New record for Halophila decipiens Ostenfeld in Kenya based on morphological and molecular evidence

The seagrass Halophila decipiens Ostenfeld was recorded for the first time in Kenya in 2003. It was growing in subtidal mixed meadows with H. ovalis in protected bays at a depth of 3 m. DNA sequence analysis and morphological characteristics confirmed the identification. It is possible that this species is more widely distributed in the east African region. There was very little sequence differentiation between the Kenyan H. decipiens and the other samples in the Indo-West Pacific, and between this region and the Atlantic Ocean, further validating from an evolutionary perspective recent dispersal of this species.     

Megagametogenesis in Halophila johnsonii, a threatened seagrass with no known seeds,and the seed-producing Halophila decipiens (Hydrocharitaceae)

Megagametogenesis, the development of a megaspore into an embryo sac, has been identified in the seagrass Halophila johnsonii, a threatened species with no known sexual reproduction or seeds. Megagametogenesis in H. johnsonii was compared with megagametophyte development in Halophila decipiens, a related species known to readily produce viable seeds. In both species, ovules were structurally similar, megaspore mother cells were seen in premeiotic ovules, and linear tetrads and megagametophytes with two to eight nuclei were present in postmeiotic ovules. However, H. decipiens postmeiotic ovules had a chalazal pouch that was absent in the postmeiotic ovules of H. johnsonii. Late-stage H. decipiens ovules also contained embryos, indicating that they had been fertilized, whereas all late-stage H. johnsonii ovules were degrading and showed no signs of fertilization. These observations suggest that meiosis does occur in H. johnsonii megasporocytes, leading to the formation of viable megagametophytes and egg cells that could be fertilized if pollination occurred. Thus, the lack of seed set is due to a lack of pollination rather than any loss of capacity to produce seeds in this species.     

Palatability of the Antarctic rhodophyte Palmaria decipiens (Reinsch) RW Ricker and its endo/epiphyte Elachista antarctica Skottsberg to sympatric amphipods

Although many macroalgae that occur throughout Western Antarctic Peninsular waters are known to produce defensive secondary metabolites that deter grazing, the rhodophyte, Palmaria decipiens is palatable to several sympatric meso- and macro-grazers. It has been hypothesized that high levels of mesoherbivory by amphipods may account for the conspicuous lack of filamentous epiphytes emerging from the thalli of marcophytes in this region. Nonetheless, Elachista antarctica is a filamentous phaeophyte found growing within, and emerging from the thallus of the rhodophyte P. decipiens. It is surprising that E. antarctica occurs exclusively in association with a palatable species of macroalgae considering the standing biomass of other chemically defended unpalatable species is very high. We tested the hypothesis that E. antarctica grows on P. decipiens due to the host's overwhelming palatability compared to that of the epiphyte. That is, the hypothesis that mesograzers prefer the host over the epiphyte, grazing around emerging filaments. Choice and no choice feeding assays with live tissues of E. antarctica and P. decipiens were conducted in three different trials with four sympatric amphipod species (Prostebbingia gracilis, Gondogeneia antarctica, Oradarea bidentata, and Paraphimedia integricauda) commonly found in association with P. decipiens. G. antarctica consumed both species but ate P. decipiens at a faster rate than the epiphyte in two of three trials. P. gracilis, O. bidentata, and P. integricauda fed on the epiphyte, E. antarctica at faster rates than upon P. decipiens. Aggressive grazing of the epiphyte by this suite of amphipods indicates that differences in palatability and differences in grazing pressure on host and epiphyte do not explain the exclusive epiphytism of E. antarctica on P. decipiens.     

