This study is the first attempt aiming to assess the composition and number of free-living marine nematode species on the coasts of the Marches region, Italy. A high number of putative species of nematodes were recognized (84), these belonging to 52 genera in 22 families. Fifty-one taxa have been identified to the species level increasing the number of known nematode species for the Adriatic Sea from 283 to 310 and for the Mediterranean Sea from 700 to 723. The highest diversity and abundance were registered for the nematode families typically of intertidal zones characterized as medium-fine sands. The majority of the species found in the present study are known to occur in the North European coasts or the North Atlantic Sea, the best known regions for nematode distribution. Inferences on the biogeography of marine nematodes are preliminary since most Biodiversity literature concerning the Mediterranean of the basin is very out of date. Considering the great importance of nematodes in the assessment of ecosystem health conditions, an intensification of sampling efforts should be pursued in other regions in order to improve our current knowledge of the distribution pattern of marine nematode species as well as clarify their biogeographical patterns. 1. Introduction Marine nematodes are the most abundant metazoans in marine sediments, reaching densities as high as 20 million individuals per square meter [1]. They generally are the dominant component of the meiofauna in any aquatic habitat, often one order of magnitude higher than any other major taxon [1]. Estimates of global nematode species diversity have significantly varied over the past 15 years, but with a growing agreement suggesting about one million species [2, 3]. Their great importance in marine ecology as bioindicators is well recognized [4, 5]. The study of nematode communities offers several advantages for assessing the quality of freshwater, marine, and terrestrial ecosystems. These organisms show great diversity and abundance which make easier their sampling; they present different trophic groups as well as being intimately related with their environment, the sediment. Therefore, they can provide important information on the ecological state of a given area once they are exposed to pollutants. Furthermore, they have been recently proposed within the Water Framework Directive (WFD, Directive 2000/60/EC) [6] as a tool for evaluating the ecological quality status of marine vulnerable ecosystems. The taxonomy of marine nematodes is known to be very difficult (see for review [7]), in part due
References
[1]
H. M. Platt and R. M. Warwick, “Chapter 10, The significance of free-living nematodes to the littoral ecosystem,” in The Shore Environment—2. Ecosystems, J. H. Price and D. E. G. Irvine, Eds., pp. 729–759, London, UK, 1980.
[2]
P. J. D. Lambshead, in Nematology: Advances and Perspectives—Vol 1: Nematode Morphology, Physiology and Ecology, Z. X. Chen, S. Y. Chen, and D. W. Dickson, Eds., Marine Nematode Biodiversity, pp. 436–467, CABI Publishing, Wallingford, UK, 2004.
[3]
I. Andrássy, “A short census of free-living nematodes,” Fundamental and Applied Nematologie, vol. 15, pp. 187–188, 1992.
[4]
C. Heip, M. Vincx, and G. Vranken, “The ecology of marine nematodes,” Oceanography and Marine Biology an Annual Review, vol. 23, pp. 399–489, 1985.
[5]
O. Giere, Meiobenthology: The Microscopic Motile Fauna of Aquatic Sediments, Springer, Berlin, Germany, 2nd edition, 2009.
[6]
M. Moreno, F. Semprucci, L. Vezzulli, M. Balsamo, M. Fabiano, and G. Albertelli, “The use of nematodes in assessing ecological quality status in the Mediterranean coastal ecosystems,” Ecological Indicators, vol. 11, no. 2, pp. 328–336, 2011.
[7]
E. Abebe, W. Decraemer, and P. De Ley, “Global diversity of nematodes (Nematoda) in freshwater,” Hydrobiologia, vol. 595, no. 1, pp. 67–78, 2008.
[8]
M. Balsamo, G. Albertelli, V. U. Ceccherelli et al., “Meiofauna of the adriatic sea: present knowledge and future perspectives,” Chemistry and Ecology, vol. 26, no. 1, pp. 45–63, 2010.
