Visual observations of fish from seamounts of the Southern Azores region (the Atlantic Ocean)

Results of observations from the underwater inhabited device “Sever-2” of the behavior and distribution of fish on seamounts of the Azores region up to a depth of 1200 m are provided. In the natural habitat, 52 species of fish of 46 genera belonging to 36 families were recorded. In the ichthyofauna of the studied region, bottom (37.0%) and near-bottom (29.2%) species dominate; the proportion of off-bottom and off-bottom-pelagic species is 18.0 and 12.4%, respectively, and pelagic species account for only 3.4%. Pelagic species Scomber japonicus and Trachurus picturatus; off-bottom-pelagic Beryx splendens, Lepidopus caudatus, and Aphanopus carbo; and near-bottom species Zenopsis conchifer, Macrorhamphosus scolapax, Antigonia capros, Capros aper, Anthias anthias, and Callanthias ruber dominate by numbers and the amount of biomass.     

Feeding of Fish at the Seamounts of the Whale Ridge (South-Eastern Atlantic Ocean). 2. Splendid alfonsino Beryx splendens (Berycidae)

Journal of Ichthyology - The feeding characteristics of splendid alfonsino Beryx splendens from the seamounts of the Whale Ridge have been studied. A wide range of food organisms in feeding of...     

Species composition,distribution, and behavior of fish on the Vavilov Underwater Ridge (the Atlantic Ocean)

From the data of commercial landings and underwater observations on the Vavilov Ridge (the eastern part of the Atlantic Ocean), approximately 50 bottom, near bottom, and near bottom-pelagic fish species of 38 families are recorded. The following species have the highest commercial importance: mackerel scads Decapterus longimanus,and D. macarellus,,mackerel Scomner japonicus, Beryx splendens, Allocyttus guineensis, Epigonus affinis,,etc.     

Preliminary observations on the benthic marine algae of the Gorringe seabank (northeast Atlantic Ocean)

Examination of marine samples collected in 2006 from the Gettysburg and Ormonde seamounts on the Gorringe seabank southwest of Portugal has revealed 29 benthic Chlorophyta, Phaeophyceae (Ochrophyta), and Rhodophyta that were identified provisionally to genus and to species. Combining lists for the present and a previous expedition brings the total of algae thus far recorded to 48. The brown alga Zonaria tournefourtii and the red alga Cryptopleura ramosa were the most abundant species in the present collections. The kelp Laminaria ochroleuca was present only in the Gettysburg samples while Saccorhiza polyschides was observed only on the Ormonde seamount. Comparisons with the benthic marine algae recorded on seamounts in the mid-Atlantic Azores archipelago show features in common, notably kelp forests of L. ochroleuca at depths below 30 m and Z. tournefortii dominance in shallower waters.     

Feeding of Cardinalfish Epigonus affinis (Epigonidae) from the Seamount of the Northern Part of the Vavilov Ridge,the Atlantic Ocean

Journal of Ichthyology - Food of cardinalfish Epigonus аffinis in the northeastern part of the Vavilov Ridge (Guinean Elevation) consists of the pelagic organisms that are a part of the...     

Description of a New Species of Pelagic Eelpout Melanostigma thalassium sp. nova (Zoarcidae) from Walvis Ridge (Southeastern Atlantic) and Identification Key for Species of the Genus from the Atlantic Ocean

Journal of Ichthyology - A new species Melanostigma thalassium sp. n. is described from the underwater Walvis Ridge (Southeast Atlantic Ocean). This species differs from the other species of the...     

Radiolarian taxa from Southern Ocean sediment traps (Atlantic sector)

Summary This study gives a first inventory of radiolarian taxa collected with sediment traps in different areas of the Southern Ocean (Drake Passage, Powell Basin and Bransfield Strait). It includes 66 taxa or taxa groups of which 46 were already described. Two previously described species groups and 20, yet undescribed, taxa are documented. The name Protocystis bicornis (Haecker) is replaced by P. spinosus as it is a later homonym of P. bicornis (Borgert). The occurrence pattern of the radiolarian taxa indicates distinct differences in the species composition between neritic environments (Bransfield Strait and Powell Basin) and pelagic, open ocean conditions (Drake Passage).     

