scholarly journals Spatial Dynamics of Two Host-Parasite Relationships on Intertidal Oyster Reefs

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 260
Author(s):  
Marc H. Hanke ◽  
Martin H. Posey ◽  
Troy D. Alphin
Keyword(s):  
Carapace Width ◽  
Spatial Dynamics ◽  
Host Density ◽  
Eastern Oyster ◽  
Population Characteristics ◽  
Habitat Characteristics ◽  
Marine Habitats ◽  
Pea Crab ◽  
Eurypanopeus Depressus ◽  
Host Parasite

Intertidal reefs comprised of the eastern oyster (Crassostrea virginica) have long experienced habitat loss, altering habitat patch characteristics of size and distance from edge to interior, potentially influencing spatial dynamics of host-parasite relationships. Using two parasitic relationships, one between eastern oyster host and parasitic oyster pea crab (Zaops ostreum) and the other between a xanthid crab (Eurypanopeus depressus) and a parasitic rhizocephalan barnacle (Loxothylacus panopaei), we examined how host-parasite population characteristics varied on intertidal reefs by season, reef size, and distance from edge to interior. Pea crab prevalence was more related to habitat characteristics rather than host density, as pea crab prevalence was the highest on large reefs and along edges, areas of comparatively lower oyster densities. Reef size did not influence densities of parasitized or non-parasitized xanthid crabs, but densities varied from edge to interior. Non-parasitized xanthids had significantly lower densities along the reef edge compared to more interior reef locations, while parasitized xanthid crabs had no significant edge to interior pattern. Organismal size had a varied relationship based upon habitat characteristics, as pea crab carapace width (CW) varied interactively with season and reef size, whereas CW of parasitized/non-parasitized xanthid crabs varied significantly between edge and interior locations. These results demonstrated that influential habitat characteristics, such as patch size and edge versus interior, are both highly species and host-parasite specific. Therefore, continued habitat alteration and fragmentation of critical marine habitats may further impact spatial dynamics of host-parasite relationships.

Consistent differences in macroparasite community composition among populations of three-spined sticklebacks,Gasterosteus aculeatusL.

Parasitology ◽  
2012 ◽  
Vol 139 (11) ◽  
pp. 1478-1491 ◽  
Author(s):  
JOB DE ROIJ ◽  
ANDREW D. C. MacCOLL
Keyword(s):  
Spatial Variation ◽  
Community Composition ◽  
Gasterosteus Aculeatus ◽  
Parasite Community ◽  
Field Studies ◽  
Habitat Characteristics ◽  
Parasite Communities ◽  
Geographical Distances ◽  
Host Parasite ◽  
Relative Differences

SUMMARYParasite ecologists are often interested in the repeatability of patterns in parasite communities in space and/or time, because of implications for the dynamics of host-parasite interactions. Field studies usually examine temporal and spatial variation in isolation or limit themselves to a small number of host populations. Here, we studied the macroparasite communities of 12 populations of three-spined stickleback,Gasterosteus aculeatusL., on North Uist, Scotland, separated by small geographical distances, during the breeding season in 2 consecutive years (2007 and 2008) to determine: (1) the extent of spatial variation in macroparasite communities, (2) whether this variation is consistent across years, and (3) whether habitat characteristics can explain differences in macroparasite community composition among populations. We found substantial variation in parasite communities among populations. Generally, measures of parasite community composition were higher in 2008 than in 2007, but this effect of year was consistent across populations, such that the relative differences in these measures among populations changed little between years. These data suggest that there is short-term stability in the spatial variation in macroparasite communities of North Uist sticklebacks. However, none of the 5 habitat characteristics measured explained spatial variation in any measure of parasite community composition.

scholarly journals Short Communication: Habitat and population characteristics of the endemic Java Tree Frog (Rhacophorus margaritifer) in Ranca Upas, West Java, Indonesia

2019 ◽  
Vol 20 (6) ◽  
Author(s):  
TINA SAFARIA NILAWATI ◽  
HERNAWATI HERNAWATI ◽  
REZA AHMAD TAUFIK
Keyword(s):  
Short Communication ◽  
Population Distribution ◽  
Population Characteristics ◽  
Habitat Characteristics ◽  
Tree Frog ◽  
West Java ◽  
Population Number ◽  
Mark Release Recapture ◽  
Distribution Index ◽  
Average Size

