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Abstract

The first records from samples from the IceAGE cruise ME85/3 in 2011 include seven species of Caudofoveata with a distribution range in Icelandic waters. From this first cruise of the project, two new records for Iceland have been registered. Psilodens balduri sp. n. is new to science and Falcidens halanychi , with a known distribution in the American North−Atlantic, is new to Iceland. The current study thus increases the number of known caudofoveate species around Iceland to nine.
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Abstract

During August–September 2011, scientists aboard the R/V Meteor sampled marine animals around Iceland for the IceAGE project (Icelandic marine Animals: Genetics and Ecology). The last sample was taken at a site known as “The Rose Garden” off north− eastern Iceland and yielded a large number of two species of Proneomenia (Mollusca, Aplacophora, Solenogastres, Cavibelonia, Proneomeniidae). We examined isolated sclerites, radulae, and histological section series for both species. The first, Proneomenia sluiteri Hubrecht, 1880, was originally described from the Barents Sea. This is the first record of this species in Icelandic waters. However, examination of aplacophoran lots collected during the earlier BIOICE campaign revealed additional Icelandic localities from which this species was collected previously. The second represents a new species of Proneomenia, which, unlike other known representatives of the genus, broods juveniles in the mantle cavity. We provide a formal description, proposing the name Proneomenia custodiens sp. n. Interestingly, the sclerites of brooded juveniles are scales like those found in the putatively plesiomorphic order Pholidoskepia rather than hollow needles like those of the adults of this species. Cytochrome c oxidase subunit I (COI) DNA barcode sequences are provided for both species of Proneomenia .
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Abstract

Zoidbergus , a new genus of Apseudidae, is described for deep−water Tanaidacea classified previously in the genus Apseudes : A. abyssalis , A. lagenirostris , A. paragracilis , A. tenuimanus , A. tenuis and A. vicinus . The new genus differs from Apseudes s. str. by having acute eyelobes without visual elements, elongated second article of mandibular palp, and carpus of pereopods 2–3 longer than or as long as propodus. Zoidbergus gen. n. can also be distinguished from Apseudes s. str. by the lack of large bases of pereopods 5–6 covered by numerous plumose setae as well as the lack of dense plumose setation on lateral margins of pereonites and pleonites. By general body habitus and structure of pereopods Zoidbergus gen. n. resembles the apseudid genus Leviapseudes , although the genera can be distinguished by the presence of leaf−shaped seta and elongated pereonites 3–6 in Leviapseudes . Based on specimens collected during the IceAGE1 Cruise in September 2011, Zoidbergus tenuis is redescribed and morphology of an undescribed species Zoidbergus sp. A is provided. Supplementary description for Zoidbergus vicinus is given based on type material from Statens Naturhistoriske Museum, University of Copenhagen. Additionally comments on the other deep water Apseudes species: A. siegi and A. vitjazi , are given.
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Abstract

Based on material collected during the BIOICE project off Iceland, the taxonomy and distribution of seventeen species (11 genera) of polychaetous annelids belonging to the family Ampharetidae (Annelida; Polychaeta) is reviewed. Eleven of these species were previously reported in the area or nearby areas: Amage auricula , Anobothrus gracilis , Glyp− hanostomum pallescens , Grubianella klugei , Lysippe fragilis , L. labiata , L. sexcirrata , L. vanelli , Samythella elongata, Sosane bathyalis and S. wireni . Five species, Amage benhami, Melinnampharete eoa, Noanelia hartmanae , Ymerana pteropoda and Zatsepinia rittichae , either never or only once reported after original description, are redescribed or discussed. A potentially new species, Amage sp., is described but not named because only one specimen is present. Several body characters of high taxonomic relevance in Ampharetidae are reviewed using SEM. The distribution of each species off Iceland is provided.
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Abstract

