scholarly journals Independent origins of parasitism in Animalia

2016 ◽  
Vol 12 (7) ◽  
pp. 20160324 ◽  
Author(s):  
Sara B. Weinstein ◽  
Armand M. Kuris

Nearly half of all animals may have a parasitic lifestyle, yet the number of transitions to parasitism and their potential for species diversification remain unresolved. Based on a comprehensive survey of the animal kingdom, we find that parasitism has independently evolved at least 223 times in just 15 phyla, with the majority of identified independent parasitic groups occurring in the Arthropoda, at or below the level of Family. Metazoan parasitology is dominated by the study of helminthes; however, only 20% of independently derived parasite taxa belong to those groups, with numerous transitions also seen in Mollusca, Rotifera, Annelida and Cnidaria. Parasitism is almost entirely absent from deuterostomes, and although worm-like morphology and host associations are widespread across Animalia, the dual symbiotic and trophic interactions required for parasitism may constrain its evolution from antecedent consumer strategies such as generalist predators and filter feeders. In general, parasitic groups do not differ from their free-living relatives in their potential for speciation. However, the 10 largest parasitic clades contain 90% of described parasitic species, or perhaps 40% of all animal species. Hence, a substantial fraction of animal diversity on the Earth arose following these few transitions to a parasitic trophic strategy.

2019 ◽  
Author(s):  
Silvia G. Acinas ◽  
Pablo Sánchez ◽  
Guillem Salazar ◽  
Francisco M. Cornejo-Castillo ◽  
Marta Sebastián ◽  
...  

AbstractThe deep sea, the largest compartment of the ocean, is an essential component of the Earth system, but the functional exploration of its microbial communities lags far behind that of other marine realms. Here we analyze 58 bathypelagic microbial metagenomes from the Atlantic, Indian, and Pacific Oceans in an unprecedented sampling effort from the Malaspina Global Expedition, to resolve the metabolic architecture of the deep ocean microbiome. The Malaspina Deep-Sea Gene Collection, 71% of which consists of novel genes, reveals a strong dichotomy between the functional traits of free-living and particle-attached microorganisms, and shows relatively patchy composition challenging the paradigm of a uniform dark ocean ecosystem. Metagenome Assembled Genomes uncovered 11 potential new phyla, establishing references for deep ocean microbial taxa, and revealed mixotrophy to be a widespread trophic strategy in the deep ocean. These results expand our understanding of the functional diversity, metabolic versatility, and carbon cycling in the largest ecosystem on Earth.One Sentence SummaryA whole community genomic survey of the deep microbiome sheds light on the microbial and functional diversity of the dark ocean.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1634
Author(s):  
Tatiana Carolina Gomes Dutra de Souza ◽  
Danielle Gava ◽  
Rejane Schaefer ◽  
Raquel Arruda Leme ◽  
Gisele da Silva Porto ◽  
...  

Porcine circovirus 3 (PCV-3) was identified in domestic pigs worldwide. Although PCV-3 has also been detected in wild boars, information regarding its circulation in this free-living animal species is scarce. To investigate PCV-3 occurrence in free-living wild boars in Brazil, 70 serum samples collected between January 2017 and June 2019 in Paraná state, Brazil were analyzed by PCR assay. Amplicons measuring 330 bp in length were amplified in seven (10.0%) of the serum samples and confirmed to be PCV3-specific by nucleotide (nt) sequencing. As the amplified products from the serum samples yielded only intermediate levels of viral DNA, lung samples from the seven PCR-positive wild boars were also evaluated by PCR. Of these samples, five lung samples were positive and provided high levels of viral DNA. The three lung samples that presented the highest levels of viral DNA were selected for amplification and sequencing of the whole PCV-3 genome. The three full-length sequences obtained were grouped in PCV-3 clade “a”, and the sequences exhibited 100% nucleotide similarity among them. The PCV-3 field strains of this study showed nucleotide and amino acid similarities of 98.5–99.8% and 98.8–100%, respectively, with whole-genome PCV-3 sequences from around the world.


