Free-living Platyhelminthes of the Pacaya-Samiria National Reserve, a Peruvian Amazon floodplain

Zootaxa ◽  
2006 ◽  
Vol 1313 (1) ◽  
pp. 39 ◽  
Author(s):  
CAROLINA NOREÑA ◽  
CRISTINA DAMBORENEA ◽  
FRANCISCO BRUSA ◽  
MARIO ESCOBEDO

Twenty-one free-living species of turbellaria (Platyhelminthes) were found in the Pacaya-Samiria National Reserve (Loreto, Peru), a Peruvian Amazon floodplain. The total 21 observed taxa comprise five species of Catenulida, two species of Macrostomida, two species of "Lecithoepitheliata", 10 species of Rhabdocoela and two species of Tricladida. Most of the species are cosmopolitan and occur in freshwater habitats worldwide. Of the species collected, only Mesostoma ehrenbergi was previously known from this region, whereas five species of Rhabdocoela were only recently described from the Pacaya-Samiria Reserve. Some morphological, distributional and ecological remarks are provided.

Zootaxa ◽  
2019 ◽  
Vol 4706 (3) ◽  
pp. 494-496
Author(s):  
JHOE REYES ◽  
DANIELA BINOW ◽  
ROGÉRIO T. VIANNA ◽  
SAMANTHA E. MARTINS

Within Dalyelliidae Graff, 1905, Gieysztoria Ruebush & Hayes, 1939 is the most widely distributed and speciose genus, members of which live in marine, brackish, or freshwater habitats (Van Steenkiste et al., 2012). Gieysztoria is composed by ~97 free-living species (Tyler et al. 2016), and species identification is mainly made on the male copulatory system, which has an armed penis (stylet) with different configurations of spines (Noreña et al., 2016). The stylet configuration of Gieysztoria species is traditionally split into two groups: Aequales (spines of similar shape and size) and Inaequales (spines of different shape and size) (Luther, 1955). In the neotropics, specimens of Gieysztoria belong to both the Aequales and Inaequales group   and are well represented (Damborenea et al., 2005; Noreña et al., 2003). According to Braccini et al. (2016, 2017), there are 16 species of Gieysztoria in Brazil, mainly distributed in the southern region. South Brazil harbours a mosaic of wetlands that are considered hot spots of biodiversity, including the Taim Ecological Station (ESEC Taim) protected area that was designated as a Ramsar site (Ramsar, 2017). In the present study, Gieysztoria falx Brusa, Damborenea & Noreña, 2003 is registered in the ESEC Taim, located in Rio Grande do Sul. It represents the first record of G. falx in Brazil. Illustrations and comments on stylet configuration are given.


2021 ◽  
Vol 7 (11) ◽  
pp. eabe4164
Author(s):  
Grant L. Norbury ◽  
Catherine J. Price ◽  
M. Cecilia Latham ◽  
Samantha J. Brown ◽  
A. David M. Latham ◽  
...  

Efficient decision-making integrates previous experience with new information. Tactical use of misinformation can alter choice in humans. Whether misinformation affects decision-making in other free-living species, including problem species, is unknown. Here, we show that sensory misinformation tactics can reduce the impacts of predators on vulnerable bird populations as effectively as lethal control. We repeatedly exposed invasive mammalian predators to unprofitable bird odors for 5 weeks before native shorebirds arrived for nesting and for 8 weeks thereafter. Chick production increased 1.7-fold at odor-treated sites over 25 to 35 days, with doubled or tripled odds of successful hatching, resulting in a 127% increase in modeled population size in 25 years. We demonstrate that decision-making processes that respond to changes in information reliability are vulnerable to tactical manipulation by misinformation. Altering perceptions of prey availability offers an innovative, nonlethal approach to managing problem predators and improving conservation outcomes for threatened species.


