Received: 23 March 2005 / Accepted: 20 July 2005
Endoparasitic mite infections of anuran amphibians from Bolivian montane rain forests, with descriptions of two new Hannemania species (Acari: Parasitengona: Trombiculidae: Leeuwenhoekiinae)Download PDFAbstract
Endoparasitic chiggers were collected from juvenile Bufo quechua (Bufonidae) and adult Eleutherodactylus platydactylus (Leptodactylidae) sampled in perhumid montane forests in Bolivia. Complete taxonomic descriptions are given for Hannemania yungicola n. sp., which parasitizes both amphibian hosts in higher montane rain forests, and for H. chaparensis n. sp., which seems to be restricted to lower montane rain forests. In histological sections, the mites are completely embedded in capsules produced by the host. The parasites’ mouthparts obviously are adapted to rupturing host cells, the contents of which are ingested. The life style of Hannemania species, its evolution, and the parasites’ potential influence on their hosts are discussed.
Received: 28 April 2005 / Accepted: 08 September 2005
Australian Iphimediidae (Crustacea: Amphipoda)Download PDFAbstract
Australian species of the iphimediid amphipod genus Iphimedia are revised. Based on new material from inshore and continental shelf habitats six new species are described: Iphimedia beesleyae; I. filmersankeyi; I. kateae; I. lisae; I. neuweileri and I. oetkeri. Four established species are redescribed: I. ambigua Haswell, 1879; I. discreta Stebbing, 1910; I. edgari (Moore, 1981) and I. warraina (Thomas and Barnard, 1991). A key to Australian species of Iphimedia is provided. Full article published online at http://www.senckenberg.de/odes/06-09.htm
Received: 13 December 2004 / Accepted: 08 July 2005
Halacaroidea (Acari): A guide to marine generaDownload PDFAbstract
Halacarid mites (Halacaroidea: Halacaridae) are meiobenthic organisms. The majority of species and genera are marine, only few are restricted to freshwater. Halacarid mites are present from the tidal area to the deep sea. It is the only mite family completely adapted to permanent life in the sea. The first record was published more than 200 years ago.At present, 51 marine and brackish water genera of halacarid mites are known, including more than 1000 species. The genera are Acanthohalacarus, Acanthopalpus, Acarochelopodia, Acaromantis, Acarothrix, Actacarus, Agaue, Agauides, Agauopsis, Anomalohalacarus, Arenihalacarus, Arhodeoporus, Atelopsalis, Australacarus, Bathyhalacarus, Bradyagaue, Camactognathus, Caspihalacarus, Coloboceras, Colobocerasides, Copidognathides, Copidognathus, Corallihalacarus, Enterohalacarus, Halacarus, Halacarellus, Halacaroides, Halacaropsis, Halixodes, Isobactrus, Lohmannella, Metarhombognathus, Mictognathus, Parhalixodes, Pelacarus, Peregrinacarus, Phacacarus, Rhombognathides, Rhombognathus, Scaptognathides, Scaptognathus, Simognathus, Spongihalacarus, Thalassacarus, Thalassarachna, Thalassophthirius, Tropihalacarus, Werthella, Werthelloides, Winlundia, and Xenohalacarus.The guide, which includes marine and brackish water genera, starts with an introduction to methods of collection, extraction and examination of halacarid mites, an outline of the external morphology and life history, and an overview of the commonly used terminology. Both a dichotomous key and tabular keys to the genera are presented. The keys have been prepared on the basis of adults. In general, in adults and nymphs the outline of idiosoma, gnathosoma and legs is similar, whereas the outline of plates, the sculpturing and number of setae on idiosoma and legs differ. In the tabular keys idiosoma, gnathosoma, palps, legs, tarsi and shape of claws are treated separately.The major part of the guide deals with descriptions of the 51 genera. Each genus is diagnosed and illustrated, namely a dorsal and ventral aspect of the idiosoma, the gnathosoma, leg I and tarsi I, II and IV. The diagnoses mention both, characters expected to be relevant in a phylogenetic sense and those thought to be mainly correlated with environment and mode of life. Rare character variants are included in the diagnoses; more variants are expected to be found in the future. In addition to the diagnoses, short notes are given on biology and geographical distribution, on similar-looking genera, and distinguishing characters. At the end of the presentation of a genus, relevant and most recent descriptive or phylogenetic references are listed. Full article published online at: http://www.senckenberg.de/odes/06-06.htm
Received: 15 December 2004 / Accepted: 01 December 2005
Monophyly and systematic position of Glypthelmins (Digenea), based on partial lsrDNA sequences and morphological evidenceDownload PDFAbstract
