Are taxonomic details of relevance to ecologists? An example from oncaeid microcopepods of the Red Sea

Abstract

The marine microcopepod family Oncaeidae in the Red Sea has been the subject of comprehensive ecological studies over the past 15 years, providing for the first time insights into their community structure, vertical distribution and feeding ecology. Owing to taxonomic problems in species identification, however, many of the earlier ecological results were based on provisionally named species or morphotypes. A recent, ongoing taxonomic study of Red Sea Oncaeidae resulted in a considerable increase in the estimated numbers of species, since many of the species had not been described before. The present paper focuses on the potential significance of an improved taxonomic resolution of oncaeids with respect to various ecological aspects in this area, such as indicator species, community analysis and vertical distribution. The progress in our knowledge of the diversity of Red Sea Oncaeidae is summarized, including latest findings on the taxonomy and zoogeography of very small species (<0.5 mm), and the importance of sibling species in the family is pointed out. The south-north gradient in species diversity of Oncaeidae within the Red Sea appears to be greater than previously assumed, since several of the newly described species were restricted to the southern part. The number of endemic species among Red Sea oncaeids is very low, however, most of the new species being also recorded outside the Red Sea. New quantitative data on the abundance and vertical distribution of selected oncaeid siblings obtained during a recent cruise in the northern Red Sea are provided to exemplify the changes in the knowledge of oncaeid community structure attributable to the improved taxonomic resolution. The potential ecological importance of a more differentiated consideration of oncaeid species in marine microcopepod communities is discussed.

Differential routing of ‘new’ nitrogen toward higher trophic levels within the marine food web of the Gulf of Aqaba, Northern Red Sea

“…This course of action has not universally been accepted yet (Ho et al 2006). Due to the apparently different ecological role, the poecilostomatoidan families play in the copepod community as a specific functional group (see review by Boettger-Schnack et al 2004), the earlier defined order of Poecilostomatoida has been kept in the present study.…”

Utility of DNA taxonomy and barcoding for the inference of larval community structure in morphologically crypticChironomus(Diptera) species

“…Additionally, the majority of species on this planet is lacking a formal taxonomic description and will thus not occur in published keys (May 1988). This so‐called ‘taxonomic impediment’ is creating bias in biodiversity studies as the applied taxonomic resolution is crucial for the outcome (Bottger‐Schnack et al . 2004; Waite et al .…”

Molecular phylogeny of Oncaeidae (Copepoda) using nuclear ribosomal internal transcribed spacer (ITS rDNA)

“…The ecological traits and the role played by oncaeids in the planktonic communities are still poorly known [15–18] and many aspects of their biology are still not completely understood. In the last two decades, numerous studies have increased our knowledge on oncaeid taxonomy and systematics, discussing their potential ecological relevance [12,13,62]. …”