A new pseudoscorpion genus from western Georgia (Pseudoscorpiones: Neobisiidae: Cornuroncus n. gen.), with a key to all Neobisiinae genera

A new genus and species of epigean pseudoscorpions belonging to the subfamily Neobisiinae Chamberlin, 1930, is described from western Georgia and its diagnostic characters are illustrated. Cornuroncus n. gen. resembles the genus Roncus L. Koch, 1873 in several characters but differs by having a short dorso-distal spine on tarsus IV, and the presence of a ventral tooth on one of the claws of tarsus IV. An identification key for all valid Neobisiinae genera is provided.

A new species of the hermit crab genus Diogenes Dana, 1851 (Decapoda: Anomura: Diogenidae) from southern India

A new species of the hermit crab genus Diogenes Dana, 1851, D. spongicola, is described and illustrated on the basis of material collected from two locations off southern India. It appears close to D. takedai Rahayu, 2012 among about 70 congeners, but easily differentiated from the latter by the spinulose anterolateral margins of the shield, the article 2 of the antennal peduncle armed only with one distal spine, the longer, spinose antennal acicle, the absence of prominent spines on the ventrolateral margin of the cheliped meri, and the different color of the cheliped palm. Specimens of the new species were all collected from cavities of a callyspongiid sponge Callyspongia diffusa (Ridley, 1884), suggesting a possible association between the hermit crab and sponge.

Syllidae (Annelida) from the Boreal and sub-Arctic seas off Norway (North Sea, Norwegian Sea, Barents Sea)

A collection of more than 1500 specimens of Syllidae (Annelida, Polychaeta) from sub-Arctic and Boreal regions along the coast of Norway has been studied. We report 32 species, two of them new to science, belonging to the generaSphaerosyllisClaparède, 1863 andSyllisSavigny in Lamarck, 1818, and 16 new to Norway.Sphaerosyllis tarqueisp. nov. is characterized by having long blades on its compound chaetae and the presence of glands inside the dorsal cirri.Syllis kassp. nov. was reported, figured and described by Uschakov (1955) asSyllis oerstedi(Malmgren, 1867); however, revision of the types ofChaetosyllis oerstedireveals that they are sexual stolons ofSyllis cornutaRathke, 1843; this species is characterized by the shape of the spiniger-like chaetae, which are relatively short, distally blunt, with a thin distal spine, and unidentate falcigers some of which have similar spines. We also include descriptions and figures ofParexogone longicirris(Webster & Benedict, 1887) andSyllides longocirrataØrsted, 1845. Finally we include a key of all reported species in the area.

Local differentiation in the defensive morphology of an invasive zooplankton species is not genetically based

Evolutionary changes in functional traits represent one possible reason why exotic species spread to become invasive, but empirical studies of the mechanisms driving phenotypic differentiation between populations of invasive species are rare. This study tested whether differences in distal spine length among populations of the invasive cladoceran, Bythotrephes longimanus, could be explained by local adaptation or phenotypic plasticity. We collected Bythotrephes from six lakes and found that distal spine lengths and natural selection on distal spine length differed among populations, but were unrelated to the gape-limitation of the dominant fish predator in the lake from which they were collected. A common garden experiment revealed significant genetic and maternal variation for distal spine length, but phenotypic differences among populations were not genetically based. Phenotypic differences among lakes in this ecologically important trait are, therefore, the result of plasticity and not local adaptation, despite spatially variable selection on this heritable trait. The ability of Bythotrephes to plastically adjust distal spine length may explain the success of this species at invading lake ecosystems with diverse biotic environments.

A new species of Boholina (Copepoda, Calanoida, Boholinidae) from Ganghwa Island in western Korea

A new species of Boholina, B. ganghwaensis sp. nov. is described, based on specimens collected from burrows of the manicure crab, Cleistostoma dilatatum, in the tidal flat of Ganghwa Island in western Korea. The new species is closely similar to B. purgata and B. parapurgata by having a pointed process on the posterior angles of the second and third pedigerous somites and a similar rostrum in the female, but can be distinguished from its congeners by the following characters: in females by the genital double-somite with small hook-like process on each gonoporal plate, the setation of the distal endopodal segment of mandible, the basis and first endopodal segment of the maxillule incompletely separated, the inner distal spine/outer terminal spine length ratio on P5; and in males by the distal spine present on the posterior surface of the basis of both P5 and the length/width ratio of the endopod of the right P5. This is the first Bololina species recorded from the north-west Pacific.

