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Published on: March 15, 2018
Cryptic species complexes in manipulative echinostomatid trematodes: when two become six
T L F Leung1, D B Keeney, R Poulin
1Department of Zoology, University of Otago, Dunedin, New Zealand. leuto618@student.otago.ac.nz
Parasitology
|December 19, 2008
Summary
Cryptic species of Acanthoparyphium and Curtuteria trematodes were identified in New Zealand. These genetically distinct parasites exhibit localized distribution patterns, challenging assumptions about host manipulation and parasite dispersal.
Area of Science:
- Parasitology
- Molecular Ecology
- Marine Biology
Background:
- Digenean trematodes often exhibit cryptic speciation, with genetically distinct species appearing morphologically identical.
- Acanthoparyphium sp. and Curtuteria australis are known host-manipulating echinostomes impacting intertidal ecosystems.
- Understanding parasite diversity and distribution is crucial for ecological studies.
Purpose of the Study:
- To genetically identify cryptic species within Acanthoparyphium sp. and Curtuteria australis.
- To investigate the distribution patterns of these trematode species in the Otago Peninsula, New Zealand.
- To explore potential explanations for observed small-scale spatial segregation.
Main Methods:
- Mitochondrial 16S and nuclear ITS1 gene sequencing of redial stages from snails and whelks.
- Phylogenetic analyses to determine genetic distinctness.
- Comparison of sequences from rediae and metacercariae found in cockles.
Main Results:
- Acanthoparyphium sp. comprises at least 4 genetically distinct species.
- A cryptic species of Curtuteria was identified alongside Curtuteria australis.
- Cryptic species exhibited highly localized distributions, with varying prevalence between Otago Harbour and nearby inlets.
Conclusions:
- Morphologically similar digenean trematodes can harbor significant hidden genetic diversity.
- The localized distribution of cryptic echinostome species suggests factors beyond host dispersal influence their spatial ecology.
- Further research is needed to elucidate the drivers of this small-scale spatial segregation, including host adaptation and environmental factors.
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