scholarly journals Risk of Infection, Local Prevalence and Seasonal Changes in an Avian Malaria Community Associated with Game Bird Releases

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 657
Author(s):  
Jesús T. García ◽  
Javier Viñuela ◽  
María Calero-Riestra ◽  
Inés S. Sánchez-Barbudo ◽  
Diego Villanúa ◽  
...  
Keyword(s):  
Avian Malaria ◽  
Anthropogenic Activities ◽  
Temporal Structure ◽  
Temporal Distribution ◽  
Sampling Period ◽  
Parasite Community ◽  
Parasite Fauna ◽  
Management Technique ◽  
Alectoris Rufa ◽  
Hunting Season

Anthropogenic activities, such as the translocation or introduction of animals, may cause a parallel movement of exotic parasites harboured by displaced animals. Although introduction and/or relocation of animals for hunting purposes is an increasingly common management technique, the effects of gamebird release as a major vehicle for the introduction of parasites into new geographic regions have rarely been reported. We examined the prevalence and distribution of avian malaria parasites infecting resident avian hosts (red-legged partridge Alectoris rufa) at a local scale, with a particular emphasis on the effects of releasing farm-reared birds for hunting on the spatial and temporal structure of the parasite community. We collected blood samples from adult partridges from two game estates with partridge releases and two sites without releases over two periods (spring and autumn). We tested the probability of infection and differences in the parasite community in relation to the management model (releases vs. non releases) and sampling period, comparing autumn (when farm-reared birds are released) and spring (after hunting season, when mostly wild birds can be found in the population). We found a high prevalence (54%) of Plasmodium spp., and substantial differences in the spatial and temporal distribution of parasite lineages among the populations studied. Some parasite lineages occurred at high frequencies in game estates without introduction of farm-reared partridges, while other lineages were more abundant in game estates with releases than in those without releases. Overall, the prevalence of avian malaria was similar between spring and autumn at non-release sites, whereas in sites with releases, it was higher in autumn than in spring—probably due to artificial restocking with infected farm-reared birds at the onset of the hunting season. In short, humans may be an important agent driving the alteration of the spatial structure of local parasite fauna via the introduction of exotic parasites by gamebird release, which could cause avian malaria outbreaks with severe repercussions for native avifauna.

scholarly journals DEM Based Study on Shielded Astronomical Solar Radiation and Possible Sunshine Duration under Terrain Influences on Mars by Using Spectral Methods

2021 ◽  
Vol 10 (2) ◽  
pp. 56
Author(s):  
Siwei Lin ◽  
Nan Chen
Keyword(s):  
Solar Radiation ◽  
Spatial Structure ◽  
Sunshine Duration ◽  
Temporal Structure ◽  
Temporal Distribution ◽  
Planetary Science ◽  
Shielding Effect ◽  
Critical Area ◽  
Martian Surface ◽  
Test Region

Solar radiation may be shielded by the terrain relief before reaching the Martian surface, especially over some rugged terrains. Yet, to date, no comprehensive studies on the spatial structure of shielded astronomical solar radiation (SASR) and the possible sunshine duration (PSD) on Mars have been conducted by previous researchers. Previous studies generally ignored the influences of the terrain on the SASR and PSD, which resulted in a corresponding unexplored field on SASR. The purpose of this paper is to study the Martian spatial-temporal structure of SASR and the PSD under terrain influences. In this paper, the theory of Earth’s SASR, the previous Martian SASR model and the theory of planetary science were combined to propose the SASR model that can be applied to Mars. Then, with the spectrum method theory of geography, we defined two new concepts of spectrums to explore the spatial-temporal distribution of SASR and PSD in different Martian landforms. We found SASR and PSD on Mars were significantly influenced by terrain relief and latitude and showed sufficient regularity, which can be concluded as a gradual attenuation with terrain relief and a regularity of latitude anisotropy. The latitude anisotropy feature is a manifestation of the terrain shielding effect. With the latitude varying, SASR and PSD at different temporal scale generally showed different features with those of Earth, which may be attributed to the imbalanced seasons caused by Martian moving orbits and velocity. Compared to PSD, SASR showed more regular variation under terrain relief and was more influenced by the terrain relief which revealed that SASR is more sensitive to terrain relief than PSD. Additionally, the critical area is a quantitative index to reflect the stable spatial structure of SASR and PSD in different landforms and may be viewed as the minimum test region of sample areas. The corresponding result of the experiments herein indicated that either spectrum can effectively depict the spatial-temporal distribution of SASR and PSD on Mars under terrain relief and deepen the understanding of the variation of SASR and PSD influences by terrain. The critical area of either spectrum can be employed to explore and determine the stable spatial structure of SASR and PSD in different landforms. The proposed Martian SASR model and the new spectral method theory shed new light on revealing the spatial-temporal structure of SASR and PSD under terrain influences on Mars.

