Search publications of the members of the Royal Belgian institute of natural Sciences
-
On the genus Halirages (Crustacea, Amphipoda), with the description of two new species from Scandinavia and Arctic Europe
- A new common deep-sea species of Halirages Boeck, 1871 closely related to H. qvadridentatus G.O. Sars, 1877, H. cainae sp. nov., is described after specimens collected in the Norwegian Sea during the MAREANO 2009-111 cruise. Examination of the syntypes of H. elegans Norman, 1882 demonstrates that Norman's species is a junior synonym of H. qvadridentatus G.O. Sars, 1877 and that the species usually named H. elegans in literature was actually undescribed. The name H. stappersi sp. nov. is proposed for that species. A key to and a checklist of Halirages species is given.
-
The genus Liljeborgia in the Mediterranean Sea, with the description of a new species (Crustacea: Amphipoda: Liljeborgiidae)
- A new amphipod crustacean, Liljeborgia clytaemnestra sp. nov., is described based on specimens from Malta and the Bay of Naples. It is quite similar to the sympatric L. dellavallei Stebbing, 1906, but it has narrower and more regular-sized spines on the propodus of pereiopods 3–4. The longest spine on the dorsolateral border of the peduncle of uropod 1 is not strongly elongate in adult males, as in L. dellavallei. The apical spines on the lobes of the telson are much longer than in L. dellavallei. L. clytaemnestra sp. nov. is actually more similar to two northeastern Atlantic species, the British L. pallida (Spence Bate, 1857) and the Scandinavian L. brevicornis (Bruzelius, 1859) than to the Mediterranean L. dellavallei. In L. clytaemnestra sp. nov., article 2 of the mandibular palp has setae on distal third, whilst setae are restricted to tip in the two other species. Article 3 of the mandibular palp is also longer in L. clytaemnestra sp. nov. than in the two Atlantic species. The spines of the outer plate of the maxilliped are longer in L. clytaemnestra sp. nov. than in the two other species. The most distal spine of the propodus of pereiopods 3–4 is reduced in L. clytaemnestra sp. nov. and L. brevicornis, but not in L. pallida. The serration of the posterior border of the basis of pereiopod 7 is much stronger in L. clytaemnestra sp. nov. than in the two other species. Finally, in L. clytaemnestra sp. nov., the spines of the lobes of the telson are longer than in L. pallida. A lectotype is designated for L. dellavallei. The presence/absence of a posterodorsal tooth on pleonite 3 in L. dellavallei is discussed. The validity of L. kinahani (Spence Bate, 1862) is questioned. An identification key is proposed for Mediterranean Liljeborgia species.
-
Two new Pseudorchomene species from the Southern Ocean, with phylogenetic remarks on the genus and related species (Crustacea: Amphipoda: Lysianassoidea: Lysianassidae: Tryphosinae)
- Two new lysianassoid amphipods of the genus Pseudorchomene Schellenberg, 1926 from the Southern Ocean are described: P. debroyeri sp. n. collected in baited traps deployed around the Falkland Islands, Burdwood Bank and Îles Kerguelen between 55 and 470 m, and P. lophorachis sp. n. collected in baited traps and Agassiz trawls deployed in the Scotia and Weddell Seas at depths between 847 and 1943 m. P. lophorachis sp. n. is characterized by an strongly elongated first gnathopod and by the occurrence of low posterodorsal humps on the body segments. P. debroyeri sp. n. is very similar to P. coatsi (Chilton, 1912) but exhibits slight differences of proportions in the articles of gnathopods 1 and 2, more spines on pereopods and more acute spines on the propodus of pereopods 3–7. Molecular data indicate the existence of a welldefined clade comprising P. lophorachis sp. n., P. debroyeri sp. n., P. coatsi (Chilton, 1912), Abyssorchomene plebs (Hurley, 1965) and A. rossi (Walker, 1903). On the other hand, A. plebs and A. rossi do not form a clade with A. chevreuxi (Stebbing, 1906), which is the type species of the genus Abyssorchomene De Broyer, 1984. The definition of Pseudorchomene is amended, so that it now includes P. coatsi, P. debroyeri, P. lophorachis, P. plebs and P. rossi. The triangular coxa 1 in these 5 species is unique for ‘orchomenid’ lysianassoids, thus considered as a putative synapomorphy. P. coatsi (Antarctic species) is morphologically extremely similar to P. debroyeri (sub-Antarctic species) but it is genetically closer to the morphologically distinct P. lophorachis (Antarctic species). Hypotheses for these recent speciations and the morphological evolution within Pseudorchomene are discussed. The type species and the nomenclatural history of the genus Tryphosa Boeck, 1871, which is the type genus of the subfamily Tryphosinae, are discussed.