Species composition and systematic placement within the order Plagiorchiida has been controversial. Species number in Glypthelmins Stafford, 1905, a genus of cosmopolitan parasites of anurans, has varied between 19 and 28 species, depending on the taxonomic treatment. The present study performs a phylogenetic analysis using partial lsrDNA sequences to test the monophyly of the genus, and compares new sequences obtained with those published for different plagiorchiids to clarify the systematic position of Glypthelmins within the order Plagiorchiida. Maximum parsimony (MP) and maximum likelihood (ML) analyses result in identical tree topology. The single MP tree (L=1587, CI=0.40, RI=0.76) includes several clades with high bootstrap and Bremer support values. Glypthelmins sensu lato as traditionally classified is paraphyletic. Based on molecular and/or morphological evidence, the taxonomic diagnosis for Glypthelmins is emended, only eight species are retained in the genus, and re-establishment of the genera Choledocystus Pereira & Cuocolo, 1941 and Rauschiella Babero, 1951 is proposed, resulting in the following new combinations: Choledocystus simulans (Teixeira de Freitas, 1941) comb. nov., C. vitellinophilum (Dobbin, 1958) comb. nov.; Rauschiella chaquensis (Mañé-Garzón & Holcman-Spector, 1967) comb. nov., R. lenti (Teixeira de Freitas, 1941) comb. nov., R. linguatula (Rudolphi, 1819) comb. nov., R. poncedeleoni (Razo-Mendivil & León-Règagnon, 2001) comb. nov., R. robusta (Brooks, 1976) comb. nov., R. rugocaudata (Yoshida, 1916) comb. nov., R. staffordi (Tubangui, 1928) comb. nov. In the phylogenetic reconstruction, Glypthelmins sensu stricto forms the sister group of Haematoloechus Looss, 1899.
Received: 08 January 2005 / Accepted: 14 November 2005
A multigene framework for polychaete phylogenetic studiesDownload PDFAbstract
Producing a robust phylogenetic reconstruction for Polychaeta using either morphological or molecular data sets has proven very difficult. There remain many conflicts between morphological analyses and hypotheses based on DNA data, the latter principally derived from 18S rRNA sequences. For the present study a data set covering a broad range of polychaete diversity was assembled, including 38 new sequences from 21 species. Besides available 18S rRNA data, five additional gene segments were examined: the D1 and D9-10 expansion regions of 28S rRNA, histone H3, snU2 RNA and cytochrome c oxidase subunit I. Maximum parsimony, maximum likelihood and Bayesian analyses were conducted.Annelida and Mollusca were reciprocally monophyletic in maximum likelihood analyses, but Polychaeta included a cephalopod in maximum parsimony analyses, and a patellogastropod in Bayesian analyses. When rooted on the Mollusca, optimal topologies from maximum likelihood analyses showed a recognisable basal group of taxa, including Oweniidae, Chaetopteridae and Amphinomidae. The six studied phyllodocidan families plus Orbiniidae (as the sister group of the scale-worms) formed the next most basal group. All analyses support the inclusion of Echiura, Clitellata and Siboglinidae within polychaetes. Bayesian analyses show Echiura as the sister group of Capitellidae, in agreement with previous 18S rRNA results, In contrast, Echiura formed the sister group to Trichobranchidae in maximum likelihood and maximum parsimony analyses.Supra-familial groupings consistently recovered within Polychaeta in the analyses are: (i) Terebellida without Ampharetidae; (ii) Scolecida (excepting Orbiniidae); (iii) Eunicidae, Lumbrineridae and Clitellata; and (iv) “Cirratuliformia” (including Sternaspidae) plus Sabellidae, Serpulidae and Spionidae.
Received: 20 April 2005 / Accepted: 08 December 2005
Paralaophonte harpagone sp. n. (Copepoda: Harpacticoida), a laophontid with an extremely specialised maxillipedDownload PDFAbstract
Paralaophonte harpagone sp. n. is described from the coast of Kenya. Its most distinguishing feature is the robust, enlarged and specialised maxilliped, present in both sexes. This maxilliped is similar in robustness and position to the highly specialised maxilliped in the laophontid genus Namakosiramia Ho & Perkins, 1977 the two members of which live as ectoparasites on holothurians. The detailed description of P. harpagone sp. n. and a discussion of the possible role of the maxilliped are presented in the accompanying Organisms Diversity & Evolution Electronic Supplement.For full article, see Electronic Supplement at: http://www.senckenberg.de/odes/06-14.htm
Received: 22 December 2004 / Accepted: 03 May 2005
Apherusa delicata n. sp., a new suprabenthic amphipod (Crustacea, Eusiroidea, Calliopiidae) from the northern Bay of Biscay, with a discussion of the genusDownload PDFAbstract
A new calliopiid amphipod, Apherusa delicata n. sp., is described from specimens sampled with a suprabenthic sled in the ‘Grande Vasière’ area (northern Bay of Biscay). The new species can be distinguished from its sympatric congeners, A. bispinosa and A. ovalipes, mainly by the posterodorsal tridentate armature of pleosomites 2 and 3 and by the smooth posterior margin of epimeral plate 3. Its geographical distribution seems to be restricted to muddy sand bottoms of the ‘Grande Vasière’ fishing grounds. A key to the 20 known species of Apherusa is provided, followed by a discussion on the morphological characters to be considered for a future cladistic analysis of species within this genus.
