Aquatic versus terrestrial locomotion: comparative performance of two ecologically contrasting species of European natricine snakes

One indicator of ecological differences between species is differential locomotory performance in different media. In this study, we compare locomotory speed of two species of natricine snakes on land and in water at a range of temperatures in the laboratory. As expected, both species moved more quickly at higher temperatures and both swam faster than they moved on land. However, the difference between aquatic and terrestrial speed was much greater for the aquatic species, Natrix maura , than for the semi-aquatic Natrix natrix . Furthermore, although N. maura was significantly faster than N. natrix in water, the opposite was true on land. In fact, N. maura was reluctant to move very far on land at all and would not complete a 2 m terrestrial course. Although we found no evidence of a negative correlation between the aquatic and terrestrial speeds of individual N. natrix , this interspecific comparison is consistent with the notion of a tradeoff between performance abilities on land and in water.     

Heterologous amplification of microsatellite markers from colubroid snakes in European natricines (serpentes: natricinae)

Eighteen microsatellite loci developed for a range of snake species (New World natricines, elapids, crotalids) were tested against European natricines (Natrix natrix, N. maura, and N. tessellata) in cross-species amplification experiments. Five loci were polymorphic (average expected heterozygosity 0.749 for a population of N. natrix in Amsterdam, mean sample size 47.8) and three loci were monomorphic. The remainder could not be consistently scored or failed to amplify. Further tests on single individuals of a diverse set of eight species of colubroid snakes showed that 15 of the 18 loci could be cross-amplified in at least one of these species. We conclude that our results show promise for the utilization of these markers for experimental assessments of genetic variation in the phylogenetically closely related group of European natricine snakes with emphasis on N. natrix. The full suite of microsatellite markers now available for snakes may show additional potential for subsequent investigation across a broader range of colubroid snakes.     

Fritillary phylogeny, classification, and larval host plants: reconstructed mainly on the basis of male and female genitalic morphology (Lepidoptera: Nymphalidae: Argynnini)

Species-level phylogeny of the Butterfly tribe Argynnini is established based on 141 characters derived from wing and genitalia morphology of both sexes. The Argynnini can be divided into three subtribes; Yrameina comprising Yramea and Boloria s . l ., Argynnina comprising Prokuekenthaliella , Issoria , Brenthis , and all the 'large fritillary' species joined in the genus Argynnis s . l . and a new subtribe Euptoietina comprising only the genus Euptoieta . The classical genus Issoria s . l . is polyphyletic regarding Yramea and possibly paraphyletic regarding the two Afrotropic species baumanni and hanningtoni ; these two species are tentatively transferred to the old genus/subgenus Prokuekenthaliella . Surprisingly, one Afrotropic species, Issoria smaragdifera is closely related to the East Palaearctic Issoria species. A revised classification of Argynnini is proposed based on the obtained phylogeny. Studies of larval host plants based on the obtained phylogeny suggest that the ancestral Argynnini used Passiflora and Violaceae, but already the ancestor of Yrameina + Argynnina was probably specialized on Violaceae. Whereas the Boloria species have turned to other food plants such as Dryas , Vaccinium and Salix on several occasions, only Brenthis among the Argynnina use other host plants than Viola (mainly Rosaceae). The habit of laying eggs away from the food plant has probably evolved twice within Argynnina.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 627–673.     

A new species of the genus Lightiella: the first record of Cephalocarida (Crustacea) in Europe

A new species of Cephalocarida belonging to the genus Lightiella is described. Like all known species of Lightiella , the new species is characterized by reduction of trunk segment 8, which also lacks both pleura and thoracopods. The diagnostic characters of the species are: (1) one seta on the inner distal corner of the penultimate endopodal segment of second maxilla and thoracopods 1–5; (2) only one claw on the distal segment of the endopod of thoracopod 6. A cladistic analysis of 27 morphological characters was used to estimate the phylogeny of all species of Lightiella , with all other cephalocarid species used as outgroups. The discovery of this species in the Mediterranean fills a gap in the distribution of the genus and of the entire class.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 209–220.     

Morphological character evolution and molecular trees in sepiids (Mollusca: Cephalopoda): is the cuttlebone a robust phylogenetic marker?

