Cost of interspecific competition between trematode colonies

2020 ◽  
Vol 94 ◽  
Author(s):  
K.N. Mouritsen ◽  
C.K. Elkjær
Keyword(s):  
Intermediate Host ◽  
Interspecific Competition ◽  
Parasite Species ◽  
Division Of Labour ◽  
The Other ◽  
Trematode Species ◽  
Littorina Littorea ◽  
Fitness Costs ◽  
Species Specific ◽  
First Intermediate Host

Abstract In a range of trematode species, specific members of the parthenitae colony infecting the molluscan first intermediate host appear specialized for defence against co-infecting species. The evolution of such division of labour requires that co-infection entails fitness costs. Yet, this premise has very rarely been tested in species showing division of labour. Using Himasthla elongata (Himasthlidae) and Renicola roscovita (Renicolidae) infecting periwinkles Littorina littorea as study system, we show that the size of emerged cercariae is markedly reduced in both parasite species when competing over host resources. Cercarial longevity, on the other hand, is negatively influenced by competition only in R. roscovita. Season, which may impact the nutritional state of the host, also affects cercarial size, but only in H. elongata. Hence, our study underlines that cercarial quality is, indeed, compromised by competition, not only in the inferior R. roscovita (no division of labour) but also in the competitively superior H. elongata (division of labour).

Reproduction and caste ratios under stress in trematode colonies with a division of labour

Parasitology ◽  
2013 ◽  
Vol 140 (7) ◽  
pp. 825-832 ◽  
Author(s):  
MELANIE M. LLOYD ◽  
ROBERT POULIN
Keyword(s):  
Intermediate Host ◽  
Reproductive Output ◽  
Environmental Variability ◽  
Division Of Labour ◽  
Environmental Pressures ◽  
Caste Ratio ◽  
Infection Types ◽  
First Intermediate Host

SUMMARYTrematodes form clonal colonies in their first intermediate host. Individuals are, depending on species, rediae or sporocysts (which asexually reproduce) and cercariae (which develop within rediae or sporocysts and infect the next host). Some species use a division of labour within colonies, with 2 distinct redial morphs: small rediae (non-reproducing) and large rediae (individuals which produce cercariae). The theory of optimal caste ratio predicts that the ratio of caste members (small to large rediae) responds to environmental variability. This was tested in Philophthalmus sp. colonies exposed to host starvation and competition with the trematode, Maritrema novaezealandensis. Philophthalmus sp. infected snails, with and without M. novaezealandensis, were subjected to food treatments. Reproductive output, number of rediae, and the ratio of small to large rediae were compared among treatments. Philophthalmus sp. colonies responded to host starvation and competition; reproductive output was higher in well-fed snails of both infection types compared with snails in lower food treatments and well-fed, single infected snails compared with well-fed double infected snails. Furthermore, the caste ratio in Philophthalmus sp. colonies was altered in response to competition. This is the first study showing caste ratio responses to environmental pressures in trematodes with a division of labour.

One snail – three Digenea species, different strategies in host-parasite interaction

2011 ◽  
Vol 61 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Elżbieta Żbikowska
Keyword(s):  
Intermediate Host ◽  
Parasite Species ◽  
Lymnaea Stagnalis ◽  
Behavioral Changes ◽  
Diplostomum Pseudospathaceum ◽  
Second Intermediate Host ◽  
Host Parasite ◽  
The Impact ◽  
Plagiorchis Elegans ◽  
First Intermediate Host

AbstractThe mostly lab-based studies on snail-trematode interactions should be complemented by research on naturally invaded hosts. In this mini-review, three different ways of snail exploitation by Digenea larvae are presented. Morphological, physiological and behavioral changes caused by three parasites in the same naturally infected host – Lymnaea stagnalis – differ in species-dependent fashion. The impact of a snail-trematode interaction depends on parasite virulence (i.e. parasite induced lost of fitness of the host). The pathogenicity varies with the survival strategy of the invader. Sporocyst-born Plagiorchis elegans, which uses the same Lymnaea stagnalis individual as a first but also as a second intermediate host, does not disturb host processes as strongly as redia-born Echinoparyphium aconiatum. The third parasite species – Diplostomum pseudospathaceum, also sporocyst-born – is more virulent than P. elegans, but it can modify and relax host exploitation to overwinter in the snail. The data presented demonstrate that successful use of first intermediate host can be arranged in different ways.

