New records and species of deep-sea squat lobsters (Galatheoidea, Munidopsidae) from the Hawaiian Archipelago: an integrative approach using micro-CT and barcodes.

The Hawaiian Archipelago remains extensively under-sampled for many marine invertebrate taxa, including squat lobsters. During the last few years, several deep-sea expeditions carried out in the Pacific Ocean have conducted opportunistic collections of specimens and image data from the vicinity of Hawai'i. Here we describe a new species: Munidopsis hawaii sp. nov. and provide new records for Munidopsidae in the Archipelago and its associations. We illustrate and describe the new species using an integrative approach including micro-CT 3D imaging. Phylogenetic analyses of the species collected from seamounts from Hawai'i indicate that the new species represents a divergent lineage compared to morphologically similar species such as M. dispar and M. papanui. We also study the genetic distances for the species recorded in Hawai'i and other populations of the same species in the adjacent West Pacific. Three species are now known in the Hawaiian region. We also compiled identifications from images captured with ROVs in the area. These observations suggest that munidopsid species are common in the deep sea of Hawaiian waters below 1,000 m.

Two new species of Petalophthalmus and Ipirophthalmus (Crustacea: Mysida: Petalophthalmidae), from New Zealand.

Two new deep-water mysids from the subfamily Petalophthalminae (Crustacea: Mysida: Petalophthalmidae) are described from specimens collected from Challenger Plateau, Chatham Rise, and off the east coast of the North Island of New Zealand. These new species raise the number of species of both genera to five. Petalophthalmus lobatus sp. nov. differs from its congeners by the structure of an elongated ventilation lobe on the seventh oostegites, laterally flattened eyes, and the armature of the telson. Ipirophthalmus crusulus sp. nov. can easily be distinguished by the rudimentary sixth to eighth thoracic endopods. Both species were found to be the prey of several fishes, including commercially caught species, providing insight into their ecology. An identification key to the subfamily is provided.

The squat lobster genus Phylladiorhynchus Baba, 1969 in New Zealand and eastern Australia, with description of six new species.

The small galatheid squat lobster genus Phylladiorhynchus currently contains five species, three of which supposedly have wide Indo-Pacific distributions. To date, two putatively widespread species, P. pusillus and P. integrirostris have been recorded from New Zealand and Australian waters. Here, we review the New Zealand and eastern Australian species of Phylladiorhynchus based on extensive collections from the region using morphological and molecular data. The type species, P. pusillus (Henderson, 1885) (type locality: Twofold Bay, Australia) is redescribed and shown to occur on both sides of the Tasman Sea. Phylladiorhynchus integrirostris, for which the original Hawaiian type material has been lost, is redescribed based on a neotype and shown not to occur in New Zealand or Australian waters, previous records being referable to other species. Six new species of Phylladiorhynchus are described. Seven species of Phylladiorhynchus are now known from New Zealand and eastern Australia. A key to all species of the genus is provided. Results of the present study show that the regional diversity of Phylladiorhynchus is significantly higher than previously reported and demonstrates the utility of a number of subtle morphological characters as diagnostic of species.

De novo innovation allows shark parasitism and global expansion of the barnacle Anelasma squalicola.

The barnacle Anelasma squalicola is a marine epibiont found on members of the species-rich, deep-sea lantern shark family Etmopteridae (Figure 1A) but is unlike any other epibiotic thoracian barnacles [1]. While many barnacle species are associated with various marine animals including turtles and whales, with the exception of Anelasma these all retain a filter-feeding lifestyle and have a commensal relationship with their host; despite often being deeply embedded in the dermis, no other species has been reported as feeding on its host. Although Anelasma is fully equipped with cirri (thoracic appendages), these are no longer used for filter feeding [1]. Instead, Anelasma embeds a stalk with root-like structures into the flesh of the shark (Figure S1C in Supplemental Information, published with this article online) that it uses to parasitize its host. Here, we show that specimens of Anelasma sampled from all over the world show very little genetic differentiation, suggesting that this innovation coincided with a rapid worldwide expansion.

Development and characterization of 20 polymorphic microsatellite loci in the deep sea squat lobster, Munida isos Ahyong and Poore, 2004 and cross-amplification in two congeneric species.

Munida isos is a deep sea squat lobster species that is widely distributed across the New Zealand and east Australian region, and is often associated with deep sea vulnerable marine ecosystems. To investigate its population genetic structure and patterns of regional connectivity, microsatellite loci were developed for M. isos from two genomic libraries using the Illumina HiSeq 2500 sequencing platform. Twenty-six loci amplified consistently in M. isos from the Tasman Sea, among which 20 were polymorphic and selectively neutral. Evidence of null alleles was observed at eight loci. Most loci exhibited moderate to high levels of polymorphism, with an average polymorphic information content value of 0.482. The mean number of alleles per locus was 7.45, with a mean expected heterozygosity of 0.520. Thirteen loci exhibited significant deviation from Hardy-Weinberg equilibrium, while only one locus pair was in linkage disequilibrium after false discovery rate correction for multiple testing (P < 0.05). Cross-species amplification tests revealed that the transferability of 14 loci (70%) was positive for the two congeners M. endeavourae and M. gracilis. The accessibility to new polymorphic microsatellite loci will facilitate population genetic studies and aid in developing conservation and management strategies for vulnerable marine ecosystems.