2006 ◽  
Vol 15 (5) ◽  
pp. 1609-1620 ◽  
Author(s):  
Noreña Carolina ◽  
Damborenea Cristina ◽  
Escobedo Torres Mario

Nematology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Taciana Kramer de Oliveira Pinto ◽  
Sérgio A. Netto ◽  
André Morgado Esteves ◽  
Francisco José Victor de Castro ◽  
Patricia Fernandes Neres ◽  
...  

Summary Brazil has one of the largest varieties of aquatic ecosystems and rich freshwater biodiversity, but these components have constantly been damaged by the expansion of unsustainable activities. Free-living nematodes are an abundant and ubiquitous component of continental benthic communities, occurring in all freshwater habitats, including extreme environments. Despite this, hardly any studies have examined the generic composition of nematodes in different latitudes and the geographic overlap of assemblages. We provide data on nematode genera from six regions in Brazil, over a north-south gradient spanning about 4000 km, encompassing rivers, coastal lakes, and reservoirs with different levels of human impact. Interpolation/extrapolation curves were generated and the zeta diversity was used to assess the overlap of nematode assemblages. Freshwater nematode assemblages comprised 54 families and 132 genera. Mononchidae, Monhysteridae, Chromadoridae, Tobrilidae and Dorylaimidae were the most diverse families. Differences in diversity and high turnover of genera were found among regions, probably related to stochastic processes. Mononchus was the only widely distributed genus. Our results revealed a high biodiversity of free-living freshwater nematodes among the regions. The limited spatial coverage of the data reveals an enormous knowledge gap in a country with 12% of the world’s freshwater resources. The lack of spatial patterns, e.g., latitudinal variation, suggests that freshwater nematode assemblages are primarily structured by the intrinsic properties of habitats. This reinforces the uniqueness of freshwater ecosystems and suggests that the nematode assemblages may be sensitive to environmental disturbances, since the limited distributions of taxa may lead to lower resilience.


2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Xuehua Wan ◽  
Alex J. Lee ◽  
Shaobin Hou ◽  
Blake Ushijima ◽  
Yen P. Nguyen ◽  
...  

One species of Piscirickettsia , a pathogen of salmonid fish, has been described. The genome sequence of a putative second and free-living species may provide insights into the evolution of pathogenicity in the genus.


2015 ◽  
Author(s):  
Abigail Z. Jacobs ◽  
Jennifer A. Dunne ◽  
Cristopher Moore ◽  
Aaron Clauset

Food webs represent the set of consumer-resource interactions among a set of species that co-occur in a habitat, but most food web studies have omitted parasites and their interactions. Recent studies have provided conflicting evidence on whether including parasites changes food web structure, with some suggesting that parasitic interactions are structurally distinct from those among free-living species while others claim the opposite. Here, we describe a principled method for understanding food web structure that combines an efficient optimization algorithm from statistical physics called parallel tempering with a probabilistic generalization of the empirically well-supported food web niche model. This generative model approach allows us to rigorously estimate the degree to which interactions that involve parasites are statistically distinguishable from interactions among free-living species, whether parasite niches behave similarly to free-living niches, and the degree to which existing hypotheses about food web structure are naturally recovered. We apply this method to the well-studied Flensburg Fjord food web and show that while predation on parasites, concomitant predation of parasites, and parasitic intraguild trophic interactions are largely indistinguishable from free-living predation interactions, parasite-host interactions are different. These results provide a powerful new tool for evaluating the impact of classes of species and interactions on food web structure to shed new light on the roles of parasites in food webs.


