Dennis Richardson

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• Doctor of Philosophy
• Professor (Full) at Quinnipiac University

Species of Placobdella have been the frequent subject of revisionary and alpha-taxonomy in the past 2 decades. Recent molecular analyses introduced uncertainty about the taxonomic status of several broadly distributed and morphologically variable Placobdella species, including Placobdella picta (Verrill 1872), compounded by incomplete original desc...

Abstract In the late 1990s, the San Miguel Island fox (Urocyon littoralis littoralis) faced near-extinction. Fourteen of the 15 remaining foxes were placed into an island-based captive breeding program used to repopulate the island. Although the fox population in San Miguel reached pre-decline numbers by 2010, a second decline started around 2014,...

Alboglossiphonia pallida (Verrill, 1872) comb. nov. is resurrected and redescribed based on morphological and molecular data from specimens of the type locality (New Haven County, Connecticut, USA) that demonstrate it is distinct from North American Alboglossiphonia heteroclita , European Alboglossiphonia heteroclita , and Alboglossiphonia papillos...

The prevalence of leech attachment on anuran taxa is largely uncharacterized. When parasitic, such relationships may regulate amphibian populations and function as an obstacle to the recovery of imperiled species. We evaluated the prevalence of leech attachment in a population of endangered Bufo (= Anaxyrus) houstonensis (Houston Toad) in Bastrop C...

La bioacumulación por metales por helmintos es un fenómeno bien reconocido que ha provocado un incremento de interés en investigación en las dos décadas pasadas y ha encontrado aplicaciones en estudios ambientales. La literatura ecológica es bastante abundante pero aun muestra lagunas con algunos taxas que no han sido estudiados. Variaciones en la...

Placobdella parasitica (Say, 1824) is one of the most commonly encountered turtle leeches in North America. Molecular analysis of individuals of P. parasitica representing various populations throughout its range in North America using the cytochrome c oxidase subunit I gene, revealed the presence of nine distinct groups: (1) P. parasitica sensu st...

Placodella michiganensis (Sawyer, 1972) was originally described from free-living individuals collected from Mill Creek, St. Joseph County, Michigan, USA. The acquisition of contemporary specimens from its type locality has facilitated redescription of P. michiganensis. Placobdella michiganensis does not have a confusing taxonomic history like many...

The Bawa Health Initiative (BHI) was established in 2005 with the goal of initiating a comprehensive public health care program in Bawa, a rural village in the West region of Cameroon. Interventions undertaken include a comprehensive helminth control program, provision of water filters, sanitary latrines, insecticide-treated bed nets, and a health...

Placobdella pediculata Hemingway, 1908 was originally described from individuals that were attached to Aplodinotus grunniens (freshwater drum) in Lake Pepin, Minnesota, USA. Apparently, no type material was deposited. The acquisition of contemporary specimens from its type host in the type locality facilitated redescription of P. pediculata. Placob...

Ten leeches were collected from a Gulf Coast box turtle, Terrapene carolina major, found crossing a road in Gulfport, Harrison County, Mississippi, USA. Eight of the leeches were identified as Placobdella multilineata and 2 were identified as Helobdella europaea. This represents the second vouchered report of leeches from a box turtle. Helobdella e...

Placobdella nuchalis Sawyer and Shelley, 1976 was originally described based on specimens from Four Hole Swamp (type locality) and a stream near Ashepoo River in South Carolina, USA, and Merchant's Millpond and Nine Mile Creek in North Carolina, USA. Leeches collected during August 2014 and August 2015 from Four Hole Swamp (type locality) and Merch...

Single juvenile specimens of a species of Centrorhynchus were collected from the small intestines of 3 stray dogs in Qom, Qom Province, Iran, constituting the third report of a centrorhynchids from a dog. The proboscis morphology and armature, 24-28 longitudinal rows of 9-10 hooks, were most similar to juveniles of Centrorhynchus mysentri from the...