scholarly journals Temporal distribution of fruit-feeding butterflies (Lepidoptera, Nymphalidae) in the eastern extreme of the Amazon region

2020 ◽  
Vol 50 (1) ◽  
pp. 12-23
Author(s):  
Elias da Costa ARAUJO ◽  
Lucas Pereira MARTINS ◽  
Marcelo DUARTE ◽  
Gisele Garcia AZEVEDO
Keyword(s):  
Temporal Dynamics ◽  
Abiotic Factors ◽  
Temporal Structure ◽  
Temporal Distribution ◽  
Amazon Region ◽  
Influential Factors ◽  
Northeastern Brazil ◽  
Amazon Forest ◽  
Dry Seasons ◽  
Species Richness And Abundance

ABSTRACT Rainfall is one of the most influential factors driving insect seasonality in the Amazon region. However, few studies have analyzed the temporal dynamics of fruit-feeding butterflies in the Brazilian Amazon, specially in its eastern portion. Here, we evaluated the diversity patterns and temporal distribution of fruit-feeding butterflies in a remnant of eastern Amazon forest in the Baixada Maranhense, northeastern Brazil. Specifically, we tested whether fruit-feeding butterflies are temporally structured and whether rainfall influences species richness and abundance. Butterflies were collected with baited traps in both the rainy and dry seasons for two consecutive years. In total, we captured 493 butterflies belonging to 28 species, 15 genera and eight tribes. Three species comprised about half of the overall abundance, and Satyrinae was the most representative subfamily. The fruit-feeding butterfly assemblage showed a strong temporal structure during the second year of sampling, but not during the first year. Species composition and richness did not differ between rainy and dry seasons, and neither abundance nor richness was influenced by rainfall. Our results indicate that seasonality is not a strong environmental filter in this region, and that other biotic and abiotic factors are probably driving the community structure. The predominance of palms in the Baixada Maranhense, which are used as host plants by larvae of several lepidopteran species (specially satyrines) and are available year-round, might have contributed to the observed patterns of temporal diversity.

Habitat, benthic prey, and distribution of juvenile lake sturgeon (Acipenser fulvescens) in northern Ontario rivers

1997 ◽  
Vol 54 (12) ◽  
pp. 2866-2871 ◽  
Author(s):  
Wayne B Chiasson ◽  
David LG Noakes ◽  
F William H. Beamish
Keyword(s):  
Trophic Status ◽  
Anthropogenic Activities ◽  
Temporal Distribution ◽  
Benthic Fauna ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Benthic Organisms ◽  
Foraging Success ◽  
Northern Ontario ◽  
Northern Rivers

The spatial and temporal distribution and relative abundance of juvenile lake sturgeon (Acipenser fulvescens) and benthic macroinvertebrates were examined in the Mattagami and Groundhog rivers, tributaries of the Moose River in northern Ontario, Canada. Relative density and diversity of the benthic fauna were low, the most common taxa being Ablabesmyia sp. (Diptera) and Hexagenia sp. (Ephemeroptera). Benthic organisms were most abundant in substrate dominated by sand and clay. An appreciable portion of the riverbed was strewn with wood chips and was particularly depauperate of macrobenthos. Lake sturgeon foraged exclusively on the benthos, especially taxa of Ephemeroptera, Diptera, and Trichoptera. Hexagenia was the only prey species in greater density in sturgeon stomachs than in the benthos. The largest concentration of juvenile lake sturgeon was found adjacent to substrate dominated by sand and clay. Gillnet catches of lake sturgeon suggest that they are more active at night, which may enhance their foraging success. In these northern rivers, the trophic status of juvenile lake sturgeon is marginalized by an impoverished food supply, in part the consequence of habitat loss resulting from anthropogenic activities.

