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Published on: July 30, 2019
Multilevel fine-scale diversity challenges the 'cryptic species' concept.
Tatiana Korshunova1,2, Bernard Picton3,4, Giulia Furfaro5
1Koltzov Institute of Developmental Biology RAS, 26 Vavilova Str., 119334, Moscow, Russia.
Scientific Reports
|May 3, 2019
Summary
This study reveals three new nudibranch species, challenging the definition of cryptic species. Integrating morphological and genetic data is crucial for accurate taxonomic frameworks and biodiversity assessments.
Area of Science:
- Marine Biology
- Taxonomy
- Evolutionary Biology
Background:
- The definition of 'cryptic' species, characterized by low morphological but high genetic divergence, is debated.
- Existing species concepts struggle with the continuum of variation observed across taxa.
- Nudibranch molluscs of the genus Trinchesia serve as a model system for exploring species complex dynamics.
Purpose of the Study:
- To investigate the species complex within the nudibranch genus Trinchesia from European waters.
- To determine if the 'cryptic' species concept adequately describes the observed morphological and genetic diversity.
- To propose a refined taxonomic framework integrating multiple lines of evidence.
Main Methods:
- Analysis of unique nudibranch material from European waters.
- Application of both morphological and molecular (genetic) analyses.
- Examination of a broad range of metazoan-wide data to assess species concept applicability.
Main Results:
- Identification of three new Trinchesia species within the studied complex.
- Demonstration of stable, albeit subtle, morphological differences alongside molecular divergence.
- Evidence for rapid speciation rates within this nudibranch group.
- The 'cryptic' species concept is deemed insufficient due to the continuous nature of divergence.
Conclusions:
- A dual nature of species complexes, exhibiting both overall similarity and distinct differences, is highlighted.
- The 'cryptic', 'pseudocryptic', and 'non-cryptic' labels are shown to be potentially interchangeable or redundant.
- A concordance of morphological and molecular methods is essential for a fine-scale, multilevel taxonomic framework.
- Findings have significant implications for conservation biology and biodiversity assessments.
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