The conserved mitochondrial gene distribution in relatives of Turritopsis nutricula,an immortal jellyfish

Turritopsis nutricula (T. nutricula) is the one of the known reported organisms that can revert its life cycle to the polyp stage even after becoming sexually mature, defining itself as the only immortal organism in the animal kingdom. Therefore, the animal is having prime importance in basic biological, aging, and biomedical researches. However, till date, the genome of this organism has not been sequenced and even there is no molecular phylogenetic study to reveal its close relatives. Here, using phylogenetic analysis based on available 16s rRNA gene and protein sequences of Cytochrome oxidase subunit-I (COI or COX1) of T. nutricula, we have predicted the closest relatives of the organism. While we found Nemopsis bachei could be closest organism based on COX1 gene sequence; T. dohrnii may be designated as the closest taxon to T. nutricula based on rRNA. Moreover, we have figured out four species that showed similar root distance based on COX1 protein sequence.     

Morphological and ultrastructural analysis of Turritopsis nutricula during life cycle reversal

The hydrozoa life cycle is characterized, in normal conditions, by the alternation of a post-larval benthic polyp and an adult pelagic medusa; however, some species of Hydrozoa react to environmental stress by reverting their life cycle: i.e. an adult medusa goes back to the juvenile stage of polyp. This very uncommon life cycle could be considered as some sort of inverted metamorphosis. A morphological study of different stages during the reverted life cycle of Turritopsis nutricula led to the characterization of four different stages: healthy medusa, unhealthy medusa, four-leaf clover and cyst. The ultrastructural study of the cellular modifications (during the life cycle reversion of T. nutricula) showed the presence of both degenerative and apoptotic processes. Degeneration was prevalent during the unhealthy medusa and four-leaf clover stages, while the apoptotic rate was higher during the healthy medusa and cyst stages. The significant presence of degenerative and apoptotic processes could be related to the occurrence of a sort of metamorphosis when an adult medusa transforms itself into a polyp.     

A taxonomic catalogue of Japanese nemerteans (phylum Nemertea)

A literature-based taxonomic catalogue of the nemertean species (Phylum Nemertea) reported from Japanese waters is provided, listing 19 families, 45 genera, and 120 species as valid. Applications of the following species names to forms previously recorded from Japanese waters are regarded as uncertain: Amphiporus cervicalis, Amphiporus depressus, Amphiporus lactifloreus, Cephalothrix filiformis, Cephalothrix linearis, Cerebratulus fuscus, Lineus vegetus, Lineus bilineatus, Lineus gesserensis, Lineus grubei, Lineus longifissus, Lineus mcintoshii, Nipponnemertes pulchra, Oerstedia venusta, Prostoma graecense, and Prostoma grande. The identities of the taxa referred to by the following four nominal species require clarification through future investigations: Cosmocephala japonica, Dicelis rubra, Dichilus obscurus, and Nareda serpentina. The nominal species established from Japanese waters are tabulated. In addition, a brief history of taxonomic research on Japanese nemerteans is reviewed.     

Molecular ecology and phylogenetics of the water beetle genus Ochthebius revealed multiple independent shifts to marine rockpools lifestyle

Marine rockpools represent a dynamic ecosystem where inhabiting species usually suffer changeable conditions, with consequent phenomena of local populations’ size expansions and reductions. Nevertheless, a few specialized insect groups are known to live in marine rockpools, and among them, several species belong to the water beetle family Hydraenidae. Three groups of Ochthebius sensu lato (s.l.) live in fact in marine rockpools: the putative subgenus Calobius, the former subgenus Cobalius (both mostly Mediterranean–Macaronesian) and two species of the O. capicola group from South Africa. In this work, we performed a molecular phylogeny of Ochthebius s.l., running molecular clocks, aiming to address the following questions: Are these three groups related? Which is their position within Ochthebius s.l.? How many different times and in how many lineages of Ochthebius s.l. a shift from inland waters to marine rockpools environments happened? Is the current taxonomic status of these three groups supported by genetics? We found that Calobius, Cobalius and the O. capicola group represent three distinct groups, with no sister relationships, suggesting that a shift from fresh/brackish waters to marine rockpools happened independently at least three different times along the diversification of the genus. Cobalius represents an effective separate subgenus, whereas such a rank is not supported by molecular data for Calobius, which represents a monophyletic clade within the nominal subgenus Ochthebius sensu stricto (s.str.). However, as Calobius is monophyletic and characterized by strongly peculiar and distinguishing morphology, we suggest referring to this group as the ‘Calobius’ lineage. Three Mediterranean taxa within this lineage represent likely valid new species, to be described soon. In the same way, the taxonomy of Cobalius should be revised, with two previously formally recognized species found to be paraphyletic, and the possible presence of two additional cryptic species.     