The parasite community infecting flounders, Platichthys flesus, in the tidal Thames

1999 ◽  
Vol 73 (3) ◽  
pp. 203-214 ◽  
Author(s):  
H.E.M. El-Darsh ◽  
P.J. Whitfield
Keyword(s):  
Species Richness ◽  
Parasite Species ◽  
Parasite Community ◽  
Parasite Fauna ◽  
Component Community ◽  
Species List ◽  
Pomphorhynchus Laevis ◽  
Platichthys Flesus ◽  
First Time ◽  
Middle Estuary

The composition of the parasite fauna of the flounder,Platichthys flesus, retrieved from two locations in the tidal Thames is described in detail for the first time. The combined parasite species list of the flounders from Lots Road in the upper tideway and West Thurrock in the middle tideway consisted of one protozoan (Glugea stephani), one monogenean (Gyrodactylussp.), four larval digeneans (Cryptocotyle concava,Timoniella imbutiforme,T. praeterita, andLabratrema minimus), five adult digeneans (Derogenes varicus,Lecithaster gibbosus,Podocotylesp.,Plagioporus varius, andZoogonoides viviparus), one larval cestode (unidentified tetraphyllidean), one or possibly more larval nematodes (unidentified) plus five adult nematodes (Capillariasp.,Cucullanus heterochrous,C. minutus,Contracaecumsp. andGoeziasp.), two acanthocephalans (Pomphorhynchus laevisandAcanthocephalus anguillae), three copepods (Lepeophtheirus pectoralis,Acanthochondriasp. andLernaeocera branchialis), and one mollusc (unidentified glochidia). The overall parasite community of flounders from Lots Road and West Thurrock were compared in terms of species richness and diversity. The parasite community in flounders from the former location in the upper tideway was found to be less diverse than that of its counterpart at West Thurrock in the middle estuary. The component community of Lots Road flounders was dominated by the acanthocephalanPomphorhynchus laevis.

Parasite communities of the elongate tigerfish Hydrocynus forskahlii (Cuvier 1819) and redbelly tilapia Tilapia zillii (Gervais 1848) from Lake Turkana, Kenya: influence of host sex and size

2014 ◽  
Vol 60 (1) ◽  
Author(s):  
Elick O. Otachi ◽  
Beata Szostakowska ◽  
Franz Jirsa ◽  
Christine Fellner-Frank
Keyword(s):  
Influencing Factor ◽  
Parasite Community ◽  
Parasite Fauna ◽  
Lake Turkana ◽  
Parasite Communities ◽  
Large Size ◽  
Tilapia Zillii ◽  
Hydrocynus Forskahlii ◽  
Host Sex ◽  
Important Food Source

AbstractFish is an important food source for an estimated 300,000 people inhabiting the shores of Lake Turkana, Kenya. Despite its large size (7560 km2) and importance, the lake remains one of the least studied in the Great Lakes Region of Africa. This study describes the parasite community of the elongate tigerfish Hydrocynus forskahlii (Cuvier, 1819) and the redbelly tilapia Tilapia zillii (Gervais, 1848). A total of 87 individuals (43 H. forskahlii and 44 T. zillii) were dissected and examined for parasites. Two taxa infected H. forskahlii, the dominant one being an anisakid nematode Contracaecum sp. (L3) (P = 83.7%, mean intensity (MI) = 46.0, abundance (A) = 38.5). Twelve parasite taxa were recovered from T. zillii, with metacestodes of the gryporhynchid cestode Amirthalingamia macracantha being dominant (P = 79.5, MI = 10.3, A = 8.2). This was the first report of a mixture of merocercoids and plerocercoids in the same host. Fish size was positively correlated with the major parasite infection levels, but, the prevalence of Contracaecum sp. in H. forskahlii was negatively correlated with size, probably reflecting ontogenetic shifts in habitats and diets with age. Fish sex was not a significant influencing factor, with the exception of Contracaecum sp. in H. forskahlii, where prevalence differed significantly between sexes (p<0.05), with the females having a higher prevalence than the males. We conclude that H. forskahlii had a poor parasitic community but that the infection levels with Contracaecum sp. were high. T. zillii had a rich parasite fauna, although, most parasites occurred at low intensities.