Received: 20 June 2005 / Accepted: 09 September 2005
Phylogeny, biogeography and a new taxonomy for the Gecarcinucoidea Rathbun, 1904 (Decapoda: Brachyura)Download PDFAbstract
Phylogenetic relationships of gecarcinucoid freshwater crabs were investigated, based on morphology of the male second gonopod. In addition, a comparison of sequences from the mitochondrial large subunit rRNA gene helped to resolve the phylogeny of this group and relationships to other Old World freshwater crabs. As a result, we recognise two sister groups within the Gecarcinucoidea, the African Deckeniidae and the Asian Gecarcinucidae. Deckeniidae includes three monophyletic clades, the Deckeniinae in East Africa and on the Seychelles, the West African Globonautinae and the Malagasy Hydrothelphusinae. Gecarcinucidae comprises two sister groups, the Gecarcinucinae with representatives in Sri Lanka, India and southeast Asia, and the Parathelphusinae in India, southeast Asia, the Sundaic Islands and Australia. Interpretation of our phylogenetic results leads us to propose a new biogeographic hypothesis for the Gecarcinucoidea. Most likely, the gecarcinucoid freshwater crabs have an African origin; their distribution can be explained by successive events of dispersal. This model can be correlated with palaeogeographical and palaeoclimatological data for the Cenozoic, suggesting a gecarcinucoid dispersal to Asia via the “Lemurian Stepping-Stones”, a chain of islands in the West-Indian Ocean that were emergent in times of low sea levels during the Oligocene.
Received: 03 March 2005 / Accepted: 04 April 2005
Taxonomical and distributional notes on Polylepis (Rosaceae)Download PDFAbstract
Polylepis pacensis M. Kessler & Schmidt-Leb. spec. nov. is described; P. flavipila (Bitter) M. Kessler & Schmidt-Leb., P. incarum (Bitter) M. Kessler & Schmidt-Leb., P. lanata (Kuntze) M. Kessler & Schmidt-Leb., and P. subtusalbida (Bitter) M. Kessler & Schmidt-Leb. are elevated from subspecies or varietal to species rank; P. triacontandra Bitter is reinstated as a species. The accompanying Electronic Supplement provides an updated key to species in Polylepis, and reports extensions to the known distribution ranges of three additional species of the genus.See also Electronic Supplement at: http://www.senckenberg.de/odes/06-01.htm
Received: 07 September 2005 / Accepted: 06 December 2005
New species and records of tree ferns (Cyatheaceae, Pteridophyta) from the northern AndesDownload PDFAbstract
Four new species of Cyatheaceae from Ecuador are described: Alsophila conantiana Lehnert, Cyathea brucei Lehnert, C. moranii Lehnert, and C. sylvatica Lehnert. Range extensions are documented for Alsophila esmeraldensis R.C. Moran and Cyathea macrocarpa (C. Presl) Domin.For full article, see Electronic Supplement at: http://www.senckenberg.de/odes/06-13.htm
Received: 10 November 2004 / Accepted: 23 March 2005
Identification of evolutionary conserved structural elements in the mt SSU rRNA of Zygaenoidea (Lepidoptera): A comparative sequence analysisDownload PDFAbstract
Knowledge of the secondary structure of ribosomal RNA (rRNA) molecules has become increasingly important in phylogenetic analyses. Advances in RNA substitution models have underlined the need for reliable secondary-structure models for individual taxonomic groups. The present investigation aims to infer a secondary-structure model of the mt SSU (12S) rRNA of Zygaenoidea using a comparative approach. Structural variation of the 12S rRNA molecule proves to be minor among the investigated species, although at least two helices exhibit taxon-specific deviations. The consensus structure of the zygaenoid mt SSU rRNA clearly differs from the structure published for Bombyx mori and challenges some helices proposed in the silk moth model. Our analyses demonstrate the need for taxon-specific rRNA models, which can capture evolutionary patterns in these molecules far better than general eukaryotic consensus structures and thus provide an improved basis for phylogenetic analyses incorporating secondary-structure information.