Bait-attending amphipods of the Tonga Trench and depth-stratified population structure in the scavenging amphipod Hirondellea dubia Dahl, 1959.

BACKGROUND: The hadal zone encompasses the deepest parts of the world's ocean trenches from depths of ∼6,000-11,000 m. The communities observed at these depths are dominated by scavenging amphipods that rapidly intercept and consume carrion as it falls to the deepest parts of the trenches. New samples collected in the Tonga Trench provide an opportunity to compare the amphipod assemblages and the population structure of a dominant species, Hirondellea dubia Dahl, 1959, between trenches and with earlier data presented for the Tonga Trench, and other trenches in the South Pacific. METHODS: Over 3,600 individual scavenging amphipods across 10 species were collected in seven baited traps at two sites; in the Horizon Deep site, the deepest part of the Tonga Trench (10,800 m) and a site directly up-slope at the trench edge (6,250 m). The composition of the bait-attending amphipods is described and a morphometric analysis of H. dubia examines the bathymetric distribution of the different life stages encountered. RESULTS: The amphipod assemblage was more diverse than previously reported, seven species were recorded for the first time from the Tonga Trench. The species diversity was highest at the shallower depth, with H. dubia the only species captured at the deepest site. At the same time, the abundance of amphipods collected at 10,800 m was around sevenfold higher than at the shallower site. H. dubia showed clear ontogenetic vertical structuring, with juveniles dominant at the shallow site and adults dominant at the deep site. The amphipods of the deeper site were always larger at comparable life stage. DISCUSSION: The numbers of species encountered in the Tonga Trench is less than reported from the New Hebrides and Kermadec trenches, and six species encountered are shared across trenches. These findings support the previous suggestion that the fauna of the New Hebrides, Tonga and Kermadec Trenches may represent a single biogeographic province. The ontogenetic shift in H. dubia between the two Tonga Trench sites supports the hypothesis of interspecific competition at the shallower bathymetric range of the species, and the presence of competitive physiological advantages that allow the adults at the trench axis to exploit the more labile organic material that reaches the bottom of the trench.

Rediagnosis of the squat lobster genus Gastroptychus Caullery, 1896, with a new genus Sternostylus and a new family Sternostylidae (Crustacea: Decapoda: Anomura: Chirostyloidea).

The chirostyloidean squat lobster genus Gastroptychus Caullery, 1896 is revised and is split into two genera: Gastroptychus sensu stricto (type species, Ptychogaster spinifer A. Milne-Edwards, 1880) and Sternostylus new genus (type species, Ptychogaster formosus Filhol, 1884). Gastroptychus sensu stricto, is restricted to nine species with a sternal plastron, at sternite 3, abruptly demarcated from the preceding sternites (excavated sternum) by a distinct step forming a well-defined transverse or concave anterior margin at the articulation with maxillipeds 3, the maxillipeds 3 widely separated, with the distal parts accommodated in the excavated sternum between the left and right maxillipeds 3 when folded, and the P2-4 dactyli with the terminal spine demarcated by a suture. Sternostylus new genus, represented by 12 species, has the sternite 3 anteriorly bluntly produced medially and steeply sloping anterodorsally to the anterior sternite, with a pair of spines directly behind the anterior margin, the left and right maxillipeds 3 adjacent, and the P2-4 dactyli ending in an indistinctly demarcated corneous spine. The above-mentioned characters of Gastroptychus are consistent with Chirostylidae sensu stricto. Published molecular phylogenies indicate, however, that Sternostylus is the sister group to all the other Chirostylidae, and is designated the type genus of a new family, Sternostylidae.

Southern high latitude squat lobsters II: description of Uroptychus macquariae sp. nov. from Macquarie Ridge.

Squat lobsters have only recently been recorded from the Macquarie Ridge, which extends south between New Zealand and Antarctica. Among these, Uroptychus insignis (Henderson, 1885) was recorded for the first time outside the western Indian Ocean, exhibiting only subtle morphological differences. Reexamination of the Macquarie Ridge and Indian Ocean specimens attributed to U. insignis using morphological and molecular data revealed the Macquarie Ridge form to represent a separate species. Subtle but consistent morphological differences are evident and partial CO1 sequence data indicates that the specimens collected on Macquarie Ridge differ from those collected in the Indian Ocean by more than 7%. The Macquarie Ridge species is described herein as Uroptychus macquariae n.sp. Subtle morphological differences between the new species and U. insignis are discussed.

A new amphipod Nicippe rogeri sp. nov. (Crustacea, Pardaliscidae) from New Zealand's deep sea.

