To invade or not to invade? Exploring the niche-based processes underlying the failure of a biological invasion using the invasive Chinese mitten crab

Invasive alien species represent a serious threat to global biodiversity, causing considerable damage to native ecosystems. To better assess invasion risks, it is essential to better understand the biological processes that determine the success or failure of invasions. The catadromous Chinese mitten crab Eriocheir sinensis, whose native distribution is the Pacific Coast of China and Korea, has successfully invaded and established populations in North America and Europe. In Japan, where E. sinensis is also regarded as potentially invasive and multiple introduction vectors exist, the species is not yet established. These settings can be used to explore niche-based processes underlying the apparent failure of a biological invasion. We first quantified native and invasive realized niches of E. sinensis in freshwater habitats using geometrical n-dimensional hypervolumes. Based on the assumption of niche conservatism, we then projected habitat suitability of this species in Japan using species distribution models (SDMs) calibrated with distinct sets of distribution data: native occurrences, invasive occurrences, and both. Results showed that E. sinensis has undergone either niche shifts or niche contractions during invasions in different areas of the world. Projections from SDMs indicate that although part of Japan is suitable for E. sinensis, this does not include the freshwater habitats around the Ariake Sea, which is considered to be a suitable marine environment for E. sinensis larvae. The mismatch between suitable freshwater and marine environments provides a possible explanation for the failure of establishment of E. sinensis in Japan to date. Our findings have useful general implications for the interpretation of biological invasions.info:eu-repo/semantics/publishedVersio

Tri-locus sequence data reject a Gondwanan origin hypothesis for the African/South Pacific crab genus Hymenosoma

Crabs of the family Hymenosomatidae are common in coastal and shelf regions throughout much of the southern hemisphere. One of the genera in the family, Hymenosoma, is represented in Africa and the South Pacific (Australia and New Zealand). This distribution can be explained either by vicariance (presence of the genus on the Gondwanan supercontinent and divergence following its break-up) or more recent transoceanic dispersal from one region to the other. We tested these hypotheses by reconstructing phylogenetic relationships among the seven presently-accepted species in the genus, as well as examining their placement among other hymenosomatid crabs, using sequence data from two nuclear markers (Adenine Nucleotide Transporter [ANT] exon 2 and 18S rDNA) and three mitochondrial markers (COI, 12S and 16S rDNA). The five southern African representatives of the genus were recovered as a monophyletic lineage, and another southern African species, Neorhynchoplax bovis, was identified as their sister taxon. The two species of Hymenosoma from the South Pacific neither clustered with their African congeners, nor with each other, and should therefore both be placed into different genera. Molecular dating supports a post-Gondwanan origin of the Hymenosomatidae. While long-distance dispersal cannot be ruled out to explain the presence of the family Hymenosomatidae on the former Gondwanan land-masses and beyond, the evolutionary history of the African species of Hymenosoma indicates that a third means of speciation may be important in this group: gradual along-coast dispersal from tropical towards temperate regions, with range expansions into formerly inhospitable habitat during warm climatic phases, followed by adaptation and speciation during subsequent cooler phases

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

5. Crustacea Decapoda : The Sponge Crabs (Dromiidae) of New Caledonia and the Philippines with a review of the genera

Volume: 156Start Page: 111End Page: 25

A new genus and species of dromiid crab (Brachyura, Dromiidae) from the Timor Sea, North-West Australia with records of other species from the China Sea

Volume: 20Start Page: 339End Page: 35

Dynomenidae et Dromiidae (Decapoda, Brachyura) de Guam, Tonga, Samoa et des Philippines

