Deep-Sea Research Papers - Academia.edu (original) (raw)

The fishery survey of the REVIZEE program was carried out along the central Brazilian slope between latitudes 11º -
22ºS. This batimetric zone is scarcely explored and known along the Brazilian coast which leads to a high number of new
Crustacea records for Brazil. A total of 147 species of Crustacea were identified, being 17 sessile or parasites and 129
free living. In the first case there are nine sessile species of the infraorder Cirripedia, which includes two Lepadomorpha;
two Scalpellomorpha, five Verrucomorpha and eight parasitic species of the superorder Peracarida including five
Amphipoda and three Isopoda. From these 17 species, 11 are new records for Brazil. The other 129 free living species
are distributed in 39 families between the class Malacostraca as follows: two Stomatopoda; nine Peracarida; two
Euphausiacea; 27 Dendrobranchiata; 38 Caridea; six Achelata; five Astacidea; four Polychelida; 17 Anomura; and 19
Brachyura. Economic important species of Aristeidae were found. Aristeus antennatus is a new record for Brasil, and Aristaeomorpha foliacea, Aristaeopsis edwardsiana and Aristeus antillensis have its records expanded until Bahia and or
Espírito Santo. From these 129 species, 39% are new records for the Brazilian coast and 31% are new records for the
study area, totalizing 70% of new records. A total of 17.874 free living crustaceans, being 13.885 from Bahia I campaign
and 3.989 from Bahia II campaign were sampled. In the campaign Bahia I, the pelagic oplophorid Janicella spinicauda
dominate on the samples with a high percentual abundance of 73.66% followed by Euphausia sp. (6.99%) and other
species with a lower value. In the campaign Bahia II only demersal sampling were made and Benthesicymus sp. has the
higher abundance rate of 13.99% followed by Munida longipes (12.26%), Penaeopsis serrata (6.57%), Nematocarcinus
sp. (5.92%), Acanthephyra eximia (4.34%) and others. The family that presents the highest CPUE value in the entire
slope was Benthesicymidae. An increase of abundance from the 200-300 m, with greatest values at 500 m, a slightly
decrease until 1200 m and drop from this depth was observed. Relating the diversity (Shannon-Weaver) and species
richness to depth, was concluded that both variables increase from the continental shelf to the slope until 1800 m. The
correspondence analysis showed three species associations related to depth that define the slope zonation in: upper
slope (continental edge to 500 m); middle slope (500-900 m) and lower slope (900-2076 m). The collection made by the
REVIZEE program -Central region is an important step in the improvement of the knowledge of deep sea Brazilian
Crustacea fauna. This environment is still considered remote and poorly known, although it has a huge potential resource
to be explored by man. Thus, the understanding of the natural processes and a long term conservation of the deep sea
are one of the great challengers of our time to be achieved.

- by and +2
- •
- Fisheries, Crustacean Biology, Deep-Sea

It could be said in different ways. Désoeuvrement for Blanchot. Melville’s Bartleby formula: “I would prefer not to”. The procadence that Fellini’s cinema professes, or the exhaustion of the speech that phagocytes itself and occupies, without counting or telling, in Beckett. Ways of appearing of the refusal, the unfinished, the fugitive movement that recedes before the forms. Going back to Heraclitus, and moving on by Whitehead’s side, declaring that you never think twice about the same thing, because thought is pure process, continuum without beginning and end, modulation of forms to de-formation, rhythms to proliferation. Neither recognizing or surrendering to the prevailing hylemorphism. It could be said in a singular and profoundly anomalous way: Deep Blue. A place? No, rather an affective tonality, an anonymous occasion for a possible adventure of thought. A speculative fabulation, Donna Haraway would have said. A pre-individual community of thinkables that finds a singularizing attractor in cinema. A radical nomadism, where cinema, as a connective technique, makes up unprecedented relationships and connections across transversalities that make the cosmos germinate in multiverses that the point of view of creation explores, experiments and exhausts. A devotion to the moving of life that is affirmed in the course of devorations, diffractions, and obliquities. Without a priori, without presuppositions, without location or measure, being a remaining rest, ruin and excess of life to come. Aqueous immediation as journey and medium.

- by Beth O'Donnell
- •
- Oceanography, Diversity, Biology, Deep-Sea

This visual guide is illustrated with images captured by Anadarko Colombia Company (ACC), a subsidiary of Anadarko Petroleum
Corporation (APC), during its normal offshore hydrocarbon exploration process at depths between 375 and 3288 m in the Colombian Caribbean Sea. Images were taken by towed camera, Remote Operated Vehicle (ROV), and by samples taken in Piston Core projects. Images were classified by large taxonomic groups. National experts were contacted to identify the organisms to the most specific taxonomic level possible. International experts were also contacted to confirm organisms previously identified or to identify those for which no national expert
was available. This guide includes introductions for each major taxonomic group and other ones for more specific groups (if applicable),
provided by the experts themselves, who participated in the identification of the organisms. This is the first visual guide of
deep-sea organisms (mega fauna) for the Colombian Caribbean.

