Dhugal J. Lindsay

Phylogenetics of Trachylina (Cnidaria: Hydrozoa) with new insights on the evolution of some problematical taxa

Some of the most interesting and enigmatic cnidarians are classified within the hydrozoan subclass Trachylina. Despite being relatively depauperate in species richness, the clade contains four taxa typically accorded ordinal status: Actinulida, Limnomedusae, Narcomedusae and Trachymedusae. We bring molecular data (mitochondrial 16S and nuclear small and large subunit ribosomal genes) to bear on the question of phylogenetic relationships within Trachylina. Surprisingly, we find that a diminutive polyp form, Microhydrula limopsicola (classified within Limnomedusae) is actually a previously unknown life stage of a species of Stauromedusae. Our data confirm that the interstitial form Halammohydra sp. (Actinulida) is derived from holopelagic direct developing ancestors, likely within the trachymedusan family Rhopalonematidae. Trachymedusae is shown to be diphyletic, suggesting that the polyp stage has been lost independently at least two times within trachyline evolution. Narcomedusae is supported as a monophyletic group likely also arising from trachymedusan ancestors. Finally, some data, albeit limited, suggest that some trachyline species names refer to cryptic species that have yet to be sorted taxonomically.

Marine Biodiversity in Japanese Waters

To understand marine biodiversity in Japanese waters, we have compiled information on the marine biota in Japanese waters, including the number of described species (species richness), the history of marine biology research in Japan, the state of knowledge, the number of endemic species, the number of identified but undescribed species, the number of known introduced species, and the number of taxonomic experts and identification guides, with consideration of the general ocean environmental background, such as the physical and geological settings. A total of 33,629 species have been reported to occur in Japanese waters. The state of knowledge was extremely variable, with taxa containing many inconspicuous, smaller species tending to be less well known. The total number of identified but undescribed species was at least 121,913. The total number of described species combined with the number of identified but undescribed species reached 155,542. This is the best estimate of the total number of species in Japanese waters and indicates that more than 70% of Japans marine biodiversity remains un-described. The number of species reported as introduced into Japanese waters was 39. This is the first attempt to estimate species richness for all marine species in Japanese waters. Although its marine biota can be considered relatively well known, at least within the Asian-Pacific region, considering the vast number of different marine environments such as coral reefs, ocean trenches, ice-bound waters, methane seeps, and hydrothermal vents, much work remains to be done. We expect global change to have a tremendous impact on marine biodiversity and ecosystems. Japan is in a particularly suitable geographic situation and has a lot of facilities for conducting marine science research. Japan has an important responsibility to contribute to our understanding of life in the oceans.

Biodiversity in midwater cnidarians and ctenophores: submersible-based results from deep-water bays in the Japan Sea and north-western Pacific

The oceans’ midwater is the most extensive habitaton the surface of our planet but remains largelyunknown. A modicum of information exists concern-ing its more robust inhabitants, such as fish, shrimps,copepods and other organisms that are still recogniz-able after collection in a trawled net, but the gelati-nous fauna remains largely unstudied. Cnidarians andctenophores are two of the most dominant groups inmidwater communities. However, few of the specieshave been described, principally the more robustspecies that remain recognizable after collection in atrawled net (Youngbluth, 1989). Critical studies of thebiodiversity and ecological roles of these fragile faunarequire access to the vast mesopelagic environmentvia submersibles and remotely operated vehicles(ROVs) (Robison, 1983; Hunt & Lindsay, 1999;Armstrong et al., 2004). Reports of biodiversity patterns in gelatinousmacroplankton are limited, with one study usingcrewed submersibles that recorded medusan speciesnumber vs depth and temperature at three sites in thenorth-western Atlantic (Larson et al., 1991) and themajority of other studies being based on net-caughtsamples (e.g. Pugh, 1974; Roe et al., 1984). No infor-mation is yet available for the Pacific Ocean or theJapan Sea. Diversity maintenance mechanisms in themidwater zone are thought to differ from those inbenthic or terrestrial environments (Madin & Madin,1995; Tsuda, 1995; Armstrong et al., 2004) and aclearer understanding of them will undoubtedly forceus to rethink paradigms based on terrestrial and ben-thic systems. Species diversity patterns are known to affect bothecosystem stability and function (McCann et al.,1998). Because marine zooplankton are significantmediators of fluxes in carbon, nitrogen, and othercritical elements in ocean biogeochemical cycles (seeBerger et al., 1989), it is imperative to understand thepatterns of species diversity, community structure,their maintenance mechanisms, and their effect onthe global system. However, efforts using traditionaltechniques to describe species and map their distribu-tions in space and time (spatio-temporal niche appor-tionment) can never hope to yield complete knowledgeof plankton biodiversity. This paper describes the bio-diversity of cnidarians and ctenophores in two mid-water regimes near Japan and discusses the utility ofsubmersibles for future explorations in this realm.The Japan Sea is a relatively closed marginal seathat is separated from the Deep Sea Proper by shallowsills. It is also the second coldest sea in the world with

