Page 8 - MS_Egadi

Author's personal copy

C. Brugnano et al. / Journal of Marine Systems 81 (2010) 312–322 319

Table 3 Spanish neritic zones (Estrada et al., 1985) to Sicily Channel and,
Mean abundance vertical distribution (ind. m−3) of the most representative copepod eastward in the southern area of the Aegean Sea (Kiortsis, 1974) and
the Central Levantine Sea (Siokou-Frangou et al., 1997) and
species for each depth interval (A= 0–20 m; A*= 20–40 m; B = 40–60 m; C = 60–80 m; completely absent, in the same season, in the Northeastern Aegean
D = 80–100 m; E = 100–200 m; F = 200–300 m; G N 300 m). Sea (Isari et al., 2006). However, A. negligens primarily inhabits open
waters of the entire Mediterranean Sea, both in the Western (Vives,
Copepod taxa Depth intervals 1967) and Eastern (Siokou-Frangou et al., 1997) basins (Razouls et al.,
2005–2009). The copepod community structure of Mediterranean
G F E D C B A* A coastal, neritic and pelagic surface waters is constituted by few
perennial species of the genera Acartia, Paracalanus, Temora,
Acartia adriatica 0.00 0.00 0.00 0.00 0.00 0.00 0.09 0.71 Centropages, Clausocalanus, and Oithona, whose species follow one
Acartia clausi 0.00 0.00 0.00 0.00 0.05 0.10 0.77 1.09 another during the year, characterizing with their dominance,
Acartia copepodites 0.01 0.00 0.00 0.07 0.53 0.14 3.60 8.66 different seasonal periods (Scotto di Carlo et al., 1985; Fernàndez de
Acartia danae 0.00 0.00 0.00 0.00 0.00 0.17 0.04 0.00 Puelles et al., 2003, 2004). Since most copepods consist of species
Acartia negligens 0.00 0.00 0.02 0.00 0.64 0.12 1.73 6.48 generally found in the whole Mediterranean Sea, it is difficult to find
Calocalanus copepodites 0.00 0.00 0.01 0.02 0.26 0.64 2.32 1.45 species with a clearly defined region distribution (Gaudy, 1985), with
Calocalanus pavo 0.00 0.00 0.00 0.00 0.20 0.89 2.00 0.92 exception of particular areas, such as the northern Adriatic Sea, where
Centropages copepodites 0.08 0.02 0.00 0.00 6.62 8.25 3.50 2.13 Pseudocalanus elongatus represents a relict population of Atlantic
Centropages typicus 0.16 0.00 0.03 0.00 2.68 3.64 1.86 1.29 origin not occurring in the most part of Mediterranean regions (Sidoti
Centropages violaceus 0.00 0.00 0.01 0.00 0.00 0.05 0.21 0.44 et al., 2001).
Chiridius copepodites 0.04 0.01 0.01 0.00 0.00 0.00 0.00 0.00
Clausocalanus arcuicornis 0.02 0.01 0.08 0.28 1.24 2.31 1.43 0.12 In late summer and early autumn, C. furcatus, A. negligens, T.
Clausocalanus copepodites 0.12 0.09 0.53 2.27 5.98 12.08 18.05 13.24 stylifera and O. plumifera could be considered the key species of the
Clausocalanus furcatus 0.08 0.01 0.02 0.02 1.34 1.72 8.72 10.24 Egadi Island Archipelago surface water copepod assemblages. The
Clausocalanus jobei 0.02 0.00 0.46 0.65 1.06 2.38 1.17 0.77 most abundant copepod genera (such as, Clausocalanus and Oithona),
Clausocalanus paululus 0.00 0.00 0.23 0.09 0.03 0.02 0.00 0.00 including small size organisms, characterize the oligotrophic areas of
Clausocalanus pergens 0.00 0.08 0.04 0.10 0.06 0.31 0.08 0.01 Eastern Mediterranean Sea, both in autumn and spring (Siokou-
Corycaeus clausi 0.00 0.00 0.00 0.16 0.27 0.43 0.62 0.09 Frangou et al., 1997; Mazzocchi et al., 2003) and play an important
Corycaeus copepodites 0.06 0.03 0.55 2.74 4.66 4.42 4.23 2.40 role in pelagic systems (Dam et al., 1993a; Hopcroft et al., 1998; Calbet
Corycaeus flaccus 0.00 0.00 0.00 0.00 0.01 0.05 0.19 0.12 and Landry, 1999).
Corycaeus furcifer 0.16 0.19 1.54 3.92 1.94 1.13 0.39 0.70
Corycaeus giesbrechti 0.02 0.00 0.00 0.00 0.32 0.08 0.42 1.92 The second cluster of samples is more heterogeneous and includes
Corycaeus latus 0.02 0.00 0.00 0.04 0.13 0.35 0.94 1.54 mainly neritic and pelagic subsurface waters, between 40 and 80 m
Corycaeus typicus 0.06 0.05 0.35 0.73 0.68 1.21 1.05 0.36 depth, below the thermocline layer, and, in most cases, coinciding
Ctenocalanus copepodites 0.00 0.02 0.62 3.47 8.65 8.94 0.38 0.09 with DCM layer, even though depth of chlorophyll maximum is
Ctenocalanus vanus 0.02 0.05 0.83 1.89 3.54 2.51 0.40 0.01 variable in relation to the hydrographical character of the stations.
Diaixis copepodites 0.00 0.00 0.06 0.07 0.19 0.04 0.00 0.00 This cluster of samples exhibits simultaneous presence of subsurface
Diaixis pigmoea 0.00 0.00 0.02 0.09 0.14 0.01 0.11 0.00 neritic (N. minor and C. typicus) and epipelagic, weak diel migrant
