Lopes D.A.,Federal University of Rio de Janeiro |
Hajdu E.,Federal University of Rio de Janeiro |
Reiswig H.M.,Natural History Section |
Reiswig H.M.,University of Victoria
Canadian Journal of Zoology | Year: 2011
The present study reports three species of Farrea Bowerbank, 1862 from Campos Basin (southwestern Atlantic): Farrea herdendorfi Duplessis and Reiswig, 2004, Farrea occa Bowerbank, 1862, and Farrea campossinus sp. nov. This is the first record of F. herdendorfi for the South Atlantic and only the second record of the species worldwide. Farrea occa is described and reported to form mass occurrences in the area's sponge and coral banks, as seen in extensive video recording undertaken between 900 and 1100 m depth. The new species approaches Farrea foliascens Topsent, 1906 very closely, but differs in that its hooked anchorate clavules are much larger and the meshes of its dictyonal framework rather more irregular. Our thoughts on whether the proposed new species deserved species or subspecies rank led to an investigation on the usage of subspecies rank in Porifera. A historical overview, mainly contrasting Demospongiae and Hexactinellida is offered here. We concluded that no rule of thumb is readily made out from the comparative analysis of various authors' taxonomic decisions. Until one such agreement is achieved, it appears to us that naming new subspecies should be objectively argued for, or better, totally avoided, as a useless further dimension to taxonomic uncertainty in poriferan classification.
Morgan N.B.,Florida State University |
Cairns S.,Smithsonian Institution |
Reiswig H.,Natural History Section |
Reiswig H.,University of Victoria |
Baco A.R.,Florida State University
Deep-Sea Research Part I: Oceanographic Research Papers | Year: 2015
In the North Pacific Ocean, the seamounts of the Hawaiian Archipelago and the Mid-Pacific Mountains are connected by Necker Ridge, a 600. km-long feature spanning a depth range of 1400-4000. m. The Necker Ridge is a part of a large area of the central and western Pacific under consideration for cobalt-rich manganese crust mining. We describe the fauna and community structure of the previously unsampled Necker Ridge based on explorations with the submersible Pisces IV. On five pinnacles and a portion of the Ridge ranging from 1400 to 2000. m deep, 27 transects were recorded using HD video, and voucher specimens were collected to aid in species identification. The video was analyzed to identify and count the megafauna found on each transect and to characterize the substrate. Diversity increased from south to north along the feature. There was a significant difference in community structure between southern and northern pinnacles, with southern pinnacles dominated by crinoids of the Family Charitometridae and northern pinnacles dominated by octocorals, especially the Families Isididae and Chrysogorgiidae. DistLM demonstrated a correlation between community structure on the pinnacles and at least six environmental variables, including latitude, sediment cover, and oxygen concentration, but not including depth. The discontinuous and patchy nature of these distinct megafaunal communities highlights growing evidence that cobalt-rich seamounts are highly heterogeneous habitats, and that managing seamounts may require more complex regulations than treating them as a single ecological unit. These results suggest that extensive community analysis should occur at a given site to determine management priority areas, prior to consideration of that site for exploitation of natural resources. © 2015 Elsevier Ltd.
Reiswig H.M.,Natural History Section |
Reiswig H.M.,University of Victoria |
Dohrmann M.,Ludwig Maximilians University of Munich
Zoological Journal of the Linnean Society | Year: 2014
Three new species and a new genus of dictyonal Hexactinellida (Hexasterophora: Sceptrulophora: Euretidae and Auloplacidae) are described from hard-bottom communities of the West Indies. The holotypes were all collected by manned submersibles operated by the Harbor Branch Oceanographic Institute between 2006 and 2011, and remained in excellent physical condition at the time of their examination and description. As a result of their relatively recent collection and ethanol storage, molecular markers established previously for the phylogenetics of glass sponges were retrievable from all three holotypes. These are the first sequences for their respective genera, Conorete, Verrucocoeloidea, and Dictyoplaxgen.nov. In addition, the first sequences of the genus Lefroyella could be obtained. Because the only (alleged) member of the family Euretidae previously included in molecular phylogenetic studies turned out to belong to the recently resurrected family Auloplacidae (i.e. Dictyoplaxgen.nov.), in the present study the phylogenetic position of Euretidae within Sceptrulophora could be inferred for the first time. Furthermore, the increased taxon sampling allowed us to conduct a first test of the monophyly of Euretidae and one of its two subfamilies, Euretinae, with molecular data. Maximum-likelihood phylogenetic analysis revealed a close relationship between Euretidae and Farreidae, but also indicated that Euretidae might be paraphyletic with respect to Farreidae. The monophyly of subfamily Euretinae, at least in its current scope, was strongly rejected by the molecular data, in line with results from other hexactinellid families with a subfamilial division. The genus Sarostegia, which was only recently provisionally moved to Euretidae, is here transferred to an incertae sedis position within the classification of Sceptrulophora, because it is clearly unrelated to the other three included euretids. Besides from that, we refrain from any changes to the classification of Euretidae until more genera of this most diverse but poorly defined sceptrulophoran family are sampled for molecular systematic studies. © 2014 The Linnean Society of London.
