Alcedoffula alcyonae Carriker (Phthiraptera: Ischnocera: Philopteridae) infesting belted kingfisher, Megaceryle alcyon (Linnaeus) (Aves: Coraciiformes, Alcedinidae), in Manitoba, Canada

2020 ◽  
pp. 1-6
Author(s):  
Terry D. Galloway
Keyword(s):  
Sex Ratio ◽  
Chewing Louse ◽  
Mean Intensity ◽  
Feather Mite ◽  
Unidentified Species ◽  
The Mean ◽  
Bird Distribution

Abstract Forty-one belted kingfishers, Megaceryle alcyon (Linnaeus) (Aves: Coraciiformes: Alcedinidae), from Manitoba, Canada were examined for ectoparasites in 1995–2020. One species of chewing louse, Alcedoffula alcyonae Carriker (Phthiraptera: Ischnocera: Philopteridae), infested 48.8% of hosts. The mean intensity of infestation was 17.1, and mean abundance was 8.5 lice per bird. Distribution of infestation was highly aggregated. Although female lice outnumbered males, the sex ratio was not significantly different from 1.0. The ratio of nymphs to females was 2.6. An unidentified species of feather mite of the genus Proterothrix Gaud (Acari: Astigmatina: Proctophyllodidae) infested three of 35 hosts (8.6%). No mites were found in the quills of primary feathers from 19 birds, and no nasal mites were collected from 32.

Seasonal population dynamics of Neoechinorhynchus qinghaiensis in the carp, Gymnocypris przewalskii przewalskii, from Qinghai Lake, China

2001 ◽  
Vol 75 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Yang Tingbao ◽  
Liao Xianghua
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Feeding Habits ◽  
Host Population ◽  
Qinghai Lake ◽  
Mean Intensity ◽  
Gymnocypris Przewalskii ◽  
The Mean ◽  
Seasonal Population ◽  
Seasonal Population Dynamics

Studies on the seasonal population dynamics ofNeoechinorhynchus qinghaiensis(Acanthocephala: Neoechinorhynchidae) in its fish hostGymnocypris przewalskii przewalskiiin the Qinghai Lake, China, were carried out with samples taken in May 1991, August 1992, November 1992 and February 1993. Prevalences were higher than 44% in all seasons. The mean intensity of infection was above 124 worms per fish. The maximum intensity of worms recovered from a single fish was 1402 in the autumn of 1992. Differences in the mean abundance, mean intensity and prevalence are not statistically significant relative to season and this is likely to be related to the stable temperatures recorded at the bottom of Qinghai Lake. Over-dispersed distributions ofN. qinghaiensisin the host population, due to heterogeneity and feeding habits, were observed in all seasons. The size composition of both sexes ofN. qinghaiensisshowed males to be less than 3.5 mm and females between 0.5 and 4.25 mm, with the main recruitment phase in the worm populations occurring in the autumn, extending through winter and spring with the lowest recruitment occurring in the summer. The maturation and copulation of worms were mainly focused in the summer season. The sex ratio of female to male was both high in winter (1.51:1) and spring (1.48:1). The higher proportion of females and the change in the worm sex ratio in winter can be attributed to the reduced longevity of male worms. As immature male worms exhibit a higher proportion of the worm population than females in all seasons, further studies are needed to determine if such a situation compensates for the shorter life span of males.