Spatio-temporal variations of caddisfly assemblages in a chalk stream, Balaton Upland, Hungary

Zoosymposia ◽  
2011 ◽  
Vol 5 (1) ◽  
pp. 439-452
Author(s):  
ILDIKÓ SZIVÁK ◽  
ARNOLD MÓRA ◽  
JÚLIA KATALIN TÖRÖK
Keyword(s):  
Indicator Species ◽  
Cold Water ◽  
Human Impacts ◽  
Temporal Structure ◽  
Temporal Distribution ◽  
Weather Conditions ◽  
Temporal Variations ◽  
Aquatic Habitats ◽  
Indicator Value ◽  
Spatio Temporal

In 2006–2007 larval caddisfly assemblages of a semi-natural calcareous stream (Örvényesi Creek) were studied. Characteristic sections can be detected along the whole length of the stream, which passes through diverse types of vegetation, resulting in highly heterogeneous aquatic habitats. Based on an annual survey of different aquatic habitats, our aims were to give an overview of the spatio-temporal distribution of the larval caddisfly assemblages in the Örvényesi Creek and to find indicator species characterizing different sections of the stream. In order to show the spatio-temporal patterns, samples were collected at 7 locations with different streambed morphology, from spring to the mouth of the stream. Caddisfly larvae were collected in every 3rd week during a 1 year period using the “kick and sweep” method. Multivariate analyses were carried out to explore the spatio-temporal structure of caddisfly assemblages. The indicator value method was applied to detect indicator species for different sections of the stream. A rich caddisfly fauna (20 taxa) was found in the Örvényesi Creek. Fast-running and relatively cold-water hypocrenal sections were characterized by Beraea maurus and Apatania muliebris at high indicator value. Three Limnephilidae species (Limnephilus rhombicus, Limnephilus lunatus and Glyphotaelius pellucidus) were identified as significant indicator species for slow flowing, lentic habitats. Along the length of the stream, distinctive spatial and temporal changes were detected in the distribution of the caddisfly assemblages. These changes were mainly connected to variations in morphology of the streambed, phenology of individual taxa, extreme weather conditions and human impacts.

scholarly journals Population biology and distribution of the tanaid Kalliapseudes schubarti Mañé-Garzon, 1949, in an intertidal flat in Southeastern Brazil

2003 ◽  
Vol 63 (3) ◽  
pp. 469-479 ◽  
Author(s):  
F. P. P. Leite ◽  
A. Turra ◽  
E. C. F. Souza
Keyword(s):  
Population Biology ◽  
Temporal Distribution ◽  
Sampling Period ◽  
Positive Influence ◽  
Southeastern Brazil ◽  
Life Strategy ◽  
Intertidal Flat ◽  
Sediment Layer ◽  
High Fecundity ◽  
Seasonal Oscillation

The population biology and the spatial and temporal distribution of Kalliapseudes schubarti Mañé-Garzon, 1949, a common tanaidacean in mud flats and estuaries in southern and southeastern Brazil, was studied in the Araçá region, São Sebastião (SP), Brazil. This species showed a clustered dispersion in the area and the individuals were concentrated in the superficial sediment layer (5 cm). Higher densities of K. schubarti were recorded in areas characterized by moderately sorted fine sediment. Multiple regression analysis revealed a positive influence of the organic matter contents and a negative effect of the silt-clay contents on the abundance of K. schubarti. This species showed a marked temporal variation with very low abundance in winter and fall (March to August). Sexual dimorphism was evidenced with males being larger than females. Ovigerous females were also larger than pre-ovigerous ones. Sex ratio was skewed towards females. Seven cohorts were identified during the sampling period, the estimated longevity was 12 months, and no seasonal oscillation in growth was evidenced. The continuous reproduction, as evidenced by the presence of larval phases (manca II and neutron) and reproductive females throughout the year, and high fecundity among the tanaids associated with fast growth and limited longevity support the case for the opportunistic life strategy suggested for this species in the literature.