- by Vladimir Puentes
- •
- Fish Biology, SHRIMP, Cephalopods, Octocorals
- by Cedric Worman
- •
- History of Science, Origins of Life, Mass extinctions, Ediacaran
- by José H. Leal
- •
- Paleontology, Biomechanics, Deep-Sea, Dilemma

In this study, a diverse fauna of fossil elasmobranch teeth from the Early Miocene (Middle Burdigalian) is analysed. The fossil diversity strongly resembles extant deep-water shark and ray assemblages. The fossils were collected from the Upper Marine Molasse of the lower Ottnangian in the Neuhofener Beds location, Mitterdorf, Germany. The collection site is a clay pit in between the Lower Bavarian villages Fürstenzell and Schmidham. The sample revealed 14 shark and four ray species. We present the first record of fossils assigned to taxa Nanocetorhinus tuberculatus, Deania and Apristurus from Germany. In addition, we describe a hitherto unknown genus and species of shark, Pseudoapristurus nonstriatus gen. et sp. nov., based on fossil teeth. The documented diversity is compared to both extant and fossil records of neoselachian deep-water diversities, and it is evident that this Miocene fauna is very similar in composition to indo-pacific deep-water assemblages. Zusammenfassung Aus der Oberen Meeresmolasse (Neuhofener Schichten, unteres Ottnangium) Niederbayerns (Tongrube zwischen Fürstenzell und Schmidham) wird eine artenreiche Tiefwasser-Elasmobranchierfauna beschrieben. Insgesamt werden 14 Hai-und vier Rochenarten nachgewiesen. Erstnachweise für Deutschland werden von Nanocetorhinus tuberculatus, Apristurus sp. und Deania sp. erbracht. Zusätz-lich wird eine bisher unbekannte Neoselachier Gattung und Art (Pseudoapristurus nonstriatus nov. gen. et sp.) anhand von Zahnfossilien beschrieben. Ein Vergleich der hier dokumentierten Diversität mit verschiedenen anderen rezenten und fossilen Neoselachier Vergesell-schaftungen zeigt, dass die vorliegende Fauna große Übereinstimmungen mit rezenter indo-pazifischer Tiefseediversität aufweist.

- by Jürgen Pollerspöck
- •
- Fossil Fish, Sharks, Elasmobranchs, Fossils

The family Ischyroceridae is analysed herein by cladistic methods based on morphological characters, using both
PAUP 4.0b and TNT. The data matrix of 41 characters × 32 terminal taxa was constructed using DELTA. Based on
the results, we comment on the phylogenetic relationships of certain genera and their synapomorphic characters, also
discussing the phylogenetic position of Myersius gen. nov., which appeared as the sister group of Bathyphotis. In
addition, Pseudischyrocerus crenatipes is removed to Bathyphotis, for which a new diagnosis is provided.Ataxonomic
study with the Ischyroceridae collected on the continental slope (depth, 700–2000 m) in the Campos Basin (20.5–24°S,
40–41°W) was also performed. Samples were collected in November–December 2002 and July–August 2003 using a
box core device. As a result, a new genus and eight new species are described: Bonnierella campensis sp.
nov., Bonnierella laurensi sp. nov., Myersius denticaudatus gen. et sp. nov., Notopoma lowryi sp. nov.,
Notopoma teresae sp. nov., Pseudericthonius bousfieldi sp. nov., Pseudericthonius concavus sp. nov., and
Pseudischyrocerus caecus sp. nov. The genus Bonnierella is recorded for the first time from Brazilian waters, and
the subspecies Bonnierella linearis linearis and Bonnierella linearis californica are elevated to species rank. Keys to
the genera of Ischyroceridae used in the cladistic analysis and the world species of Notopoma are given.

- by Cristiana Serejo
- •
- Marine Biology, Systematics (Taxonomy), Amphipoda, Deep-Sea

The livers of certain deep-sea species are rich in oil and are the primary material for the squalene industry, which is a key provider for the cosmetics and nutraceutical sectors. With fins, oil is the highest priced shark product on international markets. The 2012 global demand for shark liver oil is estimated at 2000-2200 tons. Sharks used to reach this demand are mostly the product of targeted fisheries and not simply bycatch. A first investigation on poorly known shark liver oil market.

- by Romain Chabrol and +1
- •
- Shark conservation, Deep-Sea

Some of the deep-water molluscs collected during the Marion Dufresne (MD55) expedition off SE Brazil have been studied in recent papers. The present work focuses on the heterobranch family Architectonicidae. Four species have their occurrence expanded to/in the SW Atlantic (new records in parenthesis): Psilaxis clertoni Tenório, Barros, Francisco & Silva, 2011 (off Cabo Frio, Rio de Janeiro, 610 m); Solatisonax rudigerbieleri Tenório, Barros, Francisco & Silva, 2011 (Canopus Bank, off Fortaleza, Ceará state, 260 m; off Cabo Frio, Rio de Janeiro, 610 m); Spirolaxis centrifuga (Monterosato, 1890) (off Linhares, Espírito Santo, 340–360 m); Spirolaxis cf. lamellifer (Rehder, 1935) (off Linhares, Espírito Santo, 640 m depth and off Cabo Frio, Rio de Janeiro, 610 m). Moreover, we describe herein a new architectonicid species, namely Pseudotorinia phorcysi n. sp., collected off Cabo Frio, Rio de Janeiro state, 430–450 m. Its diagnostic features are: a strong beaded sculpture, angular outline and prominent peripheral keel formed by a strong beaded spiral rib and a lower, weaker rib, with fine axial growth lines between them.

