Integrative taxonomy of the subfamily Orbioninae (Crustacea: Isopoda) based on mitochondrial and nuclear data with evidence that supports Epicaridea as a suborder.

Epicaridea is a group of isopods with high morphological diversity, reduction and loss of characters, and strong sexual dimorphism due to their parasitic lifestyles but their systematics is not well understood. Despite the use of nuclear and mitochondrial genes to test the phylogeny of many invertebrate groups, few molecular data from epicarideans are known, especially from the subfamily Orbioninae. Species in this group are obligate penaeoid shrimp parasites and the lack molecular data has hampered studies on the phylogeny of Orbioninae. To rectify this, mitochondrial and nuclear genes of 9 orbionine species are sequenced here. Compared to the isopod ground pattern, the sequences of orbionines seem to be more plastic near the control region and major translocations are located between rrns and cob. A phylogenetic analysis based on three data sets showed strong support for a monophyletic Orbioninae and that Epicaridea should be accepted at the rank of a suborder within Isopoda. The monophyly of Parapenaeon and Orbione is in doubt based on morphological and molecular data. The genus Parapenaeon is revised and a new genus Aparapenaeon is erected for Parapenaeon japonica and three closely related species.

Phylogenetic position of Bopyroides hippolytes, with comments on the rearrangement of the mitochondrial genome in isopods (Isopoda: Epicaridea: Bopyridae).

BACKGROUND: Classification of parasitic bopyrids has traditionally been based on morphological characteristics, but phylogenetic relationships have remained elusive due to limited information provided by morphological data and tendency for loss of morphological features as a result of parasitic lifestyle. Subfamily Argeiinae was separated from Bopyrinae based on morphological evidence, although the assignment of all genera has not been phylogenetically evaluated. Bopyroides hippolytes has been traditionally classified in Bopyrinae, but divergent morphological characters make this assignment questionable. To investigate the relationship of bopyrines, we sequenced the complete mitochondrial genome of B. hippolytes and four mitochondrial genes of two other Bopyrinae. RESULTS: The phylogenetic trees based on separate and combined cox1and 18S sequence data recovered Bopyridae as robustly monophyletic, but Bopyrinae as polyphyletic. Bopyroides hippolytes was a close sister to Argeia pugettensis, type species to Argeiinae. Mitochondrial phylogenomics also suggested that B. hippolytes was close to Argeiinae. We also found a novel gene order in B. hippolytes compared to other isopods. CONCLUSIONS: Bopyroides hippolytes should be excluded from the Bopyrinae and has a close affinity with Argeia pugettensis based on molecular and morphological data. The conserved syntenic blocks of mitochondrial gene order have distinctive characteristics at a subordinal level and may be helpful for understanding the higher taxonomic level relationships of Isopoda.

Two new species and a new record of Bopyrinae (Isopoda: Bopyridae) infesting Alpheidae and Hippolytidae, with comments on the genus Bopyrina Kossmann, 1881.

Two new bopyrids, Bopyrinina articulata n. sp. and Bopyrinella asymmetrica n. sp. are described from French Polynesia, the Red Sea, and the Philippines. Bopyrinina articulata n.sp. infests Salmoneus cf. gracilipes Miya, and is distinguishable from other species of this genus by the structure of the maxilliped, pleopods and oostegite 1. Bopyrinella asymmetrica n. sp. is most similar to Bopyrinella albida Shiino, 1958, but females differ from that species because all pereomeres on the short side have round dorsolateral bosses and its pleotelson is greatly distorted. Bopyrina ocellata (Czerniavsky, 1868) is newly recorded from the Western Atlantic, from Florida, USA. Review of the species of Bopyrina revealed that B. choprai Nierstrasz & Brender à Brandis, 1929 and B. sewelli Chopra, 1930 are intermediate in morphology between Bopyrina and Schizobopyrina, the taxonomic assignment of these two species needs further evaluation. Keys to Bopyrinella Nierstrasz & Brender à Brandis, 1925 and Bopyrina Kossmann, 1881 are presented. Hosts and distributions of the seven species of Bopyrinella are summarized.

Disrupted architecture and fast evolution of the mitochondrial genome of Argeia pugettensis (Isopoda): implications for speciation and fitness.

