scholarly journals Site specificity and attachment mode of Symcallio and Calliobothrium species (Cestoda: “Tetraphyllidea”) in smoothhound sharks of the genus Mustelus (Carcharhiniformes: Triakidae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7264
Author(s):  
James P. Bernot ◽  
Janine N. Caira
Keyword(s):  
Morphological Features ◽  
Mucosal Surface ◽  
Site Specificity ◽  
Shark Species ◽  
Cestode Species ◽  
Spiral Intestine ◽  
Additional Species ◽  
Species Pairs ◽  
Functional Explanations

Previous studies suggest that cestodes (i.e., tapeworms) of the sister genera Symcallio and Calliobothrium attach in different specific regions of the spiral intestine of their triakid shark hosts, with species of Symcallio attaching in the anterior region of the spiral intestine and species of Calliobothrium attaching with a broader distribution centered around the middle of the spiral intestine. In the present study, we tested the generality of this pattern of site specificity in two additional species pairs: Symcallio peteri and Calliobothrium euzeti in Mustelus palumbes and S. leuckarti and C. wightmanorum in M. asterias. Finding that these cestodes also exhibit the aforementioned pattern, we investigated a series of functional explanations that might account for this phylogenetically conserved pattern of site specificity. The mucosal surface of the spiral intestine of both shark species was characterized, as were the attachment mechanisms of all four cestode species. Although anatomical differences in mucosal surface were seen along the length of the spiral intestine in both shark species, these differences do not appear to correspond to the attachment mode of these cestodes. We find that while species of Symcallio, like most cestodes, attach using their scolex, species of Calliobothrium attach with their scolex and, to a much greater extent, also with their strobila. Furthermore, attachment of Calliobothrium species appears to be enhanced by laciniations (flap-like extensions on the posterior margins of the proglottids) that interdigitate with elements of the mucosal surface of the spiral intestine. The role of proglottid laciniations in attachment in species of Calliobothrium helps reconcile a number of morphological features that differ between these two closely related cestode genera.

scholarly journals Evaluating the role of contracting and expanding rainforest in initiating cycles of speciation across the Isthmus of Panama

2012 ◽  
Vol 279 (1742) ◽  
pp. 3520-3526 ◽  
Author(s):  
Brian Tilston Smith ◽  
Amei Amei ◽  
John Klicka
Keyword(s):  
Bird Species ◽  
Tropical Regions ◽  
Isthmus Of Panama ◽  
Species Pairs ◽  
The Matrix ◽  
High Species Richness ◽  
The Rich ◽  
The Tropics ◽  
The Impact

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.

scholarly journals The attraction of Tremex apicalis (Hymenoptera, Siricidae, Tremecinae) and its parasitoid Ibalia japonica (Hymenoptera, Ibaliidae) to the fungus Cerrena unicolor

2019 ◽  
Vol 68 ◽  
pp. 37-48 ◽  
Author(s):  
Kazumu Kuramitsu ◽  
Teruhito Ishihara ◽  
Aki Sugita ◽  
Thitaree Yooboon ◽  
Barry Lustig ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Dna Barcode ◽  
White Rot Fungi ◽  
White Rot ◽  
Searching Behavior ◽  
Host Searching ◽  
Additional Species ◽  
Saproxylic Insects ◽  
Symbiotic Fungi