Confusion regarding the identification of Placobdella hollensis (Whitman, 1892) (Hirudinida: Glossiphoniidae) has led to an unclear understanding of the distribution of the species. Two specimens of P. hollensis were collected from Merchants Millpond State Park, Gates County, North Carolina, U.S.A., representing a new geographic distribution record...

To date, the only species of leech reported from the American Alligator, Alligator mississippiensis is Placobdella multilineata. Seven specimens of a previously undescribed species of Placobdella were collected from the feet and lower jaw of a single female alligator from the Pascagoula River Wildlife Management Area, George County, Mississippi. Th...

Macracanthorhynchus ingens is a common acanthocephalan of raccoons (Procyon lotor) and blackbear (Ursus americanus). Specimens of M. ingens collected from several localities in Missouri and Ontario, Canada have been identified and are reported herein.

Helobdella octatestisaca Lai and Chang, 2009, was originally described from Taiwan where it is believed to have been introduced. It has subsequently been reported from throughout much of Mexico. Helobdella octatestisaca was collected from a small pond in Walker County, Texas, U.S.A., representing the first report of this species from the United Sta...

Although there is a large literature base reporting Placobdella ornata utilizing numerous turtle host species, those reports are all based on misidentifications of the leech resulting from taxonomic confusion in the literature and are thus invalid. In the original description of Clepsine phalera (junior synonym of P. ornata), it was suggested that...

The second volume in this landmark series includes an introductory chapter followed by 15 taxonomically specific chapters with identification keys to Nearctic freshwater invertebrates (protozoa through arthropods). Other than the second chapter’s treatment of the diverse, multi-phyla array of protozoa (ciliates, flagellates, and amoebas), each of t...

The distribution of Placobdella ornata (Verrill, 1872) is unclear as there has been much taxonomic confusion regarding this species. New collections and redetermination of museum specimens revealed 24 new locality records for Placobdella ornata, including the first reports of the species in New York and Rhode Island. Placobdella ornata is now known...

In October 2015, the dark false mussel, Mytilopsis leucophaeata, was encountered in the Duck Pond of the West River at Edgewood Park in New Haven, New Haven County, Connecticut, USA. The natural endemic range of Mytilopsis leucophaeata is the Gulf of Mexico and the temperate Atlantic coast of North America from Tampico, Mexico, northward to the Che...

Eleven (55%) of 20 Chicobolus spinigerus (Florida Ivory Millipede) collected from Miami-Dade County, FL, were infected with 1–57 cystacanths of Macracanthorhynchus ingens, a common acanthocephalan of North American Procyon lotor (Raccoon), representing a new host record. The distribution of cystacanths among the millipedes exhibited the highly over...

The site specificity and developmental morphology of Oligacanthorhynchus microcephalus was studied in its definitive host the Virginia opossum (Didelphis virginiana). Opossums were infected with cystacanths removed from the hemocoels of the millipede Narceus americanus, the intermediate host of O. microcephalus. At 2, 4, 6, and 8 wk postinfection (...

Specimens of the North American leech, Placobdella ornata (Verrill, 1872) were confirmed from the Donkmeer, a freshwater lake in the province of East Flanders, Belgium, by morphological and molecular analysis. Leech specimens from Belgium were morphologically consistent with the syntype series and description of P. ornata by Verrill (1872). Molecul...

During the summer of 2013, collection of glossiphoniid leeches from turtles in southern New England U.S.A. revealed several new host associations and geographic distribution records. Placobdella ali is reported for the first time from Massachusetts and Rhode Island. Placobdella hollensis is reported for the first time from mainland Rhode Island and...

Placobdella hollensis was originally named Clepsine hollensis by Whitman (1892) from specimens collected near Woods Hole, Massachusetts; however, type specimens were neither declared nor deposited. Specimens of P. hollensis were collected from Coonamessett Pond in Barnstable County (47°37′10.25″N, 70°34′20.42″W), Massachusetts, on 4 and 30 May, 201...

