Papers by David Bruce Conn
Conn et al 2006 aberrant metacestodes abstract ICOPA XI
Microdistribution of scavenging flies in relation to detritus and guano deposits in a Kentucky cave
Entomological News
Parasites of Desmognathus brimleyorum (Caudata: Plethodontidae) from the Ouachita Mountains of Arkansas and Oklahoma
Cave Life of Carter Caves State Park
Beetles, bats, and biologists
Book Review: Giants of Smaller Worlds, J. Audy dos Santos
Unwanted Immigrants: The European Zebra Mussel in North America
ABSTRACT
Edaphic arthropod communities in a mountain longleaf pine stand: variation relative to controlled burning
Georgia journal of science: official publication of the Georgia Academy of Science
ABSTRACT
Land-Based Education, Research, and Resource Management on America's Largest College Campus
ABSTRACT
Collaborative herpetological surveying as an experiential pedagogical tool
Opportunities in the United States of America for European Union Health Science Researchers
Navigational buoy survey of invasive and native benthic invertebrates of the St. Lawrence River, Lake Ontario, and the Welland Canal
Parasitology Research, 2014
Proglottids from adult Thysanotaenia congolensis from naturally infected black rats Rattus rattus... more Proglottids from adult Thysanotaenia congolensis from naturally infected black rats Rattus rattus from Santiago Island, Cape Verde, were examined by transmission electron microscopy (TEM). The uterus in mature proglottids is composed of an ephemeral transverse tube or sac that breaks down, releasing eggs into the parenchyma where they are sequestered in groups and encapsulated by parenchymatous layers. In gravid proglottids, eggs accumulate in groups of 6-12 at the distal end of sac-like uterine ducts. As eggs accumulate, the end of the uterine ducts expands until it pinches off, releasing groups of eggs into the parenchyma surrounded by remnants of uterine epithelium. These epithelium-bound groups of eggs remain in the parenchyma until they are encapsulated with several parenchymatous layers, forming parenchymatic egg capsules, typical for mature and gravid proglottids of Inermicapsiferinae. The parenchymatic capsules originate from the medullary parenchyma of immature proglottids, which undergoes differentiation into the three layers of gravid proglottids: (1) an outer connective tissue layer composed of long delicate filaments of unknown chemical nature embedded in a granular extracellular matrix; (2) a middle layer appearing as an accumulation of large closely packed PAS-positive mucous goblets that are intensely metachromatic after toluidine blue staining and (3) an inner compact layer composed of lipid-containing cells, muscle cells with elongated muscle fibres and cells of various sizes and shapes forming or containing calcareous corpuscles. The mature hexacanths of T. congolensis are surrounded by reduced oncospheral envelopes consisting of remnants of a very thin membranous layer of degenerating embryophore with long, irregularly shaped cytoplasmic processes and by remnants of uterine epithelium extending as numerous apical microlamellae into the parenchymatic capsule lumen.
Journal of Shellfish Research, 2012
One of the most significant ecological and economic impacts of exotic species is associated with ... more One of the most significant ecological and economic impacts of exotic species is associated with their role as vectors for the introduction of parasites into invaded areas. Exotic parasites may have devastating impacts on invaded ecosystems; moreover, invaders may also become hosts for aboriginal parasites, promoting native diseases that otherwise would not have emerged. During 2009 and 2010, exotic molluscs were collected from 27 sites in the Lower Great Lakes and their tributaries, the Finger Lakes, and Lake Oneida. Seven species of exotic molluscs were examined for the presence of trematodes, including the zebra mussel (Dreissena polymorpha), quagga mussel (Dreissena rostriformis bugensis), faucet snail (Bithynia tentaculata), European stream valvata (Valvata piscinalis), Asian clam (Corbicula fluminea), Chinese mystery snail (Cipangopaludina chinensis), and the New Zealand mudsnail (Potamopyrgus antipodarum). Most of the examined molluscs were infected with trematode larvae that may be harmful to their subsequent vertebrate hosts, including fish, birds, and mammals. These included Sphaeridiotrema sp. cercariae and Cyathocotyle bushiensis metacercariae from B. tentaculata, Echinostoma sp. cercariae from V. piscinalis, and echinostomatid metacercariae from Dreissena spp. and C. fluminea. Many exotic molluscs that were believed to be free of parasites have already acquired trematodes native to North America. Hotspots of trematode infections were recorded in the western basin of Lake Erie and in Lake Oneida, where several species of exotic molluscs had a high prevalence of trematodes, and thus potentially pose risk of transmission to definitive hosts.
Parasite collections at the Museum of Comparative Zoology, Harvard University
A widely studied aberrant strain of tetrathyridia of Mesocestoides vogei infecting laboratory mic... more A widely studied aberrant strain of tetrathyridia of Mesocestoides vogei infecting laboratory mice is the only cestode for which vertical transmission has been verified experimentally. Vertical transmission has been reported for Taenia saginata in cattle and Echinococcus sp. in humans, but the validity of these cases has proved difficult to verify. However, metacestode stages of Taenia solium, Echinococcus granulosus, Echinococcus multilocularis, Multiceps sp., Diphyllobothrium mansoni, Spirometra erinacei, and Proteocephalus ambloplitis have been reported from the mammary glands, uterus, placenta, and/or ovary of several naturally infected hosts. Such infection foci, particularly the mammary glands, suggest a potential for vertical transmission in these species. Such possibilities warrant further study in these and other cestodes. Field surveys of hosts should be conducted to elucidate the prevalence of cestode localization in female organs in which there is potential for transmission.
Colonization of navigational buoys by zebra mussels (Dreissena polymorpha) in the St. Lawrence River
Dreissenid mussels in eastern Lake Ontario and the upper St. Lawrence River: A 10-year follow-up survey of navigational buoys
Neglected Diseases, Emerging Infections, and America's Global Health Century
ABSTRACT
Applied and environmental microbiology, 1997
0% of the hemocytes, respectively. A single clam can retain by phagocytosis an average of 1.84 ؋ ... more 0% of the hemocytes, respectively. A single clam can retain by phagocytosis an average of 1.84 ؋ 10 6 oocysts per ml of hemolymph. C. fluminea bivalves can serve as biological indicators of contamination of wastewaters and agricultural drainages with Cryptosporidium.
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Papers by David Bruce Conn