Search results

Title: Dietary variability in two common Alaskan skates (Bathyraja interrupta and Raja rhina)
Description: Determining trophic relationships within and among species can provide insight into the structure and function of an ecosystem, and can inform the development of multi-species monitoring and management plans. The goal of this study was to address the need for dietary and trophic information of two common and abundant skates in Prince William Sound (PWS), the Bering skate, Bathyraja interrupta, and longnose skate, Raja rhina. Based on identification and analysis of stomach content data, both species were found to be generalist predators with diets dominated by crustaceans and supplemented with teleosts. The primary source of dietary variability for each species was total length, with spatial variables (i.e., latitude, longitude, and depth) also explaining a large portion of total dietary variability in the Bering skate. However, only a small proportion of the total intraspecific dietary variation was accounted for among the analyzed variables, suggesting substantial individual-based differences in the feeding habits of each species. Trophic level estimates indicated that the Bering skate and longnose skates <100 cm total length (TL) were secondary consumers, whereas longnose skates ≥100 cm TL were more piscivorous, tertiary consumers. Significant interspecific dietary differences were also evident, suggesting trophic separation, likely as a function of skate size. Given their abundance and generalistic feeding behavior, PWS skates can provide a means of monitoring demersal community health; information about their foraging ecology will be valuable in gaining a better understanding of trophodynamics within the PWS food web.
Author: Kemper, Bizzarro, Ebert

Title: Pristiophorus lanae sp. nov., a new sawshark species from the western north Pacific, with comments on the genus Pristiophorus Müller & Henle, 1837 (Chondrichthyes: Pristiophoridae)
Description: A new species of sawshark, Pristiophorus lanae sp. nov., is described from off the Philippine Islands. The new species is the second member of the genus Pristiophorus described from the western North Pacific and can be separated from its closest geographic congener, P. japonicus, by having fewer rostral teeth in front of rostral barbels (17-26 versus 25-32), mouth at corners extending forward to below the rear margin of the eye versus extending below the rear one-third of eye margin, a greater mouth width at 6.9-7.8 times into pre-oral length (versus 5.8-6.9), eye length into head length (15.6-15.9 versus 9.8-13.2), mouth width into head length 9.0-10.0 versus 7.4-8.5 times, head width at nostrils 5.2-6.1 times into pre-orbital length versus 3.9-4.9 times, shorter prebarbel length (from snout tip to barbel) of 50.7-54.5% of preoral length versus 53.6-59.2%, a snout angle of 10.6-13.0° versus 12.4°-14.6°, and lateral trunk denticles with flat crowns that are imbricated versus erect crowns that are not imbricated. The number of monospondylous vertebrae is slightly lower in P. lanae (43-48) versus P. japonicus (51-52). The genus is reviewed, with a revised key to its species presented. © 2013 Magnolia Press., Cited By (since 1996):1, Export Date: 11 February 2014, Source: Scopus
Author: Ebert, Wilms
Date: 2013-01-01T00:00:00Z

Title: First Record of the Dwarf False Catshark, Planonasus parini (Carcharhniformes Pseudotriakis) from Sri Lanka
Description: The dwarf false catshark, Planonasus parini, is a soft, stout to slender bodied poorly known deepwater shark, known previously only from the Socotra Islands, southwestern India, and possibly off the Maldives. Here we report on the first record of the Dwarf False Catshark from Sri Lanka, Southwest Bay of Bengal. The specimen, estimated to be approximately 55 cm in total length, was caught by a local fisherman between 300 m and 600 m depth off Trincomalee Outer Harbour near Norway Inlet (08 29'.136N, 81 14'.783E).
Author: Ebert, De Silva, Goonewardena

Title: Etmopterus alphus n. sp.: a new lanternshark (Squaliformes: Etmopteridae) from the south-western Indian Ocean
Description: Article in Press, A new species of lanternshark, Etmopterus alphus (Squaliformes: Etmopteridae), is described from the south-western Indian Ocean. The new species resembles other members of the ‘Etmopterus lucifer’ clade in having linear rows of dermal denticles and most closely resembles E. molleri from the south-western Pacific. The new species is fairly common along the upper continental slopes off central Mozambique, at depths between 472 and 558 m, and is also found on the southern Madagascar Ridge in 650–792 m depth. It can be distinguished from other members of the E. lucifer clade by a combination of characteristics, including arrangement of flank and caudal markings, dimension of flank markings and shape, size and arrangement of dermal denticles along the body. Molecular analysis further supports the distinction of E. alphus from other members of the E. lucifer clade.
Author: Ebert, Straube, Leslie, Weigmann