Biologia ◽  
2018 ◽  
Vol 73 (6) ◽  
pp. 569-575 ◽  
Author(s):  
Ruben C. Cuadros ◽  
Norma L. S. Rivadeneyra ◽  
José C. O. Malta ◽  
M. Enrique Serrano-Martínez ◽  
Patrick D. Mathews

2019 ◽  
Vol 286 (1903) ◽  
pp. 20190673 ◽  
Author(s):  
James E. Byers ◽  
J. P. Schmidt ◽  
Paula Pappalardo ◽  
Sarah E. Haas ◽  
Patrick R. Stephens

Free-living species vary substantially in the extent of their spatial distributions. However, distributions of parasitic species have not been comprehensively compared in this context. We investigated which factors most influence the geographical extent of mammal parasites. Using the Global Mammal Parasite Database we analysed 17 818 individual geospatial records on 1806 parasite species (encompassing viruses, bacteria, protozoa, arthropods and helminths) that infect 396 carnivore, ungulate and primate host species. As a measure of the geographical extent of each parasite species we quantified the number and area of world ecoregions occupied by each. To evaluate the importance of variables influencing the summed area of ecoregions occupied by a parasite species, we used Bayesian network analysis of a subset ( n = 866) of the parasites in our database that had at least two host species and complete information on parasite traits. We found that parasites that covered more geographical area had a greater number of host species, higher average phylogenetic relatedness between host species and more sampling effort. Host and parasite taxonomic groups had weak and indirect effects on parasite ecoregion area; parasite transmission mode had virtually no effect. Mechanistically, a greater number of host species probably increases both the collective abundance and habitat breadth of hosts, providing more opportunities for a parasite to have an expansive range. Furthermore, even though mammals are one of the best-studied animal classes, the ecoregion area occupied by their parasites is strongly sensitive to sampling effort, implying mammal parasites are undersampled. Overall, our results support that parasite geographical extent is largely controlled by host characteristics, many of which are subsumed within host taxonomic identity.


Zootaxa ◽  
2008 ◽  
Vol 1961 (1) ◽  
pp. 37-57 ◽  
Author(s):  
FRÉDÉRIC BEAULIEU ◽  
ANDREA D. DÉCHÊNE ◽  
DAVID E. WALTER

The mite genus Antennoseius is composed of free-living species in soil and litter, as well as species that are phoretic on carabid beetles as adult females. Among approximately 60 described Antennoseius species, one North American species, A. janus, was found in laboratory cultures to have two female morphs: one granular, free-living morph, and one smooth, putatively phoretic morph. We here describe the adult females of A. perseus n. sp. and A. pyrophilus n. sp. collected from under the elytra of carabid beetles (Sericoda quadripunctata and S. bembidioides) associated with recently burned forests in Alberta, Canada. We also describe the female and male of a distinct, granular, non-phoretic morph of A. perseus, obtained from soil and by rearing the offspring of phoretic females. A key to the females of Antennoseius species having an ambulacrum on leg I (i.e. subgenus Vitzthumia) is provided.


1999 ◽  
Vol 9 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Yuri I. Wolf ◽  
Steven E. Brenner ◽  
Paul A. Bash ◽  
Eugene V. Koonin

A sensitive protein-fold recognition procedure was developed on the basis of iterative database search using the PSI-BLAST program. A collection of 1193 position-dependent weight matrices that can be used as fold identifiers was produced. In the completely sequenced genomes, folds could be automatically identified for 20%–30% of the proteins, with 3%–6% more detectable by additional analysis of conserved motifs. The distribution of the most common folds is very similar in bacteria and archaea but distinct in eukaryotes. Within the bacteria, this distribution differs between parasitic and free-living species. In all analyzed genomes, the P-loop NTPases are the most abundant fold. In bacteria and archaea, the next most common folds are ferredoxin-like domains, TIM-barrels, and methyltransferases, whereas in eukaryotes, the second to fourth places belong to protein kinases, β-propellers and TIM-barrels. The observed diversity of protein folds in different proteomes is approximately twice as high as it would be expected from a simple stochastic model describing a proteome as a finite sample from an infinite pool of proteins with an exponential distribution of the fold fractions. Distribution of the number of domains with different folds in one protein fits the geometric model, which is compatible with the evolution of multidomain proteins by random combination of domains.[Fold predictions for proteins from 14 proteomes are available on the World Wide Web atftp://ncbi.nlm.nih.gov/pub/koonin/FOLDS/index.html. The FIDs are available by anonymous ftp at the same location.]


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