Deep-water Fauna Research Articles

Deep-sea ichthyofauna from Eastern Mediterranean Sea, Egypt: Update and new records

This work sheds light on deep sea resources that update the list of deep sea ichthyoids fauna with new records from the Egyptian coast, Mediterranean Sea. Fish samples were collected from April to November 2015 at depths of 350–750m using deep red shrimp bottom trawlers. The presented fauna were constituted mainly of deep red shrimp (Aristeomorpha folicea and Aristeus antennatus) as target species followed by by-catch and discards which were represented by 36 fish species; Of them, 21 species were recorded previously. The rest of the species, were new ichthyofauna identified in fifteen species including 4 cartilaginous species (Centrophorus uyato, Etmopterus spinax, Hydrolagus mirabilis and Chimaera monstrosa), while the other 11 species were bony fishes (Chauliodus sloani, Diaphus metopoclampus, Sudis hyaline, Microstoma microstoma, Chlorophthalmus agassizi, Avocettina infans, Argyropelecus hemigymnus, Notacanthus bonaparte, Lampanyctus crocodilus, Centrolophus niger and Nettastoma melanurum). Centrophorus uyato was reported for the first time in the Levant Basin. The present findings added new species to the Egyptian ichthyofauna and raised the total known deep water fauna to 38 species, enhancing knowledge about such species requires continuous monitoring and studies on deep sea resources.

Polychaetous annelids in the deep Nordic Seas: Strong bathymetric gradients, low diversity and underdeveloped taxonomy

Not much is known on polychaete diversity in the deep Nordic Seas. Based on data from extensive sampling over three decades, new data on polychaetes covering depths from 550m to 3800m are presently reported. On a depth gradient, the number of polychaete families gradually declined from 35 at the upper slope (500–750m) to 11 at 3800m. Species diversity in eight polychaete families subjected to critical taxonomic studies showed a gradual decrease from a diverse group of slope species in the upper and middle slope (500–1000m) to a species poor fauna in the deepest areas (>3000m), with a distinct break at about 2000m. Faunal changes were documented both at alpha (sample species richness) and gamma (large area species richness) scales, whereas the break at about 2000m was clearly from beta (turnover) species richness. Only six species (12%) in the examined families were found in the deepest areas. The slope and deep-water polychaete fauna differs substantially from west Norwegian shelf and costal fauna. Not more than 30% of the species in the examined families were recorded in coastal and shelf waters, and several presumably refer to species complexes. The strong faunal change coincides with the upper border of cold sub-zero temperature deep water at the shelf break and upper slope. Polychaete taxonomy of the deep-water fauna is generally underdeveloped, illustrated by a high proportion of recently described or undescribed species (about 40%) in the examined families. Based on the present results, we hypothesise that the cold Nordic Sea deep-water polychaete fauna differs significantly from the North Atlantic deep fauna and rather is more similar to the fauna of deep Arctic waters.

Comparison between ROV video and Agassiz trawl methods for sampling deep water fauna of submarine canyons in the Northwestern Mediterranean Sea with observations on behavioural reactions of target species

In this paper we present a comparison between Remotely Operated Vehicle (ROV) and Agassiz trawling methods for sampling deep-water fauna in three submarine canyons of the Northwestern Mediterranean Sea and describe the behavioural reactions of fishes and crustacean decapods to ROV approach. 10 ROV dives, where 3583 individuals were observed and identified to species level, and 8 Agassiz trawls were carried out in a depth range of 750–1500m. As noticed in previous studies, abundances of fishes and decapod crustaceans were much higher in the ROV videos than in Agassiz trawl samples, as the latter are designed for the retrieval of benthic, less motile species in permanent contact with the bottom. In our observations fish abundance was one order of magnitude higher with ROV (4110.22ind/km2) than with Agassiz trawl (350.88ind/km2), whereas decapod crustaceans were six times more abundant in ROV videos (6362.40ind/km2) than in Agassiz samples (1364.52ind/km2).The behaviour of highly motile fishes was analysed in terms of stationary positioning over the seafloor and avoidance or attraction to ROV approach. The most frequently occurring fish species Coelorinchus mediterraneus, Nezumia aequalis, Bathypterois dubius, Lepidion lepidion, Trachyrincuss scabrus and Polyacanthonotus rissoanus did not react to the presence of the ROV in most cases (>50%). Only B. dubius (11%), Lepidion lepidion (14.8%), P. rissoanus (41%) and T. scabrus (14.3%) reacted to ROV approach. More than 60% of less motile species, such as crustacean decapods, did not respond to ROV presence either. Only 33.3% of Geryon longipes, 36.2% of Munida spp. and 29.79% of Pagurus spp. were observed avoiding or defensively reacting to the ROV.The comparison of results obtained with ROV and trawl sampling is of ecological relevance since ROV can report observations in areas where trawling is technically unfeasible. The lack of reaction by most fish and crustacean decapod specimens further confirms that ROV surveying is an efficient technique to assess abundance and species composition in deep-sea waters for these motile species and questions trawl-based estimations.