Title: An overview on the role of Hexanchiformes in marine ecosystems,
Description: The large size, high trophic level and wide distribution of Hexanchiformes (cow and frilled sharks) should position this order as important apex predators in coastal and deep-water ecosystems. This review synthesizes available information on Hexanchiformes, including information not yet published, with the purpose of evaluating their conservation status and assessing their ecological roles in the dynamics of marine ecosystems. Comprising six species, this group has a wide global distribution, with members occurring from shallow coastal areas to depths of c. 2500 m. The limited information available on their reproductive biology suggests that they could be vulnerable to overexploitation (e.g. small litter sizes for most species and suspected long gestation periods). Most of the fishing pressure exerted on Hexanchiformes is in the form of commercial by-catch or recreational fishing. Comprehensive stock and impact assessments are unavailable for most species in most regions due to limited information on life history and catch and abundance time series. When hexanchiform species have been commercially harvested, however, they have been unable to sustain targeted fisheries for long periods. The potentially high vulnerability to intense fishing pressure warrants a conservative exploitation of this order until thorough quantitative assessments are conducted. At least some species have been shown to be significant apex predators in the systems they inhabit. Should Hexanchiformes be removed from coastal and deep-water systems, the lack of sympatric shark species that share the same resources suggests no other species would be capable of fulfilling their apex predator role in the short term. This has potential ecosystem consequences such as meso-predator release or trophic cascades. This review proposes some hypotheses on the ecology of Hexanchiformes and their role in ecosystem dynamics, highlighting the areas where critical information is required to stimulate research directions. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles., CODEN: JFIBA, , , Fish and Fisheries
Author: Barnett, Braccini, Awruch, Ebert
Date: 2012-01-01T00:00:00Z

Title: A new species of chimaera, Hydrolagus melanophasma sp. nov. (Chondrichthyes: Chimaeriformes: Chimaeridae), from the eastern North Pacific.,
Description: A new species of chimaera, Hydrolagus melanophasma sp. nov. (Chimaeridae), is described from the eastern North Pacific. It is distinct from other eastern Pacific chimaeroids by the following characteristics: a large slightly curved dorsal fin spine extending beyond dorsal fin apex, a long second dorsal fin of uniform height throughout, large pectoral fins extending beyond the pelvic fin insertion when laid flat, trifid claspers forked for approximately one-quarter the total clasper length and a uniform black coloration throughout. The new species is compared to other eastern Pacific members of the genus Hydrolagus including H. alphus, H. colliei, H. macrophthalmus, and H. mccoskeri. Remote Operated Vehicle (ROV) video footage has identified and documented Hydrolagus melanophasma from the Gulf of California. ROV observations suggest that individuals typically occur over soft-bottom habitats or cobble patches with minimal vertical relief. This is in contrast to other eastern Pacific Hydrolagus species that tend to occur in areas of high rocky relief. The known distribution of this new species at present extends from southern California, U.S.A., along the Pacific coast of Baja California, Mexico, and into the Gulf of California. © 2009 Magnolia Press., Cited By (since 1996):6, , , Fish and Fisheries
Author: James, Ebert, Long, Didier
Date: 2009-01-01T00:00:00Z

Title: Introduction to the systematics and biodiversity of sharks, rays, and chimaeras (Chondrichthyes) of Taiwan
Description: All 13 orders of chondrichthyan fishes occur in Taiwanese waters, representing 52 chondrichthyan families (31 shark, 19 batoid, 2 chimaeroid) and 98 genera (64 shark, 31 batoid, 3 chimaeroid). A total of 119 shark, 58 batoid, and 4 chimaera species may occur in the waters surrounding Taiwan, pending taxonomic resolution of some groups. Of the 34 nominally described species from Taiwan, 17 are currently considered valid. The majority of named species occurred during two peak periods in Taiwanese chondrichthyan research; the first between 1959-63, when 13 nominal species were described, of which 7 remain valid today, and a second peak period between 2003-13 when 9 nominal species were described, of which 6 remain valid. The overall species diversity of Taiwan's chondrichthyan fauna is comparable to that of other adjacent marine zoogeographic hotspots, e.g. Japan (126 shark, 75 batoid, 11 chimaeroid species) and the Philippines (81 shark, 46 batoid, 2 chimaeroid species). The Carcharhiniformes, Squaliformes, Myliobatiformes, and Rajiformes are the most dominant orders in terms of abundance and species-richness within this region. Each of these groups may increase in relative diversity with improved taxonomic resolution resulting from the incorporation of molecular tools and renewed morphological studies. Improved identification of Taiwan's chondrichthyan fauna will aid in developing better conservation and management practices. © 2013 Magnolia Press., Export Date: 11 February 2014, Source: Scopus
Author: Ebert, Ho, White, De Carvalho
Date: 2013-01-01T00:00:00Z