Journal of the Arkansas Academy of Science

AbstractThe hellbender (Cryptobranchus alleganiensis) is among the most intriguing and imperiled amphibians in North America. Since the 1970s and 80s, western populations of the Ozark and eastern subspecies in Missouri have declined by nearly 80%. As a result of population declines, the Ozark hellbender was recently federally protected as an endang...

Oligacanthorhynchus microcephalus (Rudolphi, 1819) Schmidt, 1972 was originally described from the philander opossum Caluromys philander from Brazil. Oligacanthorhynchus tortuosa (Leidy, 1850) Schmidt, 1972 was originally described from the Virginia opossum (Didelphis virginiana) in North America. Six years after describing O. tortuosa, Leidy indic...

Nine species of acanthocephalans have previously been reported from the raccoon, Procyon lotor, from North America: Centrorhynchus conspectus, Centrorhynchus sp., Echinorhynchus gadi, Moniliformis sp., Neoechinorhynchus cylindratus, Oligacanthorhynchus tortuosa, Plagiorhynchus cylindraceus, Profilicollis botulus, and Macracanthorhynchus ingens. Her...

Nine raccoons (Procyon lotor), 6 Virginia opossums (Didelphis virginiana), and 1 striped skunk (Mephitis mephitis) collected from Keith County, Nebraska were examined for helminth parasites. Raccoons were infected with the nematodes Arthrocephalus lotoris, Baylisascaris procyonis, and Capillaria plica, the trematode Fibricola cratera, and the tapew...

Helobdella bowermani n. sp. is described from specimens collected in fine sediment of open water benthos of Upper Klamath Lake, Klamath County, Oregon. The new species has pale yellow/buff coloration with scattered chromatophore blotches throughout the dorsal surface, lateral extensions or papillae only on the a2 annulus, dorsal medial row of papil...

Placobdella cryptobranchii (Johnson & Klemm, 1977) was originally described from specimens collected from Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) from the North Fork of the White River in Missouri, U.S.A. Leeches collected during August 2009 to August 2011 from five localities in Missouri (including the type locality) facilitated a...

Placobdella parasitica (Say, 1824) was originally described from lakes of the “North-western region.” Leeches collected during May and June, 2012, from Minnesota, USA, the type locality of Hirudo parasitica Say, 1824, were consistent with P. parasitica (Say, 1824) Moore, 1901 as described by Say (1824). The acquisition of these specimens from the t...

Six Virginia opossums (Didelphis virginiana), nine raccoons (Procyon lotor) and one striped skunk (Mephitis mephitis) collected from Keith County Nebraska were examined for ectoparasites. All three host species were parasitized by adults of the American dog tick, Dermacentor variabilis. Opossums were also parasitized by the flea Pulex simulans and...

The identification and taxonomy of Placobdella papillifera (Verrill, 1872) Moore, 1952 have been blurred by its varieties and have been compounded by the apparent lack of type material. Leeches collected from May 2008 through August 2012 from West River, New Haven, New Haven County, Connecticut, the type locality of Clepsine papillifera Verrill, 18...

The phylum Acanthocephala is comprised of more than 1000 species of pseudoceolomic helminths, which, as adults, occur exclusively in the vertebrate small intestine. The most commonly parasitised definitive hosts are bony fishes, followed by birds, mammals and rarely amphibians and reptiles. Acanthocephalans are characterised by the possession of a...

The identification and taxonomy of papillated leeches of the genus Placobdella have been extremely problematic, confounded by vague descriptions, redescriptions of species without reference to type material or type locality, and more than a century of numerous dubious taxonomic acts. Leeches collected on August 5 and 6, 2011, from North Dakota, USA...

