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1.
《Journal of Natural History》2012,46(14):1747-1760
The present study was undertaken to examine the parasite fauna of spiny dogfish, and to determine seasonal variations in infection rates and faunal composition. A total of 10 metazoan parasite species was recorded, of which four species occurred in the intestine, three species were parasitic on the gills, two species occurred on the skin, and one species parasitized the spiracle. However, a cumulative parasite species richness curve indicated that a larger sample may have yielded additional parasite species. The parasite assemblage consisted of five species of copepods (Eudactylina acanthii Scott, Caligus curtis Müller, Pandarus bicolor Leach, Echthrogaleus coleoptratus (Guerin-Meneville) and Pseudocharopinus bicaudatus (Krøyer)), two species of nematodes (Anisakis simplex Rudolphi and Hysterothylacium aduncum (Rudolphi)), two species of cestodes (Trilocularia gracilis Olssen and Gilguina squali (Fabricius)), and one species of monogenean (Erpocotyle abbreviata (Olssen)). The parasite fauna was found to be similar to that of S. acanthias from the North Sea, and from New Zealand waters. Results obtained during the present study indicate that the infection rates of certain parasite species display seasonal cycles, most species displaying their greatest prevalence in spring and their lowest prevalence in autumn.  相似文献   

2.
We sampled both subspecies of the Idaho ground squirrel ( Spermophilus brunneus ) to document the larger ectoparasites of this rare endemic. S. b. brunneus was host (+ = new host record, ? = new Idaho record) to 4 flea species ( Neopsylla inopina + , Oropsylla idahoensis + , O. tuberculata , and Thrassis pandorae +), 1 tick ( Ixodes sculptus +), and an eyeworm (Nematoda: Rhabditis orbitalis ? + , also 1st records from Seiuridae); S. b. endemicus was host to a louse species ( Neohaematopinus laeviusculus +), 5 flea taxa ( Rhadinopsylla sp. + , O. t. tuberculata, Thrassis f. francisi + , T. f. barnest + , and T. f. rockwoodi ), and a mite ( Androlaelaps fahrenholzi +). Spermophilus brunneus had fewer known ectoparasite species than other congeners. Although all of their parasites had many other hosts, S. b. endemicus and S. b. brunneus shared only a single parasite species in common, whereas all but one of their ectoparasites also occurred on the closely related Townsend's ground squirrel ( S. townsendii ). The proportion of parasitized individuals and the parasite loads per individual were significantly lower in S. b. brunneus , which lives in small, isolated populations, than in S. b. endemicus , which has larger, less fragmented populations, suggesting a relationship between host population structure, parasite loads, and parasite species diversity. All but one of the flea species have been linked to plague transmission.  相似文献   

3.
Juveniles of two species of commercially important prawns, Metapenaeus dobsoni (Miers) and Macrobrachium rosenbergii (De Man) collected from Gosthani estuary, Bheemunipatnam near Visakhapatnam, India during the period August 1995 to August 1996 were subjected to a detailed study with a view to identifying the various species of epibionts and parasites and to monitor the seasonal changes in the occurrence and abundance of common species of ciliates and larval helminths. A wide range of protozoan and metazoan parasite species was encountered in the prawns. The protozoans were represented by epicommensal ciliates belonging to the genera Zoothamnium, Epistylis, Acineta, Vorticella, an unidentified apostome ciliate and two species of gregarines. The metazoan parasites included metacercariae of families Opecoelidae and Microphallidae, a larval cestode, a larval nematode and two species of bopyrid isopods. Altogether eight species were found infecting M. rosenbergii and 11 species infected M. dobsoni. A majority of the parasite species infected both the hosts. The peritrichous and apostome ciliates constituted the dominant members of the parasite fauna, occurring on both species of prawns as epibionts with high prevalence and density. All the other infections were rarely encountered. Infections with gregarines were restricted to M. dobsoni while those of microphallid metacercariae were found only in M. rosenbergii. Zoothamnium infections were more common on M. rosenbergii than on M. dobsoni. Apparent differences in the parasite fauna, attributed to differences in the behaviour of the two species, were noted. Seasonally Zoothamnium infections were at their peak during monsoon and post-monsoon months and these infections appear to be governed directly by salinity of the habitat and indirectly by the rainfall. Apostome ciliate infections were at their peak during the months November and February. Opecoelid metacercarial infections were confined to the period August to February, with peak during summer months.  相似文献   

4.
Summary

The zoogeography of the Cayman Islands is discussed. Two species of Lutzomyia were found on Cayman Brac and they are described and their relation to other forms discussed. One is a Cuban species, or a close relative, and the other is allied to a Jamaican sand-fly.