The 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 path− ways). To test potential colonization pathways we quantified geographic variation in nu− clear and mitochondrial markers from Atlantic samples of Nucula atacellana, a pan−Atlantic deep−sea protobranch bivalve, using N. profundorum in the eastern central Pacific as an outgroup. We combined existing 16S data from North and South Atlantic populations of N. atacellana with 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 in N. atacellana , which suggests that colonization pathways may differ significantly between shallow− and deep−water fauna.
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Abstract

Brittle stars (Echinodermata: Ophiuroidea) comprise over 2,000 species, all of which inhabit marine environments and can be abundant in the deep sea. Morphological plasticity in number and shape of skeletal parts, as well as variable colors, can complicate correct species identification. Consequently, DNA sequence analysis can play an important role in species identification. In this study we compared the genetic variability of the mitochondrial cytochrome c subunit I gene (COI) and the nuclear small subunit ribosomal DNA (SSU, 18S rDNA) to morphological identification of 66 specimens of 11 species collected from the North Atlantic in Icelandic waters. Also two species delimitation tools, Automatic Barcode Gap Discovery (ABGD) and General Mixed Yule Coalescence Method (GMYC) were performed to test species hypotheses. The analysis of both gene fragments was successful to discriminate between species and provided new insights into some morphological species hypothesis. Although less divergent than COI, it is helpful to use the SSU region as a complementary fragment to the barcoding gene.
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Abstract

In Tanaidacea morphological identification of male individuals to the species level is complicated by two factors: the presence of multiple male stages/instars confuse the assessment of sexual stage while strong sexual dimorphism within several families obscures the morphological affinities of undescribed males to described females. Males of Paratanaoidea are often morphologically quite different from females and have not been discovered for most genera so far, which has led to the assumption that some tanaidaceans might have parthenogenetic reproduction or simply have undeveloped secondary sex traits. As a part of the IceAGE project (Icelandic marine Animals: Genetics and Ecology), with the support of molecular methods, the first evidence for the existence of highly dimorphic (swimming) males in four families of the superfamily Paratanaoidea (Agathotanaidae, Cryptocopidae, Akanthophoreidae, and Typhlotanaidae) is presented. This study suggests that these males might be the next instars after juvenile or preparatory males, which are morphologically similar to females. It has been assumed that “juvenile” males with a restricted ability for swimming ( e.g. , undeveloped pleopods) have matured testes, are capable of reproduction, and mate with females nearby, while swimming males can mate with distant females. Our explanation of the dimorphism in Tanaidomorpha lies in the fact that males of some species ( e.g. , Nototanais ) retain the same lifestyle or niche as the females, so secondary traits improve their ability to guard females and successfully mate. Males of other species that have moved into a regime (niche) different than that of the female have acquired complex morphological changes ( e.g. , Typhlotanais ).
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Abstract

During the IceAGE ( Icelandic marine Animals – Genetics and Ecology ) expeditions in waters around Iceland and the Faroe Islands in 2011 and 2013, visual assessments of habitats and the study of surface sediment characteristics were undertaken in 119–2750 m water depth. Visual inspection was realized by means of an epibenthic sled equipped with a digital underwater video camcorder and a still camera. For determination of surface sediment characteristics a subsample of sediment from box corer samples or different grabs was collected and analyzed in the lab. Muddy bottoms predominated in the deep basins (Iceland Basin, Irminger Basin, deep Norwegian and Iceland Seas), while sand and gravel dominated on the shelves and the ridges, and in areas with high currents. Organic contents were highest in the deep Norwegian and Iceland Seas and in the Iceland Basin, and at these sites dense aggregations of mobile epibenthic organisms were observed. Large dropstones were abundant in the Iceland Sea near the shelf and in the Denmark Strait. The dropstones carried diverse, sessile epibenthic fauna, which may be underestimated using traditional sampling gear. The paper supplies new background information for studies based on IceAGE material, especially studies related to ecology and taxonomy.
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Abstract