Title: A revision of the western North Pacific swellsharks, genus Cephaloscyllium Gill 1862 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae), including descriptions of two new species.,
Description: The genus Cephaloscyllium Gill 1862 (Chondrichthyes, Carcharhiniformes, Scyliorhinidae) until recently had only two species recognized, C. isabellum [= C. umbratile (Jordan & Fowler 1903)] and C. fasciatum Chan 1966, from the western North Pacific (WNP), with one dubious species, C. formosanum, having been described by Teng in 1962. Recently, three additional species were described, C. circulopullum Yano et al. 2005, C. sarawakensis Yano et al. 2005, and C. parvum Inoue & Nakaya 2006 from this region. Here we present a revision of this genus for the WNP, including redescriptions of C. fasciatum and C. umbratile based on the holotypes, a re-examination of the recently described species, and descriptions of two new species from Taiwan. Cephaloscyllium umbratile can be distinguished from its congeners based on maximum size, length of first dorsal-fin base, anal-caudal space, and dorsal-caudal space. We conclude, based on a comparison of C. parvum and C. sarawakensis, that the former is a junior synonym of the latter species. The two new Taiwanese species can be separated from other WNP species by color pattern, shape of the anterior nasal flap, anal and dorsal-fin size, internarial width, and mouth size. Finally, we present a revised dichotomous key to the WNP Cephaloscyllium recognizing six contemporary taxa: C. circulopullum, C. fasciatum, C. sarawakensis, C. umbratile, C. pardelotum sp. nov. and C. maculatum sp. nov. Copyright © 2008 Magnolia Press., Cited By (since 1996):2, , , Fish and Fisheries
Author: Schaaf-Da Silva, Ebert
Date: 2008-01-01T00:00:00Z

Title: Chlamydoselachus africana, a new species of frilled shark from southern Africa (Chondrichthyes, Hexanchiformes, Chlamydoselachidae),
Description: Frilled sharks (Chondrichthyes, Hexanchiformes, Chlamydoselachidae), long believed to be a monotypic family and genus, consisting of a single wide ranging species, Chlamydoselachus anguineus (Garman, 1884), is now known to contain at least two species. A new species of frilled shark, Chlamydoselachus africana, sp. nov., is described from five specimens collected from southern Africa. The new species, although difficult to distinguish externally from the well known C. anguineus, differ internally by the structural differences in the chondrocranium, lower total vertebral and spiral valve counts, and pectoral-fin radial counts. The new species, Chlamydoselachus africana, is known from off southern Angola, Namibia, and South Africa. © 2009 · Magnolia Press., Cited By (since 1996):3, Fish and Fisheries, ,
Author: Ebert, Compagno
Date: 2009-01-01T00:00:00Z

Title: Trophic ecology of the gopher rockfish Sebastes carnatus inside and outside of central California marine protected areas
Description: Marine protected areas (MPAs) can potentially alter food web dynamics by increasing the density of fishes within their borders. Such increases in the density of potential competitors can cause generalist predators to contract the scope of their diets. This study investigated the effects of increased conspecific fish density on the diets of gopher rockfish Sebastes carnatus at a 35 yr old MPA in Point Lobos, California, and at 4 newly established MPAs in Año Nuevo, Point Lobos, Piedras Blancas, and Point Buchon in central California. Analyses were conducted for 707 stomachs collected from 2007 to 2009. Diets did not differ inside versus outside the old Point Lobos MPA in terms of prey richness, evenness, composition, or gopher rockfish trophic level. However, fish outside the MPA had greater levels of individual specialization. No consistent differences in these metrics were observed inside versus outside the 4 new MPAs, although prey composition and evenness did differ significantly among geographic locations. Diets at Año Nuevo, the most northern and shallow location, consisted predominantly of Cancer spp. and porcelain crabs (Porcellanidae), while diets from southern, deeper locations were dominated by brittle stars (Ophiuroidea). The case study of the old Point Lobos MPA indicates that fish feeding ecology may not change in an MPA after several decades. Differences in prey observed among geographic locations suggest variation in the community composition among central California's new MPAs, which may influence the effect of each MPA on food web dynamics over time. Copyright © 2015 Inter-Research., Export Date: 19 October 2015
Author: Loury, Bros, Starr, Ebert, Cailliet
Date: 2015-01-01T00:00:00Z