- by Rodrigo B . Salvador and +1
- •
- Mollusc Taxonomy, Marine Gastropod, Gastropods, Deep-Sea

The paper focuses on the geostatistical analysis of the data set on the Philippine archipelago. The research question is understanding variability in several geospatial parameters (geology, geomorphology, tectonics and bathymetry) in different segments of the study area. The initial data set was generated in QGIS by digitizing 25 cross-sectioning profiles. The data set contained information on the geospatial parameters in the samples by profiles. Modelling and statistical analysis were performed in SPSS IBM Statistics software. The analysis of the topography shows strong variability of the elevations in the samples with the extreme depths in the central part of the study area (profile 13 with-9,400 m) and highest elevations in its southwestern part (profile 17 with 1950 m). The analysis of the geological classes and lithology shows maximal samples of the basic volcanic rocks (40,40%) followed by mixed sedimentary consolidated rocks (31,90 %). Pairwise analysis of the sediment thickness and slope aspect demonstrates correlation between these two variables with the maximal sediment layer in the profiles 1-4 crossing the Philippines. The hierarchical dendrogram clustering of the bathymetry by three approaches shown maximal correlation of 5 clusters containing profile groups: 12-18 (centre), 22-25 (south-west), 1-2 (north), 7-8 (north-east), 19-21 (south-west). Other profiles show lesser similarities in the bathymetric patterns. The forecasting models were computed for the geospatial variables showing gradual increase in the gradient angles southwards and increased values for the sediment thickness in the north. Technically, the results proved effectiveness of the SPSS application of the geological data modelling.

- by Polina Lemenkova
- •
- Geography, Geology, Oceanography, Statistics

The ‘scaly-foot gastropod’ is widely recognized as an iconic species of deep-sea hydrothermal vent ecosystems in the Indian Ocean. Uniquely among gastropods, this species carries hundreds of dermal sclerites on its foot and these scales can be covered in iron sulphide that also covers its shell, making it the only extant metazoan known to utilize iron sulphide as part of its skeleton. It has not been formally named, despite attracting great attention from both scientists and the general public alike, although a manuscript name has occasionally been used in various sources. The RRS James Cook JC67 expedition in 2011 sampled the biota of the Longqi vent field (37°47.027′S, 49°38.963′E), Southwest Indian Ridge, for the first time, revealing a previously unknown population of the ‘scaly-foot gastropod’. The present study gives a formal name to the ‘scaly-foot gastropod’, Chrysomallon squamiferum n. gen., n. sp. with Longqi vent field as the type locality. The erection of the new monotypic genus is supported by both morphological and molecular characterization, differentiating it from existing genera of the family Peltospiridae. Analysis of the cytochrome c oxidase subunit I gene reveals a 24–26% pairwise distance between Chrysomallon and five other genera of Peltospiridae, while the range among those five genera is 14–25%. The new genus is placed in the family Peltospiridae based on morphological characteristics, including lack of sexual dimorphism, no copulatory organ, the distal end of marginal teeth being subdivided into many denticles and the ventral margin of the gill leaflets carrying a series of bulges. A five-gene Bayesian phylogenetic reconstruction does not contradict the placement within Peltospiridae.

- by Chong Chen
- •
- Systematics (Taxonomy), Taxonomy, Deep sea ecology, Chemosynthetic Environments
- by Beverly Goodman
- •
- Mediterranean, Deep-Sea

Deep-water corals are some of the slowest growing,
longest-lived skeletal accreting marine organisms.
These habitat-forming species support diverse faunal
assemblages that include commercially and ecologically
important organisms. Therefore, effective management
and conservation strategies for deep-sea corals can be
informed by precise and accurate age, growth rate,
and lifespan characteristics for proper assessment of
vulnerability and recovery from perturbations. This is
especially true for the small number of commercially
valuable, and potentially endangered, species that are
part of the black and precious coral fisheries (Tsounis
et al. 2010). In addition to evaluating time scales of
recovery from disturbance or exploitation, accurate age
and growth estimates are essential for understanding
the life history and ecology of these habitat-forming
corals. Given that longevity is a key factor for
population maintenance and fishery sustainability,
partly due to limited and complex genetic flow among
coral populations separated by great distances, accurate
age structure for these deep-sea coral communities is
essential for proper, long-term resource management.