A nematode parasite was found in one sand-fly.  相似文献   

5.
《Journal of Natural History》2012,46(23-24):1465-1479
ABSTRACT

The diversity, similarity and seasonal variation of metazoan parasite communities in Calophysus macropterus in the Acre and Iaco rivers, in the western Amazon (Brazil), was investigated. Parasites from 13 taxa were collected from C. macropterus in both rivers: four species of monogeneans, four nematodes, two cestodes, one digenean, one crustacean and one pentastomid. In hosts from the Acre river, Cucullanus pinnai predominated; while in hosts in the Iaco river, Monticellia amazonica predominated. The component communities of the parasites among the hosts in the two rivers presented high similarity (100%). Prevalence of Alinema amazonicum was higher in hosts in the Acre river; while the prevalence of C. pinnai was higher in hosts in the Iaco river and the mean prevalence and abundance of M. amazonica were higher in fish from the Iaco river. Regarding C. macropterus from the Acre river, infection levels by A. amazonicum were higher during the rainy season, while Demidospermus pinirampi only occurred in the dry season and Procamallanus (Spirocamallanus) inopinatus only occurred in the rainy season. In hosts from the Iaco river, infections by larvae of Anisakidae gen. sp. were higher during the dry season, while infection by Rudolphiella piracatinga and Sebekia sp. only occurred in the rainy season. However, P. (S.) inopinatus, Ergasilus callophysus, Ameloblastella unapi, Demidospermus luckyi, Demidospermus macropteri and D. pinirampi only occurred in the dry season. High similarity of the component communities of the parasite was observed between the rainy and dry seasons. These results suggest that factors other than location and seasonality were influencing the communities and infracommunities of the parasites found. Lastly, C. macropterus is a new host for almost 50% of the parasite species found. In addition, the results from the present study have expanded the geographical range of these 13 species of parasites to the western Amazon region.  相似文献   

6.
《Journal of Natural History》2012,46(10):1155-1172
In Finland Dermocystidium percae Reichenbach-Klinke was first recorded by Pekkarinen in the fins of a perch in 1988. Because it is a poorly known parasite, its occurrence and life stages are studied here. In occasional sampling during 1995-1998 and 2001, and more systematic sampling during 1999 and 2000 in two different lakes (one oligotrophic, the other slightly eutrophic), it was found to occur almost continuously, although sometimes very sparsely, in both lakes. The life cycle is maintained from year to year by overwintering cysts. Young perch acquire first infections in their first summer of life, and fish over 3 years possibly develop some immunity. In Estonia, in the Kasari River and the Matsalu Bay, the parasite seems to be very rare. Cysts of D. percae, capable of sporogenesis, can occasionally occur in the ruff, too. In perch in Finland, cysts were found differing from the longish and thin-walled cysts typical of D. percae. These roundish to dumbbell-shaped cysts with thicker walls are here suggested to belong to a different Dermocystidium species, called D. sp. Cysts of D. percae occurred in the skin of all fins, but most often in abdominal fins and rarely elsewhere. In ruff, cysts of D. percae were also found in the gills. Of the fins D. sp. favoured the first dorsal fin, but also occurred elsewhere, e.g. in the head region of perch. Cysts of D. percae develop from thin-walled, round plasmodium mother cells, about 10 µm in diameter, by elongating and increasing in size. The nucleus of the plasmodium mother cell degenerates, and a reticular chromatin-containing structure with dense centra spreads out between conspicuous lipid droplets in the plasmodium. Nuclei reappear during fragmentation of the plasmodium. The sporonts thus formed divide to form sporoblasts, which in addition to small lipid droplets acquire a non-lipid 'central' inclusion. The inclusion grows in size to the typical inclusion of the ultimate Dermocystidium spore. Sporogenesis both in D. percae and D. sp. takes place mostly in summer, and at least in D. percae can continue until autumn. In addition, both species can produce numerous zoospores from their spores within 2 days in water at 25°C and at slower rates at lower temperatures. The body of the zoospore is about 1.2-2.2 µm in length and the flagellum is about six times the body length. The zoospores may then slightly grow in size and transform into amoebae. Small cysts, which possibly originated from an experimental infection by zoospores of D. sp., developed in 0-group perch kept in an aquarium at 17°C. The two Dermocystidium species here discussed can be grouped together with some other species, in which nuclei reappear and the plasmodium divides late in development and in which sporogenesis, unlike that in D. vejdovskyi Jírovec and D. cyprini ?ervinka and Lom, does not take place in compartments.  相似文献   