Cinq espèces de la famille des Dynomenidae sont signalées de Guam, îles Mariannes. Deux espèces nouvelles de Dynomene sont décrites. Les caractères distinctifs de D. kroppi n. sp. sont : rapport largeur/longueur de la carapace = 1,1, six dents antéro-latérales petites et émoussées, cinq ou six épines sur le bord interne du dactyle des pattes ambulatoires ; et pour D. guamensis n. sp. : rapport largeur/longueur de la carapace = 1,3, cinq dents antéro-latérales acérées, deux proéminences frontales saillantes, deux tubercules en arrière de l’angle postorbitaire, et sept ou huit épines sur le bord interne du dactyle des pattes ambulatoires. À Guam neuf nouveaux signalements de Dromiidae sont rapportés et une nouvelle espèce de Dromiidae est décrite. Les caractères distinctifs de C. pitiensis n. sp. sont : rapport largeur/ longueur de la carapace = 1,3, un renflement saillant au-dessus du bord antéro-latéral, surface de la carapace en grande partie lisse, mais aréolée et avec des tubercules épars. Neuf nouveaux signalements de Dromiidae sont également rapportés aux îles Tonga et aux Samoa. Cinq nouveaux signalements de Dromiidae sont rapportés, basés sur du matériel récolté par l’Albatross Expedition, 1907-1910 aux Philippines. Au total, 29 espèces de Dynomenidae et de Dromiidae sont signalées des îles Mariannes des Philippines, qui n’ont en commun que sept espèces. De nouvelles clés d’identification sont présentées pour les genres Dynomene, Sphaerodromia et Cryptodromia. Les Dynomenidae et les Dromiidae primitifs partagent des caractères similaires pour les gonopodes. Les Dromiidae avancés ont des gonopodes dont la structure peut être mise en rapport avec les sutures 7/8 des femelles plus longues. Une crista dentata du troisième maxillipède telle qu’on l’observe chez les crabes podotrèmes est absente chez tous les Eubrachyura. Chez ces crabes, les tubercules marginaux du troisième maxillipède pourraient être nommés marginal dentata. Les crabes podotrèmes montrent une grande variété de mécanismes coxaux et sternaux pour le maintien de l’abdomen en rapport avec la présence des uropodes.Five species of Dynomenidae are recorded from Guam, Mariana Islands. Two new species of Dynomene are described. Distinctive characters of D. kroppi n. sp. are: carapace width/length ratio= 1.1, six small, blunt anterolateral teeth, and five or six spines on inner margins of walking leg dactyli; and for D. guamensis n. sp. are: carapace width/length ratio = 1.3, five acute anterolateral teeth, two prominent frontal swellings, two tubercles behind postorbital corner, and seven or eight spines on inner margins of walking leg dactyli. Nine new records and one new dromiid species are reported from Guam: the distinctive characters of Cryptodromia pitiensis n.sp. are: carapace width/length ratio= 1.3, a prominent swelling above the anterolateral margin, carapace surface mostly smooth, but areolate and with scattered tubercles. Nine new dromiid records are also reported for Tonga and Samoa. Five new dromiid records are reported, based on material collected by the Albatross Expedition, 1907-1910, to the Philippine Islands. A total of 29 dynomenid and dromiid species are reported from the Mariana and Philippine Islands, of which only seven species are shared. New keys are provided to identify species of Dynomene, Sphaerodromia and Cryptodromia. Dynomenids and primitive dromiids share similar gonopod characters. Advanced dromiids have gonopods whose derived structure may be linked to the longer sternal sutures 7/8 in females. The third maxilliped crista dentata, as found in podotreme crabs, is absent from all Eubrachyura. Tooth-like maxilliped marginal tubercles in these crabs should be called the marginal dentata. Podotreme crabs show a variety of coxal and sternal abdominal locking mechanisms linked to the presence of uropods.</p

Les Dromiidae de Polynésie française et une nouvelle collection de crabes (Crustacea, Decapoda, Brachyura) des Îles Marquises

