Three new species of sea star parasite Dendrogaster (Crustacea: Thecostraca) from Japan.

Three new species of ascothoracidan crustaceans, Dendrogaster danni sp. nov., Dendrogaster tanabensis sp. nov., and Dendrogaster jinshomaruae sp. nov. are described from the sea around the Kii Peninsula on the Pacific coast of central Japan. They are found in the coelomic cavities of the sea stars, Neoferdina japonica Oguro & Misaki, 1986., Henricia sp., and Coronaster volsellatus (Sladen, 1889), respectively. Morphological examinations and DNA barcoding analyses of these new species are reported in this study. The emergence of Dendrogaster from their host sea stars is also noted. These findings represent the 11th to 13th species of Dendrogaster that infest Japanese sea stars.

Exploring evolutionary trends within the Pennellidae (Copepoda: Siphonostomatoida) using molecular data.

The family Pennellidae comprises ecto- and mesoparasitic copepods on marine fishes. Although a preliminary scheme of phylogenetic relationships of pennellids based on morphological characters exists, it is difficult to objectively define character states because of their highly modified bodies and reduced appendages. This molecule-based study analysed phylogenetic relationships among seven genera and 12 species of pennellids, using 18S and 28S ribosomal DNA sequences in order to infer evolutionary trends within the family. Our molecular analysis recovered three clades (Clade-I, Peniculus; Clade-II, Haemobaphes-Lernaeocera-Phrixocephalus-Exopenna-Lernaeenicus radiatus; and Clade-III, Pennella-Lernaeenicus spp.). This result was congruent with some of the morphology-based phylogenetic relationships previously proposed but did not support a sister group comprising Exopenna, Phrixocephalus and Pennella. The second and third offshoots after the divergence of Clade-I species are characterized by reduced body tagmosis and changes in lifestyle from ectoparasites to mesoparasites. In some gill parasites of Clade-II, their sigmoid-shaped bodies and coiled egg strings have likely evolved in adaptation to the limited available space within the gill cavities of the hosts. Phrixocephalus is an eye parasite in Clade-II, which also has coiled egg strings, may have descended from an ancestral gill parasite. All species of Clade-III are characterized by the possession of a head region with processes deeply embedded into the host tissues and functioning as an anchor.

Finding the Missing Puzzle Piece of the Nisto Stage in the Larval Cycle of the Slipper Lobster Scyllarides squammosus: A Molecular and Morphological Approach.

Slipper and spiny lobsters are crustaceans that are in high demand and possess great commercial potential as valuable foods. The early life stages are important to understand the distribution and resource ecology of those lobsters. However, much less information is available about slipper lobsters than spiny lobsters. Biological information concerning the transition stage from the planktonic to the benthic phase, the so-called nisto stage, is limited probably due to its short duration. An individual scyllarid nisto was discovered while scuba diving off Chichijima Island. DNA analyses using mitochondrial 16S rRNA and cytochrome c oxidase subunit 1 (COI) genes confirmed this specimen to be Scyllarides squammosus (H. Milne Edwards, 1837). Detailed morphological observations of this specimen and its comparison with previous reports on Scyllarides nistos suggest that the diagnostic character of S. squammosus nisto is the pleura of the second to fifth pleonites possessing prominent teeth entirely on the lateral margin. Other morphological characteristics are the carapace with the widest distance in the middle and the second to fifth pleonites bearing two tubercles on each side. This report describes the identification of the first worldwide record of a Scyllarides nisto, confirmed by molecular barcoding.

Choniomyzon taiwanensis n. sp. (Crustacea: Copepoda: Nicothoidae) Parasitic on the External Egg Mass of the Longlegged Spiny Lobster Panulirus longipes longipes (Crustacea: Decapoda: Palinuridae) from Taiwanese Waters.

Choniomyzon taiwanensis n. sp. is described based on specimens collected from examining external egg masses of spiny lobster Panulirus longipes longipes (Milne-Edwards, 1868), obtained from Hualien, Taiwan. The new species differs from its congeners in possessing the following characteristics: (1) small prosome (about 0.84 mm); (2) armature of antennule being 1, 1, 2, 2, 1, 1, 1, 2, 1, 1+1 (aesthetasc), 4, 6+1 (aesthetasc); (3) five-segmented antenna; (4) second segment of antenna bearing 1 inner seta; (5) two-segmented maxilla. Based on the evidence of distinctive morphological features and host preference, Choniomyzon taiwanensis n. sp. is a new species. Until now, four species of Choniomyzon have been known living on decapods, and the new species reported here is the first record of Choniomyzon species from spiny lobster in Taiwanese waters.

Evolutionary Modification of Pereopods in Phronimid Amphipods (Crustacea: Amphipoda: Hyperiidea: Phronimidae) Reflects Host Differences.