First record of an Early Barremian caprinid rudist from Japan – implications for the palaeobiogeography of the Caprinidae (Bivalvia)

Abstract: Pachytraga Paquier, 1900, the stratigraphically oldest genus of caprinine caprinid rudist, was previously known from only two chronospecies from a single lineage, that is the Hauterivian P. tubiconcha Astre, 1961 and the early Aptian P. paradoxa (Pictet and Campiche, 1869). Here, a new species, Pachytraga? tanakahitoshii, is erected on the basis of isolated left valves recovered from the Osaka and Sanchu areas, south‐west Japan. This species has a moderate shell size (antero‐posterior commissural diameter c. 30 mm), and its left valve is characterized by at least one possibly autapomorphic character (narrow anterior myophore, inclined inwards), as well as a mosaic of primitive (single longitudinal carina developed on the anterior side) and derived (simple marginal canals in the antero‐dorsal valve margin) characters of Mediterranean and Middle East Tethyan Pachytraga. The Japanese Pachytraga? represents the first probable record of this genus outside the Mediterranean/Middle Eastern Tethyan province, and its early Barremian age partly fills the ‘gap’ in its previously known stratigraphical record, although the evolutionary relationship of the Japanese form with Mediterranean and Middle East Tethyan Pachytraga remains unsolved. However, the discovery of early Barremian Pachytraga? in Japan indicates that the evolutionary history of the genus is more complex than previously thought and should thus be discussed in a broader palaeogeographical context that must now include the Pacific.     

A redescription ofLepidauchen stenostoma Nicoll, 1913 (Digenea), and a reassessment of the status of the genusLepidauchen Nicoll, 1913

The genusLepidauchen is discussed and defined. It is removed from the family Lepocreadiidae and placed in the family Acanthocolpidae based mainly on its possession of a uterine seminal receptacle. The type, and only valid species,L. stenostoma, is redescribed using material fromLabrus merula from Corsica. Material fromCoris julis andSymphodus tinca from the western Mediterranean off Marseille,L. merula from the western Mediterranean off Valencia,Diplodus annularis andLithognathus mormyrus from the Adriatic Sea off Montenegro, andArchosargus unimaculatus from Venezuela was also examined. Other nominal species are discussed, but none are considered valid within this genus.     

Genetic variation and clonal diversity in island Cephalanthera rubra populations from the Biebrza National Park, Poland

Three populations of the orchid species Cephalanthera rubra localized on neighbouring mineral islands in the Biebrza National Park (north-east Poland) were examined using 16 allozyme loci. The percentage of polymorphic loci in these C. rubra populations ranged from 25 to 31.3% and the mean number of alleles per polymorphic locus from 1.25 to 1.31. The levels of observed heterozygosity at polymorphic loci were higher than expected for all populations. The overabundance of heterozygotes was noted in every population. The values of fixation indices were highly negative. The genetic differentiation among the three populations was small ( F _ST = 0.0173), albeit statistically significant ( P  < 0.001). The level of gene flow varied from 13 to 16. Fourteen multilocus genotypes were found among the 401 ramets sampled from the populations. Only four of them were common for all populations. The frequency of genotypes was different in these three populations of C. rubra . Some of the multilocus genotypes dominated in the given populations, others were found sporadically. Genetic variation within C. rubra populations is mainly the result of small population sizes and reflects the influences of breeding system and type of reproduction. On the other hand, these properties are also connected with habitat conditions.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 143 , 99–108.     