- by Allen H Andrews
- •
- Paleoclimatology, Longevity, Chronology, Deep sea ecology

Marine sediments are home to one of the richest species pools on Earth, but logistics and a dearth of taxonomic work-force hinders the knowledge of their biodiversity. We characterized α- and β-diversity of deep-sea assemblages from submarine canyons in the western Mediterranean using an environmental DNA metabarcoding. We used a new primer set targeting a short eukaryotic 18S sequence (ca. 110 bp). We applied a protocol designed to obtain extractions enriched in extracellular DNA from replicated sediment corers. With this strategy we captured information from DNA (local or deposited from the water column) that persists adsorbed to inorganic particles and buffered short-term spatial and temporal heterogeneity. We analysed replicated samples from 20 localities including 2 deep-sea canyons, 1 shallower canal, and two open slopes (depth range 100–2,250 m). We identified 1,629 MOTUs, among which the dominant groups were Metazoa (with representatives of 19 phyla), Alveolata, Stramenopiles, and Rhizaria. There was a marked small-scale heterogeneity as shown by differences in replicates within corers and within localities. The spatial variability between canyons was significant, as was the depth component in one of the canyons where it was tested. Likewise, the composition of the first layer (1 cm) of sediment was significantly different from deeper layers. We found that qualitative (presence-absence) and quantitative (relative number of reads) data showed consistent trends of differentiation between samples and geographic areas. The subset of exclusively benthic MOTUs showed similar patterns of β-diversity and community structure as the whole dataset. Separate analyses of the main metazoan phyla (in number of MOTUs) showed some differences in distribution attributable to different lifestyles. Our results highlight the differentiation that can be found even between geographically close assemblages, and sets the ground for future monitoring and conservation efforts on these bottoms of ecological and economic importance.

- by M. Guardiola and +2
- •
- Marine biodiversity, Deep sea ecology, Deep-Sea, Marine Benthos

The behaviour of the scorpionfish Helicolenus
dactylopterus and Pontinus kuhlii towards the zooplanktivores
Anthias anthias and Callanthias ruber are described from rare
in situ remote-operated vehicle (ROV) observations. The events
were recorded by ROV SP on gorgonian habitats of
Dentomuricea meteor and Viminella flagellum, at the summit
of Condor seamount (212–223 m; Azores, Northeast Atlantic).
Behaviour in both species included approaching the
zooplanktivores from a sitting position, orientating the snout
in front of the object and swimming in a straight line. After an
initial slow displacement, it follows an adduction of dorsal,
pectoral and anal fins and an increase in speed, occasionally
accompanied of a burst swim. H. dactylopterus can reach up to
0.8 m above the seafloor, departing from more than 1.5m
distance; P. kuhlii was observed only on one occasion, chasing
A. anthias from 0.64-m distance, with average swimming
velocities of 1–2 m/s. The possibility of predatory or agonistic
behaviour is discussed, with more evidence being gathered
towards the former, representing a possible linkage between
the pelagic and the benthic realm.

Abstract The geo-biological exploration of a pockmark field located at ca.− 800m in the Gela basin (Strait of Sicily, Central Mediterranean) provided a relatively diverse chemosymbiotic community and methane-imprinted carbonates. To date, this is the first occurrence of such type of specialized deep-water cold-seep communities recorded from 5 this key region, before documented in the Mediterranean as rather disjunct findings in its eastern and westernmost basins.

- by Alessandro Ceregato and +1
- •
- Deep-Sea, Pockmarks

The deep-sea bivalve Acesta oophaga lives attached to the anterior end of the vestimentiferan tubeworm, Lamellibrachia luymesi, at cold methane seeps. The bivalve is found almost exclusively on female tubeworms, where it consumes the lipid-rich eggs of L. luymesi that are spawned year round (Biological Bulletin, 209, 2005, 87). It is apparent that A. oophaga benefits directly from this close association, but the consequences for the tubeworm host may be more complicated than just a simple predator–prey interaction. Since A. oophaga completely surrounds the tube opening and plume of the worm, it is likely that its presence would limit oxygen uptake by L. luymesi, thereby inhibiting worm growth and reproduction. We hypothesized that occupied tubeworms would compensate for this by growing larger plumes for oxygen uptake. To explore the effects of bivalve presence/absence on female tubeworms, several morphological features, including body size, plume length, tube diameter, and tube segment length, as well as instantaneous fecundity, were compared. Results suggest that the mere presence of A. oophaga has a significant impact on the morphology of its host worm, as all measures of worm size, except for tube segment length, were significantly greater with clams present. Additionally, instantaneous fecundity was 3.5 times higher in occupied worms, implying that tubeworms are not oxygen-deprived or energy limited as a result of bivalve presence. Our findings suggest that the association between these two deep-sea organisms may be a more complex form of symbiosis than the simple predator–prey relationship, as previously thought.

- by Joshua Lord
- •
- Deep sea ecology, Deep-Sea
- by Robert Sprackland
- •
- Ichthyology, Symbiosis, Benthic Ecology, Fishes

Up to three miles below the ocean surface, deep-sea hydrothermal vents are home to a community of extraordinary mollusks. In an environment without light, under intense pressure and volcanic heat, many gastropods and bivalves living directly on the vent chimneys show adaptations that have driven important scientific breakthroughs. For example, the famous ‘scaly-foot’ gastropod, Chrysomallon squamiferum, has hard scales on its foot with a crystalline iron coating that has inspired novel defensive armor designs. This iconic species has only been reported from three sites in the Indian Ocean, each site hundreds of miles apart and only around half the size of a football field. Two of these three sites are already designated under international exploration licenses for deep-sea mining, to extract rare minerals from the vent chimneys. Economic and political pressures to exploit the seabed are advancing much faster than scientific exploration, putting these vent ecosystems and their molluscan residents at risk.