Abstract. Nilawati TS, Hernawati, Taufik RA. 2019. Short Communication: Habitat and population characteristics of the endemic Java Tree Frog (Rhacophorus margaritifer) in Ranca Upas, West Java, Indonesia. Biodiversitas 20: 1644-1649. The Java tree frog (Rhacophorus margaritifer) is one of the endemic frogs of Indonesia. Ranca Upas forest, West Java, Indonesia is one of the habitats of this species which is threatened by the extension of the ​​campground and tourism area. The aim of this study was to identify the habitat and population characteristics of Rhacophorus margaritifer in Ranca Upas forest. Data was collected through Capture-Mark-Release-Recapture method in every 100 m distance of a 300 m transect, along the river. The captured frogs were tagged using modified shoelaces. Habitat characteristics were analyzed descriptively and quantitatively, population number was estimated by the Schnabel method, and population distribution was calculated using the Morisita distribution index. The results showed that R. margaritifer habitat was at an altitude of 1630-1670 m asl with 16.6 oC average air temperature and 90.8% air humidity. The habitat was near river with clear water and mud substrate at 14.8 oC water temperature, 0.068 m/s water velocity, and neutral acidity. Furthermore, three species of plants, namely Strobilanthes crispus, Curculigo capitulata, and Cyathea sp. were identified to be very often used by R. margaritifer. Population abundance of R. margaritifer was estimated to be 286 individuals, with 5 individuals /100m2 density and it showed a clumped disp.ersion. Average size of frogs found in the study area was 40 mm Snout to Vent Length (SVL) and the range was 36 to 65 mm. This showed that the location is dominated by young frogs and the study area is a good habitat for R. margaritifer.

Effect of Host Distribution on the Reproduction of Encarsia formosa Gahan (Hymenoptera: Chalcidoidea)

1958 ◽  
Vol 90 (3) ◽  
pp. 179-191 ◽  
Author(s):  
T. Burnett
Keyword(s):  
Physical Environment ◽  
Host Selection ◽  
Parasite Species ◽  
Insect Pests ◽  
Host Density ◽  
Host Population ◽  
Average Density ◽  
General Consideration ◽  
Encarsia Formosa ◽  
Host Parasite

That insect parasites regulate and, in the case of newly introduced species, sometimes reduce the average density of insect pests has led to an exmination of the properties of parasites in general. Consideration has been given to the manner in which parasites select hosts for oviposition and to the physiological and psychological basis of this selection. The distribution of parasite progeny among suitable hosts has been analysed in many cases, for the fewer the hostS that are superparasitized for any given number of parasite eggs laid the greater the efficiency of the parasite in reducing host density. It is obvious that before the factors of host selection and superparasitism become important in host-parasite interaction the parasite must find the host individuals. When the hosts are confined to a relatively small area the potential oviposition of the parasite, subject to discrimination among hosts and restraint in oviposition, often determines the level of parasitism. As distance between individuals of the host population becomes greater, however, it is necessary for the parasite to search the environment more extensively. Therefore, the ability of the parasite to find hosts is a factor of prime importance in determining its influence on the density of its host. The success with which a parasite discovers hosts in relation to host density is determined, of course, by several characteristics of the parasite species and by the modification of these characteristics through variations in the physical environment.

scholarly journals Dwarf Mistletoe-Host Interactions in Mixed-Conifer Forests in the Sierra Nevada

2002 ◽  
Vol 92 (6) ◽  
pp. 597-602 ◽  
Author(s):  
Patricia E. Maloney ◽  
David M. Rizzo
Keyword(s):  
Sierra Nevada ◽  
Bark Beetles ◽  
Spatial Dynamics ◽  
Host Density ◽  
Lake Tahoe ◽  
Host Size ◽  
Lake Tahoe Basin ◽  
Dwarf Mistletoe ◽  
Jeffrey Pine ◽  
White Fir

