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1.
Hemiodus iratapuru, a new species of the Hemiodontidae from the Rio Iratapuru, a left bank tributary of the Rio Jari, Amazon Basin, Brazil, is described. The new species is diagnosed from other species of Hemiodus by modifications in the ectopterygoid, tooth form, scale counts, dorsal‐fin form and colour pattern. The new species is proposed to be related to the Hemiodus quadrimaculatus species group.  相似文献   

2.
Frontal shields have been examined in the type species of several genera of ascophorine cheilostomates. Desmacystis (Desmacystidae) is not an'anascan'as previously thought, but has a cryptocystal shield which is here interpreted to be derived from an umbonuloid shield by foreshortening, possibly from a rhamphostomellan ancestor. Rhamphostomella (type species Rscabra ) and Rhamphosmittina (type species R. bassleero ) (both in the family Porellidae Vigneaux, here raised from subfamily rank) also have umbonuloid shields. Arctomula , new genus, is established for Lepralia arctica M. Sars and transferred from the Umbonulidae to the Exochellidac. Rhamphostomellina (type species R. posidoniue ) has a lepralioid shield. It is here included in the family Celleporidae.  相似文献   

3.
R. Poulin 《Oecologia》1996,105(4):545-551
Within a host population, parasite infracommunities vary in both richness and species composition. If interspecific interactions among parasites are important in shaping infracommunities, the structure of these assemblages is expected to differ from the one predicted by null models, i.e. from the one that would result from chance alone. Using data from the literature, I tested for discrepancies between observed and random patterns in the richness and composition of gastrointestinal helminth infracommunities of birds and mammals. Both the Poisson distribution and a more sophisticated null model, derived from prevalence of the different parasite species in the host population, usually provided a good fit to the observed distributions of infracommunity richness among hosts. This suggests that parasite species do not co-occur more or less frequently than expected by chance. In mammals, the co-occurrence of all available parasite species in the same host individual, or maximum potential infracommunity richness, was less likely to be observed when several parasite species were available; this is also a phenomenon expected from the random assembly of parasite species. Finally, there was no evidence for a nested subset pattern among parasite species in a host population: rate species were distributed independently of common ones. The overall picture emerging from these results is one in which parasite assemblages are more likely to be the product of random events than of predictable and repeatable processes.  相似文献   

4.
ABSTRACT: BACKGROUND: Coral reefs are areas of maximum biodiversity, but the parasites of coral reef fishes, and especially their species richness, are not well known. Over an 8-year period, parasites were collected from 24 species of Lutjanidae, Nemipteridae and Caesionidae off New Caledonia, South Pacific. RESULTS: Host-parasite and parasite-host lists are provided, with a total of 207 host-parasite combinations and 58 parasite species identified at the species level, with 27 new host records. Results are presented for isopods, copepods, monogeneans, digeneans, cestodes and nematodes. When results are restricted to well-sampled reef fish species (sample size[THIN SPACE]>[THIN SPACE]30), the number of host-parasite combinations is 20[EN DASH]25 per fish species, and the number of parasites identified at the species level is 9[EN DASH]13 per fish species. Lutjanids include reef-associated fish and deeper sea fish from the outer slopes of the coral reef: fish from both milieus were compared. Surprisingly, parasite biodiversity was higher in deeper sea fish than in reef fish (host-parasite combinations: 12.50 vs 10.13, number of species per fish 3.75 vs 3.00); however, we identified four biases which diminish the validity of this comparison. Finally, these results and previously published results allow us to propose a generalization of parasite biodiversity for four major families of reef-associated fishes (Lutjanidae, Nemipteridae, Serranidae and Lethrinidae): well-sampled fish have a mean of 20 host-parasite combinations per fish species, and the number of parasites identified at the species level is 10 per fish species. CONCLUSIONS: Since all precautions have been taken to minimize taxon numbers, it is safe to affirm than the number of fish parasites is at least ten times the number of fish species in coral reefs, for species of similar size or larger than the species in the four families studied; this is a major improvement to our estimate of biodiversity in coral reefs. Our results suggest that extinction of a coral reef fish species would eventually result in the coextinction of at least ten species of parasites.  相似文献   