Phronimid amphipods are oceanic crustaceans associated with gelatinous zooplankters. Their host organisms belong mainly to two taxonomic groups: tunicates (salps or pyrosomes; subphylum Tunicata) and siphonophores (Cnidaria). After these amphipods devour the inner tissues of their hosts, they display the unique behavior of modifying their hosts into hollow barrel-shaped shelters, which are then utilized as neonatal nurseries by the females. Although previous studies have revealed the host specificity of these amphipods, it has not been inferred which types of hosts ancestral phronimids could have originally used. Moreover, morphological changes associated with host switching have not yet been studied. To deduce the evolutionary patterns of host switching, we investigated the phylogenetic relationships of phronimid species by using two genes: (1) cytochrome c oxidase subunit I (COI) and (2) 18S ribosomal RNA (18S). In addition, a morphometric analysis was conducted in order to better understand the morphological relationships between phronimids and their host organisms. Our phylogenetic analysis suggests that the ancestral host animals of phronimids could have been tunicates and that the host organisms have independently switched from tunicates to siphonophores at least twice in the family Phronimidae. Our morphometric analysis revealed that phronimids using siphonophores as hosts have a relatively shorter pereopod 5 compared to those using tunicates. The shortening of pereopod 5 seems to be an adaptation to the narrower internal space of siphonophore barrels compared to those of tunicates.

A new species of Fibularia from Japanese waters with a redescription of F. japonica and F. ovulum (Echinodermata: Echinoidea: Clypeasteroida).

A new species, Fibularia coffea sp. nov., occurs from shallow waters in Japan. This new species is distinguished from the other species of Fibularia by the following characters: test height is low, oral surface is slightly depressed toward the peristome, number of pores of petal III continues to increase with the test growth, reaching over 30 at TL > 7.5 mm, and black pigments form symmetric pentaradial on aboral surface in living animals. Two further Japanese species, Fibularia japonica and F. ovulum, are redescribed based on the type specimens (F. japonica) and additional specimens (F. ovulum), respectively. A tabular key to the extant species of Fibularia is also provided. A partial fragment of the mitochondrial gene cytochrome oxidase subunit I (COI) of the type specimens of F. coffea sp. nov. and the additional specimen of F. japonica was sequenced for barcoding in future works.

14-3-3 protein sigma isoform co-localizes with phosphorylated α-synuclein in Lewy bodies and Lewy neurites in patients with Lewy body disease.

α-Synuclein shares structural homology with 14-3-3 proteins. Seven 14-3-3 protein isoforms have been identified in mammals. Among them, the 14-3-3 sigma isoform was initially considered absent in the mammalian brain. However, we previously identified immunohistochemical association of 14-3-3 sigma with Pick bodies. Because 14-3-3 isoforms other than sigma isoform have been identified in Lewy bodies, we were prompted to look for this 14-3-3 sigma-like immunoreactivity (IR) in Lewy bodies in the brainstem, cerebral cortex, and Lewy neurites in seven patients with Lewy body disease. Unexpectedly, 14-3-3 sigma-like IR was consistently found in various types of Lewy pathologies in all cases examined. Double labeling studies confirmed its colocalization with alpha-synuclein. In general, 14-3-3 proteins can trap and hold some phosphorylated proteins in the cytoplasm and they can prevent or mediate apoptosis and survival of some cells. More precisely, the 14-3-3 sigma isoform is unique in its multiple cellular functions such as facilitating cell cycle arrest in the G2 phase, positively regulating p53, and suppressing tumor growth. Although the precise role of 14-3-3 sigma in the development of Lewy pathology remains elusive, its consistent association to Lewy pathology may expand our understanding of Lewy pathogenesis.

Life-cycle of Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae) with the morphological descriptions of the nauplius, copepodid and adult male.

Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae), an associate of the scyllarid lobster Ibacus novemdentatus Gibbes, was found to pass through at least four developmental stages: nauplius, copepodid I (CI), copepodid II or later (CII+) and adult. Free-living nauplii were observed hatching from the ovisacs of adult females. CI was found on the body surface of both female and male hosts, whereas CII+ and adult were obtained from the female host's egg masses. The life-cycle of this copepod is presumed to be as follows: (i) nauplius develops into CI in the water column; (ii) infective CI settles on body surface of host; (iii) CI moults into the following stage, changing its microhabitat from host's body surface to egg masses; (iv) CII+ develops on egg masses of host until adult stage; and (v) adult female and male mate on the host's egg masses.

Porous frameworks constructed by non-covalent linking of substitution-inert metal complexes.