Some deep-water cheilostome Bryozoa from the south coast of South Africa

Twelve species of deep-water cheilostome Bryozoa are reported from an incidental deep-water collection from the south coast of South Africa. The collection represents nine families and ten genera. One species, Arthropoma lioneli sp. nov., is new to science. The results reinforce the need for targeted sampling of South Africa's poorly known deep-water benthic fauna to assist the assignment of offshore marine protected areas within its Exclusive Economic Zone. With the addition of the new species, the bryozoan fauna of South Africa comprises no fewer than 271 valid marine species.

The "Abyssal Society". François-Alphonse Forel and the Case of Deep Fauna in Late 19th Century.

Ichthyological investigations and technological advancements, such as the laying of submarine telegraph cables, promoted new dredging methods in the second half of the 19th century. In contrast to the idea of a lifeless deep ocean (Edward Forbes' azoic hypothesis), the discovery of deep water fauna and the challenge of defining its systematics opened up new theoretical perspectives. In this frame, which was already marked by the impact of Darwin's theory, naturalistic surveys in freshwater environments in western Switzerland intertwined with those of oceanographic expeditions. The study of the fauna in the depths of subalpine lakes by the Swiss savant François-Alphonse Forel was one of the most striking examples of this turning point, because the relatively recently evolution of its freshwater fauna allowed him to investigate: (a) the role of isolation, (b) the progressive differentiation of species from a common ancestor, and (c) the constitution of a species-specific category in form transition, from a genealogical viewpoint to an ecological one.

Large-scale spatial variability of decapod and stomatopod larvae along the South Brazil Shelf

The spatial distribution of a spring/summer community of combined decapod and stomatopod larvae along the southwestern Atlantic shelf, and its possible linkages with hydrographical processes and with parental habitats were investigated. Vertical plankton hauls were performed between 21°S and 34°S, at 107 stations, distributed along 2000km of coastline and up to 400km offshore, during late spring 2010 and early summer 2011. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll and nutrient concentrations. A coupling between chlorophyll concentration and abundance of early larvae of benthic species was observed, suggesting that the larval release could be synchronized with phytoplankton maxima. Our findings indicated that the composition and abundance of larvae are strongly influenced by distance from the coast, freshwater sources and water mass distribution. Assemblages of larvae were observed in the most relevant environmental scenarios: (1) coastal environments, dominated by intertidal, shallow water or coastal species; (2) offshore environments, with predominance of holopelagic and deepwater species; and (3) southern continental runoff, mainly represented by benthic neritic crabs and shrimps. In addition, the large-scale distribution of larvae revealed a relationship with the adult’s distribution, shown mainly by the occurrence of larvae transported from the estuaries in the inner shelf and by larvae of the deepwater fauna found mainly along the outer shelf.

Distribution of Benthesicymus tanneri Faxon, 1893 (Dendrobranchiata, Benthesicymidae) off the west coast of Mexico and notes on its morphology

A large series of specimens of Benthesicymus tanneri Faxon, 1893 (Dendrobranchiata; Benthesicymidae) was collected during an extensive survey of deep-water invertebrate fauna off western Mexico. In total, 61 males and 122 females (M:F ratio = 1:2) from 44 sampling stations were examined, considerably increasing the number of known specimens and sampling localities for this species which is widely distributed along the Pacific coast of Mexico. The collection is the largest available for this species to date and presents first records from off the west coast of the Baja California Peninsula and a slight increase of the northernmost record within the Gulf of California. On the whole, females grew larger than males. The petasma of males of different sizes and the female thelycum of Benthesicymus tanneri are illustrated. The petasma of Benthesicymus tanneri presents a ventrolateral crescent-shape process otherwide found only in Benthesicymus tirmiziae Crosnier, 1978 and in Benthesicymus bartletti S.I. Smith, 1882. A key to the four species of Benthesicymus presently known from the eastern Pacific is presented.