5.
Body size correlates with a large number of species traits, and these relationships have frequently been used to explain patterns in populations, communities, and ecosystems. However, diverging patterns occur, and there is a need for more data on different taxa at different scales. Using a large dataset of 155,418 individual beetles from 588 species collected over 13 years of sampling in Norway, we have explored whether body size predicts abundance, seasonality, and phenology in insects. Seasonality is estimated here by flight activity period length and phenology by peak activity. We develop several methods to estimate these traits from low‐resolution sampling data. The relationship between abundance and body size was significant and as expected; the smaller species were more abundant. However, smaller species tended to fly for longer periods of the summer and peaked in midsummer, while larger species were restricted to shorter temporal windows. Further analysis of repeated sampling from a single location suggested that smaller species had increased flight period lengths in warmer years, but larger species showed the opposite pattern. The results 1) indicate that smaller species are likely to be disproportionately valuable in ecological interactions, and 2) provide potential insights into the traits influencing the vulnerability of some larger species to disturbances and climate change.  相似文献   

6.
Alvarado M 《ZooKeys》2012,(163):83-90
The genus Meggoleus Townes, 1971 (Ichneumonidae, Tersilochinae) currently comprises two species, one from Brazil and one from Gabon. The genus is recorded from Peru for the first time, with a range extension of the type species, Meggoleus spirator Townes, 1971, and the discovery of two new species - Meggoleus fuscatussp. n. and Meggoleus pampahermosensissp. n. A key to the world's species is provided.  相似文献   

7.
The phylogeny of Cryptosporella is revised to include recently discovered species. Eight species new to science are described and two new combinations are proposed, raising the total number of species accepted in Cryptosporella to 19. The species delimitation and phylogeny for Cryptosporella are determined based on analyses of DNA sequences from three genes (β-tubulin, ITS and tef1-α), comparative morphology of sexual structures on their host substrate, and host associations. The inferred phylogeny suggests that Cryptosporella has speciated primarily on Betulaceae with 16 species occurring on hosts in that plant family. The host range of most species seems to be narrow with nine species reported from a single host species or subspecies and seven species occurring on plants within a single host genus. A key to species is provided. The known distribution of Cryptosporella is expanded to mountain cloud forests of the provinces of Chiriquí in Panama and Tucumán in Argentina.  相似文献   

8.
We describe a new heterophyid species, Ascocotyle (Ascocotyle) patagoniensis n. sp., based on specimens collected from the intestines of the South American sea lion Otaria flavescens from Patagonia (Argentina). Ascocotyle (A.) patagoniensis n. sp. is distinguished from the other species of the subgenus by the number of circumoral spines, which are arranged in 2 rows of 18 to 23. The new species also differs from the other species in having a gonotyl without papillae. The specimens exhibited the widest seminal receptacle described for a species of this subgenus. Species of the subgenus Ascocotyle usually infect fish-eating birds or mammals in freshwater or brackish habitats. Ascocotyle (A.) patagoniensis n. sp. is the first species of the subgenus described from a marine mammal. However, no metacercariae of Ascocotyle spp. were found in 542 marine teleosts from 20 species collected in the same locality. The life cycle of the marine species from the Ascocotyle -complex infecting pinnipeds remains elusive.  相似文献   

9.
Four new species of terrestrial earthworms from the zebrus-group in the genus Amynthas Kinberg, 1867, are described from Nan province, north Thailand: Amynthas phatubensissp. n., from Tham Pha Tub Arboretum, Amynthas tontongsp. n., from Tontong Waterfall, Amynthas borealissp. n., from Chaloemprakiat district, and Amynthas srinansp. n., from Srinan National Park.After comparing with the two closely related Laos species Amynthas chandyi Hong, 2008 and Amynthas namphouinensis Hong, 2008, the four new species show clear morphological differences, and also it is confirmed that there are no previous records of the species described here. Amynthas phatubensissp. n. is the largest (longest) sized of these earthworms and is the only species that lives in limestone habitats. The genital characters are different among them and also from the two Laotian species. Molecular systematics would be a good method for further analysis of the diversity and species boundaries in SE Asian Amynthas.  相似文献   