Title: Biodiversity, Life History, and Conservation of Northeastern Pacific Chondrichthyans
Description: The sharks, batoids, and chimaeras, collectively the class Chondrichthyes, are one of the most successful groups of fishes, with over 1250 species globally. Recent taxonomic revisions have increased their diversity by about 20% over the past 17 years (2000–2016). The Northeast Pacific Ocean is one of the top 20 most diverse regions/countries on the globe with 77 chondrichthyan species, a number less than a quarter that of the most species-rich area (Australia) but that has increased by 10% since 2000 to include three new species (two skates and a chimaera). In this chapter we discuss the species richness of chondrichthyans occurring in the Northeast Pacific Ocean, characterize their life histories, briefly review several fisheries, and summarize the conservation status of those chondrichthyans occurring in the region. Detailed descriptions and evaluations of fisheries can be found in Chapter 7 of AMB Volume 78.
Author: Ebert, Bigman, Lawson

Title: Chimaera notafricana sp. nov. (Chondrichthyes: Chimaeriformes: Chimaeridae), a new species of chimaera from southern Africa,
Description: A new species of chimaera, Chimaera notafricana sp. nov., is described from specimens collected off the west and south coasts of southern Africa. The new species is distinguished from its closest congener, the eastern North Atlantic Chimaera monstrosa, by a combination of morphometric characters and coloration: pectoral fin when depressed reaches to origin of pelvic fin base; caudal fin ventral margin terminating slightly posterior to caudal fin dorsal margin insertion; distance from anterior base of dorsal-fin spine to center of supratemporal canal short (6.5-14.8% HDL); pelvic claspers externally trifid and short (12.1-12.3% BDL), divided for distal one-third of length, not extending past distal tip of pelvic fins; uniform blackish brown with dark bluish streaking, precaudal tail with longitudinal light and dark stripes. This new species has a restricted distribution from Lüderitz, Namibia to south of Algoa Bay, Eastern Cape Province, South Africa. Copyright © 2010 Magnolia Press., Fish and Fisheries, ,
Author: Kemper, Ebert, Compagno, Didier
Date: 2010-01-01T00:00:00Z

Title: Resurrection and redescription of Squalus suckleyi (Girard, 1854) from the North Pacific, with comments on the Squalus acanthias subgroup (Squaliformes: Squalidae),
Description: A taxonomie re-evaluation of the status of the North Pacific Squalus suckleyi (Girard, 1854) combining the use of meristie, morphological and molecular data reveal this species to be clearly distinct from the widespread Squalus acanthias (Linneaus, 1758). Differences in the external morphology between S. acanthias and S. suckleyi are subtle and are likely to be masked by intraspecific variation within individuals. However, we found S. suckleyi to differ from S.acanthias based on the following morphological and meristic characteristics: a short, broadly-rounded to acute snout;first dorsal-fin midpoint more posterior to pectoral-fin insertion; pelvic-fin origin closer to second dorsal fin than first dorsal fin; total vertebral counts average 99 (97-106). Molecular analysis of approximately 650 bp of the CO1 mitochondrial gene (DNA barcode region) showed separation of S. suckleyi and S. acanthias into two distinct genetic clades with 98% bootstrap support. Within species genetic diversities were 0.109±0.036% and 0.176±0.041% for S.suckleyi and S. acanthias respectively; between species diversity was 5- 6 fold greater at 0.765+0.307%. Squalussuckleyi is thus resurrected and a neotype for this endemic North Pacific Squalus species is designated. Copyright © 2010 Magnolia Press., Cited By (since 1996):20, ,
Author: Ebert, White, Goldman, Compagno, Daly-Engel, Ward
Date: 2010-01-01T00:00:00Z