The sepiids are characterized by their cuttlebone or sepion, an internal shell resulting from secondary mineralization of a chitinous 'gladius'. The various species are identified using a combination of shell criteria and 'soft-part' characters. Using mitochondrial genes, we established phylogenetic relationships of sepiids including the three accepted genera ( Sepia , Sepiella , Metasepia ) and a species complex of uncertain status ( Doratosepion ). We showed the Sepia genus to be paraphyletic and found no direct correlation between geographical distribution and systematics. We mapped, on the molecular tree, shell characteristics commonly used as reliable diagnostic criteria for taxonomy. Due to the plasticity of the shell, these characters did not appear phylogenetically informative. In an attempt to define systematic categories related to phylogenetic relationships, new clear synapomorphies need to be established for each genus, necessitating a revision of the genus Sepia .  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 139–150.     

A new Mantalania species (Rubiaceae) from Madagascar

Mantalania longipedunculata De Block & A.P. Davis, a new species of Rubiaceae (Gardenieae) from Île Sainte Marie, Madagascar, is described, illustrated, and compared with the three other species in the genus. An extinction risk assessment is given, using the categories and criteria of the World Conservation Union (IUCN).  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 421–424.     

Phylogeny and species boundaries in the gobiid genus Gnatholepis (Teleostei: Perciformes)

Species of the goby genus Gnatholepis Bleeker, 1874, are common inhabitants of shallow tropical seas worldwide. In this study, mitochondrial DNA sequence (ND2 gene), from 349 Gnatholepis individuals sampled from across the South and Central Pacific and Caribbean, is used to infer phylogeny and determine species boundaries. Seven species of Gnatholepis are recognized: the Indo-Pacific G. anjerensis (Bleeker, 1851) [ G. cauerensis (Bleeker, 1853) is a synonym]; G. scapulostigma Herre, 1953; G. davaoensis Seale, 1910; G. knighti Jordan & Evermann, 1903; G. gymnocara Randall & Greenfield, 2001; G.  sp. Randall & Greenfield, 2001; and the Atlantic/Caribbean G. thompsoni Jordan, 1904. Results from the molecular phylogeny are compared with a previous morphology-based revision of the genus in order to establish which morphological characters diagnose species in correspondence with the molecular phylogeny.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 142 , 573–582.     

Chromosomes of four species in three genera of Commelinaceae from China and their systematic implications

Chromosomes of four species in three genera of Commelinaceae from China were examined. Spatholirion longifolium had 2 n  = 20. This small genus is considered to be of a possible polyploid origin based on x  = 5, a basic number shared by its closest ally, the monospecific genus Streptolirion , with its only species having 2 n  = 10. The two genera were found to be very different from each other in their karyotypic constitution. The differences in both chromosome number (2 n  = 20 vs. 10) and karyotypic constitution support their separation as two independent genera. The remaining three species, Amischotolype hispida , Porandra ramosa and P. scandens , all had 2 n  = 36. In view of the occasional occurrence of 2 n  = 18 in the African Coleotrype , a genus very close to Amischotolype and Porandra in gross morphology, these three species are all very probably polyploid based on x  = 9. The high degree of karyotypic similarity of the three genera also strongly indicates their close affinity and supports their placement in the subtribe Coleotrypinae. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 399–403.     

Molecular phylogeny of shrimps from the genus Lysmata (Caridea: Hippolytidae): the evolutionary origins of protandric simultaneous hermaphroditism and social monogamy

Shrimps from the genus Lysmata are known because of their wide diversity of lifestyles, mating systems, symbiotic partnerships, and conspicuous coloration. They can occur in crowds (large aggregations), in small groups, or as socially monogamous pairs. Shrimps from this genus are rare, if not unique among crustaceans, because of their unusual sexual system. To date, the sexual system of all species investigated comprises a protandric simultaneous hermaphroditism: shrimps initially mature and reproduce as males and later in life turn into functional simultaneous hermaphrodites. The evolutionary relationships of the species within the genus are unsettled. A molecular phylogeny of the group may shed light on the evolutionary origins of the peculiar sexual and social systems of these shrimps and help resolve standing taxonomic questions long overdue. Using a 647-bp alignment of the 16S rRNA mitochondrial DNA, we examined the phylogenetic relationship of 21 species of shrimps from the genus Lysmata from several biogeographical regions; the Atlantic, Pacific, and Indo-Pacific. The resulting phylogeny indicates that the genus is paraphyletic and includes the genus Exhippolysmata . The constituent species are subdivided into three well supported clades: one group exclusively composed of neotropical species; a second clade comprising the Indo-Pacific and Atlantic symbiotic fish cleaner shrimps; and a third clade including tropical and temperate species from the Atlantic and Pacific. The molecular phylogeny presented here does not support a historical contingency hypothesis, previously proposed to explain the origins of protandric simultaneous hermaphroditism within the genus. Furthermore, the present study shows that monogamous pair-living is restricted to one monophyletic group of shrimps and therefore probably evolved only once.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 415–424.     