We determined the spatial pattern of dwarf mistletoe (Arceuthobium spp.) associated with two different conifer hosts, white fir (Abies concolor) and Jeffrey pine (Pinus jeffreyi), in forests around the Lake Tahoe Basin and at the Teakettle Experimental Forest, both located in the Sierra Nevada. We also examined a number of host variables and bark beetle incidence to determine how these factors might be involved in the Arceuthobium—conifer interaction. There was no significant relationship between dwarf mistletoe-infected trees and associated bark beetles. We found the highest incidence of dwarf mistletoe on Jeffrey pine in Lake Tahoe (87%), followed by dwarf mistletoe on white fir in Lake Tahoe (30%), with the lowest incidence on white fir at Teakettle (27%). Dwarf mistletoe incidence on white fir in our Lake Tahoe grid was not correlated to density but the dwarf mistletoe rating (DMR) was positively correlated to host size. At the Teakettle Forest, dwarf mistletoe incidence on white fir was not correlated with host density but the DMR was correlated with host size. Dwarf mistletoe incidence and DMR on Jeffrey pine were correlated with host density. Individuals, of both conifer species, in all diameter size classes were susceptible to dwarf mistletoe, with the lowest infection rate in the seedling-10-cm-diameter class. Arceuthobium on white fir in Lake Tahoe showed spatial dependence to a range of 20 m. However, Arceuthobium on Jeffrey pine in Lake Tahoe and on white fir at Teakettle showed no clear pattern of spatial structuring. The degree of infection and stand history appear to be important in the spatial dynamics of Arceuthobium spp.

scholarly journals Karakteristik Bioekologi Rajungan (Portunus Pelagicus) Di Perairan Dusun Ujung Lombok Timur

2016 ◽  
Vol 16 (2) ◽  
Author(s):  
Didik Santoso ◽  
Ahmad Raksun ◽  
Karnan . ◽  
Lalu Japa
Keyword(s):  
Ph Value ◽  
Survey Methods ◽  
Carapace Width ◽  
Wide Distribution ◽  
Habitat Characteristics ◽  
Portunus Pelagicus ◽  
Male Crab ◽  
Water Ph ◽  
Males And Females ◽  
Ecological Parameters

ABSTRAK Penelitian ini bertujuan untuk mengkaji ukuran rajungan yang tertangkap, menganalisis perbandingan jumlah rajungan jantan dan betina yang tertangkap, dan  menganalisis karakteristik habitat (salinitas, suhu, pH, dan bentuk dasar substrat perairan) di daerah penangkapan rajungandi Dusun Ujung Lombok Timur. Jenis penelitian ini adalah penelitian diskriptif dengan menggunakan metode survai dalam pengambilan data. Parameter yang diteliti adalah parameter biologi dan ekologi rajungan. Parameter biologi yang diamati adalah  jenis kelamin, dan lebar karapas, sedangkan parameter ekologi adalah suhu, salinitas, dan pH perairam serta bentuk dasar substrat. Kondisi substrat didominasi oleh fraksi pasir diikuti oleh fraksi lumpur dan fraksi liat. Hasil penelitian menunjukkan bahwa kualitas air di daerah penelitian sangat sangat layak bagi kehidupan rajungan, dengan sebaran suhu antara 290C – 300C. Salinitas perairan di daerah penelitian berkisar dari 31 sampai 32  ppt, dan Nilai pH perairan di lokasi penelitian berkisar antara 7.2 sampai 7.5. Distribusi lebar karaps rajungan di dominasi oleh lebar diatas 100 mm baik jantan maupun betina. Proporsi lebar karapas rajungan jantan yang tertangkap dengan lebar diatas 100 mm adalah sebesar 41,7% dan betina sebesar 48,3% dari total sampel penelitian. Nisbah kelamin antara rajungan jantan dan betina adalah 0,8 : 1. Hal ini menunjukkan bahwa rajungan jantan dapat membuahi lebih dari satu rajungan betina.Kata-Kata Kunci: Bio-ekologi, diskriptif, karakteristik habitatABSTRACTThis study aims to assess the size of the crabs are caught, analyzing the ratio of male and female, and analyze the habitat characteristics (salinity, temperature, pH, and form of the substrate waters) in crab fishing area in the Ujung Vilage of East Lombok District.This research is a descriptive study using survey methods in data collection.The parameters studied are biological and ecological parameters. Biological parameters measured were sex and carapace width, while the ecological parameters are temperature, salinity, and pH of the water and the form of the substrate.The results showed that the water quality in the study area were very feasible for the life of crab, with a distribution of temperature between 290C - 300C.Salinity waters in the study area ranged from 31 to 32 ppt, and water pH value in the study site ranged from 7.2 to 7.5.Karaps wide distribution crab dominated by width exceeding 100 mm in both males and females. The proportion of carapace width of male crabs are caught with a width exceeding 100 mm is 41.7% and females at 48.3% of the total sample.Rajungan sex ratio between males and females was 0.8: 1. This shows that the male crab can fertilize more than one female crabs. Keywords: Bio-ekologi, descriptive, habitat characteristics

scholarly journals Dynamics model analysis of bacteriophage infection of bacteria