- by Chong Chen and +2
- •
- Conservation Biology, Conservation, Marine Protected Areas, Marine and Fisheries Policy

Marine debris, mostly consisting of plastic, is a global problem,
negatively impacting wildlife, tourism and shipping. However,
despite the durability of plastic, and the exponential increase
in its production, monitoring data show limited evidence of
concomitant increasing concentrations in marine habitats. There
appears to be a considerable proportion of the manufactured
plastic that is unaccounted for in surveys tracking the fate
of environmental plastics. Even the discovery of widespread
accumulation of microscopic fragments (microplastics) in oceanic
gyres and shallow water sediments is unable to explain the
missing fraction. Here, we show that deep-sea sediments are
a likely sink for microplastics. Microplastic, in the form of
fibres, was up to four orders of magnitude more abundant (per
unit volume) in deep-sea sediments from the Atlantic Ocean,
Mediterranean Sea and Indian Ocean than in contaminated seasurface
waters. Our results show evidence for a large and
hitherto unknown repository of microplastics. The dominance of
microfibres points to a previously underreported and unsampled
plastic fraction. Given the vastness of the deep sea and the
prevalence of microplastics at all sites we investigated, the deepsea
floor appears to provide an answer to the question—where is
all the plastic?

- by lucy woodall and +1
- •
- Microplastics in the Oceans, Deep-Sea

The opening contribution introduces the reader to concepts, discussions and practices related to the pitfalls of communally and privately exploited resources on a global scale. It offers a historical perspective and suggests understanding the global commons as markers for competing visions of world order in the course of the 20th century. To throw light onto a complex field of research, the chapter gives an outline of what has been discussed in the social sciences as global commons and sketches the contexts of the international conventions which have established these commons under the legal principle of Common Heritage of Mankind in international law. In a second part, the authors situate the subject in the wider framework of global history. The global commons serve as an analytic instrument to challenge master narratives of the post-war era. The chapter advocates a nuanced approach that explores the way global commons were connected with space and territoriality, global integration and statehood, law and international organisations. It emphasises border crossings and sets out the diversity of agencies pursued by states, international communities, non-governmental interests and multinational corporations alike.

- by Andrea Rehling
- •
- Globalization, Environmental History, Population Dynamics, Population ecology

Hadal trenches are isolated habitats that cover the greatest ocean depths (6,500–11,000 m) and are believed to host high levels of endemism across multiple taxa. A group of apparent hadal endemics is within the snailfishes (Liparidae), found in at least five geographically separated trenches. Little is known about their biology, let alone the reasons for their success at hadal depths around the world. This study investigated the life history of hadal liparids using sagittal otoliths of two species from the Kermadec (Notoliparis kermadecensis) and Mariana (Pseudoliparis swirei) trenches in comparison to successful abyssal macrourids found at the abyssal-hadal transition zone. Otoliths for each species revealed alternating opaque and translucent growth zones that could be quantified in medial sections. Assuming these annuli represent annual growth, ages were estimated for the two hadal liparid species to be from five to 16 years old. These estimates were compared to the shallower-living snailfish Careproctus melanurus, which were older than described in previous studies, expanding the potential maximum age for the liparid family to near 25 years. Age estimates for abyssal macrourids ranged from eight to 29 years for Coryphaenoides armatus and six to 16 years for C. yaquinae. In addition, 18 O/ 16 O ratios (δ 18 O) were measured across the otolith using secondary ion mass spectrometry (SIMS) to investigate the thermal history of the three liparids, and two macrourids. Changes in δ 18 O values were observed across the otoliths of C. melanurus, C. armatus, and both hadal liparids, the latter of which may represent a change of > 5 °C in habitat temperature through ontogeny. The results would indicate there is a pelagic larval stage for the hadal liparids that rises to a depth above 1000 m, followed by a return to the hadal environment as these liparids grow. This result was unexpected for the hadal liparids given their isolated environment and large eggs, and the biological implications and plausibility of interpretations of these data are discussed. This study presents a first look at the life history of some of the deepest-living fishes through otolith analyses.

- by Luciano Gomes Fischer
- •
- Marine Biology, Parasitology, Oceanography, Marine Ecology

The genus Pasiphaea Savigny, 1816 (Caridea: Pasiphaeidae) includes 71 species, of which vast majority inhabit in the meso or bathypelagic zones in the world oceans. A new species is described herein, sampled during the project "ABRA-COS 2" (Acoustic along the BRazilian COast) nearby the Rocas Atoll and Fernando de Noronha Archipelago, in Brazilian waters. Pasiphaea antea n. sp. appears close to Pasiphaea dorsolineatus Komai & Chan, 2012 described from off Hawaii, but is distinguished from the latter by the different shape of the rostrum, the mid-dorsal line of the carapace sharply cari-nate in the anterior half, and the possession of more numerous spiniform setae on the meri of the pereopods 1 and 2. This is the third species known from the southwestern Atlantic.

