A new stalked filter-feeder from the middle Cambrian Burgess Shale, British Columbia, Canada

Burgess Shale-type deposits provide invaluable insights into the early evolution of body plans and the ecological structure of Cambrian communities, but a number of species, continue to defy phylogenetic interpretations. Here we extend this list to include a new soft-bodied animal, Siphusauctum gregarium n. gen. and n. sp., from the Tulip Beds (Campsite Cliff Shale Member, Burgess Shale Formation) of Mount Stephen (Yoho National Park, British Columbia). With 1,133 specimens collected, S. gregarium is clearly the most abundant animal from this locality.This stalked animal (reaching at least 20 cm in length), has a large ovoid calyx connected to a narrow bilayered stem and a small flattened or bulb-like holdfast. The calyx is enclosed by a flexible sheath with six small openings at the base, and a central terminal anus near the top encircled by indistinct openings. A prominent organ, represented by six radially symmetrical segments with comb-like elements, surrounds an internal body cavity with a large stomach, conical median gut and straight intestine. Siphusauctum gregarium was probably an active filter-feeder, with water passing through the calyx openings, capturing food particles with its comb-like elements. It often occurs in large assemblages on single bedding planes suggesting a gregarious lifestyle, with the animal living in high tier clusters. These were probably buried en masse more or less in-situ by rapid mud flow events.Siphusauctum gregarium resembles Dinomischus, another Cambrian enigmatic stalked animal. Principal points of comparison include a long stem with a calyx containing a visceral mass and bract-like elements, and a similar lifestyle albeit occupying different tiering levels. The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward. Thus, the broader affinities of S. gregarium remain largely unconstrained.     

Fish tapeworm infections (diphyllobothriasis) in Canada,particularly British Columbia.

Although the risk of diphyllobothriasis is generally low in Canada, fish tapeworm infections seem to have become more frequent in recent years. This increase is probably a consequence of the growing popularity of raw or inadequately cooked ethnic fish dishes or of a preference for lightly cooked fish, especially salmon. Only freshwater fish become infected with the larvae, but not everyone may realize that salmon can acquire the parasites before they leave their native lakes and rivers for the sea. If fish known to be sources of the tapeworms are to be eaten raw they should first be well frozen or salted to kill the larvae. Physicians should regard fish tapeworm infection as a notifiable disease. In Canada niclosamide, the drug of choice, is available from the manufacturer on a patient-by-patient basis.     

A new parvicapsulid (Myxosporea) species in adult pink salmon, Oncorhynchus gorbuscha, from the Quinsam River, British Columbia, Canada

Myxospores consistent with species of Parvicapsula were observed in kidney of 15 of 95 (15.8%) adult pink salmon, Oncorhynchus gorbuscha, collected from the Quinsam River, British Columbia, Canada. The spores were elongate and curved with unequal valves, and 2 spherical-to-subspherical polar capsules within a highly refractile capsular region. The spores were unlike those of P. minibicornis found in nearby populations of Pacific salmon, Oncorhynchus spp. The spore dimensions were similar to those of Parvicapsula pseudobranchicola from Atlantic salmon, Salmo salar, in Norway, and the spores seemed similar to an undescribed Parvicapsula sp. from several Oncorhynchus spp. in Puget Sound, Washington. A sequence of 1,480 base pairs (bp) of the small subunit ribosomal RNA gene (SSU rDNA) of the parasite from pink salmon was most similar to, but distinct from, that of other Parvicapsula spp. The parasite is described as a new species, Parvicapsula kabatai n. sp. Polymerase chain reactions amplified a 158-bp sequence, unique to P. kabatai n. sp., from 22 of 93 (23.7%) adult pink salmon kidney samples, from 3 of 3 juvenile pink salmon collected in the ocean 125 km north of the Quinsam River, and from 2 of 5 archival coho salmon, Oncorhynchus kisutch, samples from Puget Sound. The parasite occurs within the lumen and epithelium of renal tubules and ducts, and within the renal interstitium. Concurrent infections with extrasporogonic stages of the myxosporean CKX, the microsporidian Loma salmonae, and a Myxidium sp. also were observed in the adult pink salmon.     