Human Infections with Spirometra decipiens Plerocercoids Identified by Morphologic and Genetic Analyses in Korea

Tapeworms of the genus Spirometra are pseudophyllidean cestodes endemic in Korea. At present, it is unclear which Spirometra species are responsible for causing human infections, and little information is available on the epidemiological profiles of Spirometra species infecting humans in Korea. Between 1979 and 2009, a total of 50 spargana from human patients and 2 adult specimens obtained from experimentally infected carnivorous animals were analyzed according to genetic and taxonomic criteria and classified as Spirometra erinaceieuropaei or Spirometra decipiens depending on the morphology. Morphologically, S. erinaceieuropaei and S. decipiens are different in that the spirally coiled uterus in S. erinaceieuropaei has 5-7 complete coils, while in S. decipiens it has only 4.5 coils. In addition, there is a 9.3% (146/1,566) sequence different between S. erinaceieuropaei and S. decipiens in the cox1 gene. Partial cox1 sequences (390 bp) from 35 Korean isolates showed 99.4% (388/390) similarity with the reference sequence of S. erinaceieuropaei from Korea (G1724; GenBank {"type":"entrez-nucleotide","attrs":{"text":"KJ599680","term_id":"646228164","term_text":"KJ599680"}}KJ599680) and an additional 15 Korean isolates revealed 99.2% (387/390) similarity with the reference sequences of S. decipiens from Korea (G1657; GenBank {"type":"entrez-nucleotide","attrs":{"text":"KJ599679","term_id":"646228151","term_text":"KJ599679"}}KJ599679). Based on morphologic and molecular databases, the estimated population ratio of S. erinaceieuropaei to S. decipiens was 35: 15. Our results indicate that both S. erinaceieuropaei and S. decipiens found in Korea infect humans, with S. erinaceieuropaei being 2 times more prevalent than S. decipiens. This study is the first to report human sparganosis caused by S. decipiens in humans in Korea.     

Mitochondrial Genome of Spirometra theileri Compared with Other Spirometra Species

This study was carried out to provide information on the taxonomic classification and analysis of mitochondrial genomes of Spirometra theileri. One strobila of S. theileri was collected from the intestine of an African leopard (Panthera pardus) in the Maswa Game Reserve, Tanzania. The complete mtDNA sequence of S. theileri was 13,685 bp encoding 36 genes including 12 protein genes, 22 tRNAs and 2 rRNAs with absence of atp8. Divergences of 12 protein-coding genes were as follow: 14.9% between S. theileri and S. erinaceieuropaei, 14.7% between S. theileri and S. decipiens, and 14.5% between S. theileri with S. ranarum. Divergences of 12 proteins of S. theileri and S. erinaceieuropaei ranged from 2.3% in cox1 to 15.7% in nad5, while S. theileri varied from S. decipiens and S. ranarum by 1.3% in cox1 to 15.7% in nad3. Phylogenetic relationship of S. theileri with eucestodes inferred using the maximum likelihood and Bayesian inferences exhibited identical tree topologies. A clade composed of S. decipiens and S. ranarum formed a sister species to S. erinaceieuropaei, and S. theileri formed a sister species to all species in this clade. Within the diphyllobothridean clade, Dibothriocephalus, Diphyllobothrium and Spirometra formed a monophyletic group, and sister genera were well supported.     

Genetic Identification of Spirometra decipiens Plerocercoids in Terrestrial Snakes from Korea and China