Title: Life history of the sevengill shark, Notorynchus cepedianus Peron, in two northern California bays.
Description: Abstract not available (old pdf)
Author: Ebert

Title: Confirmation of the cookiecutter shark, Isistius brasiliensis, from the eastern North Pacific Ocean (Squaliformes Dalatiidae)
Description: The cookiecutter shark, Isistius brasiliensis, is confirmed for the first time from the eastern North Pacific Ocean. The shark, a female 432 mm in total length, was caught in a sablefish pot at a depth of 1132 m off San Nicolas Island, California, USA (32°59′05″N 120°25′99″W).
Author: Ebert, Pien, Kamikawa

Title: Food habits of the sandpaper skate, Bathyraja kincaidii (Garman, 1908) off central California,
Description: The stomachs of 130 sandpaper skates, Bathyraja kincaidii (Garman, 1908), were sampled from off central California to determine their diet composition. The overall diet was dominated by euphausiids, but shrimps, polychaetes and squids were also important secondary prey. A three-factor MANOVA demonstrated significant differences in the diet by sex, maturity status and oceanographic season using numeric and gravimetric measures of importance for the major prey categories. These three main factors explained more variation in diet than interactions between the factors, and season explained the most variance overall. A detailed analysis of the seasonal variation among the prey categories indicated that abundance changes in the most important prey, euphausiids, were coupled with seasonal changes in the importance of other prey. When upwelling occurred and productivity was great (Upwelling and Oceanic seasons), euphausiids were likely highly abundant in the study area and were the most important prey for B. kincaidii. As productivity declined (Davidson Current season), euphausiids appeared to decrease in abundance and B. kincaidii switched to secondary prey. At that time, gammarid amphipods and shrimps became the most important prey items and polychaetes, mysids and euphausiids were secondary. © 2007 Springer Science+Business Media, Inc., Cited By (since 1996):15, CODEN: EBFID, ,
Author: Rinewalt, Ebert, Cailliet
Date: 2007-01-01T00:00:00Z

Title: Age, growth, and maturity of the whitebrow skate, Bathyraja minispinosa, from the eastern Bering Sea,
Description: Skates are a common bycatch in groundfish fisheries in the Bering Sea; however, their life-history characteristics are not well known. The study is the first to investigate the age, growth, and age at maturity of Bathyraja minispinosa. Ages were estimated using sectioned vertebrae and several growth models were compared. The Gompertz model was the best fit and no significant differences were detected between sexes for any model. The maximum age estimated was 37 years, and parameter estimates generated from the three-parameter von Bertalanffy model were k 0.02 year -1 and L∞ 146.9 cm total length (TL). Males reached their size at 50 maturity larger than females (70.1 and 67.4 cm, respectively), but no significant differences in the estimated size or age at maturity were found. Whereas B. minispinosa is smaller than many skate species in the eastern Bering Sea, it has a considerably longer estimated lifespan, indicating that size may not be a reliable method of estimating the vulnerability of a rajid species to population declines in the eastern North Pacific. © 2011 International Council for the Exploration of the Sea., Cited By (since 1996):1, Fish and Fisheries, CODEN: ICESE, ,
Author: Ainsley, Ebert, Cailliet
Date: 2011-01-01T00:00:00Z

Title: Lost and found: Recovery of the holotype of the ocellated angelshark, Squatina tergocellatoides Chen, 1963 (Squatinidae), with comments on western Pacific squatinids
Description: The ocellated angelshark, Squatina tergocellatoides, Chen, 1963 is redescribed from the holotype, which was thought to be lost. Its recent recovery has allowed for a revised description, including new data, and comparison to other Western Pacific squatinids. Squatina tergocellatoides can be distinguished from its congeners by three pairs of prominent large black spots, each with a diameter greater than eye length; two on each pectoral fin at anterior and posterior angles and one on each side near the tail base; another three pairs of lesser defined spots, one large spot on base of each dorsal fin and one located laterally on each side of tail located below first dorsal fin. Ventral surface is uniformly white to cream coloured, and margins of pectoral fins and tail similar in colour to dorsal side. Pectoral fins with angular lateral apices and rounded posterior lobe, pelvic fin tips not reaching origin of first dorsal fin, strongly fringed nasal barbels, small inter-orbital space, head and mouth lengths, broad internarial width and pelvic fin base, a very small pelvic girdle width, and a caudal fin with triangular ventral lobe greater in length than dorsal lobe. Comments on additional specimens are provided, as well as observations on biogeography. A review of western Pacific squatinids is also provided. © 2013 Magnolia Press., Cited By (since 1996):1, Export Date: 11 February 2014
Author: Theiss, Ebert
Date: 2013-01-01T00:00:00Z