Abundance and stability of populations of chewing lice (Phthiraptera: Amblycera and Ischnocera) infesting two species of woodpeckers (Aves: Piciformes: Picidae)

2018 ◽  
Vol 150 (2) ◽  
pp. 180-189 ◽  
Author(s):  
Robert J. Lamb ◽  
Terry D. Galloway
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Population Variability ◽  
The Other ◽  
Population Stability ◽  
Mean Intensity ◽  
Chewing Lice ◽  
The Mean ◽  
Louse Species ◽  
Colaptes Auratus

AbstractThe annual abundance of chewing lice (Phthiraptera) was recorded from 1996 to 2015 in Manitoba, Canada, on two species of woodpeckers (Piciformes: Picidae). Yellow-bellied sapsuckers (Sphyrapicus varius (Linnaeus)) were infested with Menacanthus pici (Denny) (Amblycera: Menoponidae) and Penenirmus auritus (Scopoli) (Ischnocera: Philopteridae); northern flickers (Colaptes auratus (Linnaeus)) were also infested with M. pici, as well as two other Ischnocera, Penenirmus jungens (Kellogg) and Picicola porisma Dalgleish. The mean annual abundance varied from nine to 51 lice per bird for the four species, with prevalence, mean intensity, sex ratio, and nymphs per female also varying among louse species. Menacanthus pici populations on both hosts were unstable: abundance rose over two decades because of increasing prevalence, whereas the abundance of the other three louse species fluctuated around a mean. Population variability was similar for the lice on both hosts, with the metric, PV, ranging from 0.41 to 0.51 on a 0–1 scale, once the effect of the trend in abundance for M. pici had been removed. Although the population dynamics for species of lice on these two woodpeckers were distinct, inter-specific differences in population stability were less pronounced than observed in the few other species of bird lice studied in this way.

scholarly journals Ectoparásitos asociados a polluelos del Búho Cornudo (Aves: Strigidae) en un paisaje fragmentado de la península de Baja California, México

2018 ◽  
Vol 34 (1) ◽  
pp. 1-15
Author(s):  
Raquel Bolaños-García ◽  
Ricardo Rodríguez-Estrella ◽  
Carmen Guzmán-Cornejo
Keyword(s):  
Baja California ◽  
Health Condition ◽  
Host Population ◽  
Avian Host ◽  
New Host ◽  
Chewing Louse ◽  
Fragmented Habitat ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Feather Mite

Ectoparasites are important in avian host population because they can affect health condition, regulate population dynamics and alter interspecific competition. Studies of ectoparasites in wild raptors are scarce and even few have been made in owls. This is the first study of the prevalence and intensity of ectoparasites in Great Horned Owl (Bubo virginianus) fledglings. We studied ectoparasites on fledglings from nests in a fragmented arid landscape at Baja California peninsula, during the breeding seasons of 2015 and 2017. The fledglings of 40 days of age were handled and taken from their nests for the collection of ectoparasites. A total of 81 epizoic species were collected from 36 nestlings from 15 nests, distributed in five orders: Diptera (Icosta americana); Hemiptera (Cimicidae gen. sp.); Phthiraptera (Neohaematopinus sciurinus, Colpocephalum pectinatum); Siphonaptera (Orchopea sp.) and Mesostigmata (Ornihtonysus sylviarum). Likewise, one species of chewing lice (n=5) (Geomydoecus telli) and one species of feather mite (n=7) were also recorded associated with the Great Horned Owl. Five species were hematophagous parasites. Louse fly I. americana and chewing louse C. pectinatum showed the highest levels of prevalence (26.5% and 20.6% respectively), while the hematophagous feather mite Ornihtonysus silviarum presented the higher mean intensity in only one nest (15.5). The flea Orchopea sp. and the chewing louse G. telli and sucking louse N. sciurinus exhibited the lowest values of prevalence and mean intensity; these species have been recorded in association mainly with rodents, so probably they could have been transmitted to the owls when they were captured as preys and taken into their nest. Additionally a bug (Cimicidae gen. sp.) was found in one host. Colpocephalum pectinatum is the first recorded from Great Horned owl, such as new host. The abundance of ectoparasites in one owl nest was independent of their abundance in neighbor nests (Moran´s I = 0.010; z = 0.16, P > 0.05). We discuss the implications of ectoparasitism for a Great Horned owl population in fragmented habitat of the Baja California arid desert.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

scholarly journals Reproductive Biology of Round Sardinella (Sardinella Aurita) (Valenciennes, 1847) in Senegalese Coastal Waters