Une collection de crustacés récoltés entre 35 et 112 m aux Îles Marquises, Polynésie française, inclut trois nouvelles espèces de Dromiidae. Les caractères différentiels sont : pour Dromidiopsis richeri n. sp., la présence de trois dents antérolatérales et une frange dense de soies en arrière de la marge frontale ; pour Cryptodromia marquesas n. sp., une forte dent subhépatique visible dorsalement et la présence de cinq dilatations de l’aire branchiale qui donnent à la surface de la carapace un aspect sculpté ; pour Cryptodromia erioxylon n. sp., un revêtement de soies molles, très fines, une marge orbitale finement denticulée et un tubercule proéminent en arrière de l’angle post-orbital. On mentionne pour la première fois la présence de Dromia dormia (Linnaeus, 1763), Cryptodromiopsis unidentata (Rüppell, 1830) et Cryptodromia hilgendorfi De Man, 1888. Des nouvelles clés sont fournies pour l’identification des espèces connues de Dromidiopsis et de Cryptodromia. Dromia wilsoni (Fulton &amp; Grant, 1902) et le premier spécimen femelle de Cryptodromiopsis plumosa (Lewinsohn, 1984) sont signalés d’Hawaii. Les éponges transportées par les Dromiidae ont été identifiées au niveau générique et la plupart sont mentionnées pour la première fois des Îles Marquises. La faune de Polynésie française inclut maintenant 11 Dromiidae et cinq Dynomenidae alors ques les Îles Hawaii en ont respectivement cinq et quatre espèces. Quatre Dromiidae et trois Dynomenidae sont communes aux deux faunes. La diversité est la plus grande dans les eaux peu profondes (&lt; 100 m). Le transfert du sperme est peu connu chez les Dromiidae. Le premier gonopode est tubulaire seulement à l’extrémité distale et ne peut pas pénétrer dans l’ouverture de la spermathèque de la femelle, alors que le second est plus long et en forme d’aiguille. Le prolongement long et musculeux du vas deferens est le conduit principal du sperme, qui remplit donc le rôle du premier gonopode des Eubrachyura.A collection (35-112 m) from the Marquesas Islands, French Polynesia, contains three new dromiid species. The distinctive characters of Dromidiopsis richeri n. sp. include three anterolateral teeth and a dense fringe of setae behind the frontal margin. For Cryptodromia marquesas n. sp., the distinctive characters are a strong subhepatic tooth visible dorsally and the presence of five swellings on the branchial area, which give the carapace surface a sculptured appearance and for Cryptodromia erioxylon n. sp., a covering of very fine, soft setae, a minutely denticulated orbital margin and a prominent tubercle behind the postorbital corner. There are three new records: Dromia dormia (Linnaeus, 1763), Cryptodromiopsis unidentata (Rüppell, 1830) and Cryptodromia hilgendorfi De Man, 1888. New keys are provided for the identification of the known species of Dromidiopsis and Cryptodromia. Dromia wilsoni (Fulton &amp; Grant, 1902) and the first female specimen of Cryptodromiopsis plumosa (Lewinsohn, 1984) are reported from Hawaii. Sponges carried by the dromiids were identified to genus and most of these constitute new records for the Marquesas Islands. The fauna of French Polynesia now includes 11 dromiid and five dynomenids while the Hawaiian Islands have five and four species respectively. Four dromiids and three dynomenids are shared. Diversity is greatest in shallow (&lt; 100 m) water. Sperm transfer in dromiids is poorly understood. The first gonopod is only tubular distally and cannot enter the female spermathecal aperture, while the second is longer and needle-like. The long, muscular extension of the vas deferens is the main conduit for sperm, thus taking over the role of the first gonopod in eubrachyurans.</p

Un nouveau genre et une nouvelle espèce de dromie (Brachyura, Dromiidae) de la mer de Timor, au nord-ouest de l&#039;Australie avec des signalement d&#039;autres espèces de la mer de Chine

Un nouveau genre et une nouvelle espèce de Dromiidae, Alainodromia timorensis, sont décrits du banc Holothuria, en mer de Timor, à partir de spécimens récoltés par le HMS Penguin en 1892. Les collections provenant du banc Holothuria et du banc Macclesfield, en mer de Chine, prélevés en 1888-1893 par les bateaux de la Royal Navy HMS Rambler , Penguin et Egeria , contiennent aussi les Dromiidae suivants: Lauridromia intermedia (Laurie, 1906), Dromiodopsis tridentata Borradaile, 1903, Petalomera granulata Stimpson, 1858, Cryptodromiopsis bullifera (Alcock, 1900), C. unidentata (Ruppell, 1830), Cryptodromia hilgendorfi De Man, 1888, and Epigodromia areolata (Ihle, 1913). Il est montré que Petalomera acutidens Sakai, 1983 appartient au genre Epigodromia McLay, 1993.A new genus and species of dromiid crab, Alainodromia timorensis, is described from the Holothuria Bank, Timor Sea, based on specimens collected by HMS Penguin in 1892. Collections from the Holothuria Bank and the Macclesfield Bank, in the China Sea, during the period 1888-1893 by the Royal Navy survey vessels, HMS Rambler , Penguin and Egeria also included the following dromiid crabs: Lauridromia intermedia (Laurie, 1906), Dromidiopsis tridentata Borradaile, 1903, Petalomera granulata Stimpson, 1858, Cryptodromiopsis bullifera (Alcock, 1900), C. unidentata (Ruppell, 1830), Cryptodromia hilgendorfi De Man, 1888, and Epigodromia areolata (Ihle, 1913). Petalomera acutidens Sakai, 1983 is shown to belong to the genus Epigodromia McLay, 1993.</p