Subtle Population Genetic Structure in Yelloweye Rockfish (Sebastes ruberrimus) Is Consistent with a Major Oceanographic Division in British Columbia,Canada

The boundaries between oceanographic domains often function as dispersal barriers for many temperate marine species with a dispersive pelagic larval phase. Yelloweye rockfish (Sebastes ruberrimus, YR) are widely distributed across the northeastern Pacific Ocean, inhabiting coastal rocky reefs from the Aleutian Islands in Alaska through southern California. This species exhibits an extended pelagic larval duration and has the capacity for long distance larval transport. We assayed 2,862 YR individuals from 13 general areas in the northeast Pacific Ocean for allelic variation at nine microsatellite loci. Bayesian model-based clustering analyses grouped individuals from the Strait of Georgia (SG) into a distinct genetic cluster, while individuals from outer coastal water locations (OCLs) were partitioned equally across two genetic clusters, including the cluster associated with the SG fish. Pairwise F_ST values were consistently an order of magnitude higher for comparisons between the SG and OCLs than they were for all OCL-OCL comparisons (∼0.016 vs. ∼0.001). This same pattern was observed across two time points when individuals were binned into an “old” and “young” group according to birth year (old: ∼0.020 vs. 0.0003; young: ∼0.020 vs. ∼0.004). Additionally, mean allelic richness was markedly lower within the SG compared to the OCLs (8.00 vs. 10.54–11.77). These results indicate that the Strait of Georgia “deep-basin” estuary oceanographic domain acts as a dispersal barrier from the outer coastal waters via the Juan de Fuca Strait. Alternatively, selection against maladapted dispersers across this oceanographic transition may underlie the observed genetic differentiation between the Georgia basin and the outer coastal waters, and further work is needed to confirm the SG-OCL divide acts as a barrier to larval dispersal.     

Ultrastructure of Mikrocytos mackini, the cause of Denman Island disease in oysters Crassostrea spp. and Ostrea spp. in British Columbia, Canada

An ultrastructural study was carried out on Mikrocytos mackini, the cause of Denman Island disease in Pacific oysters Crassostrea gigas in western Canada. Three forms were identified, quiescent cells (QC), vesicular cells (VC) and endosomal cells (EC). QC occurred in the vesicular connective tissue (VCT), haemocytes (hyalinocytes), adductor and heart myocytes, and extracellularly. They had a central round to ovoid nucleus, < 7 cisternae of inactive nuclear membrane-bound Golgi, few vesicles and lysosome-like bodies. VC were rarely extracellular and usually occurred in adductor and heart myocytes, in close association with host cell mitochondria. The contents of the host cell mitochondria appeared to pass through a tubular extension into the cytoplasm of the parasite. Cytoplasmic vesicles resembled the tubular structure in appearance and size. EC occurred in the VCT, in haemocytes and extracellularly. They had a dilated nuclear membrane, sometimes containing a looped membranous structure that appeared to derive from the nucleus, and pass into the cytoplasm. A well-developed anastomosing endoplasmic reticulum connected the nuclear and plasma membranes, and endosomes were present in the cytoplasm. QC and EC cells were frequently observed tightly against, or between, the nuclear membranes of the host cell. Few organelles occurred in all forms of M. mackini, especially QC. The lack of organelles found in most eukaryotic cells, including mitochondria or their equivalents, may be due to obligate parasitism and the utilization of host cell organelles reducing the need for parasite organelles. Alternatively, perhaps M. mackini is a primitive eukaryote. Although phylogenetic affinities could not be determined, it is not a haplosporidian. A developmental cycle is proposed from these findings.     

Freshwater littoral copepods of British Columbia and Alberta (Canada)

This is part of an ongoing study on the freshwater littoral copepods of northwestern North America, comprising Alaska, Yukon, western Northwest Territories, British Columbia, Alberta, and Saskatchewan. In this paper we report 13 species of calanoids and 16 species of cyclopoids found in 142 samples collected from northern British Columbia and Alberta on either side of the Rocky mountains. We discuss morphology and distribution of some of these species.     

Myriophyllum quitense and myriophyllum ussuriense (Haloragaceae) in British Columbia,Canada

Myriophyllum quitense andM. ussuriense are added to the flora of British Columbia, Canada.Myriophyllum quitense has not been previously reported in Canada, and this is the first report ofM. ussuriense for the North American continent. Problems with the identification of these species, and their distributions and habitats are discussed. The somatic chromosome numbers of 2n=42 forM. quitense and 2n=21 forM. ussuriense were found. A key for the identification ofMyriophyllum taxa growing in British Columbia is given.     