Eucalanus copepodites 0.77 0.18 0.10 0.18 0.21 0.22 0.26 0.02 (C. pavo, C. arcuicornis, C. vanus and Corycaeus typicus) copepod species
Eucalanus crassus 0.04 0.01 0.00 0.00 0.02 0.05 0.00 0.00 (Scotto di Carlo et al., 1984); the overlapping of this species can occur in
Haloptilus copepodites 0.00 0.07 1.26 0.62 0.81 0.18 0.06 0.01 areas characterized by a narrow continental shelf (Soenen, 1969; Calbet
Haloptilus longicornis 0.02 0.08 0.61 0.33 0.54 0.15 0.07 0.02 et al., 2001). Such a feature can be found in the neritic area among the
Heterorhabdus copepodites 0.00 0.01 0.09 0.39 0.84 0.42 0.14 0.00 islands. This area shows the highest values of Shannon–Wiener
Heterorhabdus papilliger 0.02 0.03 0.14 0.30 0.56 0.38 0.06 0.00 diversity index, coincident with the chlorophyll maximum. This could
Isias clavipes 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.43 be explained by the fact that an important part of the ciliate
Isias copepodites 0.00 0.00 0.00 0.00 0.09 0.00 0.01 2.41 community, one of the main copepod food items, is located at the
Lubbockia copepodites 0.00 0.00 0.05 0.00 0.00 0.02 0.09 0.02 DCM depth (Dolan and Marrasè, 1995; Perez et al., 2000). This can
Lubbockia squillimana 0.02 0.00 0.01 0.00 0.06 0.03 0.03 0.00 facilitate the coexistence of herbivorous, carnivores and omnivorous
Lucicutia copepodites 0.02 0.20 1.06 3.91 5.01 1.36 0.51 0.06 copepod species.
Lucicutia flavicornis 0.06 0.26 0.95 3.55 2.75 0.79 0.29 0.00
Lucicutia longicornis 0.00 0.01 0.08 0.48 0.12 0.05 0.01 0.00 In intermediate and deeper waters of the study area (the third and
Mesocalanus tenuicornis 0.04 0.00 0.14 0.24 0.71 0.15 0.04 0.00 fourth clusters of samples), copepod assemblages are mostly
Nannocalanus minor 0.33 0.00 0.08 0.19 1.49 2.70 3.45 1.13 composed by midwater species (C. furcifer, L. flavicornis, P. gracilis,
Neocalanus gracilis 0.02 0.03 0.04 0.02 0.33 0.11 0.16 0.06 O. mediterranea, H. longicornis, O. atlantica, O. conifera, H. papilliger and
Oithona plumifera 0.00 0.07 1.06 0.45 1.31 1.41 2.49 7.59 P. abdominalis) the same that, more or less, characterizes the
Oithona copepodites 0.02 0.06 1.90 2.79 4.81 5.24 14.13 30.13 mesopelagic layers between 100 and 500 m depth of the Western
Oithona atlantica 0.00 0.00 0.00 0.00 0.09 0.89 1.80 0.28 Mediterranean Sea (Hure and Scotto di Carlo, 1968; Scotto di Carlo et
Oncaea conifera 0.08 0.08 0.14 0.39 0.71 0.84 0.20 0.00 al., 1984). C. furcifer and H. papilliger, and O. conifera are weak migrant
Oncaea copepodites 0.25 0.23 0.41 0.86 3.05 2.00 0.59 0.08 species, L. flavicornis and O. mediterranea present a wide vertical
Oncaea mediterranea 0.17 0.06 0.37 1.09 1.08 0.61 0.15 0.08 distribution, H. longicornis is a non-migrant species (Scotto di Carlo et
Pleuromamma abdominalis 0.08 0.18 0.20 0.01 0.16 0.27 0.13 0.00 al., 1984), and P. gracilis and P. abdominalis are strong migrant species,
Pleuromamma copepodites 0.61 1.79 7.87 12.03 12.12 4.95 0.80 0.03 well documented by Andersen et al. (2001, 2004).
Pleuromamma gracilis 0.14 0.60 1.43 1.18 1.99 0.82 0.35 0.03
Scaphocalanus copepodites 0.04 0.02 0.14 0.46 0.40 0.08 0.00 0.00 According to Vinogradov (1970), in tropical and subtropical
Scaphocalanus curtus 0.04 0.01 0.09 0.66 0.60 0.19 0.03 0.00 oligotrophic waters, like the Mediterranean Sea, the communities
Scolecithricella copepodites 0.06 0.08 0.24 0.51 0.47 0.20 0.05 0.02 are characterized by sharp vertical stratification. In the pelagic system,
Scolecithricella dentata 0.12 0.09 0.08 0.26 0.38 0.07 0.00 0.00 the vertical distribution pattern for copepod species is mainly
Temora copepodites 0.29 0.06 0.34 0.11 12.07 13.18 35.45 42.44 differentiated according to the depth, which is considered as the
Temora stylifera 0.18 0.02 0.05 0.03 0.60 1.11 2.12 6.00 primary habitat dimension (Cummings, 1983). In fact, this factor
influences vertical distribution patterns of environmental parameters,
(Scotto di Carlo et al., 1984, 1985; Estrada et al., 1985; Gaudy, 1985;
Siokou-Frangou et al., 1997), even if their relative abundances were
different. For example, A. negligens was found among the most
representative species in Tyrrhenian Sea (Vives, 1967) and in the
Egadi Island area (our data), whereas it was not ranked among
abundant species from coastal waters of the Western Mediterranean
(Scotto di Carlo et al., 1984; Mazzocchi and Ribera d'Alcalà, 1995;
Champalbert, 1996; Calbet et al., 2001; Fernàndez de Puelles et al.,
2003). Furthermore, this species was found with low abundance from