessment of two genera consistently polyphyletic in phylogenetic analyses, Erythrymenia and Lomentaria, resulted in the proposition of the novel genera Perbella and Fushitsunagia. The taxonomic position of Drouetia was reinvestigated with re‐examination of holotype material of D. coalescens to clarify tetrasporangial development in this genus. In addition, we added three novel Australian species to Drouetia as a result of ongoing DNA barcoding assessments—D. aggregata sp. nov., D. scutellata sp. nov., and D. viridescens sp. nov.     

Species concept and nomenclatural changes within the genera Elliptochloris and Pseudochlorella (Trebouxiophyceae) based on an integrative approach

The genera Elliptochloris and Pseudochlorella were erected for Chlorella‐like green algae producing two types of autospores and cell packages, respectively. Both genera are widely distributed in different soil habitats, either as free living or as photobionts of lichens. The species of these genera are often difficult to identify because of the high phenotypic plasticity and occasional lack of characteristic features. The taxonomic and nomenclatural status of these species, therefore, remains unclear. In this study, 34 strains were investigated using an integrative approach. Phylogenetic analyses demonstrated that the isolates belong to two independent lineages of the Trebouxiophyceae (Elliptochloris and Prasiola clades) and confirmed that the genera are not closely related. The comparison of morphology, molecular phylogeny, and analyses of secondary structures of SSU and ITS rDNA sequences revealed that all of the strains belong to three genera: Elliptochloris, Pseudochlorella, and Edaphochlorella. As a consequence of the taxonomic revisions, we propose two new combinations (Elliptochloris antarctica and Pseudochlorella signiensis) and validate Elliptochloris reniformis, which is invalidly described according to the International Code for Nomenclature (ICN), by designating a holotype. To reflect the high phenotypic plasticity of P. signiensis, two new varieties were described: P. signiensis var. magna and P. signiensis var. communis. Chlorella mirabilis was not closely related to any of these genera and was, therefore, transferred to the new genus Edaphochlorella. All of the taxonomic changes were highly supported by all phylogenetic analyses and were confirmed by the ITS‐2 Barcodes using the ITS‐2/CBC approach.     

Specificity of root microbiomes in native‐grown Nicotiana attenuata and plant responses to UVB increase Deinococcus colonization

Plants recruit microbial communities from the soil in which they germinate. Our understanding of the recruitment process and the factors affecting it is still limited for most microbial taxa. We analysed several factors potentially affecting root microbiome structure – the importance of geographic location of natural populations, the microbiome of native seeds as putative source of colonization and the effect of a plant's response to UVB exposure on root colonization of highly abundant species. The microbiome of Nicotiana attenuata seeds was determined by a culture‐dependent and culture‐independent approach, and the root microbiome of natural N. attenuata populations from five different locations was analysed using 454‐pyrosequencing. To specifically address the influence of UVB light on root colonization by Deinococcus, a genus abundant and consistently present in N. attenuata roots, transgenic lines impaired in UVB perception (irUVR8) and response (irCHAL) were investigated in a microcosm experiment with/without UVB supplementation using a synthetic bacterial community. The seed microbiome analysis indicated that N. attenuata seeds are sterile. Alpha and beta diversities of native root bacterial communities differed significantly between soil and root, while location had only a significant effect on the fungal but not the bacterial root communities. With UVB supplementation, root colonization of Deinococcus increased in wild type, but decreased in irUVR8 and irCHAL plants compared to nontreated plants. Our results suggest that N. attenuata recruits a core root microbiome exclusively from soil, with fungal root colonization being less selective than bacterial colonization. Root colonization by Deinococcus depends on the plant's response to UVB.     

Sperm number assessed by flow cytometry in species of Daphnia (Crustacea,Cladocera)

Daphnia magna and Daphnia pulex are two important model species in ecotoxicology. In daphniids, studies of the effects of contaminants have mostly focused on female life history traits, yet it would also be important to examine male reproductive traits, particularly in relation to endocrine disruptors. In this study, we developed a protocol that uses flow cytometry to measure sperm number in individual males of different species of Daphnia. We tested our protocol on 114 males from several clones of three common species of Daphnia. Sperm count varied widely among individuals and reached high numbers (up to 1.45 × 10⁵). Positive relationships between male length and sperm number were observed in D. pulex and Daphnia pulicaria, but not in D. magna. Important inter‐clonal differences in sperm production were observed in all species, with some clones producing very little sperm. Duplicated sperm samples showed on average only 6% difference in sperm counts. Sperm counts were stable at least over a 2‐hr period and up to 5 hr for most samples. This sperm isolation protocol and flow cytometric enumeration approach will be of major interest to ecotoxicologists.     