The leeches Placobdella translucens (Sawyer and Shelley, 1976) and Myzobdella reducta (Meyer, 1940) are reported from Nebraska, U.S.A. for the first time. Individuals of M. reducta were collected from the caudal fins of 4 green sunfish (Lepomis cyanellus). A single pumpkinseed (Lepomis gibbosus) was infested with 2 individuals of P. translucens, co...

The taxonomy of papillated leeches of the genus Placobdella has been extremely problematic, confounded by vague descriptions, redescriptions of species using material across a wide geographic range without reference to type material, and a plethora of dubious taxonomic acts over the course of more than a century. Leeches collected between 2008 and...

Clepsine elegans Verrill, 1872 was described based on material collected from the West River, New Haven, New Haven County, Connecticut, USA (Verrill, 1872). Moore (1901) synonymized C. elegans with the European congener Glossiphonia complanata (Linnaeus, 1758) in view of the morphological similarities of the two species. Subsequently, all North Ame...

Although many studies have been conducted concerning human coprolites, there is a paucity of archaeohelminthological data from nonhuman animals. Eight coprolite samples were examined from dogs associated with the Chiribaya culture, a pre-Columbian agrarian and pastoral society that inhabited the lower and middle regions of the Osmore river in south...

For the kingdom Animalia, 1,552,319 species have been described in 40 phyla in a new evolutionary classification. Among these, the phylum Arthropoda alone represents 1,242,040 species, or about 80% of the total. The most successful group, the Insecta (1,020,007 species), accounts for about 66% of all animals. The most successful insect order, Coleo...

Humans occasionally become infected with acanthocephalans, particularly Moniliformis moniliformis. Although several anthelmintics have been used, no controlled studies have been conducted to assess the efficacy of common anthelmintics in the treatment of moniliformiasis. The effectiveness of pyrantel pamoate, ivermectin, praziquantel, niclosamide,...

This study investigated the postcyclic transmission of Neoechinorhynchus cylindratus and Leptorhynchoides thecatus, including gravid female worms, between largemouth bass. Twenty largemouth bass were each given 10 individuals of N. cylindratus taken from the enteric system of largemouth bass, and 10 largemouth bass were each given 10 individuals of...

Clepsine modesta was described by Verrill (1872) based on specimens collected in the West River and Whitneyville Lake, New Haven County, Connecticut, USA. Consistent with Article 73.2.3 of the International Code of Zoological Nomenclature (Anonymous 1999), the Syntype specimens of C. modesta originated from two localities and thus the type locality...

A survey of human geohelminth infections was conducted in Bawa and Nloh, two rural agrarian villages in the West Province of Cameroon. The purpose of the study was to provide baseline data to assess the efficacy of a universal geohelminth control program that the Bawa Health Initiative, a nongovernmental humanitarian organization, has implemented i...

The prevalence of the waterborne protozoan parasites Entamoeba histolytica/dispar, Giardia lamblia, and Cryptosporidium parvum were investigated in Nloh and Bawa, 2 rural agrarian villages in the West Province of Cameroon, Africa. The purpose of this study was to gather baseline data prior to the installation of biosand water filters in Nloh and to...

Malaria, water-borne diarrheal diseases, and geohelminth infections, combined with severe malnutrition ravage entire villages throughout sub- Saharan Africa. The Bawa Health Initiative (BHI) is a 501c(3) non-profit organization with the goal of implementing a comprehensive public health program in an attempt to address these problems in a series of...

We redescribe Chordodes albibarbatus Montgomery 1898 from the original holotype male and the originally described female specimen using Nomarski interference contrast microscopy. Our reinvestigation indicates that C. albibarbatus is sexually dimorphic and contains five types of areoles in the male and six types of areoles in the female. Our reinves...

Placobdella ali Huges and Siddall, 2007 has not been reported since its original description based on 3 specimens from Silver Mine Lake in Orange County, New York. The finding of 3 populations of P. ali in Connecticut along with further collection of this species from its type locality facilitated an investigation of host use by this leech, molecul...

