RICERCA ITALIANA     

Integrated approach to the identification of problematic taxa of the marine meiofauna: drafting of volumes of the series "Fauna d'Italia" and development and evaluation of methods of DNA-barcoding in Gastrotrichs, Proseriates and Rotifers

Università degli Studi di Sassari

Abstract

Marine meiofauna is a compartment of the marine biota, of particular interest for its high diversity, at all the hierarchic levels considered. Biological traits of meiobenthic organisms (such as their high specific diversity, sedentary habits, absence of larval stages, short generation times) make them ideal candidates as biological indicators for monitoring marine environmental health. However, to date, this abundant and ubiquitous assemblage of invertebrates has been largely neglected in applied sampling programmes. Disadvantages which hinder their utilisation include their small size, which requires specific competences in the handling of samples, and, eminently, the lack of supports to identification specifically addressed to non-experts taxonomists. Present project therefore aims to provide tools to facilitate the study of three groups of meiofaunal organisms, whose identification at the species level is particularly problematic, both in the grounds of traditional taxonomy and in the development of a DNA-based approach.
1) drafting of volumes of the series “Fauna d’Italia” dedicated to Gastrotricha, Platyhelminthes Proseriata and Rotifera.
Research performed under the sponsorship of the PRIN-2004 project “Contribution of meiofauna to the marine biodiversity of the italian coasts” led to the gathering of a wealth of data on the composition and distribution of the three taxa along the coasts of Italy and in general of the Mediterranean. At present, however >>>

Principal Investigator

Marco Curini Galletti Università degli Studi di SASSARI

Research Objectives

In an era marked by phenomena of global change, the problem of the reduction of biodiversity and of the measures to tackle this threat represent an important challenge for the biological research. Sound taxonomy underpins almost all study in the environmental field. Despite this, there is currently a serious crisis in taxonomic expertise throughout the scientific community, resulting in the neglect of many highly diverse groups of organisms from ecological research. This problem is particularly acute for the taxa belonging to marine meiofauna. Biological traits of the organisms belonging to meiofauna (such as their sedentarity of adults and the absence of larval stages, high specific diversity, very short generation times) make them ideal biological indicators for investigations in the field of environmental monitoring, but their use has been so far marginal.
The project aims to contribute to the resolution of the "taxonomic impediment" present in groups of meiofauna by providing tools to facilitate identification at the species level of problematic taxa, both in the grounds of traditional taxonomy and in the development of a DNA-based approach.
1) the most basic requirement for people studying and working on aspects of biodiversity is the availability of species identification guides on a geographical basis. These are important not only as a resource for identification and stimulus for the study of little known groups, but also because they >>>

First Results

The research will provide, in the first place, traditional and molecular taxonomic tools useful to facilitate the study of meiofaunal groups, whose identification at the species level is seen as particularly problematical. The resolution of the taxonomic impediment will allow a wider use of these taxa whose potential for an advantageous use in the bio-environmental fields appear extremely relevant , especially in an era marked by phenomena of global changes.
More specifically, the research will allow the drafting (in English) of three volumes of the series “Fauna d’Italia” devoted respectively to Proseriata, Gastrotricha and Rotifera, which will include a total of about 500 species found throughout the Mediterranean. Since currently there are not available worldwide monographs on these groups, the three volumes will constitute a valuable, lasting legacy which can facilitate, in the future, the work of new generations of Italian and foreign scholars. The outcome of the project will benefit not only taxonomists but also the many marine ecologists engaged in investigations of the environmental impact. With regard to the latter point, our model reference are the monographs of the series “Synopses of the British Fauna” devoted to the marine nematodes (Vol. 28, 38 and 53), largely used by ecologists throughout the world, notwithstanding the fauna treated is markedly regional.
This unique opportunity will also enable the RRUU to carry out sampling campaigns focussed >>>

Timescale

24 months

National and international background

The unprecedented rate at which human activities around the world are causing widespread habitat degradation and species extinction are alarming (World Conservation Monitoring Centre, 1992). That extinctions are occurring before even half of the world’s species have been described (May 1992; Wilson 2003) is evidence of a global taxonomic crisis. The problem is particularly serious in marine environment, where the knowledge of biodiversity is still far from being adequate - even for comparatively known macrofaunal taxa (Bouchet et al., 2002) - and based upon unrepresentative data, which make assessment of its modifications during time, impossible (Sala, 2002).Present level of knowledge is even poorer for meiofaunal, “inconspicuous” organisms. The term meiofauna refers to the assemblage of marine benthic metazoa intermediate in size between macrofauna and microfauna. By definition, it includes organisms passing through a 500 µm sieve and retained on a 42 µm sieve. This size range separates a discrete group of organisms, whose morphology, physiology and life history characteristics have evolved to exploit the interstitial matrix of marine soft sediments. Meiofauna is phyletically more diverse that any other component of the marine biota, at any taxonomic level considered. In fact, all of the most recently described phyla belong to meiofauna: Gnathostomulida (1956), Loricifera (1983) and Cycliophora (1995) (Ax, 1956; Kristensen, 1983; Funch & Kristensen, 1995) >>>