- by Flavio A . Alves-Júnior
- •
- Systematics (Taxonomy), Brazilian Studies, Taxonomy, Shrimps
- by Joachim Langeneck
- •
- Mediterranean, Polychaetes, Deep-Sea

Accumulating fossil records of deep-sea sharks are important for reconstruction of their paleoecology and evolution, because these fossils are generally rare everywhere in the world. This paper reports the newly discovered and diverse... more

- by Yuji TAKAKUWA
- •
- Fossil Fish, Fossil sharks, Miocene, Deep-Sea
- by Margarida Mendes
- •
- Oceanography, Climate Change, Ocean Studies, Deep-Sea

The first mid-Atlantic diet of Mesoplodon beaked whales is presented, from ten Sowerby’s Mesoplodon bidens stranded in the Azores region between 2002 and 2009. This doubles the worldwide number of stomachs sampled, and reveals new feeding habits for this species. the mean number of prey items per stomach was 85789 (range: 12–238), with fish accounting for 99.3% and cephalopods contributing less than 1% of total prey. Fish otoliths from 15 families and cephalopod lower mandibles from three families were identified, representing 22 taxa. The diet consisted mainly of small mid-water fish, the most numerous being Diaphus sp., Lampanyctus sp. and Melamphaidae species. Myctophids were present in all stranded individuals, followed by Diretmidae, Melamphaidae and Opisthoproctus soleatus, while the remaining fish species were scarce or single occurrences. Consistency of diet in four different years reveals a divergence from all previous records in continental areas, where mainly neritic and shelf-break benthopelagic fish species have been reported. Mid-Atlantic Sowerby’s beaked whales’ showed dietary plasticity, feeding on the most abundant mid-water groups occurring between 0 and750 m. Trophic level from prey numerical frequency was estimated at 4.470.46.

- by José Gomes-Pereira
- •
- Atlantic World, Diet, Deep-Sea, Mesopelagic

Bamboo corals from Davidson Seamount and from the Gulf of Alaska were aged using a refined 210Pb dating technique. The goal was to determine growth rates and age for several bamboo corals with higher precision. Radiometric results for 2 Davidson Seamount corals (Keratoisis sp.) converged on a radial growth rate of ~0.055 mm yr–1. One colony was aged at 98 ± 9 yr, with an average axial growth rate of ~0.7 cm yr–1. The age of a large colony was >145 yr with an estimated axial growth rate of 0.14 to 0.28 cm yr–1. Inconsistent rates may indicate nonlinear axial growth. A Keratoisis sp. specimen from the Gulf of Alaska was aged at 116 ± 29 yr from a radial growth rate of ~0.056 mm yr–1, which led to an average axial growth rate of ~1.0 cm yr–1. An Isidella tentaculum colony was aged at 53 ± 10 yr and grew most rapidly with a radial growth rate of ~0.10 mm yr–1 and an average axial growth rate of ~1.4 cm yr–1; however, the 210Pb decay pattern may have provided evidence for either a hiatus in radial growth or environmental changes in 210Pb. Our findings of slow growth and long life compared favorably with other bamboo coral studies and provided age estimates with greater precision. The high longevity of bamboo coral is an indication that recovery from disturbance or removal may take decades to a century. These age data provide a basis for a defensible position on the protection of bamboo coral and essential information for describing other life history characteristics.

- by Allen H Andrews and +1
- •
- Radiochemistry, Longevity, Deep-Sea, Coral

Recently discovered hydrothermal vents of the East Scotia Ridge (ESR) in the Southern Ocean host unique faunal communities that depend on microbial chemosyn-thetic primary production. These highly abundant invertebrates gain energy from either grazing on free-living microbes or via hosting symbiotic chemoautotrophic microorganisms. The main objective of this study was to characterise microbes associated with a newly discovered species of hydrothermal vent gastropod and therefore increase knowledge of ecosystem functioning in this largely unknown Antarctic hydrothermal vent system. We investigated the phylogenetic composition of bacteria associated with the gills and oesophageal gland of the ESR peltospirid gastropod, Gigantopelta chessoia by molecular cloning and terminal restriction fragment length polymor-phism (T-RFLP). 16S rRNA gene clone libraries revealed host tissue-specific combinations of bacteria. The oeso-phageal gland contained one Gammaproteobacteria OTU whereas a more diverse community of Gamma, Epsilon and Deltaproteobacteria was isolated from the gills. T-RFLP analysis revealed that juvenile bacterial communities were more closely related to adult gill-associated bacterial communities than oesophageal gland bacteria. Oesophageal gland Gammaproteobacteria exhibited a higher sequence similarity with sulphur-oxidising bacteria isolated from cold seep sediments and with thioautotrophic endosymbionts than with bacteria found in the surrounding water column, suggesting that these endosymbionts were not acquired directly from the water column. Juvenile G. chessoia were located within the mantle cavity of adults and we speculate that Gammaproteobacterial endosym-bionts in the oesophageal gland could be transmitted horizontally from adults to juveniles via the gills due to the close contact of juveniles with adults' gills.