Efficient distinction of invasive aquatic plant species from non‐invasive related species using DNA barcoding

Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non‐invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH‐psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH‐psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics.     

Hybridization and introgression among three Aconitum (Ranunculaceae) species of different ploidy levels in the Tatra Mountains (Western Carpathians)

Hybridization among species of A conitum effects their morphology and ecology. In this study the hybridization between the diploid 2n(2x) = 16 ( A . lasiocarpum and A . variegatum) and tetraploid 2n(4x) = 32 ( A . firmum) species was documented in the Tatra Mountains (Western Carpathians) in a small, local population in a semi‐natural site. The hybrid species were: homoploid A . × pawlowskii ( A . lasiocarpum × A . variegatum), and triploid A . × berdaui ( A . firmum × A . variegatum, 2n(3x) = 24). Chloroplast DNA (cpDNA) alleles formed two distinct haplotypes, one typical for the tetraploid and another for diploid lines, shared between the tetraploid, triploid and diploid groups, indicating introgressive hybridization. The presumed gene flow was from the tetraploid to diploid species via the triploid bridge. The only two specimens of A . × pawlowskii that harbored tetraploid ( A . firmum) type cpDNA possessed bracteoles of A . firmum‐type. The remaining introgressed (cpDNA and Inter Simple Sequence Repeats (ISSR)) specimens ( A . variegatum) were morphologically pure, implying cryptic introgression. ISSR loci shared between the tetraploid A . firmum and diploid A . variegatum support the hypothesis of an ancient allopolyploid origin of A . firmum and the diploid species of A . variegatum‐type as one of its parent.     

A molecular investigation of the genus Ecklonia (Phaeophyceae,Laminariales) with special focus on the Southern Hemisphere

Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.     

Cyst‐Theca Relationship and Phylogenetic Position of Impagidinium caspienense Incubated from Caspian Sea Surface Sediments: Relation to Gonyaulax baltica and Evidence for Heterospory within Gonyaulacoid Dinoflagellates

We investigate the cyst‐theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single‐cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. ( 2002 ). The ability of this species to belong to two types of cyst‐based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by G. baltica, which provides evidence for heterospory in this species. The affiliation to G. baltica demonstrates that I. caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other gonyaulacoid species is also documented: Impagidinium pallidum, Ataxiodinium choane, Pyxidinopsis psilata, Spiniferites belerius, and Spiniferites ramosus. The LSU and SSU rDNA based phylogenies suggest that the genera Impagidinium and Spiniferites are not monophyletic, and that P. psilata and A. choane are close to Gonyaulax verior and Gonyaulax polygramma, respectively. In addition, this study accentuates the importance of cyst morphology in the classification of the Gonyaulacales.     

Comparative morphology of surface ultrastructure of diphyllobothriidean tapeworms (Cestoda: Diphyllobothriidea)

Microtriches on the scolices and adjacent strobila of seven species of diphyllobothriidean cestodes (Bothridium pithonis, Cephalochlamys namaquensis, Dibothriocephalus latus, Duthiersia expansa, D. fimbriata, Ligula intestinalis, and Schistocephalus solidus) from different hosts (frogs, snakes, lizards, birds, and mammals) and biogeographic areas were examined using scanning and transmission electron microscopy. The basic structure of the tegument of the seven species studied does not differ markedly from that found in other cestodes. The main characteristic is the presence of electron‐dense bodies and vesicles in the distal cytoplasm. However, this study has shown differences in the morphology of microtriches even among species of the same family. Two different types of microtriches were found, filitriches and spinitriches, with the latter represented by two forms. Our study reveals that capilliform filitriches are most commonly found in Diphyllobothriidea. They were observed mainly on the strobila and the scolices of all but one studied species; individuals of L. intestinalis bore only coniform spinitriches on their surface. The same type of microtriches was found on the cirrus in D. latus. Gladiate spinitriches covered the scolex in both species of Duthiersia, and gladiate spinitriches interspersed with capilliform filitriches were observed on the anterior part of the strobila in D. fimbriata and the posterior part of the scolex in B. pithonis. Individuals of C. namaquensis were covered only by small acicular filitriches. No obvious pattern in the type and distribution of microtriches was observed among species that belong to different families and parasitize distantly related definitive hosts.