2015 ◽  
Vol 161 ◽  
pp. 16-22
Author(s):  
Katarzyna Andraszek ◽  
Magdalena Gryzińska ◽  
Mariola Ceranka ◽  
Agnieszka Larisch

Parasitology ◽  
2014 ◽  
Vol 141 (10) ◽  
pp. 1244-1254 ◽  
Author(s):  
ADRIAN STREIT

SUMMARYParasitic lifestyles evolved many times independently. Just within the phylum Nematoda animal parasitism must have arisen at least four times. Switching to a parasitic lifestyle is expected to lead to changes in various life history traits including reproductive strategies. Parasitic nematode worms of the genus Strongyloides represent an interesting example to study these processes because they are still capable of forming facultative free-living generations in between parasitic ones. The parasitic generation consists of females only, which reproduce parthenogenetically. The sex in the progeny of the parasitic worms is determined by environmental cues, which control a, presumably ancestral, XX/XO chromosomal sex determining system. In some species the X chromosome is fused with an autosome and one copy of the X-derived sequences is removed by sex-specific chromatin diminution in males. Here I propose a hypothesis for how today's Strongyloides sp. might have evolved from a sexual free-living ancestor through dauer larvae forming free-living and facultative parasitic intermediate stages.


Zootaxa ◽  
2008 ◽  
Vol 1968 (1) ◽  
pp. 65-68 ◽  
Author(s):  
ZHI-QIANG ZHANG

One of the fundamental quests of biology is discovering how many species inhabit the Earth. Yet the vast majority of the world’s animal species are waiting to be discovered, named and described—estimates of the total number vary from 5 to 30 million.  Most biologists would agree that taxonomy is important and fundamental to credible biology, and descriptive taxonomy is the most important task of taxonomy (Wheeler 2007). Unfortunately, the reality is that descriptive taxonomy has been marginalized since the mid-1950s and has sustained serious losses in funding and academic positions in universities and museums around the world, especially since phylogenetic and molecular studies became popular in the last twenty years.  During this period, there has also been an important historical trend in taxonomic publishing—many journal publishers/editors have been making increasing demands on authors to provide phylogenetic analysis, molecular systematics, and other modern types of information in taxonomic papers. In addition, there are long publication delays and/or increasing page charges for many journals that do publish descriptive taxonomic papers. Zootaxa was founded in 2001 to provide a much-needed outlet for descriptive taxonomic papers and monographs that are difficult to publish elsewhere, and as a result has received tremendous support from taxonomists worldwide, despite the fact that it is a grass-roots project without support from government and institutions (Zhang 2006a).  Zootaxa satisfied the publishing need of many zoological taxonomists, and sustained a period of rapid growth during 2001 to 2006 (Zhang 2006b). During the last two years, it has continued to grow in size, and especially in its impact, and has become a major force in reviving descriptive taxonomy on a global scale.  Here I summarize some encouraging data on the growth of Zootaxa and its impact.  I also comment on its contribution to the progress of  descriptive taxonomy.


2013 ◽  
Vol 75 (7) ◽  
pp. 494-498
Author(s):  
Christopher J. Yahnke ◽  
Tanya Dewey ◽  
Phil Myers

Most teachers agree that writing is an important skill for students to master, yet not all teachers incorporate writing assignments in their courses. Employers agree that written communication is important for college graduates, yet in a survey, less than 10% of employers thought that colleges did a good job preparing students for work. Writing an animal species account for Animal Diversity Web (http://animaldiversity.org) provides students with a real-world example of writing skills and provides resources to instructors who want to incorporate writing in their classes.


