Parasitology Commons^™

Gregarina Triboliorum (Eugregarinida: Gregarinidae) N. Sp. From Tribolium Confusum And Resolution Of The Confused Taxonomic History Of Gregarina Minuta Ishii, 1914, Stephanie Watwood, John J. Janovy Jr., Erica Peterson, Mary Ann Addison

John J. Janovy, Jr. Publications

The septate gregarine parasites of flour beetles (Tribolium spp.) include Gregarina minuta Ishii, 1914, a relatively small species in which both primite and satellite possess an obvious protomerite, and a larger species that lacks the satellite protomerite. The latter species has been placed in the genera Didymophyes and Hirmocystis by various authors, but studies reported here demonstrate that this species, herein described as Gregarina triboliorum, exhibits early pairing and produces oocyst chains, both characteristics of the genus Gregarina. The oocysts of this new species are described for the first time. In addition, experimental infections using oocysts from …

In Memoriam: John Teague Self (1906-1995), John J. Janovy Jr.

John J. Janovy, Jr. Publications

Obituary of John Teague Self, parasitologist, 1906-1995.

Behavioral Basis Of Second Intermediate Host Specificity Among Four Species Of Haematoloechus (Digenea: Haematoloechidae), Scott D. Snyder, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Cercarial behavior patterns were examined in four species of frog lung flukes (Haematoloechus spp.). Cercariae of Haematoloechus complexus, Haematoloechus medioplexus, Haematoloechus longiplexus, and Haematoloechus varioplexus were exposed to three species of experimental arthropods and an inanimate control. The number of cercariae attached to an experimental host at 5 min postexposure was recorded. Haematoloechus longiplexus and H. complexus cercariae attached to experimental hosts at higher rates than cercariae of H. medioplexus and H. varioplexus. Cercariae of H. longiplexus attached to experimental hosts in approximately the same numbers as H. complexus, but H. longiplexus penetrated only damselfly naiads, …

Host Specificity Of Rhabdochona Canadensis (Nematoda: Rhabdochonidae) In Nebraska, Michael A. Barger, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Intermediate and definitive host specificity of Rhabdochona canadensis in Nebraska were investigated. Mayfly nymphs Trichorythodes sp. and Caenis sp. were found to serve as experimental intermediate hosts. Development inside the nymphs required approximately 10 days, with the worms passing through two molts and then becoming encapsulated in the hemocoel as infective third-stage juveniles. Survey data revealed that only the red shiner Cyprinella lutrensis serves as definitive host for R. canadensis in nature. Laboratory infections of Notropis dorsalis, N. stramineus, and Fundulus zebrinus. all of which were uninfected in nature, were attempted to determine if observed specificity was due …

Second Intermediate Host-Specificity Of Haematoloechus Complexus And Haematoloechus Medioplexus (Digenea: Haematoloechidae), Scott D. Snyder, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Second intermediate host-specificity was examined for two species of the frog lung fluke genus Haematoloechus. Nine species of freshwater arthropods were exposed to cercariae of H. complexus and H. medioplexus. Metacercariae of H. complexus developed in all arthropod species used. Metacercariae of H. medioplexus developed only in anisopteran odonate naiads. This difference in host utilization may have epizootiological implications. The potential development of H. complexus in a greater number of arthropods than H. medioplexus may increase the chances of ingestion of H. complexus by an anuran host. The range of arthropods parasitized by H. complexus indicates that host-specificity …

Developmental Niche Structure In The Gregarine Assemblage Parasitizing Tenebrio Molitor, Richard E. Clopton, John J. Janovy Jr.

John J. Janovy, Jr. Publications

The exogenous developmental niche spaces of Gregarina cuneata and Gregarina polymorpha, parasites restricted to larval Tenebrio molitor, and Gregarina niphandrodes, a parasite restricted to adult T. molitor, were determined along temperature and humidity axes and associated with parasite niche space on the host resource axis. Gregarine gametocysts were incubated at controlled humidity (0, 10, and 20 mm Hg vapor pressure deficit) at 20, 25, 30, and 35 C to determine the environmental limits to survival and sporulation. Although the environmental conditions that permit gametocyst development overlap, the gregarine parasite restricted to adult T. molitor utilizes a …