Mitochondrial DNA phylogeny and morphological diversity in the genus Mastus (Beck, 1837): a study in a recent (Holocene) island group (Koufonisi, south-east Crete)

Three endemic Cretan land snail species of the genus Mastus (Beck, 1837) from the island group of Koufonisi (south-east Crete) and the eastern part of Crete, were studied by multivariate analysis of shell morphology and analysis of mtDNA sequences. The phylogeny of the populations studied and the processes effecting the genetic and morphological diversity of the species were investigated. Extremely high mtDNA sequence divergence was observed both within and between populations. The Cretan populations could not be distinguished morphologically, while the populations of the islets were more distinct. We argue that the active geological past of the area (including sea level changes) and the long-term presence of humans has produced a mixing up of Mastus populations leading to the accumulation of high divergence of mtDNA sequences on a small spatial scale. The limited morphological diversity and the distinct shell 'identity' of the islets' populations can be attributed to the selective pressures of the island group.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 78, 383–399.     

A rangewide phylogeography of Hermann's tortoise, Testudo hermanni (Reptilia: Testudines: Testudinidae): implications for taxonomy

Hermann's tortoise (Testudo hermanni), the best-known western Palaearctic tortoise species, has a rare natural distribution pattern comprising the Mediterranean areas of the Iberian, Apennine, and Balkan Peninsulas, as well as Sicily, Corsica and Sardinia. The western part of this range is traditionally considered habitat for T. h. hermanni, while T. h. boettgeri occurs in the Balkans. Taxonomy of this tortoise has been challenged in recent years, with the two subspecies being considered full species and the central Dalmatian populations of T. h. boettgeri being considered a third species, T. hercegovinensis. Using an mtDNA fragment approximately 1150 bp long (cytochrome b gene and adjacent portion of tRNA-Thr gene), we investigated mtDNA diversity with regard to contrasting concepts of two subspecies or three species. Seven closely related haplotypes were identified from the western Mediterranean and 15 different, in part much-differentiated, haplotypes from the Balkans. Western Mediterranean haplotypes differ from Balkan haplotypes in 16–42 mutation steps. One to seven mutation steps occur within western Mediterranean populations. Balkan haplotypes, differing in 1−37 nucleotides, group in parsimony network analysis into three major assemblages that display, in part, a similar degree of differentiation to that of western Mediterranean haplotypes relative to Balkan haplotypes. Rates of sequence evolution are different in both regions, and low divergence, palaeogeography and the fossil record suggest a slower molecular clock in the western Mediterranean. While monophyly in western Mediterranean haplotypes is well-supported, conflicting evidence is obtained for Balkan haplotypes; maximum parsimony supports monophyly of Balkan haplotypes, but other phylogenetic analyses (Bayesian, ML, ME) indicate Balkan haplotypes could be paraphyletic with respect to the western Mediterranean clade. These results imply a process of differentiation not yet complete despite allopatry in the western Mediterranean and the Balkans, and suggest all populations of T. hermanni are conspecific. In the western Mediterranean no clear geographical pattern in haplotype distribution is found. Distribution of Balkan haplotypes is more structured. One group of similar haplotypes occurs in the eastern Balkans (Bulgaria, Republic of Macedonia, Romania and the Greek regions Evvia, Macedonia, Peloponnese, Thessaly and Thrace). Two distinct haplotypes, differing in eight to nine mutation steps from the most common haplotype of the first group, are confined to the western slope of the Taygetos Mts. in the Peloponnese. Yet another group, connected over between four and 23 mutation steps with haplotypes of the eastern Balkan group, occurs along the western slope of the Dinarid and Pindos Mts. (Istria, Dalmatia, western Greece). Taygetos haplotypes are nested within other haplotypes in all phylogenetic analyses and support for monophyly of the other Balkan groups is at best weak. We conclude that using the traditional two subspecies model should be continued for T. hermanni. Phylogeographies of T. hermanni and Emys orbicularis, another codistributed chelonian, are markedly different, but share a few similarities. Both were forced to retreat to southern refuges during Pleistocene glaciations. With the advent of Holocene warming, E. orbicularis underwent rapid range expansion and temperate regions of Europe and adjacent Asia were recolonized from refuges in the Balkans and the northern Black Sea Region. By contrast, T. hermanni remained more or less confined to refuges and nearby regions, resulting in a much smaller range, and allopatric and parapatric distribution of haplotype groups and clades. MtDNA lineages are more diverse in E. orbicularis than they are in T. hermanni on southern European peninsulas, indicating several distinct glacial refuges in close proximity and extensive intergradation during Holocene range expansion for E. orbicularis. In T. hermanni it is likely that only on the Balkan Peninsula was more than one refuge located, corresponding to the parapatric ranges of haplotype groups currently there. On the old western Mediterranean islands Corsica and Sardinia no differentiated (E. orbicularis) or only weakly differentiated haplotypes (T. hermanni) occur, even though there is evidence for the presence of both species on Corsica since at least the Middle Pleistocene. High mountain chains constitute major barriers separating distinct mtDNA clades or groups in each species.     