A hypothesis about the origin of sperm storage in the Eubrachyura, the effects of seminal receptacle structure on mating strategies and the evolution of crab diversity: How did a race to be first become a race to be last?

The origins and evolution of sperm storage in Brachyura are enigmatic: sperm is either stored in seminal receptacles, accessible via the vulvae on the sixth thoracic sternite, or in spermathecae at the border between the seventh and eighth sternites. Crabs with spermathecae are collectively referred to as "podotremes" while crabs with seminal receptacles belong to the Eubrachyura. The position of gonopores is the primary basis for subdividing the Eurachyura into the Heterotremata (female vulvae + males with coxal gonopores) and Thoracotremata (female vulvae + males with sternal gonopores). We present a hypothesis about the evolution of seminal receptacles in eubrachyuran female crabs and argue that the sternal gonopore has been internalized into chitin-lined seminal receptacles and the vulva is in fact a secondary aperture. The loss of some or all of the ancestral chitinous seminal receptacle lining was linked to ventral migration of the oviduct connection. Male and female strategies are to maximize gamete fertilization. The most important variable for females is sperm supply, enhanced by long-term storage made possible by the seminal receptacle. To maximize their fertilization rates males must adapt to the structure of the seminal receptacle to ensure that their sperm are close to the oviduct entrance. The major evolutionary impetus for female mating strategies was derived from the consequences of better sperm conservation and the structure of the seminal receptacle. The advantages were all to the females because their promiscuity and sperm storage allowed them to produce more genetically variable offspring, thereby enhancing variation upon which natural selection could act. We extend our arguments to Brachyura as a whole and offer a unifying explanation of the evolution of seminal receptacles, comparing them with the spermathecae found in "Podotremata": they were independent solutions to the same problem: maintaining sperm supply during evolutionary carcinization. Explanation of eubrachyuran mating strategies requires analysis of the mating-moulting link, indeterminate vs. determinate growth format and seminal receptacle structure. Two alternatives for each of these characters means that there are eight possible outcomes. Six of these outcomes have been realized, which we term Portunoid, Majoid, Eriphoid, Xanthoid, Cancroid, and Grapsoid-Ocypodoid strategies, respectively. Mapping these characters on to a workable phylogeny (wherein some changes to the seminal receptacle + moulting-mating links are assumed to have occurred more than once) produces the following relationships: Portunoids + Majoids are a sister group to the rest of the Eubrachyura, which fall into two sister groups, Eriphoids + Xanthoids and Cancroids + Grapsoid-Ocypodoids and the "Podotremata" is sister group to all the Eubrachyura. We conclude that what began as a race to be the first to mate was turned on its head to become a race to be last, by the evolutionary changes to the seminal receptacle. Eubrachyuran females were advantaged by greater reproductive autonomy, more opportunity to mate with other males, resulting in more genetically variable progeny and leading to the evolution of much greater taxonomic diversity compared to "podotremes".Fil: McLay, Colin L.. University Of Canterbury; Nueva ZelandaFil: Lopez, Laura Susana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

An annotated key to the hermit crabs (Crustacea : Decapoda : Anomura) of the Otago region (southeastern New Zealand)

A key is given to the 17 species of hermit crabs of southeastern New Zealand (Otago region). The key is designed primarily for ecological work and emphasises characters readily seen in living animals still in their host shells. The depth range of each species is also includedpeer-reviewe