Paleogene marine bivalves of the deep-water Keasey Formation in Oregon, part IV: The anomalodesmatans

The late Eocene–early Oligocene Keasey Formation in Northwestern Oregon contains a unique fauna of deep-water (>200 m) marine bivalves preserved in sparsely fossiliferous massive tuffaceous siltstone as well as in several distinctive cold-seep limestone bodies and carbonate layers. The Keasey gastropod fauna has been described previously, but this treatment of the anomalodesmatan bivalves is the first systematic account for any portion of the bivalve fauna. Cenozoic evolutionary radiation and history of anomalodesmatans is less well known than their deep Paleozoic and Mesozoic history. Because internal relationships are not well resolved, ranked classification is not used above the family level, while recognizing that these rare and unusual bivalves do represent a monophyletic assemblage nested within the basal heterodonts. Six species in four anomalodesmatan families in the Keasey Formation shed new light on the Cenozoic history of the group as well as the Eocene appearance of precursors of the living deep-water fauna of the northeastern Pacific. The families represented are Pandoridae, Thraciidae, Periplomatidae, and Cuspidariidae. The new species are Pandora eocapsella, Thracia keaseyensis, Cardiomya anaticepsella, and Cardiomya pavascotti. Aperiploma? n. sp. is described in open nomenclature pending discovery of additional and more complete material. Although shells are frequently crushed and the exterior shell layers are often poorly preserved, the interior nacre is distinctive, well-preserved and useful for recognizing fragments in the field. Characteristic anomalodesmatan granules are well preserved on many specimens of the new thraciid, and the fine-grained matrix at some localities preserves shell features on external molds where no original shell material remains. High-resolution images of uncoated shell encourage greater attention to collection of fragments and imperfect specimens in the fine-grained deep-water facies on the active margin of the Pacific.

Phylogeographic Estimates of Colonization of The Deep Atlantic by The Protobranch Bivalve Nucula Atacellana

AbstractThe Pleistocene and post-Pleistocene evolutionary history of many North Atlantic intertidal invertebrate species is well known, but the evolutionary history of the deep North Atlantic fauna is poorly understood, specifically whether colonization of the deep North Atlantic paralleled the patterns observed in shallow water. Contemporary pan-Atlantic species distributions could result from several colonization pathways that connected different regions of the Atlantic at different times (e.g. Arctic, Antarctic or Panamanian pathways). To test potential colonization pathways we quantified geographic variation in nuclear and mitochondrial markers from Atlantic samples ofNucula atacellana, a pan-Atlantic deep-sea protobranch bivalve, usingN. profundorumin the eastern central Pacific as an outgroup. We combined existing 16S data from North and South Atlantic populations ofN. atacellanawith new sequences of 16S, COI, and an intron of calmodulin from those populations, and newly sampled populations near Iceland. Population genetic analyses indicated a subtropical expansion via the Central American Seaway. We found no evidence for Transarctic migration to the Atlantic inN. atacellana, which suggests that colonization pathways may differ significantly between shallow- and deep-water fauna.

Deep-water species of Crangonidae and Glyphocrangonidae (Decapoda, Caridea) collected during the TALUD XV cruise off the west coast of southern Baja California, Mexico

Four species of Crangonidae and Glyphocrangonidae were collected during a survey of the deep-water fauna off the west coast of the southern part of the Baja California Peninsula, Mexico. A total of 168 specimens were collected, with a clear dominance of Glyphocrangon spinulosa Faxon, 1893 (85% of collected specimens). A new northernmost distribution limit is set for Paracrangon areolata Faxon, 1893, Sclerocrangon atrox Faxon, 1893 and Glyphocrangon alata Faxon, 1893, while first records are made available for G. spinulosa off the west coast of the Baja California Peninsula.