[9]
F. Semprucci, R. Sandulli, and S. De Zio-Grimaldi, “Adenophorea, nematodi marini,” in Checklist della Flora e della Fauna dei Mari Italiani, G. Relini, Ed., vol. 15 of Biologia Marina Mediterranea, pp. 184–209, 2008.
[10]
C. Allgén, “Die freilebenden Nematoden des Mittelmeeres,” Zoologische Jahrbücher, vol. 76, pp. 1–102, 1942.
[11]
J. H. Schuurmans-Stekhoven, “The free-living marine nemas of the Mediterranean—I. The Bay of Villefranche,” Institut Royal Des Sciences Naturelles De Belgique Memoires, vol. 37, pp. 1–220, 1950.
[12]
S. A. Gerlach, “Die Nematodenbesiedlung des Sandstrandes und des Küstengrundwassers an der italienischen Küste—I. Systematischer Teil,” Archivio Zoologico Italiano, vol. 37, pp. 517–640, 1953.
[13]
A. Travizi and J. Vidakovi？, “Nematofauna in the Adriatic Sea: review and check-list of free-living nematode species,” Helgolander Meeresuntersuchungen, vol. 51, no. 4, pp. 503–519, 1997.
[14]
V. U. Ceccherelli and F. Cevidalli, “Osservazioni preliminari sulla bionomia dei popolamenti meiobentonici della Sacca di Scardovari (Delta del Po), con particolare riferimento ai Nematodi ed ai Copepodi,” Quaderni del laboratorio di Tecnologia della Pesca. Atti del Congresso S.I.B.M., 1981.
[15]
A. Guerrini, M. A. Colangelo, and V. U. Ceccherelli, “Recolonization patterns of meiobenthic communities in brackish vegetated and unvegetated habitats after induced hypoxia/anoxia,” Hydrobiologia, vol. 375-376, pp. 73–87, 1998.
[16]
S. De Zio, “Distribuzione dei nematodi in spiagge pugliesi,” Bollettino Di Zoologia, vol. 31, no. 2, pp. 907–920, 1964.
[17]
S. De Zio, “Nematodi marini del litorale pugliese,” Bollettino di Zoologia, vol. 33, p. 182, 1966.
[18]
S. Grimaldi-De Zio, “Il popolamento di Nematodi di una spiaggia pugliese in rapporto al ritmo di marea,” Bollettino di Zoologia, vol. 34, p. 126, 1967.
[19]
S. Grimaldi-De Zio, “Una nuova specie di nematodi Comesomatidae: dorylaimopsis mediterraneus,” Bollettino di Zoologia, vol. 35, pp. 137–141, 1968.
[20]
S. Grimaldi-De Zio, “Confronto fra Nematodi del fango coralligeno di piattaforma e una comunità del fango dello stesso distretto adriatico,” Bollettino di Zoologia, vol. 35, p. 347, 1968.
[21]
R. Sandulli, S. De Zio-Grimaldi, M. Gallo D’Addabbo, L. Caló, and E. Bressan, “Aspetti della biodiversità della meiofauna lungo il litorale pugliese,” Biologia Marina Mediterranea, vol. 9, no. 1, pp. 484–493, 2001.
[22]
R. Sandulli, C. de Leonardis, and J. Vanaverbeke, “Meiobenthic communities in the shallow subtidal of three Italian Marine Protected Areas,” Italian Journal of Zoology, vol. 77, no. 2, pp. 186–196, 2010.
[23]
J. Vidakovi？, A. Travizi, and G. Boucher, “Two new species of the genus Metacyatholaimus (Nematoda, Cyatholaimidae) from the Adriatic Sea with a key to the species,” Cahiers de Biologie Marine, vol. 44, no. 2, pp. 111–120, 2003.
[24]
C. de Leonardis, R. Sandulli, J. Vanaverbeke, M. Vincx, and S. De Zio, “Meiofauna and nematode diversity in some Mediterranean subtidal areas of the Adriatic and Ionian Sea,” Scientia Marina, vol. 72, no. 1, pp. 5–13, 2008.