New or rarely reported chromosome numbers in taxa of subtribe Artemisiinae (Anthemideae, Asteraceae) from Mongolia

This study encompasses 25 chromosome counts of 18 species in the subtribe Artemisiinae (tribe Anthemideae) of the family Asteraceae, from Mongolia. Most (15 species) belong to Artemisia , the largest genus of the subtribe, whereas the others come from two genera very closely related to it: Ajania (two species) and Neopallasia (one species). Eleven counts are new reports, three are not consistent with previous reports and the remainder confirm scanty earlier information. The majority of the species have x  = 9 as their basic chromosome number, but there are some taxa with x  = 8. Ploidy levels range from 2 x to 6 x . The presence of B-chromosomes was detected in Ajania fruticulosa .  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 203–210.     

Varying rates of diversification in the genus Melitaea (Lepidoptera: Nymphalidae) during the past 20 million years

The influence of Quarternary glacial cycles on the extant diversity of Holarctic species has been intensively studied. It has been hypothesized that palaeoclimatic changes are responsible for divergence events in lineages. A constant improvement in DNA sequencing and modeling methods, as well as palaeoclimatic reconstruction, permit a deeper exploration of general causes of speciation in geological time. In the present study, we sampled, as exhaustively as possible, the butterflies belonging to the genus Melitaea (Lepidoptera: Nymphalidae), which are widely spread in the Palaearctic region. We conducted analyses to assess the phylogeny of the genus and estimated the timing of divergence and the most likely distribution of ancestral populations. The results obtained indicate that the systematics of the genus is in need of revision and that the diversity of the genus has been profoundly shaped by palaeoenvironmental changes during its evolutionary history. The present study also emphasizes that, when employed with caveats, major palaeoenvironmental events could represent very powerful tools for the calibration of the dating of divergences using molecular data.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 346–361.     

Phylogeny and biogeography of Crinum L. (Amaryllidaceae) inferred from nuclear and limited plastid non-coding DNA sequences

The genus Crinum L. is the only pantropical genus of the Amaryllidaceae. Phylogenetic and biogeographical analyses of nrDNA ITS and plastid trnL-F sequences for all continental groups of the genus Crinum and related African genera are presented, with the genus Amaryllis used as outgroup. ITS indicates that C. baumii is more closely related to Ammocharis and Cybistetes than to Crinum sensu stricto . Three clades are resolved in Crinum s.s. One unites a monophyletic American group with tropical and North African species. The second includes all southern African species and the Australian endemic C. flaccidum . The third includes monophyletic Madagascar, Australasian and Sino-Himalayan clades, with southern African species. The trnL-F phylogeny resolves an American and an Asian/Madagscar clade, and confirms the relationship of C. flaccidum with species endemic to southern Africa. The salverform, actinomorphic perianths of subg. Crinum appear to have evolved several times in the genus from ancestors with zygomorphic perianths (subg. Codonocrinum ), thus neither subgenus is monophyletic. Biogeographical analyses place the origin of Crinum in southern Africa, as the region is optimized at all ancestral nodes in the tree topology, and in basal interior nodes of all but one of the major clades. The genus underwent three major waves of radiation corresponding to the three main clades resolved in our trees. Two entries into Australia for the genus are indicated, as are separate Sino-Himalayan and Australasian dispersal events.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 349–363.     

New chromosome counts in the genus Cousinia (Asteraceae) from Iran

Chromosome counts are reported of 38 populations representing 24 species of the genus Cousinia from Iran, one of the main centres of speciation of the genus. Sixteen of the counts are new to science. Our results confirm that Cousinia exhibits a complex dysploid series ranging from x  = 13 to x  = 9. One of the basic chromosome numbers, x  = 9, is new for the genus and must be confirmed. Some considerations on the correlation between chromosome numbers and section classification are made.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 411–419.     