Regional impact from fin-fish farming in an intensive production area (Hardangerfjord, Norway)

The Hardangerfjord is one of the largest salmon-farming areas in Norway, with an annual production of approximately 70,000 metric tonnes. The regional impact of fin-fish farming in a fjord environment was studied during 2008–2010. Ecological conditions in intertidal macroalgal and benthic deep basin communities were studied in addition to measurements of nutrients and chlorophyll-a values. Macroalgal communities in the intertidal zone and the deep water fauna communities showed a high ecological status in the intermediate part of the fjord and a good status in the inner part of the fjord. Faunal communities in the outermost basin indicate that the assimilative capacity for farm waste of this deep basin could be limited. Nutrients and chlorophyll-a values were within national thresholds defined as high water quality. The good ecological conditions of the parameters studied in the fjord show little evidence of a regional impact from the fish farming industry despite the intensive production level.

Population differentiation and species formation in the deep sea: the potential role of environmental gradients and depth.

Ecological speciation probably plays a more prominent role in diversification than previously thought, particularly in marine ecosystems where dispersal potential is great and where few obvious barriers to gene flow exist. This may be especially true in the deep sea where allopatric speciation seems insufficient to account for the rich and largely endemic fauna. Ecologically driven population differentiation and speciation are likely to be most prevalent along environmental gradients, such as those attending changes in depth. We quantified patterns of genetic variation along a depth gradient (1600-3800m) in the western North Atlantic for a protobranch bivalve ( Nuculaatacellana ) to test for population divergence. Multilocus analyses indicated a sharp discontinuity across a narrow depth range, with extremely low gene flow inferred between shallow and deep populations for thousands of generations. Phylogeographical discordance occurred between nuclear and mitochondrial loci as might be expected during the early stages of species formation. Because the geographic distance between divergent populations is small and no obvious dispersal barriers exist in this region, we suggest the divergence might reflect ecologically driven selection mediated by environmental correlates of the depth gradient. As inferred for numerous shallow-water species, environmental gradients that parallel changes in depth may play a key role in the genesis and adaptive radiation of the deep-water fauna.

Paleoecology of echinoderm assemblages from the Upper Ordovician (Katian) Dunleith Formation of northern Iowa and southern Minnesota

The Dunleith Formation echinoderms lived on a shallow water carbonate platform (Benthic Assemblages outer 2 and 3 during the latter part of the Dunleith Regressive Cycle). The echinoderms were buried rapidly by storms or a volcanic ash bed in one example. The presence of complete specimens, entire crowns, attachment structures, and excellent preservation strongly suggests that these assemblages reflect in situ communities on the seafloor that have not been significantly mixed, transported, or concentrated in time. Most taxa are suspension feeders, namely 21 crinoids, one glyptocystitid rhombiferan, a paracrinoid, and two edrioasteroids, but a deposit feeding pleurocystitid rhombiferan is also common. Three assemblages are recognized and defined by their dominant taxa; in order of increasing depth, these are theCotylacrinna sandra,Pleurocystites strimplei, andCupulocrinus crossmaniassemblages. Substrates ranged from hard- or firm-ground carbonates to soft carbonate and siliciclastic muds. Diverse attachment structures are recognized: the recumbent stems of calceocrinids, lichenocrinids on shells, small distal stem tips, and round to lobate calcite pads cemented to shells or the substrate, open distal stem coils directly on the seabed or coiled around soft objects thereon, and large conical and highly modified cirrus holdfasts on hard- or firm-grounds. The echinoderms were located at levels ranging from the seafloor to almost a meter above, with maximum diversity at about 50 mm above the seafloor. The size frequency distributions of food particles and the ranges of ambient current velocities for successful feeding by the juveniles and adults of the common crinoids are modeled using filtration theory. The food particle size distributions and the current velocities for feeding are correlated with the arm or filtration fan morphology of the crinoids. Differences between these parameters tend to partially separate the feeding ecologies of species located at the same elevation. Nevertheless, considerable overlap remains between species for small sized food particles and the lower ranges of ambient current velocities for feeding. Except for theCotylacrinna sandraAssemblage, competition for space does not seem to have been important in regulating the ecological structure of the Dunleith crinoids. However, the deposit feeding pleurocystitids possibly competed for food and space in one example. The Dunleith assemblages are much more diverse with greater ecological complexity than seen in the relatively deep water fauna from the Upper Ordovician Trenton Group of the Walcott-Rust Quarry in New York (Benthic Assemblage 5).