Received: 22 December 2004 / Accepted: 28 April 2005
Caprella scaura Templeton, 1836 sensu lato (Amphipoda: Caprellidae) in the MediterraneanDownload PDFAbstract
Caprella scaura, first described from Mauritius and later reported in several ‘forms’ from all over the world, has now been found in the central and eastern Mediterranean. The morphology shows no significant difference to the topotypical material. Specimens from Venice and Sicily have been studied in detail, the former also by cytogenetic methods.See also Electronic Supplement at: http://www.senckenberg.de/odes/06-03.htm
Received: 02 June 2005 / Accepted: 01 December 2005
Phylogeny and genus-level classification of mantellid frogs (Amphibia, Anura)Download PDFAbstract
We propose a novel classification of frogs in the family Mantellidae, based on published phylogenetic information and on a new analysis of molecular data. Our molecular tree for 53 mantellid species is based on 2419 base pairs of the mitochondrial 12S rRNA, 16S rRNA, tRNAVal and cytochrome b genes, and of the nuclear rhodopsin gene. Because the genus Mantidactylus Boulenger sensu lato is confirmed to be paraphyletic with respect to Mantella Boulenger, and is highly diverse in morphology and reproductive biology, we propose to partition Mantidactylus into seven genera by elevating four subgenera to genus rank (Blommersia Dubois, Guibemantis Dubois, Spinomantis Dubois, and Gephyromantis Methuen) and creating two new genera (Boehmantis gen. n. and Wakea gen. n.). In addition, we create the new subgenera Boophis (Sahona) subgen. n., Gephyromantis (Duboimantis) subgen. n., G. (Vatomantis) subgen. n., and Mantidactylus (Maitsomantis) subgen. n. The following species are transferred to Spinomantis, based on their phylogenetic relationships: S. elegans (Guibé) comb. n. (formerly in Mantidactylus subgenus Guibemantis); S. bertini (Guibé) comb. n. and S. guibei (Blommers-Schlösser) comb. n. (both formerly in Mantidactylus subgenus Blommersia); S. microtis (Guibé) comb. n. (formerly in Boophis Tschudi). Within Boophis, the new B. mandraka species group and B. albipunctatus species group are established. Boophis rhodoscelis (Boulenger) is transferred to the B. microtympanum group. The following five species are revalidated: Mantidactylus bellyi Mocquard and M. bourgati Guibé (not junior synonyms of M. curtus (Boulenger)); M. cowanii (Boulenger) (not syn. M. lugubris (Duméril)); M. delormei Angel (not syn. M. brevipalmatus Ahl); Mantella ebenaui (Boettger) (not syn. M. betsileo (Grandidier)). The new classification accounts for recent progress in the understanding of the phylogeny and natural history of these frogs, but it is still tentative for a number of species. Future modifications may be necessary, especially as concerns species now included in Gephyromantis and Spinomantis.Full article published online at: http://www.senckenberg.de/odes/06-11.htm
Received: 09 November 2004 / Accepted: 18 April 2005
Phylogenetic relationships of the moss genus Pleurochaete Lindb. (Bryales: Pottiaceae) based on chloroplast and nuclear genomic markersDownload PDFAbstract
The phylogenetic relationships of the moss genus Pleurochaete was investigated using evidence from chloroplast and nuclear ribosomal DNA sequences (atpB-abcL spacer, rps4+rps4-trnS IGS, trnL-trnF region, and ITS1-5.8S-ITS2 region). Monophyly of Pleurochaete is confirmed, but the genus is nested within Tortella. Five highly supported clades, including Chionoloma, Pseudosymblepharis and Trichostomum tenuirostre, were found, partially corresponding to phytogeographic areas. However, denser sampling is needed to resolve subgeneric relationships. Within Pleurochaete three monophyletic clades were recovered: neotropical Pleurochaete luteola, European Pleurochaete squarrosa, and North American P. squarrosa. The relationships between and taxonomic status of these clades are not resolved. Our results point to two hypotheses to explain the current situation: (1) an ancient, wide distribution of P. squarrosa on the Laurasian continent, with a subsequent split into two genetically isolated clades and sympatric ecological isolation of P. luteola; and (2) a neotropical origin of the genus, followed by long-distance dispersal of P. squarrosa into Eurasia. In contrast to previous molecular studies on transatlantic bryophytes, no evidence was found of recent intercontinental gene flow in P. squarrosa. Consequently, the two genetically isolated but morphologically indistinguishable clades of P. squarrosa may represent a further example for either lineage sorting or cryptic speciation in mosses.