Bacteria dominate the ammonia-oxidizing community in a hydrothermal vent site at the Mid-Atlantic Ridge of the South Atlantic Ocean

Ammonia oxidation is the first and rate-limiting step of nitrification, which is carried out by two groups of microorganisms: ammonia-oxidizing bacteria (AOB) and the recently discovered ammonia-oxidizing archaea (AOA). In this study, diversity and abundance of AOB and AOA were investigated in five rock samples from a deep-sea hydrothermal vent site at the Mid-Atlantic Ridge (MAR) of the South Atlantic Ocean. Both bacterial and archaeal ammonia monooxygenase subunit A (amoA) gene sequences obtained in this study were closely related to the sequences retrieved from deep-sea environments, indicating that AOB and AOA in this hydrothermal vent site showed typical deep ocean features. AOA were more diverse but less abundant than AOB. The ratios of AOA/AOB amoA gene abundance ranged from 1/3893 to 1/242 in all investigate samples, indicating that bacteria may be the major members responding to the aerobic ammonia oxidation in this hydrothermal vent site. Furthermore, diversity and abundance of AOA and AOB were significantly correlated with the contents of total nitrogen and total sulfur in investigated samples, suggesting that these two environmental factors exert strong influences on distribution of ammonia oxidizers in deep-sea hydrothermal vent environment.     

Probothriocephalus alaini n. sp. (Cestoda: Triaenophoridae) from the deep-sea fish Xenodermichthys copei in the North Atlantic Ocean

Probothriocephalus alaini n. sp. is described from the intestine of the deep-sea fish Xenodermichthys copei (Gill) (Osmeriformes: Alepocephalidae) from the North Atlantic. It resembles most closely the type-species of Probothriocephalus, P. muelleri Campbell, 1977 described from Alepocephalus agassizi Goode & Bean (Alepocephalidae), but it differs in the distribution of the vitelline follicles that form two medially well-separated bands (versus almost circum-cortical in P. muelleri), in the shape of gravid proglottids that are elongate, much longer than wide (always wider than long in P. muelleri), in the size of the body (much larger in the latter species) and a somewhat different shape of the scolex (widely lanceolate versus elongate and tapering anteriorly in P. muelleri). Other congeneric species, described from deep-sea fish of different orders (Myctophiformes and Beryciformes), lack a distinct neck region, their eggs were reported to be non-operculate and they have much more pronounced external segmentation.     

Deep water observations of Lophius piscatorius in the north‐eastern Atlantic Ocean by means of a remotely operated vehicle

To determine whether the current classification of the flathead trout Salmo (Platysalmo) platycephalus , endemic to the upper reaches of the Zamanti River system, Turkey, based solely on morphology, is in congruence with molecular phylogeny, the nucleotide sequence variation in mitochondrial (control region and cytochrome b gene) and nuclear (internal transcribed spacer of rRNA genes) DNA for the flathead trout and various representatives of the genus Salmo was studied. On the basis of pair‐wise genetic distance estimates, the highest differences were found to exist between the flathead trout and S. salar , S. ohridana and S. obtusirostris , whereas the differences between the flathead trout and S. trutta were minimal. All the analyses performed firmly positioned the flathead trout within the Adriatic phylogeographic lineage of S. trutta ; however, the exact position of the flathead trout within the Adriatic cluster was irresolvable. Accordingly, classifying the flathead trout as a subgenus of Salmo is unjustifiable and its reclassification in a lower taxonomic category is suggested by the present study.     

Glyceriformia (Annelida) from the deep sea of the Atlantic sector of the Southern Ocean

The faunas living in the vast deep sea regions around the Antarctic are very poorly known. This is especially true for the biodiversity of polychaetes inhabiting these remote areas. Therefore, we report new morphological data of Glyceriformia from the ANDEEP cruises to the South Atlantic Ocean and the Southern Ocean. Based on benthos samples from three expeditions aboard R/V POLARSTERN, two species of Glyceridae (Glycera capitata, G. diva) and four species of Goniadidae (Bathyglycinde sibogana, B. stepaniantsae, Goniada maculata, Progoniada regularis) were studied. Furthermore, new morphological details (especially for the previously unknown tail) for the rarely found taxon B. stepaniantsae are given. The distribution patterns of the different taxa demonstrated that some species have a high dispersal capability and show an extended level of eurybathy, whereas other species are restricted to the deep sea.     