7.
Spatial distribution, burrow morphology, phenology, defensive displays and predation of two theraphosid spiders living in meadows were studied in Uruguay. Exhaustive field studies complemented with laboratory observations were carried out. Eupalaestrus weijenberghi occurred throughout the country while Acanthoscurria suina occurred only in the southern half. Both species seemed to be the most abundant theraphosid spiders in Uruguay as they live in the dominant landscape of the country. Burrows from both species showed a similar morphological pattern but a terminal narrow tube was found only in E. weijenberghi. We observed that A. suina always co‐occurred with E. weijenberghi but this species frequently occurred in the absence of the former. When co‐occurring A. suina showed an aggregated distribution while E. weijenberghi was randomly distributed. A restricted reproductive period was found for both species, mainly between March and April, evidenced by the massive presence of walking adult males and then confirmed by pit‐fall traps. Moulting, oviposition and longevity were also studied. Conspicuous species‐specific defensive behaviours were displayed by the tarantulas in all cases, when collected. These tarantulas showed spatial co‐occurrence and temporal coexistence with the beetle Diloboderus abderus, an important pest of grasslands. Tarantula predation on adult beetles was confirmed, these spiders being one of the few beetle predators. Their maximal efficiency in beetle predation could reach 65?000 prey captured per hectare by month. These polyphagous tarantulas seem to be potential agents for the biological control of beetle pests.  相似文献   

8.
The previously unknown male of the biting midge, Culicoides reevesi Wirth, is described and illustrated; the female is also redescribed and this species is reassigned to the leoni group. Previously known from California, Arizona, and New Mexico, C. reevesi is recorded for the 1st time from Utah ( new record ). Females of this aggressive, hematophagous species were collected while biting humans during evening crepuscular periods in California. Females exhibited a strong attraction to CO 2 traps, and seasonal surveillance demonstrated that host-seeking occurred from late May until mid-October in both California and Utah. Small numbers of males were also collected in CO 2 traps; however, both sexes showed little attraction to ultraviolet and incandescent light traps.  相似文献   

9.
Between 1983 and 1985, 97 mottled sculpin, Cottus bairdi Girard, were examined from five collection sites in central Utah for parasites. Eight different species of parasites were observed, representing seven genera of Protozoa ( Plistophora, Myxidium, Myxobolus, Ichthyophthirius, Trichodina, Apiosoma, Eimeria ) and one genus of Nematoda ( Rhabdochona ). The highest number of parasites was found in sculpin from the Provo River near residential areas, while the lowest number was recorded from Hobble Creek, a nearby pristine area. A complete list of parasites for C. bairdi with literature citations is presented. Each observed parasite is discussed emphasizing pathogenesis to the host.  相似文献   