-
Voortplantende populatie van de Purperslak Nucella lapillus in Belgie na meer dan 30 jaar afwezigheid (Mollusca, Gastropoda, Muricidae)
- In the past, the dog whelk Nucella lapillus (Mollusca, Gastropoda, Muricidae) used to be a common species on jetties and groynes along the Belgian coast. During the seventies, the species became increasingly rare and the last Belgian specimen observed in situ was found in 1981. The extinction of the species is attributed to the use of paintings containing tributyltin (TBT) on the hulls of ships as antifouling protection. TBT dilutes in seawater and, even at extremely low concentration, sterilizes dog whelks. Since 1990, the use of Tributyltin (TBT) was restricted to ships smaller than 25 m; in 2003, it was totally forbidden and in 2008 old TBT paintings had to be removed from ship hulls. As a consequence the concentration in TBT of seawater presumably decreased in Belgian waters. On November 17th, 2012, several living adult dog whelks and 40 to 50 spawns ofthat species were observed on the concrete blocks of the western jetty of Zeebrugge harbour, indicating recolonization of the species in Belgium at least in one locality.
-
Exploring species level taxonomy and species delimitation methods in the facultatively self-fertilizing land snail genus Rumina (Gastropoda: Pulmonata)
-
Yaratılışçılığın çürütülmesine taksonomi katkısı Harun Yahya’nın çakma fosilleri
-
Cold tolerance and freeze-induced glucose accumulation in three terrestrial slugs.
-
Oxychilus (Drouetia) viridescens (Gastropoda: Pulmonata: Oxychilidae), a new species from Santa Maria, Açores, and a review of the subgenus
-
Organ- and species-specific accumulation of metals in two land snail species (Gastropoda, Pulmonata)
-
A Comprehensive Molecular Phylogeny of Dalytyphloplanida (Platyhelminthes: Rhabdocoela) Reveals Multiple Escapes from the Marine Environment and Origins of Symbiotic Relationships
-
The Myosotella 'myosotis-denticulata' complex: untying a morphological knot
-
Contemporary population genetic differentiation in Melarhaphe neritoides (Gastropoda: Littorinidae), a long-lived planktonic-dispersing mollusc.
- Marine invertebrates with planktonic-dispersing larvae are assumed to be good dispersers over long distances. This high dispersal capacity implies a high gene flow between populations and a homogeneous population genetic structuring over wide geographic scales.The marine gastropod Melarhaphe neritoides has a long-lived planktonic larval dispersal stage and allozyme data suggest that it is genetically homogeneous over its whole European distribution area. In contrast, preliminary mtDNA sequence data uncovered a remarkable degree of genetic diversity and genetic structuring on smaller geographic scales.In order to explore this mtDNA diversity and structuring in M. neritoides we started to survey sequence variation at COI and 16S rDNA all over the Azores archipelago. These data reveal that the Azorean populations share very few haplotypes.Hence, it seems that M. neritoides with its long-lived planktonic larval stage nevertheless shows a strong local population genetic structuring and thus challenges the current paradigm that correlates modes of larval development with levels of genetic structuring. It also stresses the importance of the sampling intensity (both in terms of numbers of specimens and genetic markers) to avoid experimental biases when assessing genetic diversity
-
Characterization of the colonizing Decollate Snail, Rumina decollata (Mollusca: Pulmonata: Stylommatophora)
- The hermaphroditic, facultatively selfing, land snail Rumina decollata is a common, widespread species indigenous in the western Mediterranean region, that has been introduced in many other parts of the world. Recent DNA sequence analyses have shown that R. decollata is a complex of several (phylogenetic) species, two of them corresponding to previously distinguished allozyme strains with different body colours (light vs. dark). Therefore, considering this new taxonomic interpretation, we here attempt to identify which, and how many, species of the R. decollata complex have been introduced outside their native area. Comparative DNA sequence analysis of introduced populations from South America, North America, Japan and the North Atlantic Islands vs. native populations from the Mediterranean area, revealed that all introduced populations belong to one single phylogenetic species, previously recognized as the dark strain. Therefore, the colonizing and invasive character of R. decollata is mainly, if not entirely, due to this dark strain. Furthermore, the Iberian Peninsula seems to be an important source for introduced R. decollata populations outside Europe. Within this work, we will discuss about the invasive character of the dark strain and the possible source areas of the introduced populations.