Species-Specific Primers Designed from RAPD Products forBithynia funiculata,the First Intermediate Host of Liver Fluke,Opisthorchis viverrini, in North Thailand

2013 ◽  
Vol 99 (3) ◽  
pp. 433-437 ◽  
Author(s):  
Jutharat Kulsantiwong ◽  
Sattrachai Prasopdee ◽  
Supawadee Piratae ◽  
Panita Khampoosa ◽  
Apiporn Suwannatrai ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Liver Fluke ◽  
Opisthorchis Viverrini ◽  
Specific Primers ◽  
Species Specific ◽  
North Thailand ◽  
First Intermediate Host

First molecular identification of Ascocotyle (Phagicola) longa in its first intermediate host the mud snail Heleobia australis

2015 ◽  
Vol 60 (4) ◽  
Author(s):  
Pilar Alda ◽  
Nicolás Bonel ◽  
Carlos J. Panei ◽  
Néstor J. Cazzaniga ◽  
Sergio R. Martorelli
Keyword(s):  
Intermediate Host ◽  
Bahía Blanca Estuary ◽  
Larval Stages ◽  
Mud Snail ◽  
Total Prevalence ◽  
Second Intermediate Host ◽  
Species Specific ◽  
Dna Primers ◽  
First Intermediate Host ◽  
Blanca Estuary

AbstractThis is the first study that used species-specific DNA primers to confirm the presence of the heterophyid Ascocotyle (Phagicola) longa Ransom, 1920 in its first intermediate host. The larval stages (rediae and cercariae) of this parasite were morphologically and genetically identified in the gonad of the intertidal mud snail Heleobia australis (d’Orbigny, 1835) (Cochliopidae) in the Bahía Blanca estuary, Argentina. In addition, we asked whether the prevalence in H. australis varied between seasons. Mullets - the second intermediate host of this heterophyid - migrate in estuaries during the warmer seasons and it is expected that piscivorous birds and mammals - the definitive hosts - prey more intensively on this species at those times. Thus, the number of parasite eggs released into the tidal flat within their feces should be higher, thereby increasing the ingestion of the parasite by H. australis.We therefore expected a higher prevalence of A. (P.) longa in H. australis in the Bahía Blanca estuary during spring and summer than autumn and winter. We found that 16 out of 2,744 specimens of H. australis had been infected with A. (P.) longa (total prevalence of 0.58%). Nonetheless, the prevalence showed no significant variation between seasons. Hence, we discuss an alternative scenario where the lack of seasonal changes might be mostly related to the permanent residence of definitive hosts in the estuary and not to the seasonal recruitment of mullets. Finally, we highlight the need for more experimental and comparative approaches in order to understand the diagnosis and geographical distribution of this worldwide heterophyid.

Guide to the trematodes (Platyhelminthes) that infect the California horn snail (Cerithideopsis californica: Potamididae: Gastropoda) as first intermediate host

Zootaxa ◽  
2019 ◽  
Vol 4711 (3) ◽  
pp. 459-494 ◽  
Author(s):  
RYAN F. HECHINGER
Keyword(s):  
Intermediate Host ◽  
Relevant Literature ◽  
Diagnostic Information ◽  
Background Information ◽  
Trematode Species ◽  
Host Use ◽  
Ecological Research ◽  
Second Intermediate Host ◽  
First Intermediate Host ◽  
Identification Tool