10.
Summary

A migratory population of wildebeest (Connochaetes taurinus) in Liuwa Plain National Park in the Western Province of Zambia was sampled for nasal bots (Diptera: Oestridae: Oestrinae) during 1975–78. Infestations from 32 antelope included Gedoelstia spp. (two species), Oestrus aureoargentatus and O. variolosus. A total of 1913 second and third instar larvae was recorded from the sinuses and nasal septa with individual parasite loads varying from 4 to 144 bots. No obvious pathogenicity was attributable to these oestrids, all four species of which were judged to be multivoltine in this habitat. The significance of this voltinism in relation to the migratory course of the wildebeest is discussed together with a consideration of parasite densities and the potential threat of myiasis to domestic livestock in the area.  相似文献   

11.
To observe the behaviour of cymothoid isopods during the infestation process, 30 experiments in aquaria were carried out, using the fish Gymnogeophagus gymnogenys (Hensel, 1870) and Jenynsia multidentata (Jenyns, 1842) as hosts, and Artystone trysibia Schioedte, 1866 as the parasite. All the specimens were collected from Guaíba Lake in Porto Alegre, Rio Grande do Sul. We recorded and analysed the behavioural acts of the parasites and hosts from the moment of encounter to the infestation, which was considered to be completed when the parasite had inserted itself into the fish's body. The behavioural acts are shown as a flow diagram, including the frequencies of occurrence of each act. Positive infestation occurred in 60% of the experiments. No relationship was observed between the sizes of the parasite and host, and the success of the infestation.  相似文献   

12.
《Journal of Natural History》2012,46(6):1239-1248
Some helminths are recorded from volcano rabbits Romerolagus diazi, originally captured in Mexico, which died at the Jersey Wildlife Preservation Trust. Teporingonema cerropeladoensis, a new genus and species of trichostrongylid nematode, is described and its position within the Libyostrongylinae discussed.  相似文献   

13.
《Journal of Natural History》2012,46(41-42):2665-2676
ABSTRACT

Corbicula fluminea is a bivalve considered to be among the 100 worst invasive species in Europe due to its economic and ecological impacts in freshwater ecosystems. Here, we report for the first time a phenomenon of shell erosion observed in two distinct populations of C. fluminea collected in 2015 from two semi-natural small streams of the River Ticino hydrographic basin (Northern Italy). We measured several biometric variables in order to quantify the shell damage: length and thickness of the right valve and the shell free dry weight of each specimen and compared results with those of ‘normal’ populations from another stream of the same area. Our results confirmed that there was abnormal shell erosion and a reduction in shell thickness in both populations. We hypothesised several potential causes for the observed erosion, but none of them could provide sufficient explanation: neither the pH of the water, nor the level of calcium or total hardness of the water or granulometry of the substrates differed among streams. Similarly, predation pressure cannot be considered a reasonable explanation, since in the study area only a few animals actively prey on these bivalves and the marks they leave on the shells are completely different from the ones observed on our specimens. Lastly, we hypothesised that the bivalves may have been affected by a disease or parasitic infestation that had weakened their shells or prevented them from self-repairing and identified a fungal parasite that could possibly cause a disease to C. fluminea, namely the Ascomycota Geotrichum candidum. However, this species occurred only in one of the two abnormally eroded populations. In conclusion, a valid explanation for the morphological alteration that our study revealed has yet to be found.  相似文献   

14.
The reproduction and parasite associates of the squat lobster Munidopsis platirostris (A. Milne Edwards and Bouvier, 1894) were investigated based on collections made in the Bahamas and Curaçao with grassmat and bundled fishing net traps used to collect sipunculan worms and other small invertebrates. Size of ovigerous M. platirostris was significantly correlated with clutch size for females from both localities but females from the Bahamas produced significantly more eggs (on average 10.1 eggs/clutch) than females from Curaçao (on average 6.6 eggs/clutch). Early embryos of M. platirostris from the Bahamas were 0.74–0.82 mm in diameter, similar to some other species of Munidopsidae as well as Chirostylidae. Two species of crustaceans, another squat lobster and a leptostracan, as well as a limpet mollusc, were collected with M. platirostris in the Bahamas, while a sipunculan was an associated species in a Curaçao collection. One specimen of M. platirostris had an unidentified cryptoniscoid epicaridean isopod, possibly representing a new genus and species. Two specimens of M. platirostris each had one rhizocephalan externa of a species belonging to Lernaeodiscus Müller, 1862 but their morphology does not match that of L. schmitti Reinhard, 1950, the only species in the genus known from squat lobsters in the western Atlantic. Additional materials and tools, such as DNA analysis, are needed to describe these potentially new parasites and we suggest that use of these traps may be an effective method to obtain additional samples.  相似文献   