- by Chong Chen
- •
- Marine Biology, Malacology, Symbiosis, Malacology (Biology)
- by Elizabeth Fisher
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- Pigments (Chemistry), Benthic foraminifera, Deep sea ecology, Foraminifera

There are 22 species of Hamacantha registered from all over the world, and frequently from deep-waters, only two of which had previously been reported from the SW Atlantic. Here we describe a third species for this area, Hamacantha (H.) boomerang sp. nov., collected from deep-sea coral mounds at Campos Basin (off Rio de Janeiro state). We found oxeas 271–630 µm long, diancistras in three size classes, 125–155, 45–69 and 20–29 µm, and toxas, 58–82 µm. This is the only Hamacantha combining oxeas and toxas, but the latter are very rare. The species approaches the Caribbean H. (H.) schmidtii (Carter, 1882), where we observed oxeas 390–495 µm long, and diancistras in three size classes, 109–124, 44–54 and 26–41 μm, however toxas appear to be absent. Both species are clearly distinct by micrometric values, as well as the overall morphology of the smaller diancistras, distinct from the intermediate category in the new species, but quite similar in H. (H.) schmidtii. Hamacantha (Vomerula) falcula approaches the new species very closely in microsclere dimensions and morphology, but is set apart by its styloid and smaller megascleres.

- by Cristiana Castello-Branco
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- Systematics (Taxonomy), Deep-Sea
- by Shelley Wachsmann
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- Archaeology, Egyptology, Maritime Archaeology, Maritime History
- by Michael Türkay
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- Marine biodiversity, Crustacea Decapoda, Red Sea, Deep-Sea

The abundance and behaviour of fish on and around coral reefs at Twin Mounds and Giant Mounds, carbonate mounds located on the continental shelf off Ireland(600–1100m),were studied using two Remotely Operated Vehicle (ROV) dives.We recorded 30 fish taxa on the dives,together with three species of Scleractinia (Lophelia pertusa, Madrepora oculata and Desmophyllum cristagalli) and a diverse range of other corals(Antipatharia, Alcyonacea, andStylasteridae). Stands of live coral provided the only habitat in which Guttigadus latifrons was observed whereas Neocyttus helgae was found predominantly on structural habitats provided by dead coral. Significantly more fish were found on structurally complex coral rubble habitats than on flatter areas where coral rubble was clogged with sand. The most common species recorded was Lepidion eques (2136 individuals),which always occurred a few cm above bottom and was significantly more active on the reefs than on sedimentary habitats. Synaphobranchus kaupii (1157indiv.), N.helgae (198 indiv.)and Micromesistius poutassou (116 indiv.) were also common; S. kaupii did not exhibit habitat-related differences in behaviour,whilst N. helgae was more active over the reefs and other structured habitats whereas M. poutassou was more active with decreasing habitat complexity. Trawl damage and abandoned fishing gear was observed at both sites. We conclude that Irish coral reefs provide complex habitats that are home to a diverse assemblage of fish utilising the range of niches occurring both above and within the reef structure.

- by Jason Hall-Spencer
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- Fisheries, Remotely Operated Vehicle, Deep-Sea, Cold-Water Corals

This paper reports two deep-sea shrimps, Acanthephyra acanthitelsonis and A. armata from southwestern Atlantic waters. The samples were collected in two different moments, the first in the Potiguar Basin, northeast of Brazil (03/05° S; 38/ 35° W), covering the states of Rio Grande do Norte (RN) and Ceará (CE) in the year of 2011, and afterward on Rocas Atoll, located in the state of Rio Grande do Norte (RN) (3° 51' S, 033° 49' W; 3° 52' S, 033° 47' W) in the year of 2015. The occurrence of A. acanthitelsonis on Rocas Atoll and A. armata found along the continental slope in the Potiguar Basin, comprising both species, which were recorded for the first time in the southwestern Atlantic. This paper increases the number of Acanthephyra species recorded in Brazilian waters up to six and adds to our knowledge and distribution of deep-sea fauna in the south Atlantic.

- by Flavio A . Alves-Júnior
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- Zoology, Deep-Sea, Crustaceans

A key objective of the United Nations Convention on the Law of the Sea (UNCLOS) as stated in its Preamble , is to contribute to the realisation of a just and equitable international economic order which takes into account the interests and needs of mankind as a whole and, in particular, the special interests and needs of developing countries. As for any other principles of international law, the context within which the principle of the common heritage of mankind (CHM) has been developed is essential to understanding the philosophy behind it, its evolution and more particularly, the challenges faced today for is effective implementation as a means to advance the concept of equity in the context of deep sea mining (DSM mining).

- by Torsten Thiele
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- Marine Conservation, Ocean governance, Deep-Sea

We report the first in situ observations of a large
Taningia danae Joubin, 1931, close to the seafloor at bathyal
depths of 2,157 m. The observation was made in the subtropical
northeast Atlantic Seine seamount during daytime on 29
September 2012, over a silt-covered seafloor (33º40.1142′N,
14º22.7301′W). Seawater temperature was 4.2ºC, salinity
35.40 ppt, oxygen saturation 50.87 Ox%, and pressure
2,178.29 dbar. Mantle length was estimated from imagery to
be 65.3 cm (STD=6.3). A repeated behaviour was observed
every time the ROVapproached: (1) swimming away fromthe
ROV by flapping the fins twice (moving forward or backward),
(2) gliding slightly inclined downward, until colliding
against the seafloor, and (3) ascending obliquely or vertically
in relation to the seafloor, finally evading the area moving
upward using jet propulsion. These observations greatly extend
the species depth range and document behaviour patterns.
T. danae is able to explore beyond the mesopelagic zone
where it has previously been reported.