10.
Phylogenetic relationships within Celastraceae (spindle-tree family) were inferred from nucleotide sequence characters from the 5' end of 26S nuclear ribosomal DNA (including expansion segments D1-D3; 84 species sampled), phytochrome B (58 species), rbcL (31 species), atpB (23 species), and morphology (94 species). Among taxa of questionable affinity, Forsellesia is a member of Crossosomataceae, and Goupia is excluded from Celastraceae. However, Brexia, Canotia, Lepuropetalon, Parnassia, Siphonodon, and Stackhousiaceae are supported as members of Celastraceae. Gymnosporia and Tricerma are distinct from Maytenus, Cassine is supported as distinct from Elaeodendron, and Dicarpellum is distinct from Salacia. Catha, Maytenus, and Pristimera are not resolved as natural genera. Hippocrateaceae (including Plagiopteron and Lophopetalum) are a clade nested within a paraphyletic Celastraceae. These data also suggest that the Loesener's classification of Celastraceae sensu stricto and Hallé's classification of Hippocrateaceae are artificial. The diversification of the fruit and aril within Celastraceae appears to be complex, with multiple origins of most fruit and aril forms.  相似文献   

11.
Three new species of Eulophidae associated, or presumed to be associated with ants are described: two species of Horismenus Walker and one species of Microdonophagus Schauff. Information on the biology is also included. The two Horismenus species are from Chiapas, Mexico. Horismenus myrmecophagussp. n. is known only from females and is a gregarious endoparasitoid in larvae of the weaver ant Camponotus sp. ca. textor. The parasitoids pupate inside the host larva, and an average of 6.7 individuals develops per host. This is the second time a species of genus Horismenus is found parasitizing the brood of a formicine ant of genus Camponotus. Horismenus microdonophagussp. n. is described from both males and females, and is a gregarious endoparasitoid attacking the larvae of Microdon sp. (Diptera: Syrphidae), a predator on ant brood found in nests of Camponotus sp. ca. textor. The new species of Microdonophagus, Microdonophagus tertius, is from Costa Rica, and known only from the female. Nothing is known about its biology but since another species in same genus, Microdonophagus woodleyi Schauff, is associated with ants through its host, Microdon larva (with same biology as Horismenus microdonophagus), it is possible that also Microdonophagus tertius has this association. A new distributional record for Microdonophagus woodleyi is also reported, extending its distribution from Panama and Colombia to Brazil.  相似文献   

12.
Strongman DB 《Mycologia》2005,97(2):552-561
The Trichomycete, Ejectosporus magnus, from Allocapnia spp. was determined to be a vegetative spore stage of another harpellid, Simuliomyces spica. A voucher slide of E. magnus made from a stonefly nymph that was part of the same collection as the holotype had thalli bearing trichospores of both E. magnus and S. spica. I conclude that these are one species; therefore Ejectosporus is emended and the species is treated as E. spica. Also, a new species, E. trisporus, is described from Allocapnia pygmaea (Plecoptera: Capniidae) collected in eastern Canada. This species has vegetative spores and trichospores with characteristics similar to E. spica, but the two species are separated by differences in zygospore sizes.  相似文献   