Human sparganosis is a zoonotic disease caused by infection with larval forms (procercoid/plerocercoid) of Spirometra spp. The purpose of this study was to identify Spirometra spp. of infected snakes using a multiplex PCR assay and phylogenetic analysis of mitochondrial DNA sequence data from the spargana of terrestrial snakes obtained from Korea and China. A total of 283 snakes were obtained that included 4 species of Colubridae comprising Rhabdophis tigrinus tigrinus (n=150), Dinodon rufozonatum rufozonatum (n=64), Elaphe davidi (n=2), and Elaphe schrenkii (n=7), and 1 species of Viperidae, Agkistrodon saxatilis (n=60). The snakes were collected from the provinces of Chungbuk, Chungnam, and Gyeongbuk in Korea (n=161), and from China (n=122). The overall infection rate with spargana was 83% (235/283). The highest was recorded for D. rufozonatum rufozonatum (100%), followed by A. saxatilis (85%) and R. tigrinus tigrinus (80%), with a negative result for E. davidi (0%) and E. schrenkii (0%). The sequence identities between the spargana from snakes (n=50) and Spirometra erinaceieuropaei ({"type":"entrez-nucleotide","attrs":{"text":"KJ599680","term_id":"646228164","term_text":"KJ599680"}}KJ599680) or S. decipiens ({"type":"entrez-nucleotide","attrs":{"text":"KJ599679","term_id":"646228151","term_text":"KJ599679"}}KJ599679) control specimens were 90.8% and 99.2%, respectively. Pairwise genetic distances between spargana (n=50) and S. decipiens ranged from 0.0080 to 0.0107, while those between spargana and S. erinaceieuropaei ranged from 0.1070 to 0.1096. In this study, all of the 904 spargana analyzed were identified as S. decipiens either by a multiplex PCR assay (n=854) or mitochondrial cox1 sequence analysis (n=50).     

Pseudoterranova decipiens species A and B (Nematoda,Ascaridoidea): nomenclatural designation,morphological diagnostic characters and genetic markers

Five genetically distinct and reproductively isolated species have been detected previously within the morphospecies Pseudoterranova decipiens from the Arctic-Boreal, Boreal and Antarctic. Morphological analysis was carried out on male specimens identified by genetic (allozyme) markers, allowing the detection of significant differences at a number of characters between two members of the P. decipiens complex, namely P. decipiens A and B. On the basis of such differences, the nomenclatural designation for the two species is discussed. The names Pseudoterranova krabbei n. sp. and P. decipiens (sensu stricto) are proposed for species A and B, respectively. Morphological and genetic differentiation between the two species is shown using multivariate analysis. Allozyme diagnostic keys for routine identification of the four members of the P. decipiens complex, namely P. decipiens (s.s.), P. krabbei, P. bulbosa and P. azarasi, irrespective of sex and life-history stage, are provided.     

Phocanema decipiens: Pathology in seals

Infective larvae of the anisakine nematode, Phocanema decipiens from cod (Gadus morhua), were fed to harbor seals (Phoca vitulina) and gray seals (Halichoerus grypus). At termination of the experimental infections, 6 of 8 harbor seals were infected with 34(6–64) P. decipiens, while the remaining 2 seals had relatively heavy infections of 250 and 547 nematodes, respectively; 10 of 11 gray seals were infected with 128 (68–229) P. decipiens, but only 2 nematodes were recovered from the 11th seal. Larvae and adults of P. decipiens occurred throughout the gastrointestinal tract, but mainly in the fundic portion of the stomach; the anterior extremities of the nematodes were embedded in mucosa and submucosa. Clusters of adult P. decipiens were associated with ulcerous gastric lesions in harbor seals and raised inflammatory areas in stomachs of gray seals. Singly occurring larvae from challenge transmissions were associated with raised inflammatory areas in the stomachs of both host species. Histological examinations revealed that the lesions and inflammatory areas were eosinophilic granulomata. Anisakis sp. larvae from the viscera of cod were also fed to 1 of the gray seals. Eighty of these larvae were subsequently found in association with a general inflammation in the cardiac area of the stomach in this seal. Natural anisakine infection were surveyed in 16 harbor and 53 gray seals from the Nova Scotia mainland. The natural incidence of P. decipiens was 62(5–177) in harbor seals and 577(11–1694) in gray seals. Clusters of adult P. decipiens were found in association with gastric lesions in 2 juvenile harbor seals; however, in gray seals, the nematodes neither occurred in clusters nor in association with gastric lesions.     