scholarly journals Spatial and temporal variation of extremely abundant maxima of precipitation in Hungary during the period between 1951 and 2010

2012 ◽  
Vol 18 (2) ◽  
Author(s):  
L. Lakatos ◽  
Z. Sümeghy ◽  
M. Soltész ◽  
J. Nyéki
Keyword(s):  
Extreme Values ◽  
Temporal Structure ◽  
Temporal Distribution ◽  
Point Of View ◽  
Spatial And Temporal Variation ◽  
Long Run ◽  
Coeffi Cients ◽  
Monthly Distribution ◽  
Geographical Maps ◽  
Short Time

The study deals with the accumulated database of 16 meteorological stations in Hungary during a period of 60 years. The purpose was to reveal the spatial and temporal structure of the appearance of extreme values in the daily distribution of data concerning precipitation. We strived to answer the question whether the frequency of incidences of daily maxima did they change or not during the 60 year-long period in the main growing regions of the country. It is demonstrated on geographical maps how the size and frequency of precipitation episodes ensued, and what are the typical traits of changes in intensity as well as in frequency of happenings projected according to their spatial and temporal distribution. From the point of view of fruit and vegetable growing, it is of prime interest what kind of frequency and intensity of changes occurred in precipitation. The temporal distribution of extremities though did not seem to change signifi cantly in some areas, but the recognition of changes may help conspicuously the planning and the choice between alternatives of species and varieties as well as technologies of horticultural managements for the long run. Extremely intense rains during a short time may cause erosion and stagnant water, thus we have to know what are the odds of risk. The temporary distribution of changes helps us to judge upon the reality of anxieties, which are expected according to the existence of trends. Seasonal or monthly distribution is visualised by maps, what is expected and what is accidental as for a decision in planning. The spatial distribution of coeffi cients of variation help us to decide what is the local chance of extreme happenings at different parts of the country and what is its coeffi cient of uncertainty. The risk of any undertaking dependent on conditions of weather could be expressed numerically by a coeffi cient of risk.

scholarly journals Biologi reproduksi udang mantis Cloridopsis scorpio di ekosistem mangrove Belawan, Sumatera Utara

DEPIK ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 227-334
Author(s):  
Rivo Hasper Dimenta ◽  
Rusdi Machrizal ◽  
Khairul Khairul ◽  
Rosmidah Hasibuan ◽  
Aini Qomariah Manurung ◽  
...  
Keyword(s):  
Random Sampling ◽  
Anthropogenic Activities ◽  
Sampling Period ◽  
Mangrove Ecosystem ◽  
Maturity Stage ◽  
Gonad Maturity ◽  
Mantis Shrimp ◽  
Shrimp Trawl ◽  
Gonad Somatic Index ◽  
Somatic Index

Anthropogenic activities that tend to be exploitative in the mangrove ecosystem of Belawan are thought to have an impact on the biota associated with the ecosystem. One of the impacts is thought to be implied by mantis shrimp Cloridopsis scorpio (Latreile, 1828). The reproductive biology of the shrimp is the main object that needs to be studied in relation to the impacts. This study aims to determine the distribution of gonad maturity stage, gonad somatic index, and the length of the first mature of C. scorpio in the Mangrove Ecosystem of Belawan, North Sumatera. The research was conducted on March to May 2019 with a biweekly sampling period. The purposive random sampling was applied to choose three sampling stations in the research location. Mantis shrimp samples were caught using shrimp trawl. The result showed that the gonad maturity stage of males and females were dominated by Stage I. The gonad somatic index (GSI) range of males were 7.00-10.93 and female were 7.40-11.15. The GSI value of C. scorpio is closely related to its gonad maturity development. The length of the first mature (L50) of males were 205.50±10.65 mmBL and females were 186.0±10.48 mmBL.Keywords: Cloridopsis scorpio, Gonad maturity stage, Gonad somatic indeks, Length of the first mature ABSTRAKAktivitas antropogenik yang cenderung eksploitatif di kawasan ekosistem mangrove Belawan diduga telah berdampak terhadap biota-biota yang berasosiasi dengan ekosistem tersebut. Salah satu dampaknya dialami oleh udang mantis Cloridopsis scorpio (Latreile, 1828). Aspek reproduksi C. scorpio menjadi salah satu objek yang perlu dikaji berkaitan dengan dampak tersebut. Penelitian ini bertujuan untuk menganalisis sebaran tingkat kematangan gonad (TKG), indeks kematangan gonad (IKG), dan ukuran pertama kali matang gonad (L50) dari C. scorpio di ekosistem mangrove Belawan, Sumatera Utara. Penelitian dilakukan pada bulan Maret sampai Mei 2019 dengan periode pengambilan sampel dua mingguan. Metode purposive random sampling digunakan untuk menentukan tiga stasiun pengambilan sampel di lokasi penelitian. Sampel C. scorpio ditangkap menggunakan pukat udang. Hasil penelitian menunjukkan distribusi TKG C. scorpio jantan dan betina didominasi oleh TKG I. Nilai IKG C. scorpio jantan berkisar antara 7,00-10,93 dan C. scorpio betina berkisar antara 7,40-11,15. Nilai IKG C. scorpio berkaitan dengan tahap perkembangan gonadnya. C. scorpio jantan mengalami pertama kali matang gonad (L50) pada ukuran 205,50±10,65 mmBL dan C. scorpio betina pada ukuran 186,00±10,48 mmBL.Kata kunci: Cloridopsis scorpio, TKG, IKG, Ukuran pertama kali matang gonad