Reiswig H.M.,Natural History Section |
Reiswig H.M.,University of Victoria
Journal of the Marine Biological Association of the United Kingdom | Year: 2014
Six new species of Hexactinellida are described from hard bottom communities of shelf, canyon and seamounts of the west coast of North America: Washington, British Columbia and Gulf of Alaska. They were collected by a variety of methods, trawl, manned submersible, and robot submersible, and hence vary greatly in condition. The six species comprise additions to five different families of the subclass Hexasterophora, Farreidae (Farrea omniclavata sp. nov. and F. truncata sp. nov.), Euretidae (Chonelasma oreia sp. nov.), Euplectellidae (Amphidiscella lecus sp. nov.), Leucopsacidae (Oopsacas olympicus sp. nov.) and Rossellidae (Acanthascus malacus sp. nov.). These additions represent an increase of 29% to the known species of Hexactinellida in this area. A completely unique form of defended tabulate stalk is described for A. lecus. The species Chauoplectella spinifera is transferred to Oopsacas. © Marine Biological Association of the United Kingdom, 2013.
Copley C.R.,Natural History Section |
Winchester N.N.,University of Victoria
Canadian Journal of Forest Research | Year: 2010
In anthropogenically disturbed forested riparian ecosystems that contain vagile organisms, we expect dispersal to be a factor that determines patterns of diversity that differ from similar, but continuous, undisturbed habitats. We studied the effects of habitat alteration on community composition by characterizing the spider assemblage of a riparian corridor in an ancient forest and a regenerating coniferous forest in the Carmanah Valley, Vancouver Island, British Columbia. Spiders were collected over a 15 month period using Malaise traps set along transects perpendicular to Carmanah Creek. We recorded 76 genera and 113 species representing 23 families. In both the regenerating coniferous forest and the ancient forest, a large proportion of the species were of the family Linyphiidae. Species abundance was similar in the two habitats but diversity was greater in the regenerating coniferous forest. The ancient forest was dominated by the web-building guild. Spatial autocorrelation analysis revealed no overall pattern in the species assemblages relative to the riparian corridor. Bray-Curtis similarity measure and principal components analysis results indicate that spider assemblages in the two habitats were significantly different in composition. These results suggest that habitat changes affect assemblages of spiders by altering dispersal, and these responses are evident a decade after disturbance.
PubMed | Georgia Aquarium, University of Washington, Brown University, University of North Carolina at Wilmington and 7 more.
Type: | Journal: PeerJ | Year: 2015
What are the greatest sizes that the largest marine megafauna obtain? This is a simple question with a difficult and complex answer. Many of the largest-sized species occur in the worlds oceans. For many of these, rarity, remoteness, and quite simply the logistics of measuring these giants has made obtaining accurate size measurements difficult. Inaccurate reports of maximum sizes run rampant through the scientific literature and popular media. Moreover, how intraspecific variation in the body sizes of these animals relates to sex, population structure, the environment, and interactions with humans remains underappreciated. Here, we review and analyze body size for 25 ocean giants ranging across the animal kingdom. For each taxon we document body size for the largest known marine species of several clades. We also analyze intraspecific variation and identify the largest known individuals for each species. Where data allows, we analyze spatial and temporal intraspecific size variation. We also provide allometric scaling equations between different size measurements as resources to other researchers. In some cases, the lack of data prevents us from fully examining these topics and instead we specifically highlight these deficiencies and the barriers that exist for data collection. Overall, we found considerable variability in intraspecific size distributions from strongly left- to strongly right-skewed. We provide several allometric equations that allow for estimation of total lengths and weights from more easily obtained measurements. In several cases, we also quantify considerable geographic variation and decreases in size likely attributed to humans.