Discovery of Poromitra macrophthalma (Melamphaidae) in the Atlantic Ocean

Journal of Ichthyology - The occurrence of big-eyed rhinofish Poromitra macrophthalma in the central part of the Atlantic Ocean is reported for the first time. This species was previously known...     

New plagioporines (Digenea: Opecoelidae) from deep-sea fishes of the North Atlantic Ocean

Three new species of digenean are described from demersal fishes taken in deep waters of the northwestern and northeastern Atlantic Ocean: Podocotyle schistotesticulata n. sp. from Antimora rostrata; P. harrisae n. sp. from Coryphaenoides (Lionurus) carapinus; and Gaevskajatrema halosauropsi n. sp. from Halosauropsis macrochir. The status of the nominal species of the genus Podocotyle Dujardin, 1845 is presented in annotated summary, along with a tabulation of the distinctive characteristics of recognised species of the genus. Gaevskajatrema Gibson & Bray, 1982 is discussed and its diagnosis amended.     

Six-year study of meiofaunal dynamics in fish farms in Tenerife (Canary Islands,NE Atlantic Ocean)

In our six-year study, we investigated the dynamics of the meiofaunal community directly under the influence of a fish farm, in adjacent areas and in control areas outside the fish farm influence. Our data showed spatial, seasonal and annual variation in the meiofaunal community under the influence of the fish farm; however, no clear trend is discernible. Copepods are positively associated with mud and very fine sands, which seem to increase with time under the fish farm and adjacent areas, particularly in summer. As shown throughout the study period, copepods could soon take over other components of the community, resulting in a community shift. Our approach to investigate the dynamics of a community with a quick response to environmental changes proves useful to detect early-stage deviations from non-affected areas, which could be critical to distinguish environmental impacts before they cause major shifts in the environment.     

Genetic identification of Carcharhinus sharks from the southwest Atlantic Ocean (Chondrichthyes: Carcharhiniformes)

Sharks of the genus Carcharhinus exhibit subtle morphological differences that are difficult to observe because of the common practice of head and fin removal, making species identification challenging. A total of 317 sharks, commonly called ‘cação‐baia’ (large individuals) or ‘machote’ (small size) in Brazil, were captured by the tuna fleet at the Santos and Guarujá fishery ports on the southeastern coast of Brazil and identified at the species level by multiplex PCR. The Internal Transcribed Spacer 2 region of ribosomal DNA was amplified using universal primers, and species‐specific primers were used for some of the Carcharhinus species. A total of 313 shark carcasses were directly identified by multiplex PCR. Four carcass samples did not amplify; therefore, the partial COI sequences were used to confirm their taxonomic identity. The results show that more than one species was being traded under the same commercial designation, including some Carcharhinus species that are under protection by federal legislation. Such species misidentification directly affects the long‐term sustainability of sharks.     

New data on Lepidion schmidti (Gadiformes: Moridae) from the north-east Atlantic Ocean

A new record of Lepidion schmidti (Gadiformes: Moridae) is reported from the Bay of Biscay (north-east Atlantic Ocean). Lepidion schmidti is a rare and poorly known species, scarcely described in the ichthyological literature. Morphometric and meristic characteristics of the specimen are given. A compilation of the specimens caught in the north-east Atlantic Ocean was carried out and the current status of the species in Atlantic waters is discussed. Lepidion schmidti is characterized mainly by the presence of an inverted V-shaped patch of vomerine teeth and a V-shaped crest on the dorsal surface of the head with the apex anterior. The presence of supernumerary anal fin rays in this species is described for the first time. The results obtained confirm the presence of L. schmidti from the north-east Atlantic Ocean.