Received: 22 March 2005 / Accepted: 06 July 2005
Immunological and ultrastructural characterization of spirotrichonymphid flagellates from Reticulitermes grassei and R. flavipes (syn. R. santonensis), with special reference to Spirotrichonympha, Spironympha and MicrojoeniaDownload PDFAbstract
Five species of spirotrichonymphids representing three genera have been studied by light and immunofluorescence microscopy, and by transmission electron microscopy. The genus Spirotrichonympha, represented by S. flagellata from Reticulitermes grassei, is characterized by a compound axostyle composed of several fibers or subaxostyles. The genus Spironympha, represented by S. kofoidi from Reticulitermes flavipes (syn. R. santonensis) and by the two new species S. verticis and S. lanceata, is characterized by flagellar lines restricted to the anterior area and a simple, tubular axostyle. Spironympha verticis and S. lanceata are mainly distinguished by ultrastructural details of their flagellar lines and axostyle. These three Spironympha species were found in hosts identified as R. flavipes or R. santonensis, but not in R. grassei. This provides additional support for the synonymy of R. santonensis with R. flavipes recently demonstrated by molecular methods. The generic diagnosis of Microjoenia is emended, based on an ultrastructure study of M. fallax.
Received: 02 December 2004 / Accepted: 11 August 2005
The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in southern Luzon, PhilippinesDownload PDFAbstract
An earthworm biodiversity survey of the Philippines has yielded 14 new species of the perichaetine megascolecid genus Pleionogaster, previously known from only a few species from scattered Philippine locations. Bicol, the southern peninsula of Luzon, has intact forests on several isolated volcanic peaks and other remote areas. Collections made in these forests yielded the following new species, here presented by type location: Mt. Malinao, Pleionogaster albayensis, P. bicolensis, P. castilloi, P. malinaoensis, P. tiwiensis; Mt. Isarog, P. ffitchae, P. isarogensis; Mt. Bulusan, P. bulusanensis, P. hongi, P. sorsogonensis; Catanduanes Island, P. nautsae, P. viracensis; Caramoan Peninsula, P. caramoanensis, P. nillosae. Most of the species were found only in the neighborhood of the type locality, but P. bicolensis occurs in two locations in northern Bicol. Intraspecific variation in P. castilloi was observed between northern and southern flanks of Mt. Malinao. The importance of several previously overlooked Pleionogaster traits is demonstrated by their homogeneity within species reported here.Full article published online at http://www.senckenberg.de/odes/06-08.htm.
Received: 30 October 2004 / Accepted: 28 April 2005
Key for the identification of crustacean naupliiDownload PDFAbstract
The nauplius is the earliest free-living stage in the development of most crustaceans, except in the majority of the Malacostraca. Several character states of the nauplius larva are used as constitutive for the Crustacea as a whole. The nauplius shows the following structural characters: a median (nauplius) eye, at least three pairs of head appendages (first and second antennae, where the second antenna bears an arthrite; mandibles), a posteriorly directed fold (the labrum) extending over the mouth, and a cephalic (=nauplius) shield. Extant taxa such as the Cephalocarida, Branchiopoda, Ostracoda, Mystacocarida, Copepoda, Cirripedia, Ascothoracida, Rhizocephala, Facetotecta, Euphausiacea, and Penaeidea are known to develop free-living nauplii. Other Crustacea show at least some vestige of an ‘egg-nauplius’ during embryonic development. The diversity of nauplii belonging to major crustacean taxa is briefly described, and a key to these nauplii is provided. The key is also available in digital format, as a JAVA program capable of being modified and expanded as new information arises. The programming structure allows uses in dichotomous or multi-branching formats.
Received: 01 February 2005 / Accepted: 23 June 2005
An amphipod of the genus Synurella Wrzesniowski, 1877 (Crustacea, Amphipoda, Crangonyctidae) found in Baltic amberDownload PDFAbstract
Two amber pieces with amphipods were studied. One contained a species placed in the genus Palaeogammarus and a second species belonging to Synurella. The latter has an unsegmented urosome and shortened uropods 3, very similar to the specimen studied by Coleman [2004. Aquatic amphipods (Crustacea: Amphipoda: Crangonyctidae) in three pieces of Baltic amber. Org. Divers. Evol. 4, 119–122; Electronic Supplement at http://www.senckenberg.de/odes/04-03.htm], confirming the occurrence of the genus Synurella in Baltic amber. The systematic position of the amphipod within the second amber piece is unclear.See also Electronic Supplement at: http://www.senckenberg.de/odes/06-05.htm
Received: 07 October 2004 / Accepted: 21 January 2005
Cladistic analysis of Maladera (Omaladera): Implications on taxonomy, evolution and biogeography of the Himalayan species (Coleoptera: Scarabaeidae: Sericini)Download PDFAbstract
The phylogeny of Maladera (subgenus Omaladera) is investigated with morphological data. Twenty-one species or subspecies in one of four subgenera of Maladera (Macroserica, Maladera, Cephaloserica, and Omaladera) were included in the cladistic analysis, with Stilbolemma sericea chosen as the outgroup. Data were analysed using two approaches, the parsimony ratchet and heuristic search with successive weighting based on the rescaled consistency index. The results of both analyses provide evidence for the monophyly of the subgenus M. (Omaladera) and the group of species occurring in the Himalayas. Each of the three principal lineages of Omaladera has diversified independently in separate geographical regions. The present phylogenetic hypothesis provides no evidence that faunal exchange has occurred between these regions as regards ancestral and terminal taxa of Omaladera. The phylogenetic analyses support the hypothesis that the strictly parapatric M. himalayica, M. incola, M. immunda, and M. thakkholae are valid species rather than subspecies.