13.
《农业工程》2021,41(6):575-583
Anthropogenic activities in inland water can cause species loss and displacement. Therefore, there is a need to regularly examine species composition, abundance and diversity of freshwater ecosystem as a means to monitor its health. Ichthyofauna of Ikere-gorge, Iseyin, Oyo State was studied for a period of 24 month, from January 2017 to December 2018. Ikere-gorge was divided into four strata, each comprises three fishing villages. One village in each stratum was randomly selected as sampling site. The catches were sorted into taxonomic groups (species and families) using standard fish identification keys. Forty-one fish species from 13 families were identified in which species richness varied among the sampling villages. Asamu had 34, Agatu had 30, Spillway had 39 and Irawote had 29 species. The freshwater fish species of Nigeria is the richest in West Africa and more than 15% of these fish species are found in Ikere-gorge. Mormyridae family was the most represented with 10 species. Cichlidae was the most abundant by catch and by weight. Sarotherodon galilaeus has the highest abundance by catch and by weight. Gnathonemus brucii was identified as a vulnerable species. The result obtained from this study show that conservation program should be urgently put in place to prevent some fish from extinction. There should be introduction of closed season to allow for proper recruitment of fish population. Likewise, minimum mesh size should be set to allow juvenile and immature fish to escape and allow them to spawn at least once before being vulnerable to gear. There should regulation to set maximum number of fishermen to be allowed to fish at a particular day, this is to reduce fishing pressure.  相似文献   

14.
We report 63 species of Curculionoidea that are new to New Brunswick (three species of Anthribidae, four species of Brentidae, three species of Dryophthoridae, three species of Brachyceridae, 50 species of Curculionidae). Among these are 27 species (two Anthribidae, two Brenthidae, one Brachyceridae, 22 Curculionidae) that are also newly recorded for the Maritime provinces, and one species, Plesiobaris disjuncta Casey (Curculionidae) that is newly recorded for Canada from New Brunswick and Quebec. Bagous planatus LeConte is reinstated to the faunal list of New Brunswick. Two species of Curculionidae are newly recorded from Nova Scotia and the Maritime provinces, and two others are reported for the first time for Prince Edward Island.  相似文献   

15.
There is little evidence from nature that divergent natural selection is crucial to speciation. However, divergent selection is implicated if traits conferring adaptation to alternative environments also form the basis of reproductive isolation. We tested the importance of body size differences to premating isolation between two sympatric sticklebacks. The species differ greatly in size, and several lines of evidence indicate that this difference is an adaptation to alternative foraging habitats. Strong assortative mating was evident in laboratory trials, but a few hybridization events occurred. Probability of interspecific mating was strongly correlated with body size: interspecific spawning occurred only between the largest individuals of the smaller species and the smallest individuals of the larger species. Probability of spawning between similar-sized individuals from different species was comparable to spawning rates within species. Disruption of mating between individuals from different species can be traced to increased levels of male aggression and decreased levels of male courtship as size differences increased between paired individuals. Interspecific mate preferences in sympatric sticklebacks appears to be dominated by body size, implicating natural selection in the origin of species.  相似文献   

16.
报道7种中国卡拉草螟属Culladia昆虫,包括新种郑氏卡拉草螟Culladia zhengi sp.nov.和中国新纪录种齿线卡拉草螟C.dentilinealis Hampson,1919。文中提供了新种和新纪录种的成虫和外生殖器图,给出了中国该属已知种的名录和检索表。研究标本保存在南开大学生命科学学院昆虫标本室。郑氏卡拉草螟,新种Culladia zhengi sp.nov.(图1,3,5)新种的雄性与刺突卡拉草螟Culladia hastiferalis(Walker,1865)相似,但是该种抱器背基突中部有1枚小刺,阳茎无微刺状角状器;雌性外生殖器交配囊与囊导管的界限不明显且无囊突。刺突卡拉草螟抱器背基突无小刺,阳茎末端有多枚微刺状角状器;囊导管与交配囊的界限显著,且交配囊有1枚条纹状囊突。正模♂,香港大帽山,海拔700m,2007-04-13,李后魂等采,外生殖器玻片号LWC08414。副模:7♂♂,1♀,采集信息同正模;2♀♀,香港嘉道理农场,海拔210m,2007-04-13,2009-09-20,李后魂等采;1♂,广西上思平龙山,海拔510m,2002-04-06,郝淑莲、薛怀君采;1♂,海南尖峰岭,海拔940m,2007-06-06,张志伟、李卫春采;1♂,1♀,海南五指山,海拔640~650m,2007-05-15~21,张志伟、李卫春采;1♀,海南吊罗山,海拔300m,2008-08-14,胡冰冰、张利采;1♂,云南瑞丽珍惜植物园,海拔1000m,2005-08-06,任应党采。词源:新种种名以著名昆虫学家郑哲民教授的姓氏命名。  相似文献   

