A molecular approach to the community ecology of parasites of freshwater fish
Notice bibliographique
Résumé
Freshwater fish have been model hosts in the study of the community and evolutionary ecology of parasites for decades. Most studies have dealt only with adult parasites, although larval stages often dominate fish parasite communities. In addition, few studies include replicates of both host species and sampling localities. For this thesis, both larval and adult parasites were surveyed in six fish species ( Notemigonus crysoleucas, Pimephales notatus, Perca flavescens, Etheostoma nigrum, Lepomis gibbosus, Ambloplites rupestris ) collected from six localities in the St. Lawrence River and molecular techniques were used to distinguish species of strigeid metacercariae (Platyhelminthes: Trematoda). Novel primers were developed to sequence the barcode region of the cytochrome c oxidase I (COI) gene and sequences of internal transcribed spacer (ITS) regions of ribosomal DNA were also obtained. Both markers indicated unexpectedly high numbers of species in strigeid metacercariae, but resolution between species was clearer with COI than with ITS sequences. Strigeid species inhabiting the lens of the eye of fish were significantly less host specific than species inhabiting other tissues, possibly due to limited immune activity in the lens. Patterns of host specificity were consistent across the separate fish communities, which included fish species that are ecologically distinctive but closely related. Together, these findings suggest that physiological incompatibility between host and parasite is a more important determinant of host specificity than the ecological availability of host species to parasites in strigeid metacercariae. The high host specificity of most strigeid species had important effects on the parasite communities as a whole. Closely related fish species showed a significant tendency to have similar parasite communities that was much stronger than the tendency of parasite communities in spatially proximate fish to be similar. Geographic distance was strongly associated with parasite community similarity only when comparisons were limited to fish of the same species. Host taxonomy explained much more structure in parasite communities than spatial categories, suggesting that host phylogeny is more important than habitat in determining parasite community composition and abundance.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».