Labile ecotypes accompany rapid cladogenesis in an adaptive radiation of Mandarina (Bradybaenidae) land snails

The endemic land snail genus Mandarina of the oceanic Bonin Islands shows exceptionally diverse morphological and ecological traits. Previous studies have already provided evidence that speciation on different islands of the three main archipelagos was such that similar ecotypes evolved independently in different lineages and islands. Here we present data to show that the same species can have different ecotypes. As most of the characters involved are inherited, then variation between ecotypes must represent genetic differences between populations. We then show that the radiation on the Bonin Islands is derived from a single colonization event, and use a mitochondrial phylogeny to provide evidence for a burst of cladogenesis soon after colonization. As divergent selection has previously been implicated in causing differences between Mandarina species, and theory predicts that most of the speciation should have taken place early in their history, then the study adds to the evidence for an adaptive radiation by ecological speciation in Mandarina . However, while the diversity of ecotypes present at each site is dependent on the regime of natural selection and competition, geography still must have an important role.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 269–282.     

Novel microsatellite loci in the grass snake (Natrix natrix) and cross-amplification in the dice snake (Natrix tessellata)

Six novel polymorphic microsatellite loci are presented for the grass snake (Natrix natrix), a species with declining populations in many regions. The number of alleles per locus ranged from two to seven. Four dice snake (Natrix tessellata) microsatellites were polymorphic in the grass snake with three to four alleles. At two loci, the expected heterozygosity differed significantly from observed heterozygosity. Cross-amplification of the grass snake markers in the dice snake showed two polymorphic microsatellites with two and four alleles.     

Molecular phylogeny of the western Atlantic species of the genus Portunus (Crustacea, Brachyura, Portunidae)

The genus Portunus encompasses a comparatively large number of species distributed worldwide in temperate to tropical waters. Although much has been reported about the biology of selected species, taxonomic identification of several species is problematic on the basis of strictly adult morphology. Relationships among species of the genus are also poorly understood, and systematic review of the group is long overdue. Prior to the present study, there had been no comprehensive attempt to resolve taxonomic questions or determine evolutionary relationships within this genus on the basis of molecular genetics. Phylogenetic relationships among 14 putative species of Portunus from the Gulf of Mexico and other waters of the western Atlantic were examined using 16S sequences of the rRNA gene. The resultant molecularly based phylogeny disagrees in several respects with current morphologically based classification of Portunus from this geographical region. Of the 14 species generally recognized, only 12 appear to be valid. We recommend that P. vossi be hereafter regarded as a junior synonym of P. spinimanus and that P. bahamensis be regarded as a junior synonym of P. depressifrons . Our analysis suggests that western Atlantic members of the genus can be subdivided into at least three well-defined clades. Pending further molecular analyses with a large subset of species, it appears that the genus is not monophyletic and that it warrants further taxonomic revision.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 150 , 211–220.     

Flies on thistles: support for synchronous speciation?

Synchronous speciation of hosts and herbivorous insects predicts a congruent topology of host and insect phylogenies and similar evolutionary ages of host and insect taxa. To test these predictions for the specialized herbivorous fly genus Urophora (Diptera: Tephritidae), we used three different approaches. (i) We generated a phylogenetic tree of 11 European Urophora species from allozyme data and constructed a phylogeny of their hosts from published sources. Superimposing the Urophora tree on the host-plant tree we found no evidence for general congruence. (ii) We correlated genetic distances (Nei distances) of the host plants vs. the genetic distances of associated Urophora species. Overall, the relationship was not positive. Nevertheless, for some pairs of Urophora species and host plants genetic distances were in the same order of magnitude. (iii) We collected allozyme data for pairs of thistle taxa and pairs of herbivores on thistles together with independent time estimates. With these data we calibrated a molecular clock. There was a non-linear relationship between phylogenetic age and genetic distance, rendering the dating of deep events in thistle–insect evolution difficult. Nevertheless the derived molecular clock showed that the split of insect taxa lagged behind the split of hosts.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 84 , 775–783.     

Distribution and genetic divergence of two parapatric sibling ant species in Central Europe

The two sibling ant species Temnothorax nylanderi and Temnothorax crassispinus are widely distributed throughout deciduous forests in Europe. Their resemblance in morphology and similar ecological requirements suggest that they evolved from the same ancestral species in different glacial refugia and re-immigrated into Central Europe after the last ice age. Here, we show that the two species are parapatrically distributed in south-eastern Germany and hybridize along a narrow contact zone close to the continental divide. Phylogeographical data based on the mitochondrial genes cytochrome oxidase subunit I and cytochrome b suggest that the dominant haplotypes for T. nylanderi and T. crassispinus might have diverged already 1.5–2 Mya. Intraspecific variability is extremely low in both species, which might be explained by severe bottlenecks during rapid postglacial expansion into Central Europe.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 223–234.     

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.