2020 ◽  
Vol 7 ◽  
Author(s):  
Bishnu Adhikari ◽  
Guillermo Tellez-Isaias ◽  
Tieshan Jiang ◽  
Brian Wooming ◽  
Young Min Kwon

The importance of microbiota in the health and diseases of farm animals has been well-documented for diverse animal species. However, studies on microbiotas in turkey and turkey farms are relatively limited as compared to other farm animal species. In this study, we performed a comprehensive survey of the litter microbiotas in 5 commercial turkey farms in the Northwest Arkansas (H, M, V, K, and R farms) including one farm with positive incidence of cellulitis (R farm). Altogether 246 boot swabs were used for 16S rRNA gene profiling of bacterial communities. At phylum level, 11 major bacterial phyla (≥0.01%) were recovered. At genus level, 13 major bacterial genera were found whose relative abundance were ≥2%. The microbial composition at both phylum and genus levels as well as their diversities varied across different farms, which were further affected by different flocks within the same farms and the ages of turkeys. Generally, the Firmicutes were higher in the flocks of younger birds, while the Actinobacteria and Bacteroidetes were higher in the flocks of the older birds. The Proteobacteria were highly enriched (47.97%) in K farm housing 56-day-old turkeys (K-56), but Bacteroidetes were found the highest in the flock C of M farm housing 63-day-old turkeys (M-C-63; 22.38%), followed by K-84 group (17.26%). Four core bacterial genera (Staphylococcus, Brevibacterium, Brachybacterium, and Lactobacillus) were identified in all samples except for those from R farm. In contrast, 24 core bacterial genera were found based in all cellulitis-associated samples (R farm), including Corynebacterium, an unknown genus of family Bacillaceae, Clostridium sensu stricto 1 (>97% similarity with C. septicum), and Ignatzschineria among others, suggesting their possible roles in etiopathogenesis of cellulitis in turkeys. Overall results of this study may provide valuable foundation for future studies focusing on the role of microbiota in the health and diseases of turkeys.


2020 ◽  
Vol 48 ◽  
Author(s):  
Marco Aurélio Cunha Del Vechio ◽  
Edson Gerônimo ◽  
Enzo Emmerich Paula De Castro ◽  
Luciana Vieira Pinto Ribeiro ◽  
Rita De Cássia Lima Ribeiro ◽  
...  

Background: Studies on intestinal parasites in cougars Puma concolor are scarce, and most of the available information on the species has been derived from individuals in captivity. One of the greatest threats to the survival of wild cats is habitat loss caused by urban sprawl, agricultural matrix, and linear developments such as highways and railways, which expose animals to direct contact with humans and to a high risk of death. Given the lack of scientific data the objective of this study was to report on the occurrence of intestinal parasites in a cougar (P. concolor) specimen from the northwestern region of Paraná State, Brazil.Case: The carcass of a free-living cougar (P. concolor) individual was sent to the Interdisciplinary Science Museum (Museu Interdisciplinar de Ciências – MIC) of Paranaense University (Universidade Paranaense - UNIPAR); an individual was killed during a collision with an unidentified vehicle on highway PR-486, in the municipality of Mariluz (PR, Brazil). The geographical coordinates of the location where the animal was found are: 23°59′29″S, 53°8′47″W. This region is characterized by semi-deciduous seasonal forest remnants. After being identified on site and collected by the inspectors of the Paraná Environmental Institute (Instituto Ambiental do Paraná - IAP), the cadaver was donated to the MIC (by the IAP) for a necropsy to elucidate the cause of death. In this context, the cadaver was sent to the Animal Pathology section of the Department of Veterinary Medicine at UNIPAR. The animal was necropsied by performing the standard necropsy technique for carnivores: opening the intestine through the mesentery and exposing the mucosa from the duodenum to the colon. The necropsy showed that the cause of death was hypovolemic shock due to trauma. During necropsy, parasites in the intestinal lumen were visible to the naked eye. Parasites and feces were collected and stored in sterile flasks containing 10% formaldehyde and saline. The parasites were subjected to Faust and Hoffman techniques, micrometry, and morphological analysis, resulting in the identification of the roundworm Toxocara cati and the tapeworm Spirometra decipiens.Discussion: Identifying the roadkill species along highways is of paramount importance, since they are living very close to man and, consequently, reservoirs and disseminators of different infectious and parasitic zoonoses may be possible. Infection by protozoa and helminths in animals usually occurs by ingesting the infective form present in food or water. Toxocara cati and the tapeworm Spirometra decipiens were only reported in captivity before. Research on parasites in free-living wild animals is not common in the scientific literature and this is due to the difficulty of capturing this animal category as they live in difficult to access places such as forests and forests, therefore, research projects in partnership with museums are extremely important for the recognition of wild animal species that circulate in the region, in addition to the parasitic identification of these animals for future sanitary measures and for the preservation of the animal species in the environment. The Parasitological studies of wild animals are highly relevant for expanding this knowledge, especially considering the possible transfer risk of specific parasitic diseases to other animals, as well as to humans.