Investigating genetic diversity and habitat dynamics in Plantago brutia (Plantaginaceae), implications for the management of narrow endemics in Mediterranean mountain pastures

Many factors have contributed to the richness of narrow endemics in the Mediterranean, including long-lasting human impact on pristine landscapes. The abandonment of traditional land-use practices is causing forest recovery throughout the Mediterranean mountains, by increasing reduction and fragmentation of open habitats. We investigated the population genetic structure and habitat dynamics of Plantago brutia Ten., a narrow endemic in mountain pastures of S Italy. Some plants were cultivated in the botanical garden to explore the species' breeding system. Genetic diversity was evaluated based on inter-simple sequence repeat (ISSR) polymorphisms in 150 individuals from most of known stands. Recent dynamics in the species habitat were checked over a 14-year period. Flower phenology, stigma receptivity and experimental pollinations revealed protogyny and self-incompatibility. With the exception of very small and isolated populations, high genetic diversity was found at the species and population level. amova revealed weak differentiation among populations, and the Mantel test suggested absence of isolation-by-distance. Multivariate analysis of population and genetic data distinguished the populations based on genetic richness, size and isolation. Landscape analyses confirmed recent reduction and isolation of potentially suitable habitats. Low selfing, recent isolation and probable seed exchange may have preserved P. brutia populations from higher loss of genetic diversity. Nonetheless, data related to very small populations suggest that this species may suffer further fragmentation and isolation. To preserve most of the species' genetic richness, future management efforts should consider the large and isolated populations recognised in our analyses.     

Phylogeography of Iurus dufoureius (Brullé, 1832) (Scorpiones, Iuridae)

Aim  This study uses molecular data in conjunction with palaeogeography to infer the most plausible biogeographical scenario accounting for the current distributional pattern of Iurus dufoureius .
Location  North-eastern Mediterranean region.
Methods  Sequencing of a 441-bp segment of the mitochondrial 16S rRNA gene in seven populations covering the whole distributional range of the species. Phylogenetic analyses performed included neighbour joining, maximum parsimony and Bayesian inference.
Results  The molecular phylogeny showed that two Iurus clades are strongly supported. These clades correspond to the two subspecies Iurus dufoureius dufoureius and Iurus dufoureius asiaticus , currently recognized within the genus. The assumption of a clock-like evolution could not be rejected, and this enabled us to estimate an approximation of the local rate of evolution for the I. dufoureius lineages. Based on the estimated evolutionary rate (0.79 ± 0.17 Myr⁻¹), the split between the two Iurus clades occurred c. 8 Ma.
Main conclusions  Contrary to what was believed in the past, the genus Iurus is an old north-eastern Mediterranean genus that has been differentiating in southern Greece and south-west Turkey at least from the middle Miocene. According to the phylogenetic trees obtained and the dating of the divergence times of lineages, the genus dispersed into the Aegean Archipelago when the Aegean was still a uniform land mass. Although the phylogenetic relationships of I. d. dufoureius populations have been shaped by the most recent vicariant events, the phylogenetic relationships of I. d. asiaticus populations are mostly attributable to older palaeoevents occurring in the area.     