2018 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Ismaïla NDIAYE ◽  
Alassane SARR ◽  
Alioune FAYE ◽  
Modou THIAW ◽  
Malick DIOUF ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Sexual Maturity ◽  
Reproductive Parameters ◽  
Monthly Variation ◽  
Relative Fecundity ◽  
The Mean ◽  
Sardinella Aurita ◽  
Somatic Index

In this study, a total of 1068 specimens Sardinella aurita of which 553 females and 515 males were examined. The objectif of this study was to determine the reproductive parameters of Sardinella aurita. The sex ratio was significantly in favor of females (55%). The size at first sexual maturity was estimated at 18.9 cm for females and 18.0 cm for males. The monthly variation of sexual maturity stages and gonado-somatic index (GSI) allowed to locate the reproduction periods from February to June and from September to December. The mean absolute fecundity was estimated at 110.794 ± 7582 oocytes whereas relative fecundity was about 422 ± 26 oocytes per gram of female.

scholarly journals Biology and parasitic potential of Doryctobracon areolatuson Anastrepha fraterculus larvae

2011 ◽  
Vol 46 (6) ◽  
pp. 669-671 ◽  
Author(s):  
Adrise Medeiros Nunes ◽  
Dori Edson Nava ◽  
Fernanda Appel Müller ◽  
Rafael da Silva Gonçalves ◽  
Mauro Silveira Garcia
Keyword(s):  
Biological Control ◽  
Sex Ratio ◽  
Adult Emergence ◽  
Parasitism Rate ◽  
Anastrepha Fraterculus ◽  
The Mean ◽  
Parasitoid Development

The objective of this work was to study the biology and parasitic potential of Doryctobracon areolatus on larvae of Anastrepha fraterculus. The egg-adult period, the sex ratio, the longevity, the pupal viability, and the parasitism rate of D. areolatus were determined in laboratory, using A. fraterculus as host. The parasitoid development from oviposition to adult emergence required 25.00±1.70 days, the sex ratio was 0.62±0.09, and the mean longevity was 16.36±3.62 days for males and 10.24±1.71 days for females. The mean parasitism rate was 53.50±8.93%, varying from 41.60 to 68.60%, which shows the potential of this parasitoid for biological control of A. fraterculus.

scholarly journals Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

2014 ◽  
Vol 23 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Maurício Orlando Wilmsen ◽  
Bruna Fernanda Silva ◽  
César Cristiano Bassetto ◽  
Alessandro Francisco Talamini do Amarante
Keyword(s):  
Haemonchus Contortus ◽  
Natural Infection ◽  
Gastrointestinal Nematode ◽  
Gastrointestinal Nematodes ◽  
Sao Paulo ◽  
São Paulo ◽  
Mean Intensity ◽  
Oesophagostomum Columbianum ◽  
The Mean ◽  
In Parenthesis

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = −0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.

scholarly journals Sudden death of adults in Togo: Autopsy results of a series of 318 cases

2019 ◽  
Author(s):  
Tchin Darre ◽  
Toukilnan Djiwa ◽  
Gado Napo-Koura
Keyword(s):  
Risk Factors ◽  
Pulmonary Embolism ◽  
Sex Ratio ◽  
Sudden Death ◽  
Traffic Accidents ◽  
Cardiac Pathology ◽  
Common Cause ◽  
Cerebral Involvement ◽  
The Mean ◽  
Death Cases

Abstract Objectives: The purpose of the study was to determine the circumstances of occurrence of these sudden deaths, risk factors, to identify the causes of sudden death in adults at autopsy. Results: A total of 318 sudden death cases were recorded. The sex ratio (M/F) was 1.8, and the mean age was 43 ± 0.36 years. Sudden deaths were the second most common reason for autopsies after traffic accidents. The place of death was home in 76.7% of cases and in hospitals in 23.3%. Obesity was noted in 59.4%, with an umbilical adipose panicle varying between 7 and 12 cm thick. Cardiovascular causes excluding cerebral involvement (n=173cases, 54.40%) followed by pulmonary causes (n=100 cases, 31.44%) were the most common cause of sudden death. The predominant cardiac pathology was infarction accounting for 32.07% of all causes of sudden death, and pulmonary embolism with 19.49% was the leading cause at the pulmonary level.