Centrorhynchus microcephalus (Bravo-Hollis, 1947) Golvan, 1956 (Acanthocephala: Centrorhynchidae) originally was described as Gordiorhynchus microcephalus Bravo-Hollis, 1947 on the basis of 8 worms collected from the small intestine of a single great-tailed grackle (Quiscalus mexicanus) from the state of Puebla, Mexico. Acquisition of 48 specimens...

Between March 1997 and September 2000, 3 species of owls (Bubo virginianus, Strix varia, Megascops asio), 4 species of hawks (Buteo jamaicensis, Buteo platypterus, Accipiter cooperii, Accipiter striatus), and 1 species of falcon (Falco sparverius) from Connecticut, U.S.A. were examined for gastrointestinal parasites. Eighteen species of helminths (...

Parenteral cystacanths of the acanthocephalan Leptorhynchoides thecatus have been reported from 50 species of fishes, and it has been suggested that transmission of paratenic worms to definitive hosts may play an important role in the life cycle of L. thecatus; however, no study has been conducted to assess the infectivity of parenteral cystacanths...

IntroductionSynonymsHistoryHost Range and DistributionEtiologyEpizootiologyClinical SignsPathogenesis and PathologyDiagnosisPublic Health ConcernsDomestic Animal Health ConcernsWildlife Population ImpactsTreatment and ControlLiteraturec Cited

Oligacanthorhynchus major (Machado-Filho, 1963) Schmidt, 1972 (Acanthocephala: Oligacanthorhynchidae) was redescribed using specimens from 2 white-lipped peccaries (Tayassu pecari) collected in the department of Santa Cruz, Bolivia. The male and the egg of O. major were described for the first time. The female worm is 241-824 mm long; the trunk is...

An electronic survey of 728 members of the American Society of Parasitologists (ASP) was conducted to determine perceptions about parasitology education and to gain insight into the current state of academic parasitology. Two hundred and seventy-five ASP members responded for a return rate of 37.7%. Most respondents perceived that fewer parasitolog...

The nematodes Kathlania leptura (Rudolphi, 1819) Travassos, 1918 and Tonaudia tonaudia (Lane, 1914) are infrequently reported intestinal parasites of marine turtles. A single loggerhead sea turtle collected from Ossabaw Island, Georgia, U.S.A., was infected with both species representing the first North American report of these species and expandin...

Leptorhynchoides thecatus, an acanthocephalan of centrarchid fishes, occurs in the pyloric ceca and the anterior intestine of green sunfish, Lepomis cyanellus. One wk post-laboratory infection, L. thecatus is found in the pyloric ceca and the anterior portion of the intestine of green sunfish, but by 3 wk postinfection, worms are present only in th...

Two hundred eighty-one stool samples were comparatively examined for the presence of ova of Ascaris lumbricoides, hookworms, and Trichuris trichiura using the traditional Kato–Katz technique and Ovassay® Plus (Synbiotics Corp., San Diego, California) with a sodium nitrate solution to test the hypothesis that use of a commercially available flotatio...

Examination of 30 Virginia opossums (Didelphis virginiana) from south-central Connecticut revealed the presence of 7 species of gastrointestinal helminths: the nematodes Capillaria sp., Cruzia americana, and Physaloptera turgida; the trematodes Brachylaima virginiana, Brachylaima didelphis, and Didelphodiplostomum variabile; and the cestode Mesoces...

Ova of Diphyllobothrium sp. were found in 7 of the 29 coprolites examined from 4 sites within the Chiribaya archaeological zone near Ilo, southern Peru. The Chiribaya represent a pre-Inca civilization of the Middle Horizon (600–1000 A.D.) and the Late Intermediate Period (1000–1476 A.D.). The Chiribaya economy was based on agriculture, animal husba...