15.
Carnivores were recorded at prairie dog towns and non-prairie dog town paired sites in the Oklahoma Panhandle over 4 sampling sessions from October 1995 to February 1997. We established carnivore presence through the use of baited tracking plates dusted with chalk and matched with infrared-triggered cameras. Five carnivore species were recorded at both prairie dog towns and paired sites across the Oklahoma Panhandle. Of these, 4 were recorded with sufficient regularity to permit analyses. Carnivores were analyzed at prairie dog towns across the entire Panhandle and in the Panhandle's westernmost county (Cimarron County) only. Canids showed no significant preference for prairie dog towns or other areas. In the Oklahoma Panhandle and Cimarron County only, occurrence of swift fox ( Vulpes velox ) between prairie dog towns and control sites was insignificant. Badgers ( Taxidea taxus ) and spotted skunks ( Spilogale putorius ) occurred significantly more often at prairie dog towns in Cimarron County but not in the Panhandle. No single mustelid species showed a significant association with either prairie dog towns or non-prairie dog town habitats. Our results indicate that whereas prairie dog towns do attract some carnivore species, the presumption that prairie dogs are ""keystone species"" for so many organisms (especially threatened or endangered species) in the current plains ecosystem may not be as clear as previously thought.  相似文献   

16.
The pygmy rabbit ( Brachylagus idahoensis ) is a secretive, obligate sagebrush-steppe resident of the Intermountain West and is one of two rabbits in North America that digs its own burrows. Although the pygmy rabbit has a recorded home range of 0.21–67.9 ha in relatively high sagebrush cover (21%–36%), they spend much of their time within 30–100 m of a burrow system. Due to big sagebrush cover in preferred habitat and the secretive behavior of pygmy rabbits, it is often difficult to study this leporid through direct observation. We used remote cameras to document pygmy rabbit activity at burrow systems in south central Utah from 2006 to 2008. We analyzed photographs from remote cameras for daily and seasonal patterns of activity. Our results suggested that time of day and season were important influences on activity level, while year and site were less so. Pygmy rabbits were active during all time periods of the day, but the greatest activity occurred in the morning, except during winter. Numerous other species were recorded by remote cameras, including other leporids, birds, rodents, reptiles, and terrestrial predators. Remote cameras are a valuable tool in understanding pygmy rabbit behavior, in addition to confirming rabbit presence in areas of interest.  相似文献   

17.
The biogeography of pelagic tunicates belonging to the two taxonomic classes Larvacea and Thaliacea was analysed using seven sampling stations along the coastal regions of Taiwan which contribute to all the China Seas surrounding Taiwan. The collected data were then compared with the information in the available literature about pelagic tunicate species diversity in the China Seas (Bohai Sea, North Yellow Sea, East China Sea and South China Sea) and previous studies on these organisms in Taiwan waters to get a better understanding of their biodiversity, abundance and distribution. A total of 19 species of pelagic tunicates were observed and identified to the speciel level: five species belonging to the class Larvacea, in the two families Oikopleuriidae and Fritillariidae; 14 species belonging to the class Thaliacea, in the families Salpidae and Doliolidae. We summarised morphological characteristics of the recorded species which were found to be useful for identification, and we provided further information about their global distribution and ecological preferences. Our results revealed that pelagic tunicates occurred in the China Seas with high species richness throughout the year. This is the first account on the class Larvacea from Taiwan. Comparing our results with available records from all China Seas, Taiwan proved to be a species diversity hotspot for pelagic tunicates, especially for the family Salpidae. The waters of southern Taiwan showed a higher species richness compared to the northern counterpart. The doliolid Doliolum denticulatum can be designated as an indicator of the low-temperature China Coastal Current species.  相似文献   