Surface nitrogen and plankton in Skaha Lake, British Columbia (Canada)

This study (1970–71) of an oligotrophic lake subject to cultural enrichment indicates the presence of complex interrelations between plankton and nitrogen levels in surface waters. Generally inorganic nitrogen was high in the winter (0.4–0.5 ppm) and Iow in summer (less than 0-1 ppm). However, in late July and August a large increase in nitrogen (1.5 ppm) was recorded. This correlated with the Gloeotrichia echinulata J. E. Smith ex P. Richt. bloom (Cyanophyceae) and the increase in nitrogen fixation, or nitrogenase activity (measured as acetylene reduction). It was calculated that the cyanophyte bloom could have contributed a minimum of 2350 kg nitrogen to the lake in August 1970 which is c. 62% of the nitrate-nitrogen occurring at any time.     

Paralygodium meckertii sp. nov. (Schizaeaceae) from the Upper Cretaceous (Coniacian) of Vancouver Island, British Columbia, Canada

More than 50 specimens of permineralized fertile pinnules with abaxially borne sporangia have been discovered in calcareous marine nodules from the Upper Cretaceous (Coniacian) Comox Formation from the Eden Main localities on Vancouver Island, British Columbia, Canada. Isolated pinnules 1.6–3.0 mm wide × 1.6–2.8 mm long are lobed and abaxially enrolled to form irregular globose structures. Pyriform sporangia 216–300 μm wide × 360–468 μm long occur in two rows on the abaxial surface of pinnule lobes. Sporangia have an apical annulus of 15–18 cells. Spores are tetrahedral and trilete, 33–42 μm in diameter, with straight to concave interradial sides, laesurae extending nearly to the equator, and a psilate exine. Spores are assignable to the sporae dispersae genus Deltoidospora. Fertile pinnules are compared to fossils of Anemia poolensis and two previously described species of Paralygodium, and show closest similarities to P. vancouverensis from the Eocene of British Columbia. The Cretaceous Eden Main specimens differ in number of pinnule lobes and their morphology and are described as a new taxon: P. meckertii sp. nov. This discovery extends the Cretaceous geographic range of Paralygodium from Japan to North America and adds to our knowledge of the diversity of extinct schizaeaceous ferns.     

Life history of Acrosiphonia (Codiolales, Chlorophyta) in southwestern British Columbia, Canada

This study establishes the phenology of the alternate life history phases of the green alga Acrosiphonia in British Columbia, Canada. Free-living, filamentous plants are seasonal, March-July, with peak percent cover (10%) in April. Plants are fertile immediately after establishment. The unicells, previously identified as Chlorochytrium inclusum and Codiolum petrocelidis, are the sporophyte phase of Acrosiphonia. 'Chlorochytrium,' spherical and 160-280 μm in diameter, colonizes the foliose red alga Mazzaella splendens 1 mo after filamentous Acrosiphonia plants appear. Maximum density (53 'Chlorochytrium' cells/cm(2) of blade) was recorded in May. 'Codiolum,' on the other hand, is stalked (the vesicle measures 150 × 50 μm) and colonizes the red algal crust Petrocelis. Peak density (22?400 'Codiolum' cells/cm(2) of crust) was recorded 2 mo after 'Chlorochytrium' density peaked. The endophytes survive high summer temperatures, which correlate with death of the free-living plants, and overwinter in their hosts. Zoospore release in late winter corresponds to decreased host abundance, suggesting the endophytes have evolved a strategy whereby duration in the host is synchronized with host seasonality. A bet-hedging strategy is proposed for Acrosiphonia's life history: two morphologically different phases have adapted to a seasonally variable environment, with the sporophyte phase capable of colonizing two different hosts.     

Henneguya sebasta sp. n. (protozoa, myxosporida) from California rockfish, Sebastes spp.

Henneguya sebasta sp. n. was found on the bulbus and truncus arteriosus and in the heart chambers of 7 species of marine rockfish, Sebastes, from central and southern California. The incidence of this parasite may be of economic interest to the sport and commercial fisheries because of its possible pathogenicity.     

Phylogenetic diversification of Equisetum (Equisetales) as inferred from Lower Cretaceous species of British Columbia, Canada

Three types of anatomically preserved vegetative shoots with features that characterize crown group Equisetum have been discovered in Lower Cretaceous deposits (≈136 Ma) of British Columbia, Canada, suggesting the genus is much older than currently believed. Specimens include two types of aerial shoots described as E. haukeanum sp. nov. and E. vancouverense sp. nov. and one type of subterranean rhizome. Shoots are 1-2 mm in diameter, jointed, and in cross section have fluted stems with a hollow pith. Distinctive patterns of cortical sclerenchyma and different ridge morphologies characterize each shoot morphotype. Nodes display irregular branching, highly fused leaf sheaths, and a nodal diaphragm. The aerial stem morphospecies have vallecular canals on alternating radii with carinal canals of an equisetostele surrounded by only a few tracheids. No secondary tissues are produced. Bands of surficial stomata flank the furrows of one morphospecies. Rhizomes and aerial shoots are of a similar size, suggesting that the plants were equivalent in stature to the smallest living Equisetum species. These fossils augment our understanding of evolutionary transformations that led from Paleozoic Archaeocalamitaceae and Calamitaceae to crown group Equisetaceae, suggesting that the initial diversification of Equisetum began far earlier than suggested by molecular-clock-based estimates.     