Two Virginia opossums (Didelphis virginiana) were experimentally infected with cystacanths of Oligacanthorhynchus tortuosa collected from naturally infected millipedes (Narceus americanus). The prepatent period of O. tortuosa was determined to be about 9 wk. Laboratory-raised millipedes fed feces from experimentally infected opossums containing ova...

The immunobiology of acanthocephaliasis was investigated using the model of Moniliformis moniliformis in experimentally infected, female Wistar rats. Serum was collected before infection and at 1, 2, 3, 4, 6, and 8 wk postinfection (PI). Marked eosinophilia was evident at wk 1 PI and persisted for the 8 wk. Serum immunoglobulin (Ig) M was first det...

Placobdella cryptobranchii is a rarely collected leech of the Ozark hellbender (Cryptobranchus alleganiensis bishopi) in northern Arkansas and southern Missouri, U.S.A. Between October 2002 and August 2005, 58 hellbenders were examined from Eleven Point River (Randolph Co., Arkansas and Oregon Co., Missouri), the north fork of the White River (Ozar...

Microhabitat specificity of Macracanthorhynchus ingens (Acanthocephala: Oligacanthorhynchidae) in the small intestine of raccoons (Procyon lotor) was investigated. Twenty-nine of 43 raccoons necropsied from Ossabaw Island, Georgia, U.S.A., were infected with 1–767 M. ingens. Macracanthorhynchus ingens occurred in the anterior 19 of 20 intestinal se...

The prevalence of agglutinating antibodies to Toxoplasma gondii was examined in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from 8 cities in Connecticut. Ten (42%) of the 24 striped skunks, 2 of 7 (29%) opossums, and 12 of 12 (100%) raccoons were positive at dilutions of 1:50 or greater. These r...

Twenty-one lotic and lentic environments throughout central and northern Arkansas were surveyed for the presence of leeches during June 2004 and April, July - October 2005. Fourteen species of leeches (Helobdella elongata, Helobdella papillata, Helobdella stagnalis, Placobdella cryptobranchii, Placobdella multilineata, Placobdella ornata, Placobdel...

Microhabitat specificity of Macracanthorhynchus ingens (Acanthocephala: Oligacanthorhynchidae) in the small intestine of raccoons (Procyon lotor) was investigated. Twenty-nine of 43 raccoons necropsied from Ossabaw Island, Georgia, U.S.A., were infected with 1-767 M. ingens. Macracanthorhynchus ingens occurred in the anterior 19 of 20 intestinal se...

Examination of 30 Virginia opossums (Didelphis virginiana) from south-central Connecticut revealed the presence of 7 species of gastrointestinal helminths: the nematodes Capillaria sp., Cruzia americana, and Physaloptera turgida; the trematodes Brachylaima virginiana, Brachylaima didelphis, and Didelphodiplostomum variabile; and the cestode Mesoces...

Few studies have been conducted in the United States to quantify the potential risk associated with encountering zoonotic ascarid ova in the environment. In an effort to raise awareness and to better understand the risk of acquiring visceral larva migrans in south central Connecticut, this environmental survey was conducted to determine the prevale...

Naegleria fowleri is the causative agent of primary amebic meningoencephalitis (PAM), a disease of the central nervous system. Healthy humans sporadically become infected with N. fowleri and develop fatal PAM after recreational or work exposure to freshwater; accordingly, there is a need for monitoring the presence of pathogenic ameboflagellates in...

Recently, leptospirosis has gained attention as a re-emerging infection in domestic dogs in the northeastern United States. In order to gain insight into the epizootiology of leptospirosis in this region, 109 small wild mammals (31 raccoons (Procyon lotor), 30 skunks (Mephitis mephitis), 28 opossums (Didelphis virginiana), and 20 gray squirrels (Sc...

North American Parasitic Zoonoses provides a concise and useful review of essential information about parasitic zoonotic diseases. North American Parasitic Zoonoses, volume six of "World Class Parasites", is written for researchers, students, veterinarians, physicians and scholars who enjoy reading research that has a major impact on human health,...