PhoxDiv

Cryptic Species and their impact on biodiversity

An estimated 90 per cent of the world’s species are currently undescribed, with a significant proportion being cryptic species. These are species that are genetically distinct but morphologically barely distinguishable. Identifying them is crucial for understanding their life cycles, population dynamics and habitats. Cryptic species complicate biodiversity assessments and conservation measures, as what is unknown can neither be counted nor protected. Whilst biodiversity hotspots such as the Neotropics are the focus of scientific attention, native cryptic species also deserve greater attention.

As part of the PhoxDiv project, we are focusing on the genetic diversity and distribution of fish known as Eurasian minnows (Phoxinus spp.) in Germany and beyond. The genus Phoxinus contains numerous cryptic species that were only identified less than a decade ago with the help of single-gene analyses. Four minnow species are now recognised in Germany, one of which is listed as a species of national responsibility on the German Red List. Due to their recent recognition as distinct species, little is known about their exact distribution ranges and their precise genetic and morphological distinctions.

Objectives

The first objective of this study is to determine the population structure and geographical distribution of all Phoxinus species in Germany. In addition, the second objective is to analyse the distribution range of the species of national responsibility, P. morella, beyond Germany. The third objective involves combining genomic analyses with morphological data to identify morphological features that are relevant from both a taxonomic and ecological perspective.
The methodology involves collecting samples from new sites – which represent gaps in the current data – and collecting material that represents the genome of P. morella; whole-genome sequencing of the individuals studied to increase the number of genetic markers for differentiation analyses; and morphological analyses using traditional and geometric morphometrics. The results will shed light on species boundaries, population structure and the impact of historical biogeographical processes on the distribution of minnows in Germany. The inclusion of morphological data will support taxonomic research and facilitate the development of effective conservation strategies.

Collection

All collected tissues will be deposited in the biobank; raw sequence data will be deposited in ENA.