A comprehensive DNA barcode library for the looper moths (Lepidoptera: Geometridae) of British Columbia, Canada

Background

The construction of comprehensive reference libraries is essential to foster the development of DNA barcoding as a tool for monitoring biodiversity and detecting invasive species. The looper moths of British Columbia (BC), Canada present a challenging case for species discrimination via DNA barcoding due to their considerable diversity and limited taxonomic maturity.

Methodology/Principal Findings

By analyzing specimens held in national and regional natural history collections, we assemble barcode records from representatives of 400 species from BC and surrounding provinces, territories and states. Sequence variation in the barcode region unambiguously discriminates over 93% of these 400 geometrid species. However, a final estimate of resolution success awaits detailed taxonomic analysis of 48 species where patterns of barcode variation suggest cases of cryptic species, unrecognized synonymy as well as young species.

Conclusions/Significance

A catalog of these taxa meriting further taxonomic investigation is presented as well as the supplemental information needed to facilitate these investigations.     

Ectoparasitic insects of bats in British Columbia, Canada

One species of parasitic bug (Hemiptera : Cimicidae), 3 species of fleas (Siphonaptera: Ischnopsyllidae), and 2 species of parasitic flies (Diptera : Nycteribiidae) were collected from 9 species of bats (Chiroptera : Vespertilionidae) in southern interior and northeastern British Columbia, Canada. Female bats that return daily to maternity roosts were more frequently infested with both cimicids and ischnopsyllids than were male bats. Some differences in ectoparasite infestation can be attributed to differences in roosting behavior of the host. New national records for 2 parasite species, and 8 new host records are established for Canada.     

Distribution, genetic richness and phage sensitivity of Vibrio spp. from coastal British Columbia

This study examined the distribution, susceptibility to viral infection and genetic diversity of Vibrio spp. in the coastal waters and sediments of British Columbia during summer (July and August). Abundances of presumptive Vibrio spp. ranged from 1.5 to 346 ml(-1) within the water column (1-291 m); whereas, abundances at the water-sediment interface were much higher (up to approximately 3 x 10(4)Vibrio spp. cc(-1)), and decreased with sediment depth (down to 30 cm). The genetic diversity of Vibrio spp. isolates was not tied to the location from which they originated and was only influenced in a minor way by the type of environment. However, the environment had a greater effect on phage-typing patterns. Vibrio parahaemolyticus isolates from environments with high abundances of cells (sediments and oysters) were generally more susceptible to viral infection than those from the water column which were highly resistant. Therefore, although Vibrio spp. were widespread in the areas investigated, the results show that there is segregation of bacterial host strains in different environments, under differing selection pressures, which ultimately will affect in situ phage production.     

Tentaculate Fossils from the Cambrian of Canada (British Columbia) and China (Yunnan) Interpreted as Primitive Deuterostomes

Molecular and morphological evidence unite the hemichordates and echinoderms as the Ambulacraria, but their earliest history remains almost entirely conjectural. This is on account of the morphological disparity of the ambulacrarians and a paucity of obvious stem-groups. We describe here a new taxon Herpetogaster collinsi gen. et sp. nov. from the Burgess Shale (Middle Cambrian) Lagerstätte. This soft-bodied vermiform animal has a pair of elongate dendritic oral tentacles, a flexible stolon with an attachment disc, and a re-curved trunk with at least 13 segments that is directed dextrally. A differentiated but un-looped gut is enclosed in a sac suspended by mesenteries. It consists of a short pharynx, a conspicuous lenticular stomach, followed by a narrow intestine sub-equal in length. This new taxon, together with the Lower Cambrian Phlogites and more intriguingly the hitherto enigmatic discoidal eldoniids (Cambrian-Devonian), form a distinctive clade (herein the cambroernids). Although one hypothesis of their relationships would look to the lophotrochozoans (specifically the entoprocts), we suggest that the evidence is more consistent with their being primitive deuterostomes, with specific comparisons being made to the pterobranch hemichordates and pre-radial echinoderms. On this basis some of the earliest ambulacrarians are interpreted as soft-bodied animals with a muscular stalk, and possessing prominent tentacles.