18.
Totals of 101 native Yellowstone cutthroat ( Oncorhynchus clarki bouvieri ), 27 introduced lake trout ( Salvelinus namaycush ), and 40 introduced longnose sucker ( Catostomus catostomus ) from Yellowstone Lake, Wyoming, USA, were examined for eye flukes. Metacercariae of the trematode fluke Diplostomum were in vitreous humor and/or lens of 94% of Yellowstone cutthroat trout, 92% of lake trout, and 78% of longnose sucker. Longnose sucker had 7% prevalence of infection in both lens and vitreous humor of metacercariae, while Yellowstone cutthroat trout had 3% and lake trout 8%. Diplostomum spathaceum was in lens tissue of 5% of infected Yellowstone cutthroat trout and 93% of longnose sucker; Diplostomum baeri was in vitreous humor of 92% each of infected Yellowstone cutthroat trout and lake trout. Morphological characteristics indicate that a single species infected the lens of Yellowstone cutthroat trout and longnose sucker, while another species infected lake trout. Impacts of the parasite interchange between native and introduced fishes of Yellowstone Lake, Wyoming, are unknown but should be monitored each year.  相似文献   

19.
Frog species of the Centrolenidae family exhibit a high variation in reproductive behaviours. Herein we describe the reproductive, ecological, acoustic and behavioural features of Hyalinobatrachium cappellei in Southern Amazon. Two hypotheses were also evaluated: (1) are ecological characteristics of the reproductive site related to male size and quantity of eggs and clutches? And (2) do males with one or more existing clutches at reproductive sites accumulate more new clutches than those males initially without them? This study was conducted at two streams, with sampling at 1 km each in Southern Amazon. Species reproduction occurred during the wet season and was considered prolonged breeding. Although male vocalization occurred on both the upper and underside of leaves, clutches were most often deposited on the underside of leaves. Males emitted a courtship call upon female approach. The process of female approach until oviposition lasted approximately eight hours. After oviposition, females left the breeding site while males remained near the clutch, covering it with the belly in ventral brooding behaviour. Thus, egg attendance is reported for the first time for this species. No intraspecific or interspecific aggressive behaviour was recorded. There was no relationship between habitat characteristics of the reproductive sites and male size, number of eggs and clutches. However, after 10 days of monitoring, we found evidences that parental males had a higher number of clutches than those males initially without clutches. Similar to other glass frog species, the behavioural characteristics of H. cappellei make this species an excellent model to use in evaluating the cost-effectiveness of parental care and the importance of egg attendance for offspring survival. Therefore, these data contribute towards a better understanding of the complex phylogenetic and biogeographic relationships between centrolenid lineages.  相似文献   

20.
During the summers of 1985-1991, bird census were conducted along 13 permanent routes located at the 2315-km 2 Idaho National Engineering and Environmental laboratory (INEEL Sturnella neglecta ), Brewer's Sparrows ( Spizella breweri ), Sage Sparrows ( Amphispiza belli ), Horned larks ( Eremophila alpestris ), and Sage Thrashers ( Oreoscoptes montanus ) comprised 72% of all individuals. Almost half of all species were represented by fewer than 10 individuals. Bird density was significantly greater along facility complex routes. Moreover, because of human-constructed wetlands and structures of various types, facility complex routes had significantly more bird species per unit area, including more species of waterfowl and human associated species. Some year-to-year variation in bird density was related to weather. More individuals were recorded in cooler, wetter years, although such increases were reflected more along facility complex routes. Among sagebrush-obligate species, trend analysis suggest that both Brewer's Sparrows and Sage Sparrows increased significantly in abundance, which may be in contrast to regional trends for these species. Of 5 species of special concern observed, trend analysis could be performed for only 2: Ferruginous Hawks ( Buteo regalis ) and Loggerhead Shrikes ( Lanius ludovicianus ). Both species had more routes with negative regression coefficients and negative trend means, indicating that declines may have occurred, although the goodness-of-fit test for neither species was significant. These data from INEEL should be used for comparison with future studies at the site and other statues from throughout the Great Basin region.  相似文献   

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