Neither a buccinid nor a turrid: A new family of deep-sea snails for Belomitra P. Fischer, 1883 (Mollusca, Neogastropoda), with a review of Recent Indo-Pacific species

The new family Belomitridae is established for the deep-water buccinoid genus Belomitra P. Fischer, 1883, based onmorphological (shell and radulae) and molecular evidence. The rachiglossate radula is uniquely characterized by amulticuspid rachidian and lateral teeth with very long narrow bases and two small cusps closer to tip. Molecular anal-ysis of a reduced set of Buccinoidea did not resolve the group as a clade, but shows that Belomitridae forms a wellsupported clade within Buccinoidea. Species of Belomitra have adult sizes in the 7–53 mm range; they live in deepwater, mostly in the 500–2,000 meters range, at low and mid latitudes. Eleven valid species described from the Indo-Pacific were originally named in the families Buccinidae, Columbellidae, Cancellariidae, Volutidae, and Turridae.Fourteen new species are described: Belomitra nesiotica n. sp. (Society Islands to Tonga and Fiji in 580–830 m), B.bouteti n. sp. (Society and Tuamotu Islands in 430–830 m), B. subula n. sp. (Solomon Islands to Vanuatu in 760–1110m), B. caudata n. sp. (Sulu Sea in 2300 m), B. gymnobela n. sp. (South Pacific, eastern Indonesia and Philippines in780–2040 m), B. hypsomitra n. sp. (Fiji in 392–407 m), B. brachymitra n. sp. (Fiji in 395–540 m), B. comitas n. sp.(Madagascar and Philippines in 1075–1110 m), B. minutula (Coral Sea in 490 m), B. granulata n. sp. (New Caledoniain 105–860 m), B. reticulata n. sp. (Tonga and Fiji to New Caledonia in 395–656 m), B. decapitata n. sp. (IndianOcean and New Caledonia in 3680–4400 m), B. admete n. sp. (off Sri Lanka in 2540 m), and B. radula n. sp. (Madagascar in 367–488 m).Key-words: Buccinoidea, molecular phylogeny, morphology, anatomy, radula, deep-water fauna

Deep-water Hydrozoa (Cnidaria: Medusozoa) in the Sea of Japan, collected during the 51st Cruise of R/V Akademik M.A. Lavrentyev, with description Opercularella angelikae, sp. nov.

A report is given about Hydrozoa collected at depths between 455 and 3666m in the Sea of Japan during the Russian-German expedition on R/V Akademik M.A. Lavrentyev. Ten species were found, with four of them being typical bathyal–abyssal and abyssal zones. A new species, Opercularella angelikae, is described, and it was the dominant hydroid in samples from 970 to 3660m. Four eurybathic species characteristics of the Sea of Japan were sampled between 455 and 582m. Abyssal (pseudoabyssal after Andriashev, 1979) hydroid fauna in the Sea of Japan is reported. The hypothesis that an exclusively deep-water fauna is lacking in abyssal regions of the Sea of Japan is disputed. The author's personal opinion considered concerning the borders of 1000m between shallow and deep hydrozoan species in the Sea of Japan.

Deep-water fauna of Oligochaeta (Annelida, Clitellata) near hydrothermal spring of the Frolikha Bay, Northern Baikal (East Siberia, Russia)

Deep-water fauna of Oligochaeta (Annelida, Clitellata) near hydrothermal spring of the Frolikha Bay, Northern Baikal (East Siberia, Russia)

A late Burdigalian bathyal mollusc fauna from the Vienna Basin (Slovakia)

A late Burdigalian bathyal mollusc fauna from the Vienna Basin (Slovakia)This is the first record of a bathyal mollusc fauna from the late Early Miocene of the Central Paratethys. The assemblage shows clear affinities to coeval faunas of the Turin Hills in the Mediterranean area and the Aquitaine Basin in France. The overall biostratigraphic value of the assemblage is hard to estimate due to the general very poor knowledge of Miocene bathyal faunas. Several species, however, are known from deep water deposits of the Middle Miocene Badenian stage as well. This implies Early Miocene roots of parts of the Middle Miocene deep water fauna and suggests a low turnover for bathyal mollusc communities at the Early-Middle Miocene boundary. The nassariid gastropodNassarius janschloegliHarzhauser nov. sp. and the naticid gastropodPolinices cerovaensisHarzhauser nov. sp. are introduced as new species.

