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SAP-BIO-Lebanon National Report Page 33 of 95
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Decapoda (pelagic)
Of the 189 species reported by Holthuis and Gottlieb (1958), 106 have been identified in Lebanon (Lakkis
and Zeidane, 1988b, 1988c): Macrura Natantia (50), Macrura Reptantia (6), Anomura (15), Brachyura
(37).
Decapoda larvae contribute 3% of the total zooplankton mass of the Lebanese waters. The largest number
of species (66) is reported in July. The most common species include Lucifer typus, Calcinus ornatus,
Diogenes pugilator, Catapaguroides timidus, Upogebia deltaura, Callianassa subterranea, Macropippus
spp., Neptunus pelagicus, Pilumnus hirtellus et Acanthonyx lunulatus.
Cirrhipedia (Pelagic): The Nauplii and the Cypris constitute an important part of the Lebanese
méroplancton (4.5%). These larvae belong to species of the following genera Chtamalus, Balanus, Lepas
anatifera.
Miscellaneous planktonic larvae: Planktonic larvae constitute between 10-25% of the zooplankton
biomass. Other than the crustaceans and the mollusks the following larval groups are noted: Nauplii of
Copepods 50% , Mollusks (Véligères) 15%, Annelids (Trochophores) 13%, Decapods (Zoea, Mysis) 8%
, Eggs and fish larvae 7%, Echinoderms (Plutei) 5% , and Miscellaneous 2%
Mollusca (Pelagic): Thecosomes and Gymnosomes spread over 5 families, 16 genera and 32 species are
reported in Lebanon. Examples of these species include Creseis virgula, Limacina inflata, Clio polita,
Cavolina sp., Limacina trochiformis,Firola coronata, F. desmaresti.
Thaliacea (Pelagic): The Thaliacea which include 3 subclasses, the pyrosomes (P.atlanticum), salpides (
Thalia democratica, T. orientalis et Salpa fusiformis), and doliolides (Doliolum denticulatum, Doliolina
mülleri et Dolioletta gegenbauri.) are all represented in Lebanese waters.
Appendicularia: They constitute 5% of the Lebanese zooplankton biomass. Of the approximately fifty
species identified, 15 belonging to 5 genra inhabit the Lebanese waters (Lakkis, 1971; Lakkis et Zeidane,
1985): Oikopleura (7 species), Fritillaria (4), Megalocercus (2) and Appendicularia (1 espèce). The most
important species in Lebanon are: Oikopleura longicauda (constituting 85% of the total populations)
followed by O. dioica, O. cophocerca, O. fusiformis and Fritillaria borealis.
L'ichtyoplankton: Local researchers indicate a high species richness whereby 84 egg and larval species
belonging to 52 families have been identified (Lakkis et Zeidane, 1993a; Zeidane et Lakkis, 1995).
Average annual density based on a 10 year study indicated a value of 140 eggs/100m3 and 40 larvae/100
m3.
Table 8. Necton (Lakkis, S. et al., 1996)
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Prepared By M. Nader & S. Talhouk June, 2002