17.
Knížek M 《ZooKeys》2010,(56):191-206
Fivenew species of the genus Triotemnus from Morocco and Yemen are described. Triotemnus is a new genus of Scolytinae for the Yemen region. External morphology of the new species and all morphologically related species of the genus were studied. While the new species from Morocco are morphologically similar to the known species from the corresponding region, all three newly described species from Yemen, mainly two of them living in Socotra, are morphologically very different from all other known species of the genus. Geographical distribution and the probability of endemicity are discussed.  相似文献   

18.
Revision of material from Australian waters previously assigned to Herdmania momus ( Savigny, 1816 ) has resulted in the recognition of five species (including two new indigenous species). A tropical Indo-West Pacific range is recorded for the type species ( H. momus ), although it is not recorded from Western Australia. A circum-continental range for the third and largest species, H. grandis ( Heller, 1878 ) is confirmed. Herdmania pallida (Heller, 1878), with a wide range in the western Pacific and Indian Ocean including the north-eastern and north-western coasts of Australia, is a different species from the Atlantic Ocean species (formerly thought to be conspecific). Herdmania fimbriae , a new species with a geographical range from southern to north-eastern Australia, is distinct from H. mentula , also a new species, from the north-western coast. The structure of the gonads and their ducts and accessory membranes and the arrangement and number of body wall muscles distinguish the species. Species differences are supported by the maximum size of individuals, nature of their test, number of branchial folds, number of internal longitudinal vessels on the folds and between the dorsal lamina and dorsal fold, the size and form of the dorsal tubercle and dorsal lamina, and the shape of the ciliated opening of the neural duct, although these characters are affected to some extent by growth. A variety of accessory membranes associated with both male and female gonoducal apertures are found in the majority of species in this genus. © 2002 The Linnean Society of London. Zoological Journal of the Linnean Society , 134 , 359–374.  相似文献   

19.
A sample of 117 fossil cercopithecids has been collected from the Middle Pleistocene site of Asbole, Afar Region, Ethiopia. A minimum of five species is present. There are two species of Cercopithecini, here recognized as cf. Chlorocebus aff. aethiops, and cf. Chlorocebus cf. patas. There are also two species of Papionini: Papio hamadryas ssp. indet. and Theropithecus oswaldi leakeyi. Finally, there is a single species of colobine present, Colobus sp. indet. The assemblage is chronologically constrained and is derived from sediments dated to approximately 600 ka. Within this sample Colobus sp. is by far the most common species present, outnumbering the other four species combined. The cercopithecid assemblage is most consistent with a woodland habitat, corroborating an earlier interpretation based on the non-primate fauna. Taxonomic, biogeographic, and evolutionary implications of the assemblage are also discussed.  相似文献   

20.
Based on a comparison of the karyotypes of two Plathyrrhini species, Cacajao melanocephalus (Pitheciinae) and Brachyteles arachnoides (Atelinae), with those of two previously studied species, Lagothrix lagothrica (Atelinae) and C calvus rubicundus (Pitheciinae), it appears that the two Cacajao species have undergone the same number of chromosome rearrangements since they diverged from their common ancestor and that the karyotype of Brachyteles is ancestral to that of Lagothrix. The chromosomal phylogeny of these four species is proposed. A Y-autosome translocation is present in the karyotypes of the two Cacajao species.  相似文献   

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