Patterns Of Morphological Variation Of Salsuginus Yutanensis (Monogenea: Ancyrocephalidae) Over Space And Time, Michael T. Ferdig, Mary Ann Mcdowell, John J. Janovy Jr., Richard E. Clopton

John J. Janovy, Jr. Publications

Salsuginus yutanensis occurs on the gills of the Plains topminnow Fundulus sciadicus Cope. The fish of this species have been found to vary morphologically and biochemically among disjunct populations. Morphological characteristics of the sclerotized parts of S. yutanensis were examined from three localities in Nebraska, over a 2-yr collecting period. Analysis of variance was used to assess morphological variation with respect to site and date. Worms from two localities, Keith and Saunders counties, differed significantly for most characters considered. A third site, also in Keith County, contained worms for which measurement means tended to be intermediate between those in the …

Nubenocephalus Nebraskensis N. Gen., N. Sp. (Apicomplexa: Actinocephalidae) From Adults Of Argia Bipunctulata (Odonata: Zygoptera), Richard E. Clopton, Tamara J. Percival Cook, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Nubenocephalus nebraskensis n. gen., n. sp. (Apicomplexa: Actinocephalidae) is described from trophozoites, sporonts, gamonts, and oocysts collected from adult Argia bipunctulata (Odonata: Zygoptera). The new genus is distinguished from existing acanthosporine genera by elongate dodecahedral oocysts, without equatorial faces, that are hexagonal in equatorial cross section with equatorial and terminal spines. The epimerite is very broadly ovoid and truncated posteriorly with equatorial lobiform tumidi that are posteriorly bilobate and do not form hooks, spines, or digitiform processes. The epimerite is borne on a long, slender stalk. The new species is also reported from naiads ofArgia bipunctulata and adults and naiads …

The Niche Of The Gill Parasite Dactylogyrus Banghami (Monogenea: Dactylogyridae) On Notropis Stramineus (Pisces: Cyprinidae), Jill A. Anderson, Kimberly J. Blazek, Tamara J. Percival Cook, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Distribution of the monogenean Dactylogyrus banghami on the gills of the fish Notropis stramineus (Cyprinidae) was described by calculation of mean relative positions and Levins' niche breadths on the linear spatial resource gradients gill filament length and gill arch length. Thirty fish with 276 worms were examined; only one of the fish had an additional gill parasite species (Trichodina sp). Worms were more broadly and evenly distributed across the length of the gill arch than they were on the filament (breadths of 0.91 and 0.67, respectively). Mean worm positions were near the center of both resources: 54% of the …

Dynamics Of The Parasite Assemblage Of Pimephales Promelas In Nebraska, Mary Ann Mcdowell, Michael T. Ferdig, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Present theory states that in species-poor assemblages interactions among species are negligible and assemblage structure is a result of host/parasite interactions. A corollary to this theory is that parasite species assemblages should behave as accumulations of multiple-kind items drawn from a population in which only the relative probability of drawing each kind varies. This study was designed to test this prediction by comparing descriptor values, including diversity indices, species density values, equitability, and prevalence to those obtained from data produced by a Monte Carlo simulation model. The parasite assemblage consisted of 7 parasite species or types found in the fathead …

The Roles Of Ecological And Evolutionary Influences In Providing Structure To Parasite Species Assemblages, John J. Janovy Jr., Richard E. Clopton, Tamara J. Percival Cook

John J. Janovy, Jr. Publications

Parasite species assemblages currently are thought to range from isolationist to interactive, their dynamic properties being related to the number of species and types of hosts involved. The literature contains few experimental tests of this concept, however, and many of the host/parasite systems studied to date are not amenable to experimental manipulation. In this review, the presence of a parasite species, in a sample of host individuals, is considered to be an evolutionary phenomenon, but the parasite's population structure is considered to be an ecological one. Studies that allow evaluation of these two influences are comparative in nature and include …

Host Stadium Specificity In The Gregarine Assemblage Parasitizing Tenebrio Molitor, Richard E. Clopton, John J. Janovy Jr., Tamara J. Percival Cook

John J. Janovy, Jr. Publications

Reciprocal cross-stadia experimental infections were used to demonstrate stadium specificity within the gregarine assemblage parasitizing Tenebrio molitor, the yellow mealworm. Gregarina cuneata, Gregarina polymorpha, and Gregarina steini are characteristic parasites of larval T. molitor. Gregarina niphandrodes is a characteristic parasite of adult T. molitor. Experimental infections were produced in all homologous host-parasite combinations. No infection was produced in heterologous or cross-stadia combinations. This study introduces the concept of separate, distinct parasite niches corresponding to separate life cycle stages and established by known, predictable life cycle events within a single host species.