The anthomedusan fauna of the Japan Trench: preliminary results from in situ surveys with manned and unmanned vehicles

dhugal lindsay, francesc pag es, jordi corbera, hiroshi miyake, james c. hunt, tadafumi ichikawa, kyohei segawa and hiroshi yoshida Japan Agency for Marine–Earth Science and Technology (JAMSTEC), Yokosuka, Japan, Institut de Ciencies del Mar (CSIC), Passeig Maritim de la Barceloneta 37–49, 08003 Barcelona, Catalonia, Spain, Carrer Gran, 90, 08310 Argentona, Catalunya, Spain, School of Fisheries Science, Kitasato University, Ofunato, Iwate 022-0101, Japan, Department of Biology, East Stroudsburg University, East Stroudsburg, PA 18301, USA, National Research Institute of Fisheries Research, Fisheries Research Agency, 2-12-4, Fuku-ura, Kanazawa-ku, Yokohama 236-8648, Japan, National Research Institute of Far Seas Fisheries, Fisheries Research Agency, 2-12-4, Fuku-ura, Kanazawa-ku, Yokohama 236-8648, Japan, deceased

Evaluation of the bioactivities of water-soluble extracts from twelve deep-sea jellyfish species

Many polypeptides isolated from shallow water cnidarian species have been utilized as valuable biochemical tools in both basic and applied biological sciences. Deepwater cnidarian species might be another potential resource for novel biochemical tools. However, because of limited access to cnidarian samples from deep-sea environments, bioactive polypeptides have never before been reported from this group. In this study, we collected twelve deep-sea jellyfish species (nine hydrozoans and three scyphozoans) using a plankton net that was specially designed for collecting deep-sea organisms, and prepared water-soluble extracts, presumably containing polypeptides, of these jellyfishes. The extracts were subjected to cytotoxicity, hemolytic activity, and crustacean lethal toxicity tests. In the cytotoxicity test, six out of the nine tested hydrozoan species showed activity. In the hemolytic activity test, only three hydrozoans showed activity and none of the scyphozoan jellyfishes showed activity. In the crustacean lethality test, two hydrozoan jellyfishes and all three of the tested scyphozoan jellyfishes showed lethal activity. These results revealed a high incidence of water-soluble bioactive substances occurring in these deep-sea jellyfishes. Furthermore, all the heat-treated and the methanol-treated crude jellyfish extracts lost their bioactivities. Thus, it is likely that the bioactive compounds in the water-soluble extracts were unstable polypeptides (proteins). This is the first published report on bioactivities in extracts from deep-sea jellyfishes.

Phylogenetic analysis of higher-level relationships within Hydroidolina (Cnidaria: Hydrozoa) using mitochondrial genome data and insight into their mitochondrial transcription

Hydrozoans display the most morphological diversity within the phylum Cnidaria. While recent molecular studies have provided some insights into their evolutionary history, sister group relationships remain mostly unresolved, particularly at mid-taxonomic levels. Specifically, within Hydroidolina, the most speciose hydrozoan subclass, the relationships and sometimes integrity of orders are highly unsettled. Here we obtained the near complete mitochondrial sequence of twenty-six hydroidolinan hydrozoan species from a range of sources (DNA and RNA-seq data, long-range PCR). Our analyses confirm previous inference of the evolution of mtDNA in Hydrozoa while introducing a novel genome organization. Using RNA-seq data, we propose a mechanism for the expression of mitochondrial mRNA in Hydroidolina that can be extrapolated to the other medusozoan taxa. Phylogenetic analyses using the full set of mitochondrial gene sequences provide some insights into the order-level relationships within Hydroidolina, including siphonophores as the first diverging clade, a well-supported clade comprised of Leptothecata-Filifera III–IV, and a second clade comprised of Aplanulata-Capitata s.s.-Filifera I–II. Finally, we describe our relatively inexpensive and accessible multiplexing strategy to sequence long-range PCR amplicons that can be adapted to most high-throughput sequencing platforms.