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiaoping Li ◽  
Rong Huang ◽  
Minyuan He
Keyword(s):  
Stability Analysis ◽  
Basic Reproduction Number ◽  
Jacobian Matrix ◽  
Reproduction Number ◽  
Host Density ◽  
Dynamics Model ◽  
Global Stability Analysis ◽  
Bacteriophage Infection ◽  
Host Parasite ◽  
The Basic Reproduction Number

AbstractA bacteriophage (in short, phage) is a virus that can infect and replicate within bacteria. Assuming that uninfected and infected bacteria are capable of reproducing with logistic law, we investigate a model of bacteriophage infection that resembles simple SI-models widely used in epidemiology. The dynamics of host-parasite co-extinctions may exhibit four scenarios: hosts and parasites go extinct, parasites go extinct, hosts go extinct, and hosts and parasites coexist. By using the Jacobian matrix and Bendixson–Dulac theory, local and global stability analysis of uninfected and infected steady states is provided; the basic reproduction number of the model is given; general results are supported by numerical simulations. We show that bacteriophages can reduce a host density. This provides a theoretical framework for studying the problem of whether phages can effectively prevent, control, and treat infectious diseases.

EFFECT OF DENSITY ON HOST–PARASITE INTERACTIONS BETWEEN HYPERA POSTICA (COLEOPTERA: CURCULIONIDAE) AND BATHYPLECTES ANURUS (HYMENOPTERA: ICHNEUMONIDAE)

1977 ◽  
Vol 109 (8) ◽  
pp. 1057-1062 ◽  
Author(s):  
M. A. Latheef ◽  
K. V. Yeargan ◽  
B. C. Pass
Keyword(s):  
Poisson Distribution ◽  
Frequency Distribution ◽  
Parasite Density ◽  
Significant Relationship ◽  
Host Density ◽  
Mutual Interference ◽  
Hypera Postica ◽  
Host Parasite Interactions ◽  
Quadratic Relationship ◽  
Host Parasite

AbstractThe effect of density on host–parasite interactions between Hypera postica (Gyllenhal) and Bathyplectes anurus (Thomson) was studied in a caged system in the laboratory. There was no significant relationship between proportion of hosts parasitized and host density. The frequency distribution of the parasite’s eggs approximated the Poisson distribution in 83% of the cases. There was a quadratic relationship between number of superparasitized hosts and parasite density. However, no significant correlation between proportion superparasitized and host density was detected. The Nicholsonian area of discovery was inversely related to parasite density with a strong mutual interference constant of −.467.

The prevalence of avian Plasmodium is higher in undisturbed tropical forests of Cameroon

2009 ◽  
Vol 25 (4) ◽  
pp. 439-447 ◽  
Author(s):  
Camille Bonneaud ◽  
Irem Sepil ◽  
Borja Milá ◽  
Wolfgang Buermann ◽  
John Pollinger ◽  
...  
Keyword(s):  
Rain Forest ◽  
Forest Type ◽  
Natural Populations ◽  
Host Density ◽  
Parasite Prevalence ◽  
Haemosporidian Parasites ◽  
Habitat Differences ◽  
Parasite Infections ◽  
Host Parasite ◽  
Avian Plasmodium

Abstract:Habitat fragmentation and deforestation are thought to disrupt host–parasite interactions and increase the risk of epizootic outbreaks in wild vertebrates. A total of 220 individuals from three species of African rain-forest bird (Andropadus latirostris, Andropadus virens, Cyanomitra obscura), captured in two pristine and two agroforests in Cameroon, were screened for the presence of avian haemosporidian parasites (species of Plasmodium and Haemoproteus) to test whether habitat differences were associated with differences in the prevalence of infectious diseases in natural populations. Thirteen mitochondrial lineages, including 11 Plasmodium and two Haemoproteus lineages were identified. Whereas levels of Haemoproteus spp. infections were too low to permit analysis, the prevalence of infections with Plasmodium spp. reached significantly greater levels in undisturbed mature forests. Importantly however, the significant association between forest type and parasite prevalence was independent of host density effects, suggesting that the association did not reflect changes in host species composition and abundance between forest types. Our results illustrate how characterizing land-cover differences, and hence changes, may be a prerequisite to understanding and predicting patterns of parasite infections in natural populations of rain-forest birds.

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