Review Of Phylogeny, Ecology, And Behavior By Daniel R. Brooks And Deborah A. Mclennan, University Of Chicago Press, 1991, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Review of Phylogeny, Ecology, and Behavior by Daniel R. Brooks and Deborah A. McLennan, University of Chicago Press, 1991.

The Niche Of Salsuginus Thalkeni, A Gill Parasite Of Fundulus Zebrinus, John J. Janovy Jr., Mary Ann Mcdowell, Michael T. Ferdig

John J. Janovy, Jr. Publications

Distribution of a monogenean parasitic helminth Salsuginus thalkeni on the gills of the fish Fundulus zebrinus is described by calculation of mean positions and niche breadths on the linear spatial resource gradients gill filament length, gill arch length and arch number. All distributions are given for parasites in the presence and absence of various combinations of potential competitors, namely the 6 other parasite species that occupy the same host species. Filament niche breadth was narrowest in the absence of potential competitors; breadth on arch was widest in the presence of potential competitors. Breadth on both resources was correlated positively with …

Salsuginus Yutanensis N. Sp. (Monogenea: Ancyrocephalidae) From Fundulus Sciadicus In Clear Creek Of Eastern Nebraska, Michael T. Ferdig, Mary Ann Mcdowell, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Salsuginus yutanensis n. sp. (Monogenea: Ancyrocephalidae) is described from the gills of the Plains topminnow, Fundulus sciadicus Cope, from Clear Creek in eastern Nebraska. Salsuginus yutanensis is distinguished from previously described species by having a shorter accessory piece and different hamulus proportions, especially in the relative lengths of deep and superficial roots. In addition, the angles between deep and superficial roots distinguish S. yutanensis from several congeners.

Life History Differences Between Two Species Of Gregarina In Tenebrio Molitor Larva, Tim R. Ruhnke, John J. Janovy Jr.

John J. Janovy, Jr. Publications

The life histories of two species of Gregarina, protozoans parasitizing Tenebrio molitor, were compared. Gregarina cuneata occurred primarily in larger larvae, whereas Gregarina steini was distributed evenly throughout all sizes of larvae. As larval size increased, an increase in prevalence of G. cuneata preceded a more substantial increase in parasite relative density. Sample variance/relative density ratios of the two parasite species also differed. When host larvae were isolated in a sterile bran medium, the prevalence of G. cuneata decreased, whereas that of G. steini remained relatively high. Trophozoites of G. cuneata were found predominantly in a paired condition, …

Salsuginus Thalkeni N. Sp. (Monogenea: Ancyrocephalidae) From Fundulus Zebrinus In The South Platte River Of Nebraska, John J. Janovy Jr., Tim R. Ruhnke, Terry A. Wheeler

John J. Janovy, Jr. Publications

Salsuginus thalkeni n. sp. (Monogenea: Ancyrocephalidae) is described from the gills of the plains killifish, Fundulus zebrinus, in the South Platte River of Nebraska. Salsuginus thalkeni is distinguished from previously described species by measurements of sclerotized parts and by proportions (measurement ratios), differences between dorsal and ventral hamuli, and angles between deep and superficial hamulus roots.

Population Dynamics Of Distoichometra Bufonis (Cestoda: Nematotaeniidae) In Bufo Woodhousii, John J. Janovy Jr., Eugene Lee Hardin

John J. Janovy, Jr. Publications

Prevalence, density, and variance/mean (= variance/density) ratios are reported for the cestode Distoichometra bufonis in 28 samples of the amphibian host, Bufo woodhousii, taken over a 3-yr period at two study sites on the South Platte River in Keith County, Nebraska, U.S.A. In addition, changes in host demography resulting from entry of newly metamorphosed toads into the terrestrial population are given. Prevalence and density (average number of worms per host, infected + noninfected) did not vary significantly either within or between sites and years unless newly metamorphosed toads were included in the analysis. Prevalence ranged from 70 to 100%, …