BACKGROUND: Argeia pugettensis is an isopod species that parasitizes other crustaceans. Its huge native geographic range spans the Pacific from China to California, but molecular data are available only for a handful of specimens from North-American populations. We sequenced and characterised the complete mitogenome of a specimen collected in the Yellow Sea. RESULTS: It exhibited a barcode (cox1) similarity level of only 87-89% with North-American populations, which is unusually low for conspecifics. Its mitogenome is among the largest in isopods (≈16.5 Kbp), mostly due to a large duplicated palindromic genomic segment (2 Kbp) comprising three genes. However, it lost a segment comprising three genes, nad4L-trnP-nad6, and many genes exhibited highly divergent sequences in comparison to isopod orthologues, including numerous mutations, deletions and insertions. Phylogenetic and selection analyses corroborated that this is one of the handful of most rapidly evolving available isopod mitogenomes, and that it evolves under highly relaxed selection constraints (as opposed to positive selection). However, its nuclear 18S gene is highly conserved, which suggests that rapid evolution is limited to its mitochondrial genome. The cox1 sequence analysis indicates that elevated mitogenomic evolutionary rates are not shared by North-American conspecifics, which suggests a breakdown of cox1 barcoding in this species. CONCLUSIONS: A highly architecturally disrupted mitogenome and decoupling of mitochondrial and nuclear rates would normally be expected to have strong negative impacts on the fitness of the organism, so the existence of this lineage is a puzzling evolutionary question. Additional studies are needed to assess the phylogenetic breadth of this disrupted mitochondrial architecture and its impact on fitness.

Toxicity of Heavy Metals to Mongoloniscus sinensis (Dollfus, 1901) (Crustacea: Isopoda: Oniscidea).

The bioaccumulation of and resistance to different heavy metals in soil was tested using Mongoloniscus sinensis, a terrestrial isopod endemic to china, and results show that: (1) the median lethal concentration (LC50) of Pb, Zn, Cd in the filter paper contact test after 48 h was 197.6, 503.7, 448.0 µg cm- 2, LC50 of Pb-Zn compounds was 173.8 and 440.8 µg cm- 2 and after 14 days of soil contamination LC50 was 2917.0, 2977.9, 5048.4 mg kg- 1, LC50 of Pb-Zn compounds was 1219 and 1463 mg kg- 1. Thus Zn turned out to be less toxic than Cd in the filter paper contact test, while their sequence of toxicity was reversed during the soil exposure test, which shows that M. sinensis can tolerate a dose of Zn and Cd. (2) analysis of body burdens showed that the sequence of internalized metal concentrations was Pb < Cd < Zn, which indicates that heavy metals in soil can be enriched and absorbed by M. sinensis, and that it is much more efficient at absorbing Zn and Cd than Pb.

The first complete mitochondrial genome of a parasitic isopod supports Epicaridea Latreille, 1825 as a suborder and reveals the less conservative genome of isopods.

The complete mitochondrial genome sequence of the holoparasitic isopod Gyge ovalis (Shiino, 1939) has been determined. The mitogenome is 14,268 bp in length and contains 34 genes: 13 protein-coding genes, two ribosomal RNA, 19 tRNA and a control region. Three tRNA genes (trnE, trnI and trnS1) are missing. Most of the tRNA genes show secondary structures which derive from the usual cloverleaf pattern except for trnC which is characterised by the loss of the DHU-arm. Compared to the isopod ground pattern and Eurydice pulchra Leach, 1815 (suborder Cymothoida Wägele, 1989), the genome of G. ovalis shows few differences, with changes only around the control region. However, the genome of G. ovalis is very different from that of non-cymothoidan isopods and reveals that the gene order evolution in isopods is less conservative compared to other crustaceans. Phylogenic trees were constructed using maxiumum likelihood and Bayesian inference analyses based on 13 protein-coding genes. The results do not support the placement of G. ovalis with E. pulchra and Bathynomus sp. in the same suborder; rather, G. ovalis appears to have a closer relationship to Ligia oceanica (Linnaeus, 1767), but this result suggests a need for more data and further analysis. Nevertheless, these results cast doubt that Epicaridea Latreille, 1825 can be placed as an infraorder within the suborder Cymothoida, and Epicaridea appears to also deserve subordinal rank. Further development of robust phylogenetic relationships across Isopoda Latreille, 1817 will require more genetic data from a greater diversity of taxa belonging to all isopod suborders.

A new genus and species of parasitic isopod (Isopoda: Bopyridae: Orbioninae) from Chinese waters, with a new locality and host record for Orbione halipori Nierstrasz & Brender à Brandis, 1923.

