Invertebrate Systematics Invertebrate Systematics Society
Systematics, phylogeny and biogeography

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Instant taxonomy: Choosing adequate characters for species delimitation and description through congruence between molecular data and quantitative shape analysis

Tomislav Karanovic , Seunghan Lee , Wonchoel Lee


The lack of university funding is one of major impediments to taxonomy, partly because traditional taxonomic training takes longer than a PhD course. Understanding ranges of phenotypic variability for different morphological structures, and their use as characters for delimitation and description of taxa, is a tedious task. We argue that the advent of molecular barcoding and quantitative shape analysis make it unnecessary. As an example, we tackle a problematic species-complex of marine copepods from Korea and Japan, approaching it in a way that a starting taxonomist might do. Samples were collected from 14 locations and the mitochondrial COI gene was sequenced from 42 specimens. Our phylogenetic analyses reveal four distinct clades in Korea and Japan, and additional nine belonging to a closely related complex from other parts of the Northern Pacific. Twenty different morphological structures were analysed for one Japanese and two Korean clades using landmark-based two-dimensional geometric morphometrics. Although there is no single morphological character that can distinguish with absolute certainty all three cryptic species, most show statistically significant interspecific differences in shape and size. We use five of them to describe two new species from Korea, and to redescribe Tigriopus japonicus Mori, 1938 from near its type locality.

IS17002  Accepted 13 September 2017

© CSIRO 2017