Population Dynamics Of The Parasites In Fundulus Zebrinus In The Platte River Of Nebraska, John J. Janovy Jr., Eugene Lee Hardin

John J. Janovy, Jr. Publications

The population dynamics of 7 parasite species or ecotypes were studied in the plains killifish, Fundulus zebrinus, at a single collection site in the South Platte River of Nebraska, U.S.A., for 5 yr. Parasites were: Myxosoma funduli (gill), Trichodina sp. (gill), Gyrodactylus bulbacanthus (gill), Urocleidus fundulus (gill), Gyrodactylus stableri (body surface), and Neascus sp. (= Posthodiplostomum; eyes and body cavity). Parasite densities, prevalences, and variance/mean ratios are reported for 22 samples, totaling 447 fish, over the summer months. Positive correlations were obtained between density and both standardized prevalence and log-transformed variance. Urocleidus fundulus populations were relatively stable with …

Inhibition Of In Vitro Macrophage Digestion Capacity By Infection With Leishmania Donovani (Protozoa: Kinetoplastida), Gerald F. Kutish, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Promastigotes of Leishmania donovani transformed into amastigotes and survived in cultured macrophages. Promastigotes of Leptomonas costoris, a kinetoplastid parasite of water striders, transformed into amastigotes but did not survive in cultured macrophages. A significant difference in size between the two species of parasitic protozoa allowed development of a bioassay in which the in vitro digestion rate of L. costoris was taken as a measure of macrophage digestive capacity following preinfection with L. donovani. In a 12- to 24-hr period, macrophage cultures infected with the 2S strain of L. donovani retained 50% more L. costoris than did control macrophages …

Morphology Of Leishmania Donovani Colonies Grown On Blood Agar Plates, Amy Doran Keppel, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Previous studies have shown that several species of Trypanosomatidae can be grown as discrete and, in some cases clonal, colonies on blood agar plates, and that species differ in colony phenotype (Noeller, 1917, Arch. Schiffs Trop. Hyg. 21: 5-94; Senekjie, 1944, J. Parasitol. 30: 303-308; Newton, 1956, Nature 177: 279-280; Keppel and Janovy, 1977, J. Parasitol. 63: 879-882). None of these previous studies, however, has addressed the following question: Does the life cycle stage used to initiate agar plate culture affect colony phenotype? The question also can be phrased as follows: Does passage through a vertebrate host alter agar plate …

Myxosoma Funduli Kudo 1918 (Protozoa: Myxosporida) In Fundulus Kansae (Pisces: Cyprinodontidae): Annual Prevalence And Geographic Distribution, Stephen A. Knight, John J. Janovy Jr., William L. Current

John J. Janovy, Jr. Publications

The occurrence and distribution of the myxosporidan, Myxosoma funduli, in the Plains killifish (Fundulus kansae) were investigated. Samples from sites on the South Platte and Platte River drainages in Nebraska were collected by seining during various months of 1976, 1977, and 1978. At a number of the localities no F. kansae were found; the remainder of the collecting sites showed the host population to be abundant, but the M. funduli infections to vary in prevalence. The protozoan parasite population in F. kansae, upstream from the Nebraska Tri-County Diversion Dam and Canal, at North Platte, Nebraska, demonstrated …

Adult Cestodes From The Coelomic Cavity Of The Teid Lizard, Cnemidophorus Sexlineatus, Wesley L. Shoop, John J. Janovy Jr.

John J. Janovy, Jr. Publications

In a survey of 64 Cnemidophorus sexlineatus, adult cestodes identified as Oochoristica bivitellobata with gravid proglottids were found in the coelomic cavity of two hand caught specimens at Cedar Point Biological Station, Ogallala, Nebraska, during June and July 1977. Two O. bivitellobata were found free in the coelom of a male lizard, whereas four were found in the coelom and one in the intestine of a female. No ruptures were found in the walls of the intestines of all lizards examined. In addition, 61 O. bivitellobata were found in the intestine of nine (14%) of the C. sexlineatus with …

Herpetomonas Megaseliae And Crithidia Harmosa: Growth On Blood-Agar Plates, Amy Doran Kepel, John J. Janovy Jr.

