1 - Various species reported in the Mediterranean were not taken into account and require confirmation: Acartia (Odontacartia) laxa Dana,1849 (very doubtful form) reported in Malta. Pseudocalanus minutus (Kröyer,1845), form of boreal arctic and subarctic waters of the Atlantic and Pacific oceans, reported by Salah (1971, p.319) in Alexandria. Aetideus mediterraneus Steuer, 1910 described in the Adriatic (Dubrovnik) is regarded as a synonym for Aetideus giesbrechti (Hure et Krsinic,1998, p.46). Calanus finmarchicus reported by Sars (1925, p.369) in Tyrrhenian Sea, by Rose (1929, p.6), puis then in Catalan Sea (Furnestin and Giron-Reguer, 1961; Furnestin and Giron, 1963), as in the Gulf of Lion (Furnestin, 1960), subsequently confirmed as exceptional in the south-western basin (Soenen, 1969). Similarly, and more surprising is report of Calanus propinquus in Malta by Thompson.(1888d, p.139). Gaidius pungens Giesbrecht,1895 erroneously identified in the Mediterranean in Razouls et Durand, 1991. Centropages aucklandicus Krämer,1895, often quoted in the Mediterranean, is only a variant of C. typicus and the form originally described by Krämer would be endemic to New Zealand (in Bradford, 1978). Lucicutia grandis (Giesbrecht,1895) reported in Tyrrhenian Sea (in Kovalev and Shmeleva, 1982) is not retained because of possible confusions.
Labidocera kroyeri (Brady,1883) cited in Malta in Giesbrecht (1892, p. 776) requires confirmation in the Mediterranean. Amallothrix pseudoarcuata (Park,1970) reported in the E Mediterranean would be a synonym of Amallothrix arcuata. Scaphocalanus similis Hure and Scotto di Carlo,1968 and S. subcurtus Park,1970 are regarded as synonymous with S. curtus (Farran,1926). Scolecithricella denticulata Tanaka,1962 is noted by mistake in the Mediterranean in Razouls and Durand (1991, p.76); Scolecithrix dubia Giesbrecht,1892 would be synonymous with Scolecithricella dentata (Giesbrecht,1892). Spinocalanus caudatus Sars,1920 would be synonymous with Spinocalanus oligospinosus Park,1970; S. paraoligospinosus Hure and Scotto di Carlo,1971 and S. neospinosus Grice,1971 are juniors synonyms from the previous one. Mimocalanus heronae Damkaer,1975 was mistakenly reported in West Mediterranean by confusion with Mimocalanus brodskyi Razouls,1974. Pontella inermis Brady,1883, reported in East Mediterranean (in Greze and Shmeleva, 1982) is a doubtful form. Corycaeus obtusus Dana,1849 may be confused with C. catus, C. ovalis et C. pacificus. Similarly, Oncaea obscura Farran,1908; Oncaea neobscura Razouls,1969 and Oncaea paraobscura Shmeleva,1979 were considered by Malt (1982) as juvenile forms unattributable to a particular species.
Scaphocalanus amplius Park,1970 and S. invalidus Hure and Scotto di Carlo,1968 are considered, with doubt, as being synonymous. They were kept in the table.
2 - The distinction between the two species (or subspecies) Eucalanus hyalinus and Eucalanus elongatus is difficult (and most often unspecified) and requires a review of these two forms. Otherwise Goetze & Bradford-Grieve (2005) distinguish Eucalanus spinifer T. Scott,1894 from E. hyalinus, sympatric twin species. The reports of Eucalanus attenuatus (= Pareucalanus attenuatus ) in the Mediterranean and Adriatic are questionable since the presence without doubt of P. sewelli of which it is different from the previous slightly, notably the shape of the head (cf. in Bradford-Grieve, 1994: fig.44: B). P. attenuatus (Dana,1849) is Indo-Pacific and et P. parki (Fleminger,1973) Pacific.
Valdiviella insignis reported to Gibraltar (in Rose, 1933), Banyuls (juvenile form in Razouls, 1972) and Tyrrhenian Sea (as sp . in Vives, 1967), bathypelagic form may have been confused with V. minor Wolfenden,1911 or V. oligarthra Steuer,1904.
Parauchaeta tonsa (Giesbrecht,1895) is difficult to distinguish from P. pseudotonsa (Fontaine,1967) whence the difficulties of ascertaining their geographical distribution. Park (1994, p.322, 326, 328) considers that the first is Indo-Pacific and the second sub-Antarctic and Atlantic. However, Vives (1982, p.291) and Lapernat (2000) report P. tonsa in the Canary region. The authors who identified this species in the Mediterranean were unaware of the description of Fontaine (1967). We did not retain this species, but a doubt remains over its presence in the Atlantic.
Paracalanus pygmaeus reported in the Alboran Sea, in the Ionian Sea and in Cyprus (Kovalev et Shmeleva, 1982) is probably P. denudatus rather than Parvocalanus scotti (East Africa: Namibia-G. of Guinea)
A doubt remains over the possible synonymy between Sapphirina opalina Dana,1849 and Sapphirina darwini Haeckel,1864; both forms being reported in the Mediterranean.