Raymunida Macpherson & Machordom, 2000 (Crustacea: Decapoda: Anomura: Munididae) from the KUMEJIMA 2009 Expedition in the Ryukyu Islands, Japan

Two species of the munidid genus Raymunida Macpherson & Machordom, 2000, are reported from Kume Island, RyukyuIslands, southwestern Japan. Raymunida striata n. sp. appears closest to R. confundens Macpherson & Machordom, 2001,and R. dextralis Macpherson & Machordom, 2001, but is distinguished by the second and third abdominal somites eachwith an uninterrupted stria between two distinct transverse ridges on the dorsal surface, the merus of the third maxillipedwith a prominent distal spine on the extensor margin, and the mero-carpal articulation of the fourth pereopod reachingonly to the lateral end of the anterior cervical groove of the carapace. The occurrence of R. vittata Macpherson, 2009, inKume Island greatly extends its distribution range to the north hemisphere. Morphological variations of R. vittata are also discussed on the basis of the present specimens. An updated key to the species of Raymunida is provided.

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 andthe Bay of Naples. It is quite similar to the sympatric L. dellavallei Stebbing, 1906, but it has narrower and moreregular-sized spines on the propodus of pereiopods 3–4. The longest spine on the dorsolateral border of the pedun-cle of uropod 1 is not strongly elongate in adult males, as in L. dellavallei. The apical spines on the lobes of the tel-son are much longer than in L. dellavallei. L. clytaemnestra sp. nov. is actually more similar to two northeasternAtlantic 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 ondistal third, whilst setae are restricted to tip in the two other species. Article 3 of the mandibular palp is also longerin L. clytaemnestra sp. nov. than in the two Atlantic species. The spines of the outer plate of the maxilliped are lon-ger in L. clytaemnestra sp. nov. than in the two other species. The most distal spine of the propodus of pereiopods3–4 is reduced in L. clytaemnestra sp. nov. and L. brevicornis, but not in L. pallida. The serration of the posteriorborder 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 lectotypeis designated for L. dellavallei. The presence/absence of a posterodorsal tooth on pleonite 3 in L. dellavallei is dis-cussed. The validity of L. kinahani (Spence Bate, 1862) is questioned. An identification key is proposed for Mediterranean Liljeborgia species.

Three species of Acanthaxius Sakai & de Saint Laurent, 1989, including two new to science, from the Solomon Islands and New Caledonia (Crustacea, Thalassinidea, Axiidae)

Material recently collected from the Solomon Islands include three species of Acanthaxius Sakai & de Saint Laurent, 1989, two of which are new to science: A. clevai n. sp. and A. gadaletae n. sp. and a specimen of A. polyacantha Miyake & Sakai, 1967. Two specimens from New Caledonia are assigned to A. gadaletae n. sp. The new taxa are readily differentiated from A. polyacantha by their longer rostrum and the glabrous postcervical region of carapace. A. clevai n. sp. is characterized by a slender rostrum longer than the eyestalks, with two lateral and a suborbital spine, the gastric region with a median, submedian and lateral carina, setose pereopods 1 with three and two upper spines on the propodal palm and dactylus respectively, the telson longer than broad with three teeth and one spinule on the lateral border. A. gadaletae n. sp. is similar to A. clevai n. sp. but differs by the gastric region with two submedian carinae, the pereopod 1 with four upper spines both on the propodal palm and the dactylus, the maxilliped 3 basis with a large lower distal spine (absent in A. clevai n. sp.) and the abdominal pleura 3–5 with an anterior spinule (absent in A. clevai n. sp.).Trois espèces d’Acanthaxius Sakai & de Saint Laurent, 1989, dont deux nouvelles, des Iles Salomon et de Nouvelle Calédonie (Crustacea, Thalassinidea, Axiidae). Du matériel récemment récolté des Iles Salomon a permis d’identifier trois espèces d’Acanthaxius dont deux sont nouvelles : A. clevai n. sp., A. gadaletae n. sp. et un spécimen d’A. polyacantha Miyake & Sakai, 1967. Deux spécimens de Nouvelle Calédonie sont placés dans A. gadaletae n. sp. Les deux nouveaux taxa se distinguent aisément d’A. polyacantha par leur rostre plus long et la région postcervicale de la carapace inerme. A. clevai n. sp. se distingue par un rostre long et grêle avec deux épines latérales et une suborbitale, la région gastrique avec une carène médiane, une submédiane et une latérale, un péréiopode 1 pourvu de nombreuses soies et de trois et deux épines dorsales respectivement sur le paume et le dactyle, un telson plus long que large muni