The eurybathic isopod species Chelator insignis shows a wide distribution south of Iceland. We analysed 51 specimens from shelf (213–305 m depth), slope (885–891 m and 1380–1390 m depth) and deep−sea habitats (2750 m) south of Iceland with different DNA markers. A fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) was studied for 47 specimens, 16S was studied for 36 specimens, and a fragment for the 18S rRNA gene could be amplified for 11 specimens. For the COI data, specimens clustered into five distinct lineages each separated by ³ 20% uncorrected pairwise distances. Both the mitochondrial 16S and the nuclear 18S sequence data further support this deep divergence, suggesting the presence of overlooked species inside the nominal C. insignis . Populations on the shelf occurring east and west of the Reykjanes Ridge were genetically identical suggesting that this ridge is not a barrier to gene flow. However, populations from different depth ranges differed substantially. Our multi−gene analysis suggests that the newly found species likely have more narrow vertical distribution ranges and highlights a possible role of bathymetry in speciation processes.
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Abstract

Field and laboratory protocols that originally led to the success of published studies have previously been only briefly laid out in the methods sections of scientific publications. For the sake of repeatability, we regard the details of the methodology that allowed broad−range DNA studies on deep−sea isopods too valuable to be neglected. Here, a com− prehensive summary of protocols for the retrieval of the samples, fixation on board research vessels, PCR amplification and cycle sequencing of altogether six loci (three mitochondrial and three nuclear) is provided. These were adapted from previous protocols and developed especially for asellote Isopoda from deep−sea samples but have been successfully used in some other peracarids as well. In total, about 2300 specimens of isopods, 100 amphipods and 300 tanaids were sequenced mainly for COI and 16S and partly for the other markers. Although we did not set up an experimental design, we were able to analyze amplification and sequencing success of different methods on 16S and compare success rates for COI and 16S. The primer pair 16S SF/SR was generally reliable and led to better results than universal primers in all studied Janiroidea, except Munnopsidae and Dendrotionidae. The widely applied universal primers for the barcoding region of COI are problematic to use in deep−sea isopods with a success rate of 45–79% varying with family. To improve this, we recommend the development of taxon−specific primers.
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Abstract

Collections of munnopsid isopods of the BIOICE (Benthic Invertebrates of Icelandic Waters; 1991–2004) and the IceAGE1 (Icelandic Marine Animals: Genetics and Ecology; since 2011) expeditions included ten species of the genus Eurycope G.O. Sars, 1864, thereof are two species new to science. Thus, the descriptions of the two new species are presented herein. Eurycope elianae sp. n. is distinguished from the other species of the genus mainly by two long, slightly robust, simple setae on the tip of the rostrum in combination with the size and shape of the rostrum itself. E elianae sp. n. shares the presence of two long, slightly robust, simple seta on the tip of the rostrum with E. tumidicarpus . The shape of the rostrum itself is more similar to E. inermis and species of the E. complanata complex. E. aculeata sp. n. is characterized by possessing dorsomedial acute projections on pereonites 5–7, which is unusual for the genus. E. aculeata sp. n. is most similar to E. cornuta . Both new species are, so far, known only from localities south of the Greenland−Scotland Ridge.
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Abstract

Sediment samples and hydrographic conditions were studied at 28 stations around Iceland. At these sites, Conductivity−Temperature−Depth (CTD) casts were conducted to collect hydrographic data and multicorer casts were conducted to collect data on sediment characteristics including grain size distribution, carbon and nitrogen concentration, and chloroplastic pigment concentration. A total of 14 environmental predictors were used to model sediment characteristics around Iceland on regional scale. Two approaches were used: Multivariate Adaptation Regression Splines (MARS) and randomForest regression models. RandomForest outperformed MARS in predicting grain size distribution. MARS models had a greater tendency to over− and underpredict sediment values in areas outside the environmental envelope defined by the training dataset. We provide first GIS layers on sediment characteristics around Iceland, that can be used as predictors in future models. Although models performed well, more samples, especially from the shelf areas, will be needed to improve the models in future.
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