2021 ◽  
Author(s):  
Suresh V Kuchipudi ◽  
Meera Surendran-Nair ◽  
Rachel M Ruden ◽  
Michele Yon ◽  
Ruth H Nissly ◽  
...  

Many animal species are susceptible to SARS-CoV-2 and could potentially act as reservoirs, yet transmission in non-human free-living animals has not been documented. White-tailed deer (Odocoileus virginianus), the predominant cervid in North America, are susceptible to SARS-CoV-2 infection, and experimentally infected fawns transmit the virus to other captive deer. To test the hypothesis that SARS-CoV-2 may be circulating in deer, we evaluated 283 retropharyngeal lymph node (RPLN) samples collected from 151 free-living and 132 captive deer in Iowa from April 2020 through December of 2020 for the presence of SARS-CoV-2 RNA. Ninety-four of the 283 deer (33.2%; 95% CI: 28, 38.9) samples were positive for SARS-CoV-2 RNA as assessed by RT-PCR. Notably, between Nov 23, 2020, and January 10, 2021, 80 of 97 (82.5%; 95% CI 73.7, 88.8) RPLN samples had detectable SARS-CoV-2 RNA by RT-PCR. Whole genome sequencing of the 94 positive RPLN samples identified 12 SARS-CoV-2 lineages, with B.1.2 (n = 51; 54.5%), and B.1.311 (n = 19; 20%) accounting for ~75% of all samples. The geographic distribution and nesting of clusters of deer and human lineages strongly suggest multiple zooanthroponotic spillover events and deer-to-deer transmission. The discovery of sylvatic and enzootic SARS-CoV-2 transmission in deer has important implications for the ecology and long-term persistence, as well as the potential for spillover to other animals and spillback into humans. These findings highlight an urgent need for a robust and proactive One Health approach to obtaining a better understanding of the ecology and evolution of SARS-CoV-2.


Bothalia ◽  
2017 ◽  
Vol 47 (2) ◽  
Author(s):  
Susana Clusella-Trullas ◽  
Raquel A. Garcia

Background: Increasing numbers of invasive alien plant (IAP) species are establishing around the globe and can have negative effects on resident animal species function and diversity. These impacts depend on a variety of factors, including the extent of invasion, the region and the taxonomic group affected. These context dependencies make extrapolations of IAP impacts on resident biota from region to region a substantial challenge. Objectives: Here, we synthesised data from studies that have examined the effects of IAPs on animal diversity in South Africa. Our focus is on ectothermic organisms (reptiles, amphibians and invertebrates). Method: We sourced relevant articles using keywords relating to (1) the effects of IAPs on species diversity (abundance, richness and composition), (2) the IAP and (3) the native ectotherm. We extracted the taxonomic and spatial coverage of IAPs and affected native species and assessed the extent of information given on potential mechanisms driving IAP impacts. Results: Across the 42 studies, IAPs had a decreasing or neutral effect on native animal abundance and richness and significantly changed species composition. This review highlighted the paucity of studies and the research deficits in taxonomic and geographic coverage and in the mechanisms underlying IAP impacts on ectotherms. Conclusion: By assessing the status of knowledge regarding the impacts of IAPs on resident animal species in South Africa, this study identifies information gaps and research priorities at the country level with a view to informing monitoring and conservation efforts, such as alien plant removal and control programmes, and ensuring that endemic terrestrial animal diversity is maintained.


Sign in / Sign up

Export Citation Format

Share Document