Woodwasps (Hymenoptera: Siricidae) are saproxylic insects and a common forest pest. Siricid woodwasps are classified into two subfamilies: Siricinae and Tremecinae. All known symbiotic fungi of Siricinae are in the genusAmylostereumBoidin while some species of Tremecinae have been observed to have a relationship with the fungusCerrenaunicolor(Bull.) Murrill. Previous studies about the host searching behavior of woodwasps and their parasitoids have focused primarily on the subfamily Siricinae.We analyzed the role ofC.unicolorvolatiles on the host searching behavior ofTremexapicalisMatsumura (Hymenoptera: Siricidae: Tremecinae) and its parasitoid Ibalia (Tremibalia) japonica Matsumura (Hymenoptera: Ibaliidae). The results of an olfactory response experiment indicated that the females ofT.apicalisand its parasitoid find their respective hosts using volatiles fromC.unicolor. Using DNA barcode, we identified basidiocarps on the trees infested withT.apicalis.The basidiocarps were all white-rot fungi that cause sapwood decay, includingC.unicolor. Two additional species that we identified belonged to genera closely related toC.unicolor.Woodwasp species are known to carry symbiotic fungi in a pair of specialized sacs called mycangia. Notably we found that mycangia-like structures were absent in the abdomens ofT.apicalisfemales. To the best of our knowledge,Xerisspectrum(Linnaeus) (Hymenoptera: Siricidae) is the only reported example of woodwasp species that do not contain symbiotic fungi in their bodies.Our results suggested that: (1)T.apicalisfemales search for host wood that is already infected with sapwood decaying fungus using volatile compounds; (2)T.apicalis’ female parasitoid also uses volatile compounds from fungus to locate wood that is infested with its potential host.

Language contact in Sardinian between the Middle and the Early Modern Ages

2018 ◽  
Vol 33 (1) ◽  
pp. 225-254
Keyword(s):  
Early Modern ◽  
Language Contact ◽  
Morphological Features ◽  
Contact Processes ◽  
The Relationship

AbstractThis paper describes the role of language contact in Sardinian lexical stratification, focusing on the Sardinian lexicon as well as on some morphological features. The major aim is to show the importance of the Sardinian lexicon for the understanding of the historical contact processes between Sardinian and other languages of the island and for the comprehension of the relationship between different varieties of Sardinian.

scholarly journals Expression of a novel isoform of Na+/H+ exchanger 3 in the kidney and intestine of banded houndshark, Triakis scyllium

2013 ◽  
Vol 304 (10) ◽  
pp. R865-R876 ◽  
Author(s):  
Shanshan Li ◽  
Akira Kato ◽  
Souichirou Takabe ◽  
An-Ping Chen ◽  
Michael F. Romero ◽  
...  
Keyword(s):  
Apical Membrane ◽  
Single Gene ◽  
Acid Base ◽  
Spiral Intestine ◽  
Diluting Segment ◽  
Aquatic Vertebrates ◽  
Promoter Usage ◽  
Distal Tubules ◽  
Immunohistochemical Analyses

Na+/H+ exchanger 3 (NHE3) provides one of the major Na+ absorptive pathways of the intestine and kidney in mammals, and recent studies of aquatic vertebrates (teleosts and elasmobranchs) have demonstrated that NHE3 is expressed in the gill and plays important roles in ion and acid-base regulation. To understand the role of NHE3 in elasmobranch osmoregulatory organs, we analyzed renal and intestinal expressions and localizations of NHE3 in a marine elasmobranch, Japanese banded houndshark ( Triakis scyllium). mRNA for Triakis NHE3 was most highly expressed in the gill, kidney, spiral intestine, and rectum. The kidney and intestine expressed a transcriptional isoform of NHE3 (NHE3k/i), which has a different amino terminus compared with that of NHE3 isolated from the gill (NHE3g), suggesting that NHE3k/i and NHE3g arise from a single gene by alternative promoter usage. Immunohistochemical analyses of the Triakis kidney demonstrated that NHE3k/i is expressed in the apical membrane of a part of the proximal and late distal tubules in the sinus zone. In the bundle zone of the kidney, NHE3k/i was expressed in the apical membrane of the early distal tubules known as the diluting segment. In the spiral intestine and rectum, NHE3k/i was localized toward the apical membrane of the epithelial cells. The transcriptional levels of NHE3k/i were increased in the kidney when Triakis was acclimated in 130% seawater, whereas those in the spiral intestine were increased in fish acclimated in diluted seawater. These results suggest that NHE3 is involved in renal Na+ reabsorption, urine acidification, and intestinal Na+ absorption in elasmobranchs.

scholarly journals Cleaning lateral morphological features of the root canal: the role of streaming and cavitation

2017 ◽  
Vol 51 ◽  
pp. e55-e64 ◽  
Author(s):  
J. P. Robinson ◽  
R. G. Macedo ◽  
B. Verhaagen ◽  
M. Versluis ◽  
P. R. Cooper ◽  
...  
Keyword(s):  
Root Canal ◽  
Morphological Features