Morphological observation and molecular phylogeny of Spirometra decipiens complex 1 (Cestoda: Diphyllobothriidae) found in cat from Chile

The systematics of tapeworms in the genus Spirometra has been progressing with the accumulation of molecular genetics data, but the taxonomic status of many nominal species remains under debate. We report morphological and molecular-phylogenetic data for a Spirometra species collected from a domestic cat (Felis silvestris catus) in Chiloé Island, Chile. The Spirometra species was shown to be genetically conspecific with Spirometra decipiens complex 1 found in a Pampas fox (Lycalopex gymnocercus) from Argentina, and was closely related to a Hoary fox (Lycalopex vetulus) and rattlesnake (Crotalus durissus) from Brazil. Therefore, the presence of S. decipiens complex 1 was molecularly confirmed for the first time in Chile. The findings of the present study add useful information for the systematics of poorly known Spirometra species in South America.     

Morphological and Molecular Identification of Spirometra Tapeworms (Cestoda: Diphyllobothriidae) from Carnivorous Mammals in the Serengeti and Selous Ecosystems of Tanzania

Spirometra tapeworms (Cestoda: Diphyllobothriidae) collected from carnivorous mammals in Tanzania were identified by the DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and internal transcribed spacer 1 (ITS1), and by morphological characteristics. A total of 15 adult worms were collected from stool samples and carcasses of Panthera leo, Panthera pardus, and Crocuta crocuta in the Serengeti and Selous ecosystems of Tanzania. Three Spirometra species: S. theileri, S. ranarum and S. erinaceieuropaei were identified based on morphological features. Partial cox1 sequences (400 bp) of 10 specimens were revealed. Eight specimens showed 99.5% similarity with Spirometra theileri ({"type":"entrez-nucleotide","attrs":{"text":"MK955901","term_id":"1796114604","term_text":"MK955901"}}MK955901), 1 specimen showed 99.5% similarity with the Korean S. erinaceieuropaei and 1 specimen had 99.5% similarity with Myanmar S. ranarum. Sequence homology estimates for the ITS1 region of S. theileri were 89.8% with S. erinaceieuropaei, 82.5% with S. decipiens, and 78.3% with S. ranarum; and 94.4% homology was observed between S. decipiens and S. ranarum. Phylogenetic analyses were performed with 4 species of Spirometra and 2 species of Dibothriocephalus (=Diphyllobothrium). By both ML and BI methods, cox1 and ITS1 gave well supported, congruent trees topology of S. erinaceieuropaei and S. theileri with S. decipiens and S. ranarum forming a clade. The Dibothriocephalus species were sisters of each other and collectively forming successive outgroups. Our findings confirmed that 3 Spirometra species (S. theileri, S. ranarum, and S. erinaceieuropaei) are distributed in the Serengeti and Selous ecosystems of Tanzania.     

Localization and antioxidant capacity of flavonoids from intertidal and subtidal Halophila johnsonii and Halophila decipiens

In this study, flavonoid localization, content and total antioxidant capacity in leaves of subtidal Halophila decipiens were compared to intertidal and subtidal Halophila johnsonii. H. johnsonii leaves had significantly higher flavonoid content (3.5 and 3.8 nmol quercetin equivalent mm⁻² leaf for intertidal and subtidal H. johnsonii, respectively) and antioxidant capacity (101.7 and 224.2 nmol Trolox equivalent mm⁻² leaf for intertidal and subtidal H. johnsonii, respectively) than H. decipiens leaves (1.4 nmol quercetin equivalent mm⁻² leaf and 21.0 nmol Trolox equivalent mm⁻² leaf). Flavonoid content did not significantly differ between intertidal and subtidal H. johnsonii, however, antioxidant capacity was significantly higher in subtidal plants. Confocal laser scanning microscopy of fresh leaf cross sections indicated that both species contained flavonoids in the cuticle, but only H. johnsonii contained intracellular flavonoids. Intracellular flavonoids are better situated to perform antioxidant functions in planta. These results suggest that flavonoid compounds in H. johnsonii are capable of sunscreen and antioxidant functions while an antioxidant role for flavonoids within H. decipiens is not supported.     