-
Contemporary population genetic differentiation in Melarhaphe neritoides (Gastropoda: Littorinidae), a long-lived planktonic-dispersing mollusc
- Marine invertebrates with planktonic-dispersing larvae are assumed to be good dispersers over long distances. This high dispersal capacity implies a high gene flow between populations and a homogeneous population genetic structuring over wide geographic scales. The marine gastropod Melarhaphe neritoides has a long-lived planktonic larval dispersal stage and allozyme data suggest that it is genetically homogeneous over its whole European distribution area. By contrast, prelimi-nary mtDNA sequence data uncovered a remarkable degree of genetic diversity and genetic structuring on smaller geo-graphic scales. In order to explore this mtDNA diversity and structuring in M. neritoides, we started to survey sequence vari-ation at COI and 16S rDNA all over the Azores archipelago. These data reveal that the Azorean populations share very few haplotypes. Hence, it seems that M. neritoides with its long-lived planktonic larval stage nevertheless shows a strong local population genetic structuring and thus challenges the current paradigm that correlates modes of larval development with levels of genetic structuring. It also stresses the importance of the sampling intensity (both in terms of numbers of speci-mens and genetic markers) to avoid experimental biases when assessing genetic diversity. An
-
Characterization of the colonising Decollate Snail, Rumina decollata (Mollusca: Pulmonata: Stylommatophora)
-
Microsatellite markers for analysis of parentage and sexual behavior of banana slugs (Pulmonata: Arionidae: Ariolimax)
- Terrestrial pulmonate slugs are hermaphroditic and often are capable of both outcrossing and self-fertilization. This mixed breeding system may severely affect population genetic structuring and taxonomic differentiation. Currently little is known about the breeding system(s) of Banana slugs (Ariolimax), a group of taxonomically ill-defined slugs living along the West Coast of North America, from California to southern Alaska. Based on genital morphology and mtDNA sequence data (COI, 16S and CytB), the genus Ariolimax is nowadays interpreted as a group of eight species level taxa, viz Ariolimax columbianus, A. buttoni, A. stramineus, A. californicus, A. dolichophallus, A. brachyphallus and two undescribed species. These species ap-pear to be closely related as 19 microsatellite DNA loci identified from A. californicus consistently amplify in all of the de-scribed taxa and share many alleles. Hence, these microsatellites can help to clarify Ariolimax taxonomy. To this end, four microsatellite loci were used to study potential interspecific crosses of A. californicus x A. dolichophallus. This showed that none of these crosses produced hybrid offspring and that A. californicus reveals multiple paternity under natural conditions. Conversely, a panel of 28 microsatellites applied to cross-breeding experiment between two populations of A. buttoni, showed that all the parental specimens involved only three homozygous multilocus genotypes (MLG) and that offspring of pairs in which both parents had a different genotype, always were monomorphic for the same homozygous MLG of one of the parents. This confirms that A. buttoni is able to self-fertilize. Yet, to what extent self-fertilization is common in natural condi-tions remains to be investigated.
-
Complex biogeography of cryptic species in the Gyratrix hermaphroditus species complex.
-
The meiofauna paradox unresolved: Cryptic speciation in Gyratrix hermaphroditus (Kalyptorhynchia, Platyhelminthes).
-
There’s more than meets the eye: population structure in the Ceratitis “FAR complex”.
- Analyses of mitochondrial and nuclear DNA sequences hitherto failed to resolve the three morphospecies of the so-called Ceratitis “FAR complex” (C. fasciventris, C. anonae, C. rosa). Therefore, we developed a set of microsatellite markers for a first population genetic survey of this species complex. Specimens of C. fasciventris, C. anonae, and C. rosa (27 populations, n=621) collected across their respective distribution ranges were genotyped at 16 polymorphic microsats. Genetic distance analyses distinguished at least five bootstrap supported population groups, each including samples from one of the three morphospecies. The Bayesian assignments implemented in STRUCTURE show that (1) C. rosa is represented by at least two clusters of individuals (R1, R2) that can occur in sympatry/parapatry, but that may have different developmental thresholds, (2) C. fasciventris is represented by at least two, geographically separated, clusters (F1, F2), and (3) C. anonae is genetically more homogeneous and doesn’t show a clear intraspecific structuring (cluster A). The differentiation of the C. rosa and C. fasciventris clusters is supported by morphological differences in the male secondary sexual characters. Genetic divergences between the C. rosa clusters and between the C. fasciventris clusters are comparable to the interspecific divergences among C. fasciventris, C. anonae, and C. rosa. Higher genetic distances were observed between the morphologically similar C. rosa and C. fasciventris, while C. anonae appears as closely related to both F1 and R2. The microsats used in this study thus unmasked a complex, and partly cryptic, population genetic structure within the FAR morphospecies. Keywords: Tephritidae, population genetics, microsats
-
Correlative and dynamic species distribution modelling for ecological predictions in the Antarctic: a cross-disciplinary concept.