3 - Species requiring confirmation:
Candacia norvegica reported with doubt in the Liguro-Provencal Chenal (in Mazza,1966) is rare, but possible by the Atlantic current action because of its presence in the Ibero-Moroccan area (Vives, 1982).
Centropages calaninus, mainly Indo-Pacific form, present in the Red Sea (in Cleve, 1904) if it is confirmed in the Mediterranean.
Lucicutia lucida Farran,1908, identified from documents of Sars (1925) et de Rose (1933) should be considered as L. pera A. Scott,1909. Lucicutia lucida Farran,1908 identified in the Mediterranean (Algiers, W Central part) and often based on Sars (1924-25) and Rose (1933) is questionable. Pancucci-Papadopoulou & al. (1990) report this species in the Levant Sea. A confusion is possible between this form and Lucicutia pera A. Scott,1909. A doubt remains over the presence or absence of the two species in the Mediterranean.
Lucicutia grandis, identified in the Tyrrhenian Sea (Vaissière & Séguin, 1980, p.23) is however questionable because of the confused synonymy, and it is very difficult to establish the geographical distribution of this species.
Pontellina elegans (Claus,1892) cited in the Adriatic (as Pontella elegans in Giesbrecht & Schmeil, 1898, p.144), unreported since its descriptor.
Scaphocalanus invalidus known in West and East Mediterranean, as in the Adriatic is considered by some as a synonym for S. amplius Park, 1970 by Greze & Shmeleva (1982, p.84)
Scolecithricella profunda and S. abyssalis may be confused, whence uncertain geographical distributions, the two forms appearing sympatric. For Vervoort (1965, p.80) the two species could be synonymous.
Spinocalanus caudatus identified south of Majorca (in Rose, 1933, p.86) and in the Adriatic (in Kovalev & Shmeleva, 1982, p.83) is not retained by Hure & Krsinic (1998). This species has been considered without certainty, as synonymous with S. oligospinosus .
Spinocalanus heterocaudatus Rose, 1937 (female) of the bay of Algiers, is synonymous with S. magnus . The male of S. heterocaudatus later described (Rose, 1942, p.315) has still not been assigned.
According Lehnhofer (1929), followed by many authors, S. auronitens et S. sinuicauda would be a single species with miscellaneous variations (S. pyrosomatis and S. vorax of which). This position is different from Giesbrecht (1892) and some authors.
Similarly S. darwini as variant of S. opalina , and S. gemma as a variation of S. ovatolanceolata. No study of these forms has been considered since the one of Crisafi & Mazza (1966, p.561 and following).
The revision of Clytemnestridae by Huys & Conroy-Dalton (2000) call into question the presence of C. scutellata and C. rostrata (= Goniopsyllus rostratus ) in the Mediterranean. These might have been confused: Goniopsyllus clausi (nov. sp.) and Clytemnestra gracilis (this one confused with C. scutellata ).
4 - Exchanges through the Strait of Gibraltar:
The main exchanges between the temperate and subtropical Atlantic and the Mediterranean is carried out by the surface and deep currents at the threshold of Gibraltar (Lacombe, 1971). The data about pelagic copepods, jointly concerning the Ibero-Moroccan Bay and the Alboran Sea, are due to Giron (1963), Giron-Reguer (1963), Vives (1975), Kovalev and Shmeleva (1982), Greze et al. (1985). The SW Morocco-Portugal Atlantic region has been prospected by Lysholm and Nordgaard (1921), Vives (1970, 1972, 1982). The influence of the Atlantic surface current can be followed by various "biological indicators" (Allain, 1966, Mazza, 1967). Linked to the particular content of salinities and in oxygen, only few forms of copepods seem good "plotters" compared to other pelagic groups such as Chaetognaths, pelagic molluscs and Cladocers. The origin of at least 73% of Mediterranean fauna being Atlantic the choice of these is difficult. Temora longicornis is the most characteristic example which acclimatization is less easy than Temora stylifera. Subeucalanus monachus, Pseudocalanus elongatus, Augaptilus megalurus, Centropages bradyi, C. chierchiae, Pleuromamma xiphias, Anomalocera patersoni, Pontella atlantica and Pontellopsis regalis would constitute other indicators. These last three epipelagic species easily penetrate into the eastern basin. Subeucalanus subtenuis noted by Mazza (1967) as related to the Atlantic current is also noticed off Malta by Lapernat (1999) in depth (2000 m). As Mazza notes (1967) some of above copepods are below the Atlantic water, even under the east intermediate current, to find temperatures more in conformity with their original environment. The presence of perennial species in the west southern basin is in favour of their continuous renewal from the Atlantic, likewise their presence during autumn-winter colder periods (Mazza, 1967, p.329).
5 - Adriatic:
Hure and Krsinic (1998) identify 144 species on the whole of the Adriatic Sea, Hajdëri (1998) in the southern part (Coastal Bari) notes the presence of 93 species.