Glomeromycetes from the Magdalen Islands archipelago: analyzing diversity and meta-community structure in a sand-dune ecosystem

Botany ◽  
2016 ◽  
Vol 94 (12) ◽  
pp. 1195-1208
Author(s):  
Yolande Dalpé ◽  
Sylvie Séguin ◽  
Pierre-Luc Chagnon
Keyword(s):  
Mycorrhizal Fungi ◽  
Sand Dune ◽  
Arbuscular Mycorrhizal ◽  
Additional Species ◽  
Generalist Species ◽  
Ammophila Breviligulata ◽  
Sand Trap ◽  
Species Pairs ◽  
Arbuscular Mycorrhizal Fungal ◽  
Magdalen Islands

This report presents the first survey and analysis of the arbuscular mycorrhizal fungi community associated with Ammophila breviligulata Fernald (American beachgrass), of the Magdalen Islands archipelago, Quebec. Of the 36 selected harvesting sites, a total of 180 sand samples were collected from the rhizosphere of American beachgrass. Analyses were performed on the original sand samples and root and sand trap cultures. Of the 34 spore-morphotypes found, 31 belonged to glomoid spore species. Of the field sand samples, 72% contained the spores of Glomeromycetes and subsequent trap cultures increased this percentage to 84%. Of the 34 species, 29 were found sporulating in indigenous sand samples at harvest time, and only five additional species were recovered from root and sand trap pot culturing. Among the more generalist species were Rhizoglomus irregulare and G. sp4, which were found in 19 sites, Rhizoglomus aggregatum and Corymbiglomus tortuosum (found in 17 sites), Funneliformis mosseae and G. sp3 (found in 15 sites). This meta-community of Glomeromycetes is shown to have significant nestedness, indicating that fungal taxa that are more frequent in the whole archipelago are also more abundant locally. Some species pairs are shown to display significant negative associations in their patterns of co-occurrence. The relevance of these results for arbuscular mycorrhizal fungal community assembly and dynamics is discussed.

scholarly journals Role of Fusobacterium nucleatum and Coaggregation in Anaerobe Survival in Planktonic and Biofilm Oral Microbial Communities during Aeration

1998 ◽  
Vol 66 (10) ◽  
pp. 4729-4732 ◽  
Author(s):  
David J. Bradshaw ◽  
Philip D. Marsh ◽  
G. Keith Watson ◽  
Clive Allison
Keyword(s):  
Anaerobic Bacteria ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Obligate Anaerobe ◽  
Obligately Anaerobic ◽  
Prevotella Nigrescens ◽  
Tolerant Species ◽  
Species Pairs ◽  
Planktonic Phase

ABSTRACT Coaggregation is a well-characterized phenomenon by which specific pairs of oral bacteria interact physically. The aim of this study was to examine the patterns of coaggregation between obligately anaerobic and oxygen-tolerant species that coexist in a model oral microbial community. Obligate anaerobes other than Fusobacterium nucleatum coaggregated only poorly with oxygen-tolerant species. In contrast, F. nucleatum was able to coaggregate not only with both oxygen-tolerant and other obligately anaerobic species but also with otherwise-noncoaggregating obligate anaerobe–oxygen-tolerant species pairs. The effects of the presence or absence of F. nucleatum on anaerobe survival in both the biofilm and planktonic phases of a complex community of oral bacteria grown in an aerated (gas phase, 200 ml of 5% CO2 in air · min−1) chemostat system were then investigated. In the presence of F. nucleatum, anaerobes persisted in high numbers (>107 · ml−1 in the planktonic phase and >107 · cm−2 in 4-day biofilms). In an equivalent culture in the absence of F. nucleatum, the numbers of black-pigmented anaerobes (Porphyromonas gingivalis and Prevotella nigrescens) were significantly reduced (P ≤ 0.001) in both the planktonic phase and in 4-day biofilms, while the numbers of facultatively anaerobic bacteria increased in these communities. Coaggregation-mediated interactions between F. nucleatum and other species facilitated the survival of obligate anaerobes in aerated environments.

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