The incorporation of active sites into metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) is an attractive way to functionalise these materials. However, the methodology to organise substitution-inert metal-based secondary building units (SBUs) with active sites into MOFs or PCPs via coordination driven self-assembly is severely limited. In this study, we successfully assembled substitution-inert paddle-wheel Rh(II) dimers to afford three novel porous frameworks, Rh2(ppeb)4(THF)2 (1-THF), Rh2(ppeb)4(3-pentanone)2 (1-PN) and Rh2(ppeb)4(1-adamantylamine)2 (1-AD) (ppeb = 4-[(perfluorophenyl)ethynyl]benzoate), by using non-covalent interactions. Multipoint arene-perfluoroarene (Ar-Ar(F)) interactions, which allow the unidirectional face-to-face interaction mode of aromatic rings, were used to assemble the substitution-inert paddle-wheel Rh(II) dimers. The obtained frameworks were structurally characterisation by single crystal X-ray diffraction, and it is found that all structures exhibited a one-dimensional channel with active axial sites exposed to the pores. The porous properties of the obtained frameworks were also investigated by thermogravimetric analysis, gas adsorption and powder X-ray diffraction measurements. Moreover, the ligand substitution reaction at the active axial sites was examined at the crystalline state and the flexible structural transformation with the change of channel shapes and sizes was observed.

Choniomyzon inflatus n. sp. (Crustacea: Copepoda: Nicothoidae) associated with Ibacus novemdentatus (Crustacea: Decapoda: Scyllaridae) from Japanese waters.

A new species of parasitic copepod, Choniomyzon inflatus n. sp., is described based on specimens collected from the external egg masses of the smooth fan lobster Ibacus novemdentatus Gibbes captured in the North Pacific Ocean off Ainan, Ehime Prefecture, western Japan. The new species differs from its congeners in having a globular to ovoid prosome, in bearing asymmetrically arranged denticles at a rounded apex of both the terminal segment of the antenna and the maxilliped, and in lacking serrate lobes on the basis of legs 1 and 2. The species is similar in size and shape to the host's eggs, which may be interpreted as egg mimicry. The new species is the first member of Choniomyzon Pillai, 1962 from subtropical regions.

Predation by the phyllosoma larva of Ibacus novemdentatus on various kinds of venomous jellyfish.

The phyllosoma, a larva of spiny and slipper lobsters, has an exceptionally flat body and long appendages. It is known to associate with several species of cnidarian jellyfish, a behavior that is not rare in crustaceans. Indeed, phyllosomas clinging onto jellyfish have been observed both in the laboratory and in the natural environment. Wild phyllosomas have been found to contain jellyfish tissues in their hepatopancreas and feces, suggesting that the larvae utilize jellyfish as a food source; however, how they capture jellyfish and what species of jellyfish they prefer have rarely been investigated. The few previous studies conducted have suggested that phyllosomas have a high specificity for jellyfish (preying on only a few species); in contrast, the results of our study indicate that specificity is low. We show that phyllosomas prey on a variety of jellyfish species including deadly stinging types, on a variety of jellyfish developmental stages, and on various parts of the jellyfish body. When making contact with a jellyfish, phyllosomas first cling onto its exumbrella, feed on its tentacles or oral arms, and then consume the exumbrella. Phyllosomas may be capable of defending themselves against any types of nematocyst sting, and it is likely that they have evolved to utilize venomous jellyfish as a food in the open sea, where food may be scarce.

A new species of parasitic copepod, Sarcotretes umitakae sp. n. (Siphonostomatoida, Pennellidae), on the rattail (Actinopterygii, Macrouridae) from the East China Sea, Japan.

A new species of copepod, Sarcotretes umitakaesp. n., of the siphonostomatoid family Pennellidae is described based on female specimens from the rattail Coelorinchus jordani Smith and Pope (Actinopterygii: Gadiformes: Macrouridae) caught in the East China Sea. This species is characterized by exhibiting the following characters: the large proboscis projects strongly; the head bears paired lateral processes which are bulbous and taper into a slender horn; the twisting neck is significantly longer than the trunk; and the trunk bears an anterior constriction with a reduced abdomen.

Morphology and gene analysis of hybrids between two congeneric sea stars with different modes of development.

The sea star Astropecten scoparius has feeding bipinnarian larvae, whereas its congener Astropecten latespinosus has nonfeeding barrel-shaped larvae. To investigate evolutionary changes in the development of asteroids, we performed reciprocal crosses between these two species with different larval forms. In the cross between A. scoparius eggs and A. latespinosus sperm, embryos developed into bipinnaria-like larvae. The larvae exhibited either a functional digestive system (a maternal feature) or a nonfunctional digestive system with the tip of the archenteron not connected to the stomodeum (a paternal characteristic). However, in the reciprocal cross between A. latespinosus eggs and A. scoparius sperm, barrel-shaped larvae resembling those of A. latespinosus were produced, in addition to bipinnaria-like larvae, some with functional digestive systems and some with nonfunctional ones. Juveniles were produced from all types of crosses. 18S rDNA was used as a gene marker in cycle sequencing analysis to investigate the genetic features of these juveniles. The sequences of juveniles from bipinnaria-like larvae showed double-peak nucleotide signals, indicating a biparental genome. On the other hand, juveniles from barrel-shaped larvae from A. latespinosus eggs and A. scoparius sperm showed the same sequence as A. latespinosus juveniles. This suggests that bipinnaria-like larvae of both crosses are always hybrids, whereas barrel-shaped larvae develop parthenogenetically.