For the total work done from the beginning in this sea, 293 species are counted, of which 181 Calanoida and 112 species species of other orders. On this total 249 species are common to both basins (154 Calanoida and 95 of other orders); 24 are common only with the western basin (16 Calanoida and 8 of other orders) and 8 only with the east basin (5 Calanoida and 3 of other orders).
6 -Beyond the threshold siculo-Tunisian, the eastern basin has 378 species including 242 Calanoida and 136 of other orders. The two West and East basins have in common 315 species of which 194 Calanoida and 121 of other orders. The Ionian Sea is the least prospected (cf. in Kovalev and Shmeleva, 1982), unless one considers that the south part (the deepest) of the Adriatic must present a common fauna. Vaissière and Séguin (1980) have compared the communities between the Ionian and Tyrrhenian Sea. Apostolopoulou (1972) explores the quantitative distribution of species on the whole of the Aegean Sea. Sioukou-Frangou et al. (1997) have analyzed assemblages of species between Sicily and Cyprus. Kimor and Berdugo (1967), Kimor and Wood (1975) have prospected all Levantine Basin to the west of Crete. La distribution des espèces au nord du basin Levantin et en Mer Egée est connue par les travaux de Pancucci-Papadopoulou et al. The distribution of species in northern Levantine basin and in Aegean Sea is known by the works of Pancucci-Papadopoulou et al. (1992). Data on the Aegean Sea and the Gulf of Saronikos give us as much information on the diversity of species (113 species) for the eastern basin (Siokou-Frangou, 1999). Uysal et al. (2002) have compiled an inventory of species in the N Levantine basin (68 species). Lakkis (1971, 1973, 1976, 1984, 1990) provides an exhaustive list of species of the Lebanese coast (99 species). El-Maghraby (1965) lists 74 species on the coasts of Egypt.
Diverse authors have suggested a transport East Basin to the West Basin by the intermediate current. Monacilla typica was considered as an indicator of this mechanism (Mazza, 1967; Casanova, 1970), however, the general distribution of this species in the Atlantic is not in favor of this thesis.
7 - The "Lessepsian" process:
Por (1969, 1971) creates the term "Lessepsian migration" in the case of species of the Red Sea and/or the west Indo-Pacific going through the Suez Canal to the eastern Mediterranean, a phenomenon that appears almost essentially unidirectional, resulting digging of the canal in 1869.
For this author, only organisms able to survive for a relatively long period and give several generations can meet the conditions of "lessepsian species", with the exception of vagile forms like crustaceans and fish, the latter having even reached the Tunisian coast (Ben Souissi & al., 2004) and the north-east coast of Sicily (Catalano & Zava, 1993).
None comprehensive survey on pelagic copepods has been done in the canal and lakes it uses, except data of Gurney (1927), the expedition of Thompson and Scott (1903) and more recent data of El-Serehy & al. (2001).
As rightly underlined by Por (1978, p.87), the criteria allowing to affirm that the migration of species from the Red Sea to the Mediterranean, and vice versa ("Anti-Lessepsian migration") require a good knowledge of biogeography these forms.
Unfortunately, in the case of pelagic copepods, data on the eastern Mediterranean are relatively recent (coasts of Egypt, Israel, Lebanon, Turkey and Aegean Sea), and even rarer in the case of the Red Sea. With the exception of works of Weikert (1982 a),
Weikert & Koppelmann (1993), Weikert & Trinkaus (1990), Weikert & al. (2001); and Böttger-Schnack (1988, 1990 (91), 1990 a, 1990 b, 1991, 1992, 1994, 1995, 1997, 1999-2003, 2005).
Many works are devoted to the role of diet on the life of copepods, but too little about the joint action of salt and thermal factors (limits of survival, reproduction and growth). These eco-physiological barriers take in the case of this type of dispersion essential importance that is sorely lacking, given the high salinity and temperature changes along the 170 km of the Canal. Katona (1969) on Eurytemora affinis and E. herdmani, as well as Bernard (1970) on Temora stylifera, have shown the limits of tolerance of these forms.
Knowledge of west Indo-Pacific species has considerably increased since the first test of biogeographic synthesis realized by Sewell (1948).
Data for each of 2587 identified species so far in all seas can nevertheless assume, for some of them, such migration through the Suez Canal, what Por defines (1978, p.91) as high probability ("HPLM").
Representatives of various taxa meet the criteria for such migration, at which following pelagic copepods can be added: Euchaeta concinna (Casanova, 1973); Calanopia elliptica, C. media (Berdugo, 1968), C. minor, Labidocera madurae, L. pavo, Acartia centrura, A. fossae (Lakkis, 1976), Candacia catula, Centropages calaninus, C. elongatus, Acrocalanus monachus, Parvocalanus elegans, P. latus. A doubt remains about Euchaeta paracuta.
Conversely, Centropages ponticus (indigenous to the East Mediterranean basin and the Black Sea) would be an example of an "antilesseptian" form that had penetrated into the Red Sea, transfer which appears more difficult to realize for Mediterranean species because of hydrologic conditions encountered.