Based on 18S-rDNA sequences of 97 isopods including 18 Sphaeromatidea, we show Sphaeromatidae, Valvifera, Serolidae, and Ancinidae is a well supported clade. The within clade relationships of these taxa are not as definitively demonstrated because taxon sampling for some groups is still limited. In our analyses the Sphaeromatidae are shown to be unequivocally monophyletic. This is contrary to the morphology-based analysis by A. Brandt and G. Poore in 2003, which included only five Sphaeromatidae and found the family to be paraphyletic. The Ancinidae are also upheld, and the Valvifera is the sister taxon to Serolidae. Surprisingly Plakarthrium (Plakarthiidae) is nested within the Sphaeromatidae in most analyses. We point out short-comings in our sampling and suggest areas which would benefit from better sampling. We also review the long and convoluted nomenclatural history of the Sphaeromatidea, Sphaeromatoidea, and Sphaeromatidae.

Biodiversity is the engine of ocean ecosystems and economies. Efficiently characterizing it, rapidly at high resolution, is the frontier for understanding global change and management. The biggest impediment to breaching that frontier is inadequate DNA reference libraries, which can currently identify <25% of animal species in environmental profiles. Over the course of the decade, we will build from our existing global network of museums, universities, federal agencies, and the private sector in a broad collaboration to produce the Ocean Biocode, a well-sampled, voucher-based, open-access reference library of U.S. marine species that will eliminate “dark taxa” (no name or phylogenetic position) from U.S. waters and support a new era in high-resolution oceanography and environmental science founded on accurate environmental DNA sampling. We need not sequence every species; a strategic, empirically guided inventory will fill key gaps by focusing BioBlitz efforts at one focal site in each marine ecoregion of the U.S. EEZ, targeting taxa missing from regional libraries, coupled with genome skimming, to create reference libraries of whole mtDNA and nuclear ribosomal cluster. This Ocean Biocode moves beyond the barcode to allow design of targeted probes for non-amplicon species detection, yielding species-level information to stakeholders and enabling future technologies.

Gnorimosphaeroma oregonense(Dana, 1852) is revised, a male neotype is designated, photographed, and illustrated; the species occurs from Vancouver British Columbia to the central California coast. 16S-rDNA sequences (~650 bp) for all available ethanol preserved species ofGnorimosphaeromawere used to hypothesize their relationships. Our analyses revealed a sister taxon relationship between the fully marineG. oregonenseand the brackish to freshwater species,G. noblei. The oyster associated and introducedG. rayiis sister to a previously not recognized or identified, but genetically distinct,Gnorimosphaeromasp. collected at two sites in San Francisco Bay.Gnorimosphaeromasp. is probably also a western Pacific species based on its genetic relationship toG. rayi. Photographic comparisons are offered forG. oregonense(marine),G. noblei(freshwater),G. rayi(introduced),G.sp. (presumably introduced), andG. insulare(San Nicolas Island). Records of the holdings at the Los Angeles County Museum of Natural History are summarized. Without material available north of Vancouver through Alaska, the range ofG. oregonensecould not be genetically verified. This review includes a diagnosis and description of the genusGnorimosphaeromaMenzies, 1954.

Carefully collected molecular data and rigorous analyses are revolutionizing today’s phylogenetic studies. Although molecular data have been used to estimate various invertebrate phylogenies for more than a decade, this study is the first survey of different regions of mitochondrial DNA in isopod crustaceans assessing sequence divergence and hence the usefulness of these regions to infer phylogeny at different hierarchical levels. I evaluate three loci from the mitochondrial genome (two ribosomal RNAs (12S, 16S) and one protein-coding (COI)) for their appropriateness in inferring isopod phylogeny at the suborder level and below. The patterns are similar for all three loci with the most speciose suborders of isopods also having the most divergent mitochondrial nucleotide sequences. Recommendations for designing an order- or suborder-level molecular study in previously unstudied groups of Crustacea would include: (1) collecting a minimum of two-four species or genera thought to be most divergent, (2) sampling across the group of interest as equally as possible in terms of taxonomic representation and the distribution of species, (3) surveying several genes, and (4) carrying out preliminary alignments, checking data for nucleotide bias, transition/ transversion ratios, and saturation levels before committing to a large-scale sequencing effort.

Isopoda are the most diverse Crustacea. In order to encourage the study of isopod crustaceans and their use in biodiversity studies, systematics, ecology, physiology and more, one needs to know who the isopods are and where to find them. This is a short “how to” guide focusing on the free-living marine and freshwater isopods: where they live and how to collect and preserve them. The tools and techniques described here are simple, but invaluable in accessing the natural history of these remarkable creatures.

(Boone, 1923) from southern California is reviewed, redescribed, and figured. The original species description did not include figures, making it difficult to attribute individuals to the species. Carvacho and Haasmann, 1984 and Carvacho & Haasman, 1984 from the Pacific Coast of Mexico and Kussakin & Malyutina, 1987, from Furugelm Island, Peter the Great Gulf in the Sea of Japan, appear morphologically more similar to each other than to western Pacific species. A large pleonal process is present in about half of the species, but is absent in this north-eastern Pacific clade and the north-western Pacific and . Shen, 1929 possess a large pleonal spine. It is known from China, Japan, and Korea and is introduced in San Francisco Bay; it can be easily distinguished from by the presence of a pleonal process in the former. A key to the Pacific West Coast is provided.