Title: The evolution of chondrichthyan research through a metadata analysis of dedicated international conferences between 1991 and 2014
Description: Science is continually evolving, with recent developments in some fields, such as conservation biology, leading to shifts in priorities and needs. Recent international conferences focused on chondrichthyan research provide an opportunity to assess how the research environment of chondrichthyan science has evolved through time. We compiled metadata from Sharks Down Under (1991) and the two Sharks International conferences (2010 and 2014), spanning 23 years. Analysis of the data highlighted taxonomic biases towards charismatic species, a declining number of studies in fundamental science such as those related to taxonomy and basic life history, and the emergence of new research fields or tools such as social science and stable isotope analysis. Although there are limitations associated with our study, which are discussed, it lays the foundation for continued assessment of the progression of chondrichthyan research as future chondrichthyan‑focused international conferences are organised. Considering the research biases that our metadata analysis identifies, we suggest that: (i) greater attention should be given to species or species groups that are of particular conservation concern but that may not necessarily be charismatic (e.g. batoids); (ii) increased support should be given to scientists from low‑income countries; (iii) new research areas should continue to be developed and included within broad integrated research programmes; and (iv) concurrent with this, foundational research should not be neglected. © 2015 NISC (Pty) Ltd., Cited By :2, Export Date: 4 September 2015
Author: Huveneers, Ebert, Dudley
Date: 2015-01-01T00:00:00Z

Title: Morphological characters of the thickbody skate Amblyraja frerichsi (Krefft 1968) (Rajiformes: Rajidae), with notes on its biology
Description: Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries. © 2012 Bustamante et al., Art. No.: e39963, Downloaded from: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0039963 (12 June 2014).
Author: Bustamante, Lamilla, Concha, Ebert, Bennett
Date: 2012-01-01T00:00:00Z

Title: Comparative age and growth of the Aleutian skate, Bathyraja aleutica, from the eastern Bering Sea and Gulf of Alaska
Description: The Aleutian skate (Bathyraja aleutica) is a large deep-water species that commonly occurs in bycatch of Alaskan trawl and longline fisheries. Although prominent in the skate biomass of the eastern Bering Sea (EBS) and Gulf of Alaska (GOA) ecosystems, minimal biological information exists. To increase our understanding of this potentially vulnerable species, and address the possibility of two separate populations in Alaskan waters, the age and growth of B. aleutica was studied. Vertebral centra were examined for age determination, and multiple growth models were evaluated to determine growth characteristics. Skates from the EBS attained maximum ages of 17 and 16 years for females and males, respectively, and the two-parameter von Bertalanffy growth functions generated estimates of k = 0.13 yr.-1 and L∞ = 162.1 cm for females, with similar results for males. Skates from the GOA reached 19 years in females and 18 years in males. Growth parameters of female skates from the GOA were estimated as k = 0.11 yr.-1 and L∞ = 160.0 cm, whereas males grew faster, with estimates of k = 0.15 yr.-1 and L∞ = 138.2 cm. The results of this study may indicate the presence of distinct populations of B. aleutica in the eastern North Pacific.
Author: Haas, Ebert, Cailliet

Title: First southeastern Atlantic record of the false catshark, Pseudotriakis microdon (Carcharhiniformes: Pseudotriakidae)
Description: The false catshark, Pseudotriakis microdon, is a large-bodied, poorly known deepwater shark, with a global distribution, except for the eastern Pacific and South Atlantic oceans. Here we report the first record of the false catshark from the southeastern Atlantic. The specimen, estimated to be approximately 290 cm in total length, was observed via an unmanned submersible 700 m depth off the western slope of Valdivia Seamount (26.2° S, 6.3° E).
Author: Clerkin, Ebert