Bennett R.,Natural History Section |
Copley C.,Natural History Section |
Copley D.,Natural History Section
Zootaxa | Year: 2016
Species of North American Cybaeus L. Koch (Araneae: Dictynoidea: Cybaeidae) are classified in Holarctic and Californian clades. We review the Nearctic species of the Holarctic clade of these common moist-forest spiders. Twenty-one species grouped in informal tetricus (nine species) and angustiarum (twelve species) groups based on female genitalic characters are recognized, including four new species endemic to the western Nearctic: C. rothi Bennett sp. nov. (tetricus group) and C. charlesi Bennett sp. nov., C. harrietae Bennett sp. nov., and C. solanum Bennett sp. nov. (angustiarum group). Other Nearctic species in the tetricus group are C. cascadius Roth 1952, C. conservans ChamBerlin & Ivie 1932, C. constrictus ChamBerlin & Ivie 1942, C. eutypus ChamBerlin & Ivie 1932, C. morosus Simon 1886, C. multnoma Cham-Berlin & Ivie 1942, C. paralypropriapus Bennett 2009, and C. waynei Bennett 2009. Other Nearctic species in the angustiarum group are C. bulbosus Exline 1935, C. giganteus Banks 1892, C. patritus Bishop & Crosby 1926, C. reticulatus Simon 1886, C. scopulatus ChamBerlin & Ivie 1942, C. shoshoneus ChamBerlin & Ivie 1932, C. signifer Simon 1886, C. silicis Barrows 1919, and C. sinuosus Fox 1937. Approximately half of the Nearctic Cybaeus species of the Holarctic clade are relatively widely distributed and frequently encountered; the remaining species have restricted ranges. Descrip-tions, illustrations, and range maps are provided for all species and identification keys are also included. © Copyright 2016 Magnolia Press.
Larson S.,Seattle Aquarium |
Ramsay C.,Seattle Aquarium |
Cosgrove J.A.,Natural History Section
Diversity | Year: 2015
A total of 77 giant Pacific octopus, Enteroctopus dofleini, tissue samples were collected from the Oregon Coast (OR), Neah Bay Washington (NB), Puget Sound Washington (PS) and the southeast coast of Vancouver Island, British Columbia, Canada (BC) for genetic analyses. A suite of eight variable microsatellite markers developed from giant Pacific octopuses were amplified in these samples to determine population diversity, structure, relatedness and paternity. The majority of loci met Hardy-Weinberg equilibrium expectations within each population. We found moderate genetic diversity (average observed heterozygosity = 0.445, range = 0.307-0.515 and average expected heterozygosity = 0.567, range = 0.506-0.696) and moderate population structuring with distinct separation of groups (FST values ranged from 0.101 between BC and PS to 0.237 between BC and NB). Several egg strings from the BC population were collected from three female octopus dens for relatedness and paternity analyses. Results suggest strong support for multiple paternity within one egg clutch with progeny sired by between two to four males. © 2015 by the authors.
PubMed | Natural History Section
Type: | Journal: Zootaxa | Year: 2015
Apostenus ducati sp. nov. is described from montane areas in or adjacent to the Columbia River basin of southeastern British Columbia in Canada and northern Washington and northwestern Montana in the United States. This is the second Nearctic species of this primarily Palaearctic genus. Unlike most liocranids, A. ducati apparently is restricted to open rocky habitats, such as talus and scree slopes, and on mountain peaks. Throughout most of its range, specimens occur in low numbers and populations are patchily distributed. Also, populations appear to be concentrated in the upper regions of the Flathead River watershed in British Columbia, an area of significant and competing ecological and economic values. Because of these factors, A. ducati is potentially a species of conservation concern.
PubMed | Natural History Section
Type: Journal Article | Journal: Zootaxa | Year: 2016
Species of North American Cybaeus L. Koch (Araneae: Dictynoidea: Cybaeidae) are classified in Holarctic and Californian clades. We review the Nearctic species of the Holarctic clade of these common moist-forest spiders. Twenty-one species grouped in informal tetricus (nine species) and angustiarum (twelve species) groups based on female genitalic characters are recognized, including four new species endemic to the western Nearctic: C. rothi Bennett sp. nov. (tetricus group) and C. charlesi Bennett sp. nov., C. harrietae Bennett sp. nov., and C. solanum Bennett sp. nov. (angustiarum group). Other Nearctic species in the tetricus group are C. cascadius Roth 1952, C. conservans Chamberlin & Ivie 1932, C. constrictus Chamberlin & Ivie 1942, C. eutypus Chamberlin & Ivie 1932, C. morosus Simon 1886, C. multnoma Chamberlin & Ivie 1942, C. paralypropriapus Bennett 2009, and C. waynei Bennett 2009. Other Nearctic species in the angustiarum group are C. bulbosus Exline 1935, C. giganteus Banks 1892, C. patritus Bishop & Crosby 1926, C. reticulatus Simon 1886, C. scopulatus Chamberlin & Ivie 1942, C. shoshoneus Chamberlin & Ivie 1932, C. signifer Simon 1886, C. silicis Barrows 1919, and C. sinuosus Fox 1937. Approximately half of the Nearctic Cybaeus species of the Holarctic clade are relatively widely distributed and frequently encountered; the remaining species have restricted ranges. Descriptions, illustrations, and range maps are provided for all species and identification keys are also included.