Received: 31 May 2005 / Accepted: 19 September 2005
Elaborate petals and staminodes in eudicots: Diversity, function, and evolutionDownload PDFAbstract
Petals, a characteristic feature of eudicots, have evolved elaborations in various ways and across diverse clades. In this survey of petal and staminode elaborations throughout the eudicots, based on both new studies and a review of the literature, the diversity of such structures and their functions is discussed. Petal elaborations are primarily present as marginal lobes and ventral lobes of various shapes. Lobation patterns can be loosely classified as pinnate, binate, or ternate. One of these patterns may be dominant within a family (e.g. pinnate in Anisophylleaceae, binate in Caryophyllaceae, ternate in Elaeocarpaceae); transitional forms also occur (e.g. between binate and ternate in Onagraceae). Coronas between the corolla and androecium are found in several groups, for example in several families of Malpighiales or in Apocynaceae. In some clades, petal elaborations are especially prominent and can be used as approximate systematic markers (Anisophylleaceae, Elaeocarpaceae, Rhizophoraceae). Petal elaborations are especially diverse in rosids. In asterids, which are characterized by sympetaly, elaborations are more conspicuous at the level of the architecture of the entire corolla, rather than at the level of individual petals. Evolutionary trends in petal elaboration in certain larger clades are shown and their involvement in floral biological functions is discussed.
Received: 20 June 2005 / Accepted: 25 January 2006
The genus Owenia (Annelida: Polychaeta) in the Persian Gulf, with description of Owenia persica sp. nov.Download PDFAbstract
Owenia persica sp. nov. is erected on the basis of specimens collected on the Iranian coast of the Persian Gulf. Two previous reports of Owenia fusiformis Delle Chiaje from the Gulf are shown to be misidentifications: the specimens from Kuwait clearly belong to O. persica sp. nov., whereas the single specimen from the Strait of Hormuz likely belongs to another new species, Owenia sp. The accompanying Organisms Diversity and Evolution Electronic Supplement provides full descriptions of O. persica sp. nov. and O. sp., as well as an analysis of the ecological characteristics and local distribution of O. persica sp. nov along the Iranian coast. The present work contributes to the growing evidence that the cosmopolitan Owenia fusiformis sensu lato constitutes a complex of several species.For full article, see Electronic Supplement at: http://www.senckenberg.de/odes/06-15.htm
Received: 15 April 2005 / Accepted: 06 June 2005
Revision of the Ochlesidae sensu stricto, including five new Australian species (Crustacea: Amphipoda)Download PDFAbstract
Species of the Ochlesidae sensu stricto are revised. Based on new material from inshore and continental-shelf Australian marine habitats five new species are described: Meraldia birgeri n. sp., M. madeleinae n. sp., M. yorki n. sp., Ochlesis caroleoninae n. sp., and O. morgani n. sp. As these new species show remarkable sexual dimorphism, both sexes are described and fully illustrated. The world species are diagnosed, and a key to all species is provided. Full article published online at: http://www.senckenberg.de/odes/06-04.htm
Received: 31 May 2004 / Accepted: 08 July 2005
The phylogenetic characteristics of three different 28S rRNA gene regions in Encarsia (Insecta, Hymenoptera, Aphelinidae)Download PDFAbstract
Two expansion segments of the large ribosomal subunit (28S-D2 and 28S-D3) and the ribosomal first internal transcribed spacer (ITS-1) were sequenced to investigate the potential of each region for defining species limits and for inferring phylogenetic relationships within the aphelinid genus Encarsia (Hymenoptera, Chalcidoidea). Alignment of the ITS-1 region was complicated by the presence of high levels of length polymorphism. Secondary-structure models of the ITS-1 molecule are proposed which led to an improved alignment and the inclusion of some highly polymorphic sequences. The additional information obtained from the secondary-structure models can provide a justification for the exclusion of hypervariable regions from the phylogenetic analysis. The D3 region is the most conserved, ITS-1 the most variable of the three gene regions investigated. Phylogenetic analyses suggest the D2 region to be most suitable not only for inferring relationships, but also for taxonomic and diagnostic purposes at species level. The ITS-1 region is best suited for inferring relationships between closely related species or among populations of the same species. The combined analysis using all three regions led to a better tree and a reduced number of equally most parsimonious trees.See also Electronic Supplement at: http://www.senckenberg.de/odes/06-07.htm
Received: 07 June 2005 / Accepted: 06 October 2005
Geoemyda silvatica, an enigmatic turtle of the Geoemydidae (Reptilia: Testudines), represents a distinct genusDownload PDFAbstract
The systematic position of the rare Indian turtle Geoemyda silvatica Henderson is examined by a phylogenetic analysis of mtDNA sequence data (cytochrome-b gene) of most species of Geoemydidae. Geoemyda silvatica represents a basal and isolated taxon within Geoemydidae, definitely not a close relative of any species of Geoemyda or Heosemys, the genera in which G. silvatica has been placed in the past. Therefore, the new genus Vijayachelys is proposed for G. silvatica. Cranial morphology and some other osteological characters of Vijayachelys silvatica are described and illustrated. Differential diagnoses are given for the type species of Melanochelys and the respective type species of the superficially similar genera Geoemyda, Heosemys, and Leucocephalon. According to Bayesian analysis of mtDNA data, Melanochelys trijuga could be distantly related to V. silvatica, whereas the morphological similarity of the other species probably is the result of a similar mode of life. The discovery of the phylogenetically isolated position of V. silvatica highlights the importance of the Western Ghats as a biodiversity hotspot rich in higher-level endemics.
