Karanovic_2015.pdf (8.1 MB)
Barcoding of ancient lake ostracods (Crustacea) reveals cryptic speciation with extremely low distances
journal contribution
posted on 2023-05-18, 16:10 authored by Ivana KaranovicOstracods are drastically reduced crustaceans, with never more than eight appendages enclosed between two valves, leaving only a limited number of morphological characters for species delineation. Conservative morphology of characters used to define genera, along with high variability of characters used to define species are creating problems in applying a morphospecies concept. A high intraspecific variability in a Lake Biwa (Japan) endemic, Physocypria biwaensis (Okubo, 1990), has been observed previously but was never studied in detail. Two sympatric forms, differing in pigmentation and size, suggest a presence of reproductive isolation. The aim of this study is to employ molecular and morphometric tools to aid in species delineation within P. biwaensis complex and reconstruct their phylogenetic relationships. A fragment of the mtCOI gene was amplified from 30 specimens, and an additional 37 specimens were studied for morphological characters. Resulting phylogenies showed that each morphologically distinct form is associated with a distinct phylogenetic group based on mtDNA. The average pairwise distance is very low (5%), indicating a recent divergence time. I speculate that there is a possibility that one of them originated in the lake, while the other probably colonized it afterwards. This seems to be supported with an apparent niche partitioning at different depths. In spite of the fact that traditionally used sexual characters are highly variable in these two species, the morphometric analysis of shell and soft part related characters clearly delineates them and suggests that such characters may be useful for future detection of seemingly cryptic ostracod species.
History
Publication title
PLoS ONEVolume
10Article number
e0121133Number
e0121133Pagination
1-17ISSN
1932-6203Department/School
Institute for Marine and Antarctic StudiesPublisher
Public Library of SciencePlace of publication
United StatesRights statement
Copyright: © 2015 Ivana Karanovic. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/Repository Status
- Open