John J. Janovy, Jr. Publications

A technique for culturing two species of trypanosomatid flagellates on blood-agar plates is described. Herpetomonas megaseliae and Crithidia harmosa were grown as discrete clone colonies on plates prepared in sterile petri dishes with a medium derived from that of Tobie et al. (1950, J. Parasitol. 36: 48-54). Plates were inoculated with 0.01 ml flagellate suspension and the inoculum was spread evenly over the surface of the agar with a sterile glass spreader. Plates were incubated in a high humidity chamber at 25 C and colonies of both species, easily visible to the unaided eye, appeared within 1 week. There was …

Myxosoma Funduli Kudo 1918 (Protozoa: Myxosporida) In Fundulus Kansae: Summer Epizootiology, Stephen A. Knight, John J. Janovy Jr., William L. Current

John J. Janovy, Jr. Publications

The occurrence and distribution of the myxosporidan Myxosoma funduli on the gills of the plains killifish (Fundulus kansae) were investigated; Fundulus kansae is reported as a new host. Host samples from various sites on the South Platte River, Nebraska, were collected during the summer months of 1975 and 1976. The protozoan parasite population was shown to be overdispersed within the host population, and this distribution was similar to that described by the negative binomial equation. Demographic characteristics of the infected fish subpopulation were virtually identical to those of the whole fish population. Infection intensity was independent of gill …

Ultrastructure Of Interlamellar Henneguya Exilis In The Channel Catfish, William L. Current, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Ultrastructural aspects of interlamellar Henneguya exilis infections in channel catfish are reported. The plasmodium wall of this form differs from that of other species in that it is composed of two outer unit membranes which give rise to a zone of numerous pinocytic canals. Single-membraned canals appeared to be a stable feature of the wall while double-membraned canals are interpreted as those actively carrying out pinocytosis. Evidence suggests that host cellular cytoplasm as well as interstitial material is taken in by plasmodia. Plasmodium wall integrity, aggregation of parasite ectoplasmic components, numbers of pinocytic canals, and number of mitochondria proximal to …

Herpetomonas Megaseliae: Architectural Rearrangements During Amastigote Formation, John J. Janovy Jr., P. M. Daggett, K. W. Lee

John J. Janovy, Jr. Publications

The ultrastructure of Herpetomonas megaseliae Daggett, Dollahon, and Janovy, 1972, culture forms has been described in detail by Janovy et aI. (1974, J. Prot. 21: 53-59). Pellicular microtubules were described in pro- and opisthomastigotes as parallel to the longitudinal axis of the body and to the axis of the flagellar pocket. Microtubules lay in an electron translucent zone directly beneath the limiting membrane, and the flagellar pocket opened at the anterior end.

Unpublished studies in this laboratory have indicated that Herpetomonas megaseliae and a number of other "lower" trypanosomatid parasites are capable of transforming into amastigotelike forms upon phagocytosis by …

The Other Side Of Biology, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Discusses biology as increasingly multidisciplinary.

Herpetomonas Megaseliae Sp. N. (Protozoa: Trypanosomatidae) From Megaselia Scalaris (Loew, 1866) Schmitz, 1929 (Diptera: Phoridae), Pierre M. Daggett, John J. Janovy Jr., Norman R. Dollahon

John J. Janovy, Jr. Publications

A new intestinal trypanosomatid was found parasitizing Megaselia scalaris. Forms with posterior kinetoplasts occurred in both natural infections and cloned cultures, but not in experimental infections. Average size and morphological variation were reduced in experimental infections with cloned stocks, compared to natural infections. A growth comparison was made between Herpetomonas muscarum and H. megaseliae. Differences in day of peak population, maximum numbers, and total time of survival were observed in culture. Attempts to infect Drosophila melanogaster with H. megaseliae were unsuccessful.

Insect Flagellates From Feces And Gut Contents Of Four Genera Of Lizards, Norman R. Dollahon, John J. Janovy Jr.

John J. Janovy, Jr. Publications

During investigations of experimental leishmaniasis in American lizards, insect flagellates of at least two genera were isolated from freshly deposited fecal material and gut contents of two genera of Central American lizards (Basilicus and Ameiva).

It appears to us that some of the conclusions regarding the biology of certain flagellates described as reptilian leishmanias must be accepted with caution. Insect flagellates do persist in the lizard intestine for several days, and it is entirely possibly that some reptilian "leishmanias," particularly those described with gut involvement, such as Leishmania henrici, may actually be insect flagellates.