Received: 07 June 2005 / Accepted: 25 August 2005
The pregenital abdominal musculature in phasmids and its implications for the basal phylogeny of Phasmatodea (Insecta: Polyneoptera)Download PDFAbstract
Recently several conflicting hypotheses concerning the basal phylogenetic relationships within the Phasmatodea (stick and leaf insects) have emerged. In previous studies, musculature of the abdomen proved to be quite informative for identifying basal taxa among Phasmatodea and led to conclusions regarding the basal splitting events within the group. However, this character complex was not studied thoroughly for a representative number of species, and usually muscle innervation was omitted. In the present study the musculature and nerve topography of mid-abdominal segments in both sexes of seven phasmid species are described and compared in detail for the first time including all putative basal taxa, e.g. members of Timema, Agathemera, Phylliinae, Aschiphasmatinae and Heteropteryginae. The ground pattern of the muscle and nerve arrangement of mid-abdominal segments, i.e. of those not modified due to association with the thorax or genitalia, is reconstructed. In Timema, the inner ventral longitudinal muscles are present, whereas they are lost in all remaining Phasmatodea (Euphasmatodea). The ventral longitudinal muscles in the abdomen of Agathemera, which span the whole length of each segment, do not represent the plesiomorphic condition as previously assumed, but might be a result of secondary elongation of the external ventral longitudinal muscles. Sexual dimorphism, common within the Phasmatodea, also applies to the muscle arrangement in the abdomen of some species. Only in the females of Haaniella dehaanii (Heteropteryginae) and Phyllium celebicum (Phylliinae) the ventral external longitudinal muscles are elongated and span the length of the whole segment, possibly as a result of convergent evolution.
Received: 09 November 2004 / Accepted: 19 May 2005
A new species of Cycliophora from the mouthparts of the American lobster, Homarus americanus (Nephropidae, Decapoda)Download PDFAbstract
The present study describes a new species of Cycliophora with the aid of light- and electron microscopy. The animals live attached or free-living on the mouth appendages of the American lobster, Homarus americanus. Individuals occur in dense clusters of up to several thousand individuals. The new species is named Symbion americanus sp. nov. according to the name of its host; it can be distinguished from the previously described species Symbion pandora by the presence of a posterior pair of retractable tubular appendages or toes in the Prometheus larva. Morphological variation among cycliophorans on H. americanus collected in different localities seems to be high. In several sexual populations of S. americanus, older feeding individuals with a female typically have 5–13 rings of cuticular scars and a thicker cuticle. Moreover, attached Prometheus larvae frequently contain three males, chordoid cysts possess a distal appendix, and chordoid larval morphology varies among localities. These differences in morphology might indicate the existence of cryptic species. The presence of toes in the Prometheus larva could support a cycliophoran relationship with rotiferan taxa, although additional ultrastructural studies are needed. Considering that the genus Homarus is at least 60My years old, and with regard to its history of speciation, it seems possible that the two Symbion species separated during the Pleistocene.
Received: 22 October 2004 / Accepted: 02 November 2005
New hyalellids (Crustacea, Amphipoda, Hyalellidae) from Lake TiticacaDownload PDFAbstract
Two new species of hyalellid amphipods, Hyalella crawfordi and H. gauthieri, are described from Lake Titicaca; H. echinus (Faxon, 1876) is redescribed. The H. echinus group of species is newly proposed for these three species, and a group diagnosis is provided. A key to the three species in the group is provided Full article published online at http://www.senckenberg.de/odes/06-10.htm.