- by José Gomes-Pereira
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- Deep Ecology, Cephalopods, Deep sea ecology, Cephalopoda
- by Douglas J Long
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- Marine Biology, Ichthyology, Taxonomy, Biogeography

Fish integument can have varying structures and functions depending on the species, habits, and the specialized environmental niches inhabited by these organisms. It is in the interest of this paper to delve deep into the integumentary features of deep-sea fishes from the aphotic zones of the ocean. This paper will also correlate said adaptations with the predominant environmental conditions wherein the subjects thrive and rationalize the necessity for such features in specific contexts that will be provided.

- by Juris Justin
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- Biology, Fish Biology, Fish Ecology, Fish anatomy

A new species of deep-water oregoniid spider crab of the genus Pleistacantha Miers, 1879, is described from the Indian Ocean. The species is distinct in possessing a prominently inflated carapace in which the median parts of the branchial regions almost meet. It can also be distinguished from its closest congeners, P. moseleyi (Miers, 1885), P. pungens (Wood-Mason, in Wood-Mason and Alcock 1891), and P. ori Ahyong & Ng, 2007, in its more elongate and less spinose chelipeds and ambulatory legs, shorter third maxilliped, trapezoidal male pleon and a male first gonopod which is relatively stout with a short subdistal dorsal papilla.

- by Ravinesh R.R
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- Deep sea ecology, Deep-Sea, Brachyuran crabs

Background: Extreme environments prompt the evolution of characteristic adaptations. Yet questions remain about whether radiations in extreme environments originate from a single lineage that masters a key adaptive pathway, or if the same features can arise in parallel through convergence. Species endemic to deep-sea hydrothermal vents must accommodate high temperature and low pH. The most successful vent species share a constrained pathway to successful energy exploitation: hosting symbionts. The vent-endemic gastropod genus Gigantopelta, from the Southern and Indian Oceans, shares unusual features with a co-occurring peltospirid, the 'scaly-foot gastropod' Chrysomallon squamiferum. Both are unusually large for the clade and share other adaptive features such as a prominent enlarged trophosome-like oesophageal gland, not found in any other vent molluscs. Results: Transmission electron microscopy confirmed endosymbiont bacteria in the oesophageal gland of Gigantopelta, as also seen in Chrysomallon. They are the only known members of their phylum in vent ecosystems hosting internal endosymbionts; other vent molluscs host endosymbionts in or on their gills, or in the mantle cavity. A five-gene phylogenetic reconstruction demonstrated that Gigantopelta and Chrysomallon are not phylogenetically sister-taxa, despite their superficial similarity. Both genera have specialist adaptations to accommodate internalised endosymbionts, but with anatomical differences that indicate separate evolutionary origins. Hosting endosymbionts in an internal organ within the host means that all resources required by the bacteria must be supplied by the animal, rather than directly by the vent fluid. Unlike Chrysomallon, which has an enlarged oesophageal gland throughout post-settlement life, the oesophageal gland in Gigantopelta is proportionally much smaller in juveniles and the animals likely undergo a trophic shift during ontogeny. The circulatory system is hypertrophied in both but the overall size is smaller in Gigantopelta. In contrast with Chrysomallon, Gigantopelta possesses true ganglia and is gonochoristic. Conclusions: Key anatomical differences between Gigantopelta and Chrysomallon demonstrate these two genera acquired a similar way of life through independent and convergent adaptive pathways. What appear to be the holobiont's adaptations to an extreme environment, are driven by optimising bacteria's access to vent nutrients. By comparing Gigantopelta and Chrysomallon, we show that metazoans are capable of rapidly and repeatedly evolving equivalent anatomical adaptations and close-knit relationships with chemoautotrophic bacteria, achieving the same end-product through parallel evolutionary trajectories.

- by Chong Chen and +1
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- Adaptation, Evolution, Convergence, Gastropoda

We assessed spatio-temporal patterns of diversity in deep-sea sediment communities using metabarcoding. We chose a recently developed eukaryotic marker based on the v7 region of the 18S rRNA gene. Our study was performed in a submarine canyon and its adjacent slope in the Northwestern Mediterranean Sea, sampled along a depth gradient at two different seasons. We found a total of 5,569 molecular operational taxonomic units (MOTUs), dominated by Metazoa, Alveolata and Rhizaria. Among metazoans, Nematoda, Arthropoda and Annelida were the most diverse. We found a marked heterogeneity at all scales, with important differences between layers of sediment and significant changes in community composition with zone (canyon vs slope), depth, and season. We compared the information obtained from metabarcoding DNA and RNA and found more total MOTUs and more MOTUs per sample with DNA (ca. 20% and 40% increase, respectively). Both datasets showed overall similar spatial trends, but most groups had higher MOTU richness with the DNA template, while others, such as nematodes, were more diverse in the RNA dataset. We provide metabarcoding protocols and guidelines for biomonitoring of these key communities in order to generate information applicable to management efforts.

- by Owen S. Wangensteen and +1
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- Marine biodiversity, Deep-Sea, Marine Benthic Ecology, Metabarcoding
- by Douglas J Long and +1
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- Marine Biology, Ichthyology, Taxonomy, Chondrichthyes