The untethered remotely operated vehicle PICASSO-1 and its deployment from chartered dive vessels for deep sea surveys off Okinawa, Japan, and Osprey Reef, Coral Sea, Australia

The untethered remotely operated vehicle (uROV) PICASSO-1, which is controlled in real time from a surface support vessel via a F0.9 mm fiber optic cable, is capable of dives to 1,000-m depth at a duration of up to 6 h and yet is deployable from ships of sizes as low as 17 tonnes. The vehicle was developed at the Japan Agency for Marine-Earth Science and Technology, has carried out 63 dives to date, and is now operable by a team of four biologists and one technician. PICASSO-1 can collect video (HDTV × 1, NTSC × 3) and environmental information (depth, temperature, salinity, dissolved oxygen concentration, fluorescence [chlorophyll a proxy], turbidity) concurrently, and this is output with vehicle heading, camera zoom, and other vital statistics via Ethernet. Acoustically obtained vehicle position information, deck and control room video, and sound data streams are also output via Ethernet, and the whole dive is recorded in a synchronous fashion on a logging/playback system that enables dives to be re-enacted in their entirety to facilitate analyses back in the laboratory. Operations have been successfully carried out overseas using a chartered dive boat, and the system represents a leap forward for exploration of the oceans to significant depths but at relatively low cost and with no loss in data quality.

The scyphomedusan fauna of the Japan Trench: preliminary results from a remotely-operated vehicle

A series of dives was conducted during April/May 2002 in a variety of water masses over the Japan Trench using the remotely-operated vehicle ROV HyperDolphin. The scyphomedusan fauna was catalogued, resulting in the first records of Atolla vanhoeffeni and Atolla russelli from Japanese waters. A new genus and species referable to the family Paraphyllinidae was also recognized. The ulmarid scyphomedusa Poralia rufescens is by far the most common scyphomedusa in these waters. Its distribution was determined by water mass structure and it was not present in subducted Oyashio Current-derived waters occurring within its usual depth range. Temperature and salinity affected its distribution more than dissolved oxygen concentrations. Distributional information, data on the physico-chemical parameters of the water column, and notes on biological associations with scyphomedusae are introduced.

Tropical Marginal Seas: Priority Regions for Managing Marine Biodiversity and Ecosystem Function

Tropical marginal seas (TMSs) are natural subregions of tropical oceans containing biodiverse ecosystems with conspicuous, valued, and vulnerable biodiversity assets. They are focal points for global marine conservation because they occur in regions where human populations are rapidly expanding. Our review of 11 TMSs focuses on three key ecosystems-coral reefs and emergent atolls, deep benthic systems, and pelagic biomes-and synthesizes, illustrates, and contrasts knowledge of biodiversity, ecosystem function, interaction between adjacent habitats, and anthropogenic pressures. TMSs vary in the extent that they have been subject to human influence-from the nearly pristine Coral Sea to the heavily exploited South China and Caribbean Seas-but we predict that they will all be similarly complex to manage because most span multiple national jurisdictions. We conclude that developing a structured process to identify ecologically and biologically significant areas that uses a set of globally agreed criteria is a tractable first step toward effective multinational and transboundary ecosystem management of TMSs.

The Coral Sea: Physical Environment, Ecosystem Status and Biodiversity Assets

The Coral Sea, located at the southwestern rim of the Pacific Ocean, is the only tropical marginal sea where human impacts remain relatively minor. Patterns and processes identified within the region have global relevance as a baseline for understanding impacts in more disturbed tropical locations. Despite 70 years of documented research, the Coral Sea has been relatively neglected, with a slower rate of increase in publications over the past 20 years than total marine research globally. We review current knowledge of the Coral Sea to provide an overview of regional geology, oceanography, ecology and fisheries. Interactions between physical features and biological assemblages influence ecological processes and the direction and strength of connectivity among Coral Sea ecosystems. To inform management effectively, we will need to fill some major knowledge gaps, including geographic gaps in sampling and a lack of integration of research themes, which hinder the understanding of most ecosystem processes.