Relationships, classification and evolution of Scleranthus (Caryophyllaceae) as inferred from analysis of morphological characters

Study of floral anatomy, micromorphology, palynology and onotogeny has revealed new characters for phylogenetic analysis in the genus Scleranthus . Cladistic analysis of these characters, along with those previously available, suggests that the genus consists of Eurasian/Mediterranean and Australasian sister clades. Gynoecial morphology and development are closely similar in all species, suggesting the genus is monophyletic despite its disjunct northern and southern hemisphere distribution. Variation in pollen:ovule ratios and their implications for the evolution of Scleranthus species are also discussed and it is concluded that a range of breeding strategies intermediate between autogamy and xenogamy exists in the genus. Single-stamened species of Scleranthus are likely to be obligate autogams, despite their comparatively high pollen:ovule ratios in relation to autogamic species of other genera.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 15–29.     

Revision of the dolichoderine ant genus Turneria (Hymenoptera: Formicidae)

Abstract. The Australasian ant genus Turneria is revised. T.bidentata Forel, T.dahlii Forel and T.pacifica Mann are redescribed and a lectotype designated for T.bidentata. T.frenchi Forel is transferred to Stigmacros (comb.n.), and T.butteli Forel is transferred to Iridomyrmex (comb.n.). Three new species, T.arbusta, T.collina and T.postomma, are described from Papua New Guinea. Males of the genus are described for the first time. A key to the workers of recognized species and a distribution map are provided. The group is analysed cladistically and the resulting species relationships are discussed, along with a comment on the use of polymorphic characters.     

Phylogeny and taxonomy of Potamotrygonocotyle Mayes, Brooks & Thorson, 1981 (Monogenoidea: Monocotylidae) with a description of four new species

The marine-derived stingrays of Potamotrygonidae, endemic to South American river systems, host an interesting parasite fauna equally related to marine lineages. Among those lineages, the diversity and phylogenetic relationships within Potamotrygonocotyle - a monocotylid monogenoidean specific to potamotrygonids - are poorly known, since 9 of 10 species attributed to this genus have been described in the past 3 years. Here, we readdress the diversity of Potamotrygonocotyle after examining the gills of 436 potamotrygonid individuals representing 12 described and 14 potentially undescribed species of freshwater stingrays from 19 major river systems of South America (i.e. sub-basins). We recognized 12 valid species within the parasite genus, of which four are described in this study. Our taxonomic decisions were based on the phylogenetic analysis of 14 ingroup terminal taxa and 12 morphological characters, which resulted in the following hypothesis of sister-group relationships: ((P. dromedarius, P. tatianae sp. nov.), (P. rionegrense, P. auriculocotyle sp. nov., ((P. quadracotyle, P. umbella), (P. septemcotyle sp. nov., (P. chisholmae, P. uruguayense)), (P. tsalickisi, P. eurypotamoxenus, P. rarum, (P. tocantinsense sp. nov., P. aramasae))))). According to our hypothesis, the absence of autapomorphic features for some nominal species, and the re-evaluation of morphological variation among populations, led us to consider P. eurypotamoxenus and P. uruguayense as junior synonymys of P. tsalicksi and P. chisholmae, respectively. Finally, we address the importance of biogeographic and host representation, in order to fully understand the patterns of morphological variation and host specificity within this group. We found that hypotheses of species delimitation depend greatly on efforts to sample specimens throughout its distributional range and that host specificity within this genus varies dramatically among lineages.     

