Low genetic but high morphological variation over more than 1000 km coastline refutes omnipresence of cryptic diversity in marine nematodes

Autor: Sofie Derycke, Giovanni dos Santos, Tom Moens, Daniel Apolônio Silva de Oliveira, Wilfrida Decraemer
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Male
0106 biological sciences
0301 basic medicine
PELLIODITIS-MARINA
Nematoda
Population genetics
COMPLEX NEMATODA
FLOW
01 natural sciences
DISPERSAL
MITOCHONDRIAL-DNA VARIATION
POPULATION
education.field_of_study
Connectivity
SEA
Ecology
Phylogeography
Genetic structure
Female
Brazil
Research Article
Gene Flow
ATLANTIC
Species complex
Climate Change
Oceans and Seas
Population
Zoology
Biology
DNA
Mitochondrial
010603 evolutionary biology
COI
03 medical and health sciences
Genetic variation
Animals
education
Ecosystem
Ecology
Evolution
Behavior and Systematics
SPECIES COMPLEX
Genetic diversity
Morphometry
Genetic Variation
Species diversity
Biology and Life Sciences
TAXONOMY
Seaweed
030104 developmental biology
Haplotypes
Earth and Environmental Sciences
Biological dispersal
Animal Distribution
Zdroj: BMC EVOLUTIONARY BIOLOGY
BMC Evolutionary Biology
ISSN: 1471-2148
Popis: The resilience of ecosystems to negative impacts is generally higher when high gene flow, species diversity and genetic diversity are present. Population genetic studies are suitable to investigate genetic diversity and estimate gene flow between populations. Seaweed beds form a dynamic shallow water ecosystem influenced by climate change and human exploitation, as such, seaweed beds are a particularly powerful model to investigate ecosystem resilience in coastal areas. We studied the population genetic structure of the new nematode species Paracanthonchus gynodiporata associated with seaweeds in northeastern Brazil. Nematodes are generally believed to have a limited dispersal capacity because of the lack of planktonic larvae. Yet, they can drift on seaweeds, and water currents might be a natural barrier for their dispersal. Populations of P. gynodiporata were sampled over more than 1000 km coastline in regions across major oceanic currents with and without historical exploitation of seaweed. P. gynodiporata is described in an integrative way using mitochondrial and nuclear sequences and morphological data. The 3D model of the head region shows for the first time a detailed view of the ventrosublateral teeth, a character often overlooked in older taxonomic studies of the genus. A total of 17 mitochondrial COI haplotypes were found with one haplotype representing 63 to 83% of the frequencies in each population. AMOVA showed overall little population genetic structure (F ST = 0.05204), and no genetic subdivision between the populations under the influence of the two different water currents were found. Effects of historical seaweed exploitation on population genetic diversity were not detected. In contrast, significant differences between populations were found in morphometric characters. This discrepancy in genetic and morphological differentiation between populations across 1000 km of coastline is surprising in view of the frequently observed presence of several cryptic species at small geographical scale in other macroalgal associated nematodes. Our results show that cryptic species are not omnipresent in marine nematode species, suggesting that nematodes associated with seaweeds have been able to disperse over large distances across well-known biogeographic barriers.
Databáze: OpenAIRE
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