Received: 26 September 2005 / Accepted: 01 December 2005
Rapid evolution of an ancient lake species flock: Freshwater limpets (Gastropoda: Ancylidae) in the Balkan Lake OhridDownload PDFAbstract
Ancient lakes have long been recognized as evolutionary theatres and hot spots of endemism; the evolution of their morphologically often highly diverse species flocks has received much attention. However, as each ancient lake has its own geological and evolutionary history, modes of speciation may differ from system to system. Ancient lakes can act as evolutionary reservoirs that assure the survival of relict species, but at the same time extant species may evolve through intralacustrine speciation. Other aspects of interest are the actual rates of immigration, diversification or extinction as well as the temporal framework of morphological change. Many of these questions have been addressed in the African (e.g. Lake Tanganyika) and Asian (e.g. Lake Baikal) ancient lakes. For an European ancient lakes (e.g. Lakes Ohrid and Prespa), such studies are largely missing. In the present paper, extraordinarily shaped endemic freshwater limpets of the genus Ancylus from the Balkan Lake Ohrid are used in a phylogeographic and phylogenetic context to test whether they represent an ancient lake species flock, to study the mode of speciation, and to assess the timing of morphological change. Based on DNA data from two mitochondrial genes (COI, LSU rDNA), it has been found that the Lake Ohrid Ancylus species form an endemic monophyletic group. In addition, the lake's feeder springs are inhabited by another, undescribed Ancylus species. All other studied waterbodies within the watershed do not support their own Ancylus lineages but are inhabited by a widespread Mediterranean taxon. The split between the species endemic to the lake and its sister taxon is dated to 1.4±0.6 million years ago. The study presents the first genetic confirmation for the existence of a species flock in a European ancient lake. Contrary to the prevailing opinion it shows that, concerning Ancylus, Lake Ohrid represents a site of intralacustrine speciation rather than an evolutionary reservoir. Moreover, it provides the first evidence for rapid morphological change in an European ancient lake species flock. See also Electronic Supplement at: http://www.senckenberg.de/odes/06-12.htm.
Received: 15 November 2004 / Accepted: 28 April 2005
Genetic evidence of phenotypic polymorphism in the aeolid nudibranch Flabellina verrucosa (M. Sars, 1829) (Opisthobranchia: Nudibranchia)Download PDFAbstract
The conspecificity of two forms of Flabellina verrucosa (M. Sars, 1829), one form with short and one with long cerata, was tested by sequencing the mitochondrial COI and the nuclear 5.8S-ITS2 genes. We could not establish any genetic differences between the two forms and conclude that they belong to the same species. Thus, Flabellina verrucosa is polymorphic in ceratum length.See also Electronic Supplement at: http://www.senckenberg.de/odes/06-02.htm
Received: 17 February 2004 / Accepted: 08 September 2005
Anatomy and reproduction of viviparous Pisidium (Parapisidium) reticulatum Kuiper, 1966: Implications for the phylogeny of Sphaeriidae (Mollusca: Bivalvia: Heterodonta)Download PDFAbstract
The pea clams Sphaeriidae represent a major molluscan freshwater radiation with cosmopolitan distribution in all kinds of lotic and lentic habitats. Their phylogenetic relationships are still controversial, with comprehensive taxonomic sampling and examination of morphological characters still challenging. Here, based on rare and rediscovered original material, we study in detail the anatomy and aspects of brood protection of the African Pisidium reticulatum Kuiper, 1966. Representing the monotypic subgenus Parapisidium Kuiper, 1966, this species is characterized by its peculiar combination of shell and anatomical features of potentially high phylogenetic relevance. While similar to other congeners in several anatomical characters (e.g. reduction of inhalant siphon and descending lamella of outer demibranch, simplified structure of intestine coil and nephridium), P. reticulatum differs from other Pisidium species in retaining both pairs of retractor muscles of the inhalant siphon, and particularly in its peculiar mode of brooding. The yolky eggs are relatively large (160–170μm in diameter) and are incubated in the gill, albeit in the absence of the formation of brood pouches. During later stages of incubation the larvae are surrounded by large cells similar to nourishing cells in other sphaeriids and probably with similar function. This unique combination of reproductive features is hypothesized to represent an intermediate stage between the typical ovoviviparity of Euperidae and euviviparity (i.e. nourishment by the parent animal) as found exclusively in Sphaeriidae, the latter being characterized by the possession of closed brood pouches. Phylogenetic analyses based on a comprehensive set of morphological characters reveal Parapisidium as the most basal lineage within a clade Pisidium. Evaluating the phylogenetic reconstructions based also on available molecular data for Sphaeriidae, we discuss alternative scenaria of (parallel) evolution of brood pouches and viviparity in this group.