NEW AND INTERESTING SAXICOLOUS SPECIES OFSTRIGULA

The saxicolousStrigula fractanssp. nov. andS. rupestrissp. nov. are described from Lord Howe Island, New South Wales, Australia. A new combination,S. decipiens(Malme) P. M. McCarthy, is proposed forPorina decipiensMalme, and a key to the 17 saxicolous species ofStrigulais provided.     

High allelic diversity in the methyltransferase gene of a phase variable type III restriction-modification system has implications for the fitness of Haemophilus influenzae

Phase variable restriction-modification (R-M) systems are widespread in Eubacteria. Haemophilus influenzae encodes a phase variable homolog of Type III R-M systems. Sequence analysis of this system in 22 non-typeable H.influenzae isolates revealed a hypervariable region in the central portion of the mod gene whereas the res gene was conserved. Maximum likelihood (ML) analysis indicated that most sites outside this hypervariable region experienced strong negative selection but evidence of positive selection for a few sites in adjacent regions. A phylogenetic analysis of 61 Type III mod genes revealed clustering of these H.influenzae mod alleles with mod genes from pathogenic Neisseriae and, based on sequence analysis, horizontal transfer of the mod–res complex between these species. Neisserial mod alleles also contained a hypervariable region and all mod alleles exhibited variability in the repeat tract. We propose that this hypervariable region encodes the target recognition domain (TRD) of the Mod protein and that variability results in alterations to the recognition sequence of this R-M system. We argue that the high allelic diversity and phase variable nature of this R-M system have arisen due to selective pressures exerted by diversity in bacteriophage populations but also have implications for other fitness attributes of these bacterial species.     

Seagrasses in the Zeit Bay area and at Ras Ghârib (Egyptian Red Sea coast)

The distribution and ecology of seagrasses along parts of the Egyptian Red Sea coasts have been investigated. Five of the 10 species ever reported from the Red Sea have been found in this area, i.e. Halodule uninervis (Forssk.) Aschers., Thalassodendron ciliatum (Forssk.) den Hartog, Halophila stipulacea (Forssk.) Aschers., Halophila ovalis (R. Br.) Hook. f. and Halophila ovata Gaud. H. ovata is recorded here for the first time for the west coast of the Red Sea. The finding of Halophila decipiens Ostenfeld represents a new record to the Red Sea; this species has been found at a depth of 30 m, near Ras Ghârib in the Gulf of Suez.     

Complete mitochondrial genome sequences of the three pelagic chaetognaths Sagitta nagae,Sagitta decipiens and Sagitta enflata

The complete nucleotide sequences of the mitochondrial genomes were determined for the three pelagic chaetognaths, Sagitta nagae, Sagitta decipiens, and Sagitta enflata. The mitochondrial genomes of these species which were 11,459, 11,121, and 12,631 bp in length, respectively, contained 14 genes (11 protein-coding genes, one transfer RNA gene, and two ribosomal RNA genes), and were found to have lost 23 genes that are present in the typical metazoan mitochondrial genome. The same mitochondrial genome contents have been reported from the benthic chaetognaths belonging to the family Spadellidae, Paraspadella gotoi and Spadella cephaloptera. Within the phylum Chaetognatha, Sagitta and Spadellidae are distantly related, suggesting that the gene loss occurred in the ancestral species of the phylum. The gene orders of the three Sagitta species are markedly different from those of the other non-Chaetognatha metazoans. In contrast to the region with frequent gene rearrangements, no gene rearrangements were observed in the gene cluster encoding COII–III, ND1–3, srRNA, and tRNA^met. Within this conserved gene cluster, gene rearrangements were not observed in the three Sagitta species or between the Sagitta and Spadellidae species. The gene order of this cluster was also assumed to be the ancestral state of the phylum.     