Trilobites and biofacies in the Early–Middle Ordovician of Baltica and a brief comparison with the Yangtze Plate

Baltica except for Baltoscandia was subject to an early Tremadocian immigration of trilobites similar to that on other plates. In Baltoscandia the Olenid biofacies lingered on until it was replaced by the late Tremadocian Ceratopyge biofacies. For the rest of the time (Floian to mid-Darriwilian), Baltoscandia had fairly monotonous lithologies and faunas, constituting a single Asaphid biofacies with lateral variations expressed as differences largely in the relative abundance of species. In the South Urals immigration started in the earliest Tremadocian with fairly rich deep-water faunas. A poorer fauna is known from the Polar Urals. A slightly younger, sparse fauna is known from Paj-Khoj. Over most of the Ural border north of the South Urals there was a further development of first a Ceratopyge biofacies, then an eastern Asaphid biofacies, together with more siliciclastic input to the lithofacies and with fewer asaphids than in Baltoscandia. In the South Urals there was a development in the Darriwilian of a Cheirurid biofacies following the Ceratopyge biofacies. By contrast, the shelf part of the South China Plate shows a development of fifteen biofacies distinguished on the genus level, and the number of species for each biofacies is notably small. The major difference in the pattern of distribution of the biofacies probably reflects the faunal development in rather different climatic conditions, suggesting that the Yangtze block is supposedly positioned rather distant from Baltica, but still close enough to share genera inhabiting the outer shelf.

The assessment of the age of scleractinian coral species (Anthozoa: Scleractinia) based on the temperature ranges of their habitat

Until now, the age of deep-water scleractinians was determined based only on rare finds of these corals in terrestrial sequences, which constitute <10% of their known diversity. Inasmuch as most of the non-zooxanthellate coral species dwell in the ocean beyond the shelf zone (up to the abyssal depths) and their fossil remains are missing from terrestrial sections, we propose a new approach to the assessment of their age based on paleoecological features: the seawater temperatures in the geological past and the habitat temperature ranges established for 53 coral species. The study confirmed our previous assumption concerning the very young age of the deep-water fauna.

Composition, distribution and regional affinities of the deepwater ichthyofauna of the Lord Howe Rise and Norfolk Ridge, south-west Pacific Ocean

Fishes were collected from seamounts and insular slopes of the northern Tasman and southern Coral Seas in the environs of the Reinga Ridge, Norfolk Ridge and Lord Howe Rise, at depths ranging from 49 to 1927 m. A total of 348 demersal fish species in 99 families, which were collected from 135 samples taken with a variety of sampling gear, greatly improved taxonomic knowledge of this poorly known area. Twenty five percent of the fish sampled are considered to be potentially new species. Relatively high levels of regional endemicity and diversity are attributed to geological history, and the complexity of contemporary climatology, hydrography and habitat diversity of the region. Fish assemblages were highly structured by depth, but across regions, deep-water fish faunas showed stronger taxonomic affinities than shallower faunas. Although less pronounced, spatial differences pointed towards distinct faunas between the southern and northern parts of the area. The distribution patterns and affinities to regions adjacent to the survey area indicate that (1) the fish fauna on the Lord Howe Rise near Lord Howe Island and further north is distinct from the rest of the survey regions, and exhibits eastern Australian and northern (Coral Sea) affinities, (2) the Northern Norfolk Ridge fauna is distinct from the other regions and has strong affinities with New Caledonia, (3) fishes on the Southern Norfolk Ridge, Western Norfolk Ridge and Lord Howe Plateau have more shared species compared to the other regions indicating a high level of connectedness and affinities with New Zealand fauna, and (4) some species have a wide distribution along the Norfolk Ridge providing a possible deepwater pathway between New Caledonia and New Zealand. Survey data is also useful for assessing the regions' conservation values by identifying rare or unusual components of the fauna, those with very limited distributions, those with low productivity that may be vulnerable to human disturbance (fishing, mining), and for defining bioregions.