The amphipod family Pardaliscidae has a worldwide distribution and is considered to be especially common in the deep sea. This is the first record of the genus Nicippe in New Zealand waters and a new species, N. rogeri sp. nov is described in honour of Dr. Roger Bamber. This brings the number of species in the genus Nicippe worldwide to four. The new species is described in detail and a key to the four species of Nicippe is provided.

Two new species of Munidopsis (Crustacea: Anomura: Munidopsidae) from the Kermadec and Louisville ridge systems off New Zealand.

Two new species of Munidopsis are described from the wider New Zealand region. Munidopsis bamberi sp. nov. is described from the Havre Trough adjacent to the Kermadec Volcanic Arc north-east of the New Zealand continental shelf, and is named in honour of Roger Bamber for his contributions to arthropod taxonomy and systematics. The second species is M. sculpo sp. nov. from Forde Seamount on the Louisville Ridge east of New Zealand. This brings the number of Munidopsis species known in New Zealand waters to 17 and a key to the New Zealand species is provided.

Diversity in a Cold Hot-Spot: DNA-Barcoding Reveals Patterns of Evolution among Antarctic Demosponges (Class Demospongiae, Phylum Porifera).

BACKGROUND: The approximately 350 demosponge species that have been described from Antarctica represent a faunistic component distinct from that of neighboring regions. Sponges provide structure to the Antarctic benthos and refuge to other invertebrates, and can be dominant in some communities. Despite the importance of sponges in the Antarctic subtidal environment, sponge DNA barcodes are scarce but can provide insight into the evolutionary relationships of this unique biogeographic province. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced the standard barcoding COI region for a comprehensive selection of sponges collected during expeditions to the Ross Sea region in 2004 and 2008, and produced DNA-barcodes for 53 demosponge species covering about 60% of the species collected. The Antarctic sponge communities are phylogenetically diverse, matching the diversity of well-sampled sponge communities in the Lusitanic and Mediterranean marine provinces in the Temperate Northern Atlantic for which molecular data are readily available. Additionally, DNA-barcoding revealed levels of in situ molecular evolution comparable to those present among Caribbean sponges. DNA-barcoding using the Segregating Sites Algorithm correctly assigned approximately 54% of the barcoded species to the morphologically determined species. CONCLUSION/SIGNIFICANCE: A barcode library for Antarctic sponges was assembled and used to advance the systematic and evolutionary research of Antarctic sponges. We provide insights on the evolutionary forces shaping Antarctica's diverse sponge communities, and a barcode library against which future sequence data from other regions or depth strata of Antarctica can be compared. The opportunity for rapid taxonomic identification of sponge collections for ecological research is now at the horizon.

Distributional records of Ross Sea (Antarctica) Tanaidacea from museum samples stored in the collections of the Italian National Antarctic Museum (MNA) and the New Zealand National Institute of Water and Atmospheric Research (NIWA).

Here we present distributional records for Tanaidacea specimens collected during several Antarctic expeditions to the Ross Sea: the Italian PNRA expeditions ("V", 1989/1990; "XI", 1995/1996; "XIV", 1998/1999; "XIX", 2003/2004; "XXV", 2009/2010) and the New Zealand historical (New Zealand Oceanographic Institute, NZOI, 1958-1961) and recent ("TAN0402 BIOROSS" voyage, 2004 and "TAN0802 IPY-CAML Oceans Survey 20/20" voyage, 2008) expeditions. Tanaidaceans were obtained from bottom samples collected at depths ranging from 16 to 3543 m by using a variety of sampling gears. On the whole, this contribution reports distributional data for a total of 2953 individuals belonging to 33 genera and 50 species. All vouchers are permanently stored in the Italian National Antarctic Museum collection (MNA), Section of Genoa (Italy) and at the National Institute of Water and Atmospheric Research (NIWA Invertebrate Collection), Wellington (New Zealand).

Dancing for food in the deep sea: bacterial farming by a new species of Yeti crab.

Vent and seep animals harness chemosynthetic energy to thrive far from the sun's energy. While symbiont-derived energy fuels many taxa, vent crustaceans have remained an enigma; these shrimps, crabs, and barnacles possess a phylogenetically distinct group of chemosynthetic bacterial epibionts, yet the role of these bacteria has remained unclear. We test whether a new species of Yeti crab, which we describe as Kiwa puravida n. sp, farms the epibiotic bacteria that it grows on its chelipeds (claws), chelipeds that the crab waves in fluid escaping from a deep-sea methane seep. Lipid and isotope analyses provide evidence that epibiotic bacteria are the crab's main food source and K. puravida n. sp. has highly-modified setae (hairs) on its 3(rd) maxilliped (a mouth appendage) which it uses to harvest these bacteria. The ε- and γ- proteobacteria that this methane-seep species farms are closely related to hydrothermal-vent decapod epibionts. We hypothesize that this species waves its arm in reducing fluid to increase the productivity of its epibionts by removing boundary layers which may otherwise limit carbon fixation. The discovery of this new species, only the second within a family described in 2005, stresses how much remains undiscovered on our continental margins.