The Brazilian seagrasses

Based on a critical review of the literature, and on abundant material recently collected along the coast of Brazil, a synthesis of the occurrence and distribution of the Brazilian species of seagrasses is presented. Two species of Hydrocharitaceae, namely Halophila baillonii Aschers. and H. decipiens Ostenf., and three species of Potomogetonaceae, Halodule emarginata den Hartog, H. wrightii Aschers. and Ruppia maritima L. s.s., were found. Ruppia maritima was found all along the Brazilian coast, from about 3 to 32°S latitude, in brackish water ponds and lakes, with salinities varying from 0.3 to 28?.. The other species are restricted to normal seawater ($\text{±35?.}$), although Halodule wrightii was also found in hypersaline waters (45?.). This last species is the most common seagrass in Brazil. The species of Halophila are restricted to warmer waters and were not found further south than Rio de Janeiro State, being especially common on the NE coast at depths down to 62 m. During the course of these studies, Halophila baillonii was found for the second time in Brazil since its original collection in 1888. A critical comparison of a large number of plants leads us to the conclusion that Halodule brasiliensis Lipkin cannot be distinguished from H. wrightii, and H. lilianae den Hartog cannot be distinguished from H. emarginata. Reproductive structures of H. emarginata are described for the first time.     

High photobiont diversity in the common European soil crust lichen Psora decipiens

The genetic diversity of green algal photobionts (chlorobionts) in soil crust forming lichens was studied as part of the SCIN-project (Soil Crust InterNational). A total of 64 lichen samples were collected from four different sites along latitudinal and altitudinal gradients in Europe (Tabernas/Spain; Hochtor-Großglockner/Austria; Gynge Alvar/Sweden; Ruine Homburg/Germany). The dominant lichen species at all four sites was Psora decipiens, often occurring with Buellia elegans, Fulgensia bracteata, F. fulgens and Peltigera rufescens. Genetic identification of chlorobionts was carried out using the nuclear marker (nrITS) and a chloroplast marker (psbL-J). We found P. decipiens to be associated with several different species of Trebouxia and Asterochloris, although previously described to only have Asterochloris sp. The phylogenetic analyses revealed a high chlorobiont diversity with 12 well supported clades, including Trebouxia asymmetrica, T. jamesii, T. impressa and other, as yet taxonomically unidentified clades (Trebouxia sp. URa1-4, T. sp. URa6, T. sp. URa7-13). Additionally, five clades of Asterochloris were identified (A. magna, A. sp. URa14 -17). Most of the chlorobiont species appeared to be cosmopolitan, but five clades were unevenly distributed between the sampling sites with only Trebouxia being found in the warm and dry Spanish habitats and combinations of Trebouxia and Asterochloris in the cooler and more humid habitats. The wide range of chlorobiont species might contribute to the observed domination of P. decipiens at all four research sites of the SCIN project which range from a desert in Spain to an alpine site in the Alps of Austria.     

Spirometra species from Asia: Genetic diversity and taxonomic challenges

Despite considerable controversy concerning the taxonomy of species within the genus Spirometra, human sparganosis and spirometrosis mainly in Asia and Europe has long been confidently ascribed to Spirometra erinaceieuropaei. Recently, the mitochondrial genomes of purported “S. erinaceieuropaei”, “Spirometra decipiens” and “Spirometra ranarum” from Asia have been determined. However, it has been pointed out that the morphological criteria used for identifying these species are unsuitable and thus these identifications are questionable. In the present study, therefore, Spirometra samples from Asia were re-examined based on mitochondrial cytochrome c oxidase subunit 1 gene sequences and the identification of these species was discussed. Haplotype network and phylogenetic analyses revealed that: i) two distinct Spirometra species, Type I and Type II, are present in Asia and neither of which is close to likely European “S. erinaceieuropaei”; ii) Type I is genetically diverse and widely distributed, however Type II is known so far from Japan and Korea; iii) “S. decipiens” and “S. ranarum” reported from Asia are conspecific with Type I; iv) Type I is probably conspecific with Spirometra mansoni, and Type II may represent an undescribed species.