[25]
A. Travizi, “The nematode fauna of the northern Adriatic offshore sediments: community structure and biodiversity,” Acta Adriatica, vol. 51, no. 2, pp. 169–180, 2010.
[26]
F. Semprucci, P. Boi, A. Manti et al., “Benthic communities along a littoral of the Central Adriatic Sea (Italy),” Helgoland Marine Research, vol. 64, no. 2, pp. 101–115, 2010.
[27]
P. Franco, L. Jeftic, P. Malanotte-Rizzoli, A. Michelato, and M. Orlic, “Descriptive model of the northern Adriatic,” Oceanologica Acta, vol. 5, pp. 379–389, 1982.
[28]
M. Zavatarelli, J. W. Baretta, J. G. Baretta-Bekker, and N. Pinardi, “The dynamics of the Adriatic Sea ecosystem. An idealized model study,” Deep-Sea Research Part I, vol. 47, no. 5, pp. 937–970, 2000.
[29]
J. B. Buchanan, “Sediment analysis,” in Methods for the Study of Marine Benthos, N. A. Holme and A. D. McIntyre, Eds., pp. 41–65, Blackwell Scientific Publications, Oxford, UK, 1984.
[30]
J. B. Buchanan, “Measurement of the physical and chemical environment,” in Methods for the Study of Marine Benthos, N. A. Holme and A. D. McIntyre, Eds., pp. 30–52, Blackwell Scientific Publications, Oxford, UK, 1971.
[31]
O. Pfannkuche and H. Thiel, “Sample processing,” in Introduction to the Study of Meiofauna, R. P. Higgins and H. Thiel, Eds., pp. 134–145, Smithsonian Institute, Washington, DC, USA, 1988.
[32]
H. M. Platt and R. M. Warwick, “Free-living marine nematodes—part I. British Enoplids,” in Synopses of the British Fauna, vol. 28, Cambridge University Press, Cambridge, UK, 1983.
[33]
H. M. Platt and R. M. Warwick, “Free-living marine nematodes—part II. British Chromadorids,” in Synopses of the British Fauna, vol. 38, Brill, Leiden, Holland, 1988.
[34]
R. M. Warwick, H. M. Platt, and P. J. Somerfield, “Free-living marine nematodes—part III. British monhysterids,” in Synopses of the British Fauna, vol. 53, Field Studies Council, Shrewsbury, UK, 1998.
[35]
T. Deprez, E. Vanden Berghe, and M. Vincx, World Wide Web electronic publication, 2005, http://www.nemys.ugent.be.
[36]
S. A. Gerlach and F. Riemann, The Bremerhaven Checklist of Aquatic Nematodes. A catalogue of Nematoda Adenophorea excluding the Dorylaimida. Ver？ffentlichungen des Instituts für Meeresforschung in Bremerhaven, 4 Part I and Part II,1973-1974.
[37]
C. N. Bianchi, “Proposta di suddivisione dei mari italiani in settori biogeografici,” Notiziario SIBM, vol. 46, pp. 57–59, 2004.
[38]
World Register of Marine Species (WoRMS), 2009, http://www.marinespecies.org.
[39]
M. Steyaert, N. Garner, D. Van Gansbeke, and M. Vincx, “Nematode communities from the North Sea: environmental controls on species diversity and vertical distribution within the sediment,” Journal of the Marine Biological Association of the United Kingdom, vol. 79, no. 2, pp. 253–264, 1999.
[40]
F. Semprucci, P. Colantoni, G. Baldelli, M. Rocchi, and M. Balsamo, “The distribution of meiofauna on back-reef sandy platforms in the Maldives (Indian Ocean),” Marine Ecology, vol. 31, no. 4, pp. 592–607, 2010.