Parasymmetrorbione bicauda n. g., n. sp. is described from Chinese waters infesting two species of Solenocera Lucas (Decapoda: Penaeoidea). The new genus differs from other orbionine genera by the following combination of features: a pronounced asymmetry of coxal and lateral plate development, biramous uropods, tuberculate lateral plates and a digitate internal ridge on oostegite 1. A key to the eight genera of the Orbioninae R. Codreanu, 1967 is presented. Orbione halipori Nierstrasz & Brender à Brandis, 1923 is also recorded from a new Chinese locality and a new host.

A new species and two new records of Minicopenaeon Bourdon, 1981 (Crustacea: Isopoda: Bopyridae) from China.

Three species of the parasitic isopod genus Minicopenaeon Bourdon, 1981 (Crustacea: Isopoda: Bopyridae) are reported from China, one new to science and two new records from mainland China. Minicopenaeon crosnieri (Bourdon, 1979) formerly known from Madagascar, the Philippines and Taiwan, is recorded from Zhejiang province. Minicopenaeon intermedium Bourdon, 1981 previously recorded from the Philippines and Japan, is recorded from China for the first time. The new species Minicopenaeon liuruiyui n. sp. is recorded from the East and South China Seas. As with other species of the genus, females of the new species have rudimentary coxal plates on the second pereomeres on the short side. The new species can be distinguished from other species by the presence of a widely open brood pouch, head with bilobate anterior edge and median concave groove, and male head with curved posterior margin of the pleon. A key to species of Minicopenaeon is provided and the subspecies M. intermedium curvatum Bourdon, 1981 is synonymised with M. intermedium Bourdon, 1981. Metapenaeopsis philippii (Bate, 1881) and M. coniger (Wood-Mason, 1891) are newly recorded as host species for bopyrids.

A new species of Cancricepon Giard & Bonnier, 1887 (Isopoda: Bopyridae) from China.

Specimens of the genus Cancricepon Giard & Bonnier, 1887 are recorded for the second time from China, and a new taxon, Cancricepon multituberosum n. sp., is described based on specimens parasitising the xanthid crab Liomera laevis (A. Milne-Edwards). Females of the new species can be distinguished from the other seven species of Cancricepon by the presence of mid-dorsal projections on all pereomeres and the absence of a palp on the maxilliped. Merocepon knudseni Danforth, 1970 is transferred to Cancricepon as C. knudseni (Danforth, 1970) n. comb. A table of the eight described species of Cancricepon is provided.

[Rapid cloning and functional characterization of hypericin synthase gene].

Hypericin, a red-colored naphtodianthrone, is a natural product synthesized in the medicinal plant Hypericum perforatum, commonly known as St. John's wort. Hypericin has attracted a growing attention of the pharmaceutical industry because of its potential application to various therapies, including the treatment of depression and remarkable antiviral and photodynamic activities, hyp-1 gene encodes for phenolic coupling protein which catalyzes in vitro direct and specific conversion of emodin to hypericin which, however, has not formed common opinion so far. Six pairs of primers specific to hyp-1 gene were synthesized. The rapid cloning of hyp-1 gene was performed based on step-by-step extension of a short region of the gene through a series of PCR reactions. All cloned sequences were confirmed by DNA sequencing. A vector named pET32ahyp containing hyp-1 gene was constructed and was transformed into E. coli to induce heterologous expression. SDS-PAGE and Western blot results showed the recombinant Hyp-1 protein was expressed successfully in E. coli. The soluble fraction was used to test the function of the recombinant Hyp-1. Hypericin was detected by LC-MS/MS with emodin as a substrate under in vitro conditions. The above results corroborated the Hyp-1 function, a confusing question, which lay a material foundation for the synthesis of hypericin by synthetic biotechnology.

A new species of the genus Mongoloniscus Verhoeff, 1930 (Crustacea: Isopoda: Agnaridae) from China.

A new species of suborder Oniscidea from northeast China, Mongoloniscus chevronus sp. nov., is described and illustrated. The new species is most related to M. sinensis, only can be distinguished from the latter and other congeners by all pereonites with concave-convex-concave posterior margins, pleon without any decorations. But it can be found new to science by Cox1 gene. A key to all species of genus Mongoloniscus is presented herein.

Three new species of Scyracepon Tattersall, 1905 (Isopoda: Bopyridae) from Pacific islands, with comments on the rarity of bopyrids parasitizing brachyurans.