scholarly journals Spatial-Temporal Distribution and Insecticide resistance Status of Aedes Aegypti in Ghana

2021 ◽  
Author(s):  
Christopher Mfum Owusu-Asenso ◽  
Julius Abraham Addo Mingle ◽  
David Weetman ◽  
Yaw Asare Afrane
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Rural Areas ◽  
Temporal Distribution ◽  
Sampling Period ◽  
Detailed Knowledge ◽  
Phenotypic Resistance ◽  
Ecological Zones ◽  
Spatio Temporal ◽  
Study Sites

Abstract Background: Vector control is the main intervention to control arboviral diseases transmitted by Aedes mosquitoes because for most there are no effective vaccines or treatment. This vector control relies heavily on the use of insecticides, effectiveness of which may be impacted by resistance. In addition, rational insecticide application requires detailed knowledge of vector distribution, dynamics, resting, and feeding behaviours, which are poorly understood for Aedes vectors in Africa. This study investigated the spatio-temporal distribution and insecticide resistance status of Ae. aegypti from across ecological extremes of GhanaMethods: Immature mosquitoes were sampled from containers in and around human dwellings at each of seven study sites in urban, suburban, and rural areas of Ghana. Adult Aedes mosquitoes were sampled indoor and outdoor using Biogent sentinel-2 mosquito traps, human landing catches, and prokopack aspiration. Distributions of immatures and adult Aedes mosquitoes were determined indoors and outdoors during dry and rainy seasons at all sites. Phenotypic resistance status of Aedes mosquitoes to insecticides was determined using WHO bioassays. Host blood meal source was determined by PCR.Results: A total of 16,711 immature Aedes were sampled, with over 70% found in car tires. Significantly more breeding containers had Aedes immatures during the rainy season 70.95% (11,856) compared to the dry season 29.05% (4,855). A total of 1,895 adult Aedes mosquitos were collected, including Ae. aegypti (97.8%), Ae. africanus (2.1%) and Ae. Luteocephalus (0.1%). Indoor sampling of adult Aedes mosquitoes yielded a total of 381 (20.1%) and outdoor a total of 1,514 (79.9%) (z = -5.427; p = 0.0000) over the entire sampling period. Aedes aegypti populations were resistant to DDT at all study sites. Vectors showed suspected resistance to Bendiocarb (96-97%), Permethrin (90-96%) and Deltamethrin (91-96%) and were susceptible to the organophosphate malathion from all study sites.Blood meal analysis showed that the Aedes mosquitoes were mostly anthropophilic with HBI of 0.9 i.e. [(human = 90%), (human and dog = 5%), (dog and cow = 5%)].Conclusion: Aedes mosquitoes were found at high densities in all ecological zones of Ghana. Resistance to pyrethroids and carbamates may limit control efficacy and requires careful monitoring.

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