[41]
M. Raes, W. Decraemer, and A. Vanreusel, “Walking with worms: coral-associated epifaunal nematodes,” Journal of Biogeography, vol. 35, no. 12, pp. 2207–2222, 2008.
[42]
T. Gheskiere, M. Vincx, B. Urban-Malinga, C. Rossano, F. Scapini, and S. Degraer, “Nematodes from wave-dominated sandy beaches: diversity, zonation patterns and testing of the isocommunities concept,” Estuarine, Coastal and Shelf Science, vol. 62, no. 1-2, pp. 365–375, 2005.
[43]
F. Semprucci, P. Colantoni, C. Sbrocca, G. Baldelli, M. Rocchi, and M. Balsamo, “Meiofauna in sandy back-reef platforms differently exposed to the monsoons in the Maldives (Indian Ocean),” Journal of Marine Systems, vol. 87, no. 3-4, pp. 208–215, 2011.
[44]
M. Moreno, G. Albertelli, and M. Fabiano, “Nematode response to metal, PAHs and organic enrichment in tourist marinas of the mediterranean sea,” Marine Pollution Bulletin, vol. 58, no. 8, pp. 1192–1201, 2009.
[45]
P. Jensen, “Ecology of benthic and epiphytic nematodes in brackish waters,” Hydrobiologia, vol. 108, no. 3, pp. 201–217, 1984.
[46]
C. Heip, R. Huys, M. Vincx et al., “Composition, distribution, biomass and production of North Sea meiofauna,” Netherlands Journal of Sea Research, vol. 26, no. 2–4, pp. 333–342, 1990.
[47]
A. Vanreusel, “Ecology of free-living marine nematodes in the Voordelta (Southern Bight of the North Sea)—II. Habitat preferences of the dominant species,” Nematologica, vol. 37, no. 3, pp. 343–359, 1991.
[48]
M. Schratzberger, K. Warr, and S. I. Rogers, “Patterns of nematode populations in the southwestern North Sea and their link to other components of the benthic fauna,” Journal of Sea Research, vol. 55, no. 2, pp. 113–127, 2006.
[49]
T. Bongers, R. Alkemade, and G. W. Yeates, “Interpretation of disturbance-induced maturity decrease in marine nematode assemblages by means of the Maturity Index,” Marine Ecology Progress Series, vol. 76, no. 2, pp. 135–142, 1991.
[50]
L. J. Jacobs and J. Heyns, “Notes brèves. An ecological strategy in the genus Monhystera—an hypothesis,” Revue de Nématologie, vol. 13, pp. 109–111, 1990.
[51]
F. Thiermann, B. Vismann, and O. Giere, “Sulphide tolerance of the marine nematode Oncholaimus campylocercoides—a result of internal sulphur formation?” Marine Ecology Progress Series, vol. 193, pp. 251–259, 2000.
[52]
M. Curini-Galletti, “Platyhelminthes. La checklist della fauna marina Italiana,” in Checklist della Flora e della Fauna dei Mari Italiani, G. Relini, Ed., vol. 15 of Biologia Marina Mediterranea, pp. 110–124, 2008.
[53]
M. J. Costello, P. Bouchet, C. S. Emblow, and A. Legakis, “European marine biodiversity inventory and taxonomic resources: state of the art and gaps in knowledge,” Marine Ecology Progress Series, vol. 316, pp. 257–268, 2006.
[54]
D. Fontaneto and J. Hortal, “Do microorganisms have biogeography?” The International Biogeography Society, vol. 6, no. 1, pp. 3–7, 2008.
[55]
C. A. Kellogg and D. W. Griffin, “Aerobiology and the global transport of desert dust,” Trends in Ecology and Evolution, vol. 21, no. 11, pp. 638–644, 2006.
[56]
O. Giere edition, Meiobenthology, The Microscopic Motile Fauna of Aquatic Sediments, Springer, Berlin, Germany, 1st edition, 1993.