Three new species of the bopyrid genus Scyracepon Tattersall, 1905 are described from crabs collected on Pacific Islands: Scyracepon polynesiensis n. sp. from the Society Islands, S. pseudoliomerae n. sp. from the Mariana Islands, and S. biglobosus n. sp. from the Line Islands. The first two were found infesting Xanthias lamarckii and Pseudoliomera sp. (Xanthidae), a new host family for species of Scyracepon, and the last was found parasitizing Schizophrys aspera (Majidae). Scyracepon now includes 11 species, all but one known from single collections, infesting 12 host species in 9 brachyuran families. The discovery of three new species, each rare, suggests that crab parasites are undersampled, and further suggests that the low relative diversity of bopyrids known from brachyurans may partly reflect this undersampling. Keys to all species of Scyracepon and to all 31 genera of Keponinae are provided.

Three new species of abdominal shrimp parasites (Crustacea: Isopoda: Bopyridae: Hemiarthrinae) from the Indo-West Pacific.

Three new species of the parasitic isopod subfamily Hemiarthrinae Markham, 1972 are described. Allodiplophryxus unilateralis n. sp. is described from Western Australia, infesting the palaemonid shrimp Jocaste lucina (Nobili, 1901), and females differ from the only other species in the genus in possessing six pleomeres, an asymmetrical first oostegite and pleopods restricted to the short side of the body. Loki athanus n. sp. is described from Madagascar, infesting the alpheid shrimp Athanas parvus de Man, 1910, and females differ from the only other species in the genus in possessing well-developed lateral plates on pleomere 4 and four pairs of uniramous pleopods. Hemiarthrus alphei n. sp. is described from French Polynesia, infesting the alpheid shrimp Alpheus crinitus Dana, 1852, and females differ from the four other known Hemiarthrus species in having pleomeres with well-developed, symmetrical lateral plates, a barbula with three pairs of projections and a pointed pleotelson. Keys to species of Hemiarthrus and all genera of the Hemiarthrinae are presented.

New hosts and localities for species of Cancricepon Giard Bonnier, 1887 Isopoda: Epicaridea: Bopyridae) with description of two new species and comments on the relationship between Cancricepon and Trapezicepon Bonnier, 1900.

The genus Cancricepon Giard Bonnier, 1887 is recorded for the first time from Australia, the Maldives, Papua New Guinea and Taiwan. Four species of Cancricepon are reported here, and two are new to science. Cancricepon choprae (Nierstrasz Brender à Brandis, 1925) is reported from the Gulf of Mexico on the Florida coast, infesting a new host, Micropanope cf. sculptipes Stimpson, 1871. Cancricepon castroi n. sp. is described from Australia, the Maldives, Japan and Papua New Guinea parasitizing coral crabs of the family Trapeziidae. Cancricepon cf. multituberosum An, Yu Williams, 2012 is recorded from a specimen of Leptodius affinis (De Haan, 1835) from Taiwan. Specimens previously misidentified as C. choprae parasitizing Scalopidia spinosipes Stimpson, 1858, from China are described as C. beibusinus n. sp. All known hosts and localities of species of Cancricepon are summarized, and a key to the species in the genus is provided. The similarities between species of Cancricepon and the type species of Trapezicepon Bonnier, 1900, are discussed and Trapezicepon thalamitae Markham, 1985, is transferred to Scyracepon Tattersall, 1905.

Description of three new species of Bopyrissa Nierstrasz Brender à Brandis, 1931 (Epicaridea: Bopyridae) from Oceania with a key to species in the genus.

Three new species in the parasitic isopod genus Bopyrissa Nierstrasz Brender à Brandis, 1931, recorded from Kiribati, the Mariana Islands and French Polynesia, are described. These three species, B. distorta sp. nov., B. guamensis sp. nov. and B. oceania sp. nov., are the first species of the genus recorded from Oceania, occurring on three different hermit crab host species of genus Calcinus. The diversity of the genus is therefore increased to ten species. Bopyrissa distorta sp. nov. can be distinguished from congeners by the markedly distorted sinistral body of females and fused pleon of males. Bopyrissa guamensis sp. nov. differs from other dextral species of Bopyrissa in having a strikingly tuberculated edge to the pleomeres of females. Bopyrissa oceania sp. nov. differs from related species in that females possess eyes and that the barbula has smooth falcate projections on each side. A key to the ten species of Bopyrissa is presented, together with a tabular summary of their known geographic and host ranges.

New records of Tylokepon with the description of a new species (Epicaridea, Bopyridae, Keponinae).