Title: Revision of the genus Centrophorus (Squaliformes: Centrophoridae): Part 1-redescription of Centrophorus granulosus (Bloch & Schneider), a senior synonym of C. acus Garman and C. niaukang Teng,
Description: The genus Centrophorus is one of the most taxonomically complex and confusing elasmobranch groups. A revision of this group is currently underway and this first paper sets an important foundation in this process by redescribing the type species of the genus-Centrophorus granulosus. This taxon name has been previously applied to two different morphotypes: a large species 1.5 m TL and a smaller species ∼1 m TL. Centrophorus acus and C. niaukang are the most commonly used names applied to the larger morphotype. The original description of C. granulosus was based on a large specimen of ∼1.5 m TL, but subsequent redescriptions were based on either of the large or small morphotypes. Centrophorus granulosus is herein redescribed as a large species and a neotype is designated. Centrophorus acus and C. niaukang are found to be junior synonyms of C. granulosus. Centrophorus granulosus is distinguishable from its congeners by its large size, dermal denticle shape, colouration and a number of morphological and biological characteristics. Ontogenetic changes in morphology, dentition and denticle shape for this species are described in detail. © 2013 Magnolia Press., Cited By (since 1996):3, Export Date: 11 February 2014, Source: Scopus, ,
Author: White, Ebert, Naylor, Ho, Clerkin, Veríssimo, Cotton
Date: 2013-01-01T00:00:00Z

Title: Preliminary observations of population genetics and relatedness of the broadnose sevengill shark, Notorynchus cepedianus, in two northeast Pacific estuaries
Description: The broadnose sevengill shark, Notorynchus cepedianus, a common coastal species in the eastern North Pacific, was sampled during routine capture and tagging operations conducted from 2005-2012. One hundred and thirty three biopsy samples were taken during these research operations in Willapa Bay, Washington and in San Francisco Bay, California. Genotypic data from seven polymorphic microsatellites (derived from the related sixgill shark, Hexanchus griseus) were used to describe N. cepedianus genetic diversity, population structure and relatedness. Diversity within N. cepedianus was found to be low to moderate with an average observed heterozygosity of 0.41, expected heterozygosity of 0.53, and an average of 5.1 alleles per microsatellite locus. There was no evidence of a recent population bottleneck based on genetic data. Analyses of genetic differences between the two sampled estuaries suggest two distinct populations with some genetic mixing of sharks sampled during 2005-2006. Relatedness within sampled populations was high, with percent relatedness among sharks caught in the same area indicating 42.30% first-order relative relationships (full or half siblings). Estuary-specific familial relationships suggest that management of N. cepedianus on the U.S. West Coast should incorporate stock-specific management goals to conserve this ecologically important predator. © 2015 Larson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited., Export Date: 24 July 2015
Author: Larson, Farrer, Lowry, Ebert
Date: 2015-01-01T00:00:00Z

Title: Reproductive biology of two commercially exploited skates, Raja binoculata and R. rhina, in the western Gulf of Alaska,
Description: This study provides the first detailed information on the reproductive biology of two large and abundant eastern North Pacific Ocean skate species: big skate (Raja binoculata) and longnose skate (Raja rhina). Skates were collected in the western Gulf of Alaska during 2005 and 2006 after a targeted fishery for these two species developed around Kodiak Island, Alaska; both species are also taken as by-catch to other fisheries. A total of 307 females (20.1-183.3 cm TL) and 138 males (19.5-143.7 cm TL) R. binoculata, and 354 females (18.1-145.0 cm TL) and 318 males (21.1-135.8 cm TL) R. rhina were collected. Female R. binoculata were found to attain first (e.g., smallest individual) maturity at 125.8 cm TL and 50% at 148.6 cm TL. Males were found to attain first and 50% maturity at 124.0 and 119.2 cm TL, respectively. No gravid female R. binoculata, with egg cases in utero, were encountered during the study. Female R. rhina were found to attain first and 50% maturity at 102.2 and 113.1 cm TL, respectively. Gravid female R. rhina, with egg cases in utero, were recorded throughout the sampling period. Males attained first maturity at 101.0 cm TL and 50% maturity at 102.9 cm TL. Histological analysis did not reveal significant changes in spermatocyst production for either species during the sampling period. Both species appear to be reproductively active year-round as no seasonal cycle was evident. This study provides new and essential information on the reproductive biology of these two commercially targeted skate species. © 2008 Elsevier B.V. All rights reserved., Cited By (since 1996):8, CODEN: FISRD, ,
Author: Ebert, Smith, Cailliet
Date: 2008-01-01T00:00:00Z

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