Cosmopolitan polychaetes – fact or fiction? Personal and historical perspectives

Abstract

In the biogeographical and taxonomical literature before the 1980s there was a wide perception that widespread, often referred to as ‘cosmopolitan’, species were very common among polychaetes. Here we discuss the origins of this perception, how it became challenged, and our current understanding of marine annelid distributions today. We comment on the presence of widely distributed species in the deep sea and on artificially extended ranges of invasive species that have been dispersed by anthropogenic means. We also suggest the measures needed to revolve the status of species with reported cosmopolitan distributions and stress the value of museum collections and vouchers to be associated with DNA sequences in resolving species distributions.

High diversity and pan-oceanic distribution of deep-sea polychaetes: Prionospio and Aurospio (Annelida: Spionidae) in the Atlantic and Pacific Ocean

“…A pan-oceanic distribution found for Aurospio and Prionospio species as evidenced from molecular data is so far unique for abyssal annelids, even if wide distribution ranges of polychaete species are not unusual (Böggemann 2016;Eilertsen et al 2018;Georgieva et al 2015;Guggolz et al 2019;Meißner et al 2016;Schüller and Hutchings 2012). However, Hutchings and Kupriyanova (2018) are particularly highlighting that reported "cosmopolitan" species should be treated with caution. For some species, wide distribution ranges have been based on misidentification or cryptic species and subsequently rejected using molecular marker (Álvarez-Campos et al 2017;Nygren 2014;Nygren et al 2018;Sun et al 2016).…”

“…Several of these presumably widespread species were found to be composed of a number geographically restricted and morphologically cryptic species (Bickford et al 2007;Vrijenhoek 2009) or simply misidentified (Álvarez-Campos et al 2017;Nygren et al 2018;Sun et al 2016). Hence, hypothesizing distribution patterns in the deep sea is still challenging, and integrative approaches, which combine morphological and molecular techniques, are essential to identify and delimit species Hutchings and Kupriyanova 2018). One important aspect of the present study is to examine the diversity and the dispersal capacity of Prionospio and Aurospio in the Vema-Fracture-Zone (VFZ).…”

A new species of the Marphysa sanguinea complex from French waters (Bay of Biscay, NE Atlantic) (Annelida, Eunicidae)

“…This is partly because the original description was very brief and poorly illustrated, and because all species superficially look similar. Hartman (1959) complicated the issue by synonymising several species with M. sanguinea with no explanation and the species joined a list of so-called “cosmopolitan species” (Hutchings and Kupriyanova 2017). Hutchings and Karageorgopoulos (2003) while trying to resolve the true identity of a commercially important species in Moreton Bay (Queensland, Australia) which had always been called M. sanguinea , examined material from SW England and designated a neotype of M. sanguinea and then redescribed the species.…”

“…Nevertheless, recent re-descriptions of this species (Hutchings and Karageorgopoulos 2003; Hutchings et al 2012) suggest that records of this species from outside the type locality should be checked, and that many records have been misidentified and represent new species (Zanol et al 2016, 2017). Hutchings and Kupriyanova (2017) encourage taxonomists to check carefully their specimens.…”

Some Implications of High Biodiversity for Management of Tropical Marine Ecosystems—An Australian Perspective

“…We have limited knowledge and lack taxonomic inventories or distribution patterns. Increasingly, we are finding that species have discrete distributions rather than widespread distributions which have often previously been reported [29]. Our taxonomic capacity in much of this region is limited with most residing in the capital cities of southern Australia, with developing countries in the region having other priorities.…”