The California horn snail, Cerithideopsis californica, lives in estuarine habitats from California (USA) in North America to Piura (Peru) in South America. Throughout this range, the snail serves as first intermediate host for a diverse guild of digenean trematodes. These parasites are used in teaching laboratories, and have been subject to a large amount of taxonomic, biological, evolutionary, and ecological research. Despite the abundance of research on these trematodes, we lack a satisfactory guide to these parasites. This manuscript treats the 19 trematode species that we are currently able to distinguish morphologically. I provide taxonomic affinities, information on second intermediate host use, an identification key focused on cercaria traits, information and a key for regressed infections lacking cercariae, information on early infections, and species accounts. The species accounts present photographs, additional diagnostic information, taxonomic notes, information concerning cryptic species, and connections to relevant literature. The primary aim of this manuscript is to facilitate research on this trematode guild by serving as an identification tool, and by providing background information, including highlighting gaps in our knowledge. 

scholarly journals Caste formation in larval Himasthla elongata (Trematoda) infecting common periwinkles Littorina littorea

2014 ◽  
Vol 94 (5) ◽  
pp. 917-923 ◽  
Author(s):  
Sigrid S. Nielsen ◽  
Malan Johansen ◽  
Kim N. Mouritsen
Keyword(s):  
Social Organization ◽  
Ecological Factors ◽  
Marine Species ◽  
Division Of Labour ◽  
Trematode Species ◽  
Littorina Littorea ◽  
Reproductive Division Of Labour ◽  
Reproductive Division ◽  
Trematode Parasites

Reproductive division of labour is well-known in several animal groups but the ecological factors driving the evolution of such social organization are still being discussed. Recent studies have discovered social organization in four marine species of trematode parasites having two distinct castes specialized for reproduction and defence of the clonal intra-molluscan larval colony, respectively. Here, we provide novel evidence for social structure also in colonies of the trematode Himasthla elongata infecting the common periwinkle Littorina littorea. We found two types of rediae, the parthenogenetic larval offspring of the parasite: small non-reproductive rediae and considerably larger reproductive rediae. Both redial types possessed a digestive system, collar and posterior appendages and, hence, aside from dimensions, were morphologically similar. However, in vitro experiments showed that non-reproductive morphs attacked heterospecific competing parasites at a higher rate (2–3 fold) than reproductive morphs did. No within-colony antagonism was observed. In contrast to a previous study on a congeneric trematode species, our findings suggest a relatively weak caste formation in H. elongata, possibly resulting from a corresponding weaker level of interspecific competition.

Speciation of echinostomes: evidence for the existence of two sympatric sibling species in the complex Echinoparyphium recurvatum (von Linstow 1873) (Digenea: Echinostomatidae)

Parasitology ◽  
1990 ◽  
Vol 101 (1) ◽  
pp. 35-42 ◽  
Author(s):  
A. M. McCarthy
Keyword(s):  
Small Intestine ◽  
Intermediate Host ◽  
Sibling Species ◽  
Definitive Host ◽  
Experimental Studies ◽  
Life Cycles ◽  
The Other ◽  
Excessive Competition ◽  
First Intermediate Host ◽  
Prosobranch Snail

SUMMARYEvidence for the existence of 2 first intermediate host-specific sibling species of the 45 collar-spined echinostome Echinoparyphium recurvatum is presented. Experimental studies on their life-cycles were carried out under controlled laboratory conditions. The two entities were found to be morphologically indistinguishable in all major respects, yet they exhibited distinct biological characteristics. One of the sibling species utilizes the freshwater lymnaeid pulmonate snail Lymnaea peregra as first intermediate host, and the adults occur in the anterior small intestine of the wildfowl experimental definitive host Anas platyrhynchos. The other utilizes the freshwater mesogastropod prosobranch snail Valvata piscinalis as first intermediate host, and the adults occur in the posterior small intestine and rectum of A. platyrhynchos. The existence of the two sibling species in sympatry may be explained by the fact that the life-cycles of the two forms represent two distinct cycles of transmission serving to reduce excessive competition between them.