Geographical variation in host–ant specificity of the parasitic butterfly Maculinea alcon in Denmark

Abstract  1. Maculinea alcon uses three different species of Myrmica host ants along a north–south gradient in Europe. Based on this geographical variation in host ant use, Elmes et al . (1994) suggested that M. alcon might consist of three or more cryptic species or host races, each using a single and different host-ant species.
2. Population-specific differences in allozyme genotypes of M. alcon in Denmark ( Gadeberg & Boomsma, 1997 ) have suggested that genetically differentiated forms may occur in a gradient across Denmark, possibly in relation to the use of different host ants.
3. It was found that two host-ant species are indeed used as hosts in Denmark, but not in a clear-cut north–south gradient. Furthermore, specificity was not complete for many M. alcon populations. Of five populations investigated in detail, one used primarily M. rubra as a host, another exclusively used M. ruginodis , while the other three populations used both ant species. No population in Denmark used M. scabrinodis as a host, although this species was present in the habitat and is known to be a host in central and southern Europe.
4. In terms of number of parasites per nest and number of nests parasitised, M. rubra seems to be a more suitable host in populations where two host species are used simultaneously. Host-ant species has an influence on caterpillar size but this varies geographically. Analyses of pupae did not, however, show size differences between M. alcon raised in M. rubra and M. ruginodis nests.
5. The geographical mosaic of host specificity and demography of M. alcon in Denmark probably reflects the co-evolution of M. alcon with two alternative host species. This system therefore provides an interesting opportunity for studying details of the evolution of parasite specificity and the dynamics of host-race formation.     

Genetic cohesion of Eresus walckenaeri (Araneae, Eresidae) in the eastern Mediterranean

The eresid spider genus Eresus is morphologically and ecologically conservative. At least three species occur in Europe. However, deep genetic divergence among geographical samples within two species, E. cinnaberinus and E. sandaliatus , may suggest more cryptic species. In the present study we investigate the genetic cohesion of the third species, Eresus walckenaeri , throughout its eastern Mediterranean distribution range, relative to the E. cinnaberinus–E. sandaliatus species complex. Eresus walckenaeri specimens were monophyletic. Genetic discreteness of E. walckenaeri in a region of sympatry with its sister species in Greece provides evidence for species integrity of E. walckenaeri within the European Eresus species complex. Eresus walckenaeri exhibited high concordance between geographical location and mtDNA genealogy. Two major phylogeographical clades were found in the Greek–Turkish and Syrian–Israel parts of the investigated area, respectively (∼6.5% sequence divergence). Concordance between geography and genetic divergence was further observed between Aegean island samples and their corresponding Greek and Turkish mainland samples, suggesting regional subdivision with gradual but potentially high dispersal propensity. Monophyly and limited regional distribution indicate Mediterranean endemic origin.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 1–9.     

Morphological and genetic evidence supports the existence of two species in the genus Ophelia (Annelida, Polychaeta) from the Western Mediterranean

About 900 individuals of the intertidal polychaete Ophelia cf. bicornis were collected at four sandy beaches in Corsica, ten in Sardinia and one in Tuscany (Western Mediterranean). They were analysed morphologically and genetically to clarify the taxonomic status of the littoral species of Ophelia in the study area and to assess the population genetic structuring. Two morphotypes were distinguished on the basis of the number of nephridiopore pairs (five or six). Genetic distances, F -statistics and analysis of molecular variance based on eight allozyme genetic markers were consistent in showing the two morphotypes to separate at species level. Thus, the two morphotypes which most authors have included in O. bicornis s.l. are not one morphologically variable taxon, but instead constitute two valid species, namely O. bicornis Savigny, 1818, with six pairs of nephridiopores, and O. barquii Fauvel, 1927, with five pairs of nephridiopores. Mechanisms of ecological speciation in a background of gene flow can be taken into account to explain the origin of the two species. Moderate genetic differentiation was found among populations within each species, suggesting that dispersal may not be effective over large distances, or that local selection plays an important role in population differentiation.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 101–113.