The parasitic isopod genus Tylokepon is recorded for the first time from the Mariana Islands and Australia. Tylokeponmarianensis sp. n. is described from the Mariana Islands, infesting Thusaenysirami (Laurie, 1906). The holotype female differs from other known Tylokepon females by the tri-lobed projection on pereomere 6, almost smooth lateral plates and pleopods, shape of oostegite 1, and widely opened brood pouch. The host is first recorded for bearing bopyrids. The new record of T.bonnieri Stebbing, 1904 from Australia on the type host extends the range of this species from China and India. A table of localities and hosts and a key to all species of Tylokepon are provided.

Paguristione uniuropodus, a new genus and a new species of Pseudioninae infesting hermit crabs from China (Crustacea, Isopoda, Bopyridae).

Paguristione uniuropodus gen. n., sp. n. infests Paguristes sp. in the East China Sea. Paguristione gen. n. differs from the closely related genera Pseudione and Pagurion by its females having indistinct lateral plates on the last two pleomeres and its male with a long tapering pleon of six pleomeres, lacking both pleopoda and uropoda.

A review of the genus Spiropagurus Stimpson, 1858 (Crustacea: Decapoda: Paguridae) from the China seas.

Three species of the genus Spiropagurus Stimpson, 1858, are reported in the present paper, including a new species, S. monospinosus sp. nov. This new species is easily recognized by the carpus of the cheliped bearing only one row of spines, whereas two rows are present in the other two species from the China seas. A key to all the species of Spiropagurus is provided.

A review of bopyrid isopods infesting crabs from China.

Isopod parasites of the subfamilies Ioninae and Pseudioninae infest the branchial chambers of brachyuran crabs. In total, 19 species of parasitic isopods infest crabs from China; they belong to 6 genera from the Ioninae and 1 genus from the Pseudioninae. Specifically, the following genera are represented: Allokepon Markham, 1982 (three species), Apocepon Nierstrasz and Brender à Brandis, 1930 (three species), Cancricepon Giard and Bonnier, 1887 (one species), Dactylokepon Stebbing, 1910 (four species), Gigantione Kossmann, 1881 (four species), Onkokepon, An et al. 2006 (two species) and Tylokepon Stebbing, 1906 (two species). The new species Tylokepon biturus from Menaethius monoceros (Latreille) collected in China is distinguished from other members of the genus by the striking shape of the head, two mid-dorsal projections on Pereomere 6, and entire pleopods and uropods without any tubercules on their surface. A list of all bopyrid species (19 species in seven families) along with their hosts and localities, is presented.

The cryptogenic parasitic isopod Orthione griffenis Markham, 2004 from the eastern and western Pacific.

The parasitic isopod Orthione griffenis Markham, 2004 was originally described from thalassinid mud shrimp hosts collected in Oregon. Subsequently, O. griffenis has been cited as a non-indigenous species in estuaries of the Pacific Northwest of North America; however, no taxonomic work has provided evidence that specimens from the western coast of the United States and other localities are conspecific. We report the first record of O. griffenis from Chinese waters based on collections made in the 1950s, which pre-date any records of the species from the United States by at least 20 years. Females of the Chinese specimens match the original description except in the number of articles on antennae 2 (six and five articles in the Chinese material and holotype, respectively). However, newly examined material from the United States showed females are variable in this character, exhibiting 5-6 articles on antennae 2. Although males of O. griffenis from Oregon were originally described as having second antennae with five articles, reexamination of the allotype showed that antennae 2 were damaged and missing terminal articles. Thus, the number of articles in the second antennae of males is six, as found in both the Chinese and new samples from the United States. Scanning electron microscopy (SEM) of males from USA and China revealed curled setae on the distolateral margins of the uropods, which were not reported in the original description. In China the species is found on Austinogebia wuhsienweni (Yu) from Shandong province, whereas along the western coast of North America the species extends from British Columbia to California on Upogebia pugettensis (Dana) and U. macginitieorum Williams (the latter species replacing U. pugettensis south of Pt. Conception, California). Orthione griffenis has also been reported from Japan on Upogebia issaeffi (Balss) and Austinogebia narutensis (Sakai). In Coos Bay, Oregon, the prevalence of the species was ∼65% in the mature U. pugettensis. The species was presumably introduced as larvae released in ballast water from ships originating in Asia. The epicaridium larvae of O. griffenis were examined with SEM, and aspects of the life history of the species are reviewed.