scholarly journals Prebiotic Combinations Effects on the Colonization of Staphylococcal Skin Strains

2020 ◽  
Vol 9 (1) ◽  
pp. 37
Author(s):  
Silvia Di Lodovico ◽  
Franco Gasparri ◽  
Emanuela Di Campli ◽  
Paola Di Fermo ◽  
Simonetta D’Ercole ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Commensal Bacteria ◽  
The Other ◽  
Bacteriostatic Effect ◽  
Skin Microbiota ◽  
Relevant Effect ◽  
Planktonic Phase ◽  
Species Specific ◽  
Biomass Quantification ◽  
General Reduction

Background: An unbalanced skin microbiota due to an increase in pathogenic vs. commensal bacteria can be efficiently tackled by using prebiotics. The aim of this work was to identify novel prebiotic combinations by exerting species-specific action between S. aureus and S. epidermidis strains. Methods: First, the antimicrobial/antibiofilm effect of Xylitol-XYL and Galacto-OligoSaccharides–GOS combined with each other at different concentrations (1, 2.5, 5%) against S. aureus and S. epidermidis clinical strains was evaluated in time. Second, the most species-specific concentration was used to combine XYL with Fructo-OligoSaccharides–FOS, IsoMalto-Oligosaccharides–IMO, ArabinoGaLactan–LAG, inulin, dextran. Experiments were performed by OD600 detection, biomass quantification and LIVE/DEAD staining. Results: 1% XYL + 1% GOS showed the best species-specific action with an immediate antibacterial/antibiofilm action against S. aureus strains (up to 34.54% ± 5.35/64.68% ± 4.77) without a relevant effect on S. epidermidis. Among the other prebiotic formulations, 1% XYL plus 1% FOS (up to 49.17% ± 21.46/37.59% ± 6.34) or 1% IMO (up to 41.28% ± 4.88/36.70% ± 10.03) or 1% LAG (up to 38.21% ± 5.31/83.06% ± 5.11) showed antimicrobial/antibiofilm effects similar to 1% XYL+1% GOS. For all tested formulations, a prevalent bacteriostatic effect in the planktonic phase and a general reduction of S. aureus biofilm formation without loss of viability were recorded. Conclusion: The combinations of 1% XYL with 1% GOS or 1% FOS or 1% IMO or 1% LAG may help to control the balance of skin microbiota, representing good candidates for topic formulations.

scholarly journals Species-Specific Segregation of Gender-Associated Mitochondrial DNA Types in an Area Where Two Mussel Species (Mytilus edulis and M. trossulus) Hybridize

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1359-1367 ◽  
Author(s):  
Carlos Saavedra ◽  
Donald T Stewart ◽  
Rebecca R Stanwood ◽  
Eleftherios Zouros
Keyword(s):  
Mytilus Edulis ◽  
The Other ◽  
Allozyme Analysis ◽  
Mussel Species ◽  
Species Origin ◽  
Species Pairs ◽  
Nuclear Background ◽  
Species Specific ◽  
Dna Types ◽  
Fertile Hybrids

Abstract In each of the mussel species Mytilus edulis and M. trossulus there exist two types of mtDNA, the F type transmitted through females and the M type transmitted through males. Because the two species produce fertile hybrids in nature, F and M types of one may introgress into the other. We present the results from a survey of a population in which extensive hybridization occurs between these two species. Among specimens classified as “pure” M. edulis or “pure” M. trossulus on the basis of allozyme analysis, we observed no animal that carried the F or the M mitotype of the other species. In most animals of mixed nuclear background, an individual's mtDNA came from the species that contributed the majority of the individual's nuclear genes. Most importantly, the two mtDNA types in post-F1 male hybrids were of the same species origin. We interpret this to mean that there are intrinsic barriers to the exchange of mtDNA between these two species. Because such barriers were not noted in other hybridizing species pairs (many being even less interfertile than M. edulis and M. trossulus), their presence in Mytilus could be another feature of the unusual mtDNA system in this genus.

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