scholarly journals Digenetic Trematode Parasites in Two Fresh Water Fishes Ophiocephalus Punctatus and Xenentodon Cancila From North West Himalayas

2021 ◽  
Author(s):  
Sukanya Rajput ◽  
Seema Langer
Keyword(s):  
Fresh Water ◽  
Digenetic Trematode ◽  
Host Fish ◽  
Mean Intensity ◽  
North West ◽  
Trematode Infection ◽  
Xenentodon Cancila ◽  
The Mean ◽  
Union Territory ◽  
Trematode Parasites

Abstract The study was conducted during September 2018-August 2019 to study the digenetic trematode infection in fresh water fishes of some of the water bodies viz. Gho-manhasan, Chakrali and Chadwal of Jammu region of J&K union territory A total of 220 fishes comprising Ophiocephalus punctatus and Xenentodon cancila belonging to families Channidae and Belonidae respectively were examined. A total of 4 digenetic trematode parasites belonging to 4 different families i.e., Euclinostomum heterostomum (Clinostomidae Luhe, 1901); Phyllodistomum tripathi (Gorgoderidae Looss, 1901); Genarchopsis piscicola (Hemiuridae, Luhe, 1901), and Bucephalopsis karvei (Bucephalidae Poche, 1907) were detected. The overall prevalence of digenetic trematode infection was 65.90% and the mean intensity was 3.58. Among these Genarchopsis piscicola showed the highest prevalence (40.38%) with mean intensity 2.95 in the host fish Xenentodon cancila, while in other species the prevalence ranged between 26.23% and 34.62%. Present study authenticates the presence of several species of digenetic trematode parasites in the fishes inhabiting freshwater of J&K union territory.

scholarly journals Florivory and sex ratio in Annona dioica St. Hil. (Annonaceae) in the Pantanal at Nhecolândia, southwestern Brazil

2006 ◽  
Vol 20 (2) ◽  
pp. 405-409 ◽  
Author(s):  
Hipólito Ferreira Paulino Neto ◽  
Reinaldo Chaves Teixeira
Keyword(s):  
Sex Ratio ◽  
Fruit Set ◽  
Flowering Plants ◽  
The Mean ◽  
Male Flowers

Annona dioica St. Hil. is a species that grows to approximately 2 m tall and is very widespread in the cerrados. Individual plants of this androdioecious species produce numerous hermaphroditic or male flowers, but few fruits. The aim of this study was to determine the sex ratio among the plants and to compare the frequency of herbivory between male and hermaphroditic flowers. The fieldwork was done by studying flowering plants in grasslands used as pasture for cattle at Fazenda Nhumirim. One hundred and forty-seven male plants and 71 hermaphroditic plants were examined and produced a total of 194 and 94 flowers, respectively, during the study period. The male:hermaphrodite sex ratio was 2.07:1, and was similar to the male:hermaphrodite flower ratio of 2.06:1. The frequency of florivory rate in hermaphrodites was significantly higher than in male flowers (33.0%, n = 31, and 25.7%, n = 50, respectively; G = 14.83; d.f. = 1; p < 0.001). The mean fresh weights of male and hermaphroditic flowers were significantly different (8.38 ± 2.40 g vs. 6.93 ± 2.68 g, respectively; 0 ± SEM; n = 50 each; t = 2.479; d.f. = 49; p = 0.017). These results indicate that the low fruit set in this species can be explained by the sex ratio, the greater herbivory of hermaphroditic flowers and the probable absence of pollinators.

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