El-Shabrawy, G.M. & G. Belmonte. (2004). Abundance and affirmation of Paracartia latisetosa (Copepoda, Calanoida) in the inland Lake Qarun (Egypt). Thalassia Salentina. 27:151-160.

85772

El-Shabrawy, G.M. & G. Belmonte

2004

27:151-160.

Publication

Available for editors   [request]

The Acartiidae copepod Paracartia latisetosa (Kriczaguin, 1873) has been found in many sites of the Ponto Mediterranean Province (BELMONTE, 1992; BELMONTE e POTENZA, 2001) where it prefers confined environments independently from the salinity (from 10 ‰ in the Azov Sea up to 50‰ salinity in Bitter lakes of Suez Canal). The species is considered an anti-Lessepsian migrant (FOX, 1927). The only extraMediterranean records of this species came from Mauritania (ROSE, 1933) and Madagascar (DUSSART, 1989). In confined environments P. latisetosa is generally abundant, being a typical representative of the family Acartiidae, which generally is the dominant component of zooplankton (YOUNGBLUTH, 1980; CASTEL e COURTIES, 1982). Lake Qarun (about 200 Km from the marine coastline) is the more isolated site where P. lati setosa has been recorded from. Lake Qarun is a saline ecosystem remnant of an ancient historical lake (Moeris) supplied by Nile waters from its formation (about 1980 b.C.) to the Ptolemaic period (323-246 b.C.). The lake today lies in the western desert, about 85 km southwest of Cairo (Egypt), in El-Fayoum depression, without any direct connection with the river Nile. Its abiotic features varied in the last century, consequently affecting the biotic component in it. The gradual increase of the water salinity lead to disappearance of the some fish species with low halotollerance (Latus niloticus, Claries anguillaris, Labeo niloticus, Barbas benni, and Oreochromus niloticus). The commercial fishery consequently dropped from 4,000 tons in 1920 to an average of 1,500 tons in the successive years (EL-ZARKA, 1968). To compensate for the loss of fish, the lake was periodically stocked with fish fry of coastal, brackish water origin, as mullets (Mugil cephalus, Liza ramada, and Liza saliens), and Solea aegyptiaca. The copepod Paracartia latisetosa was probably introduced to lake Qarun in consequence of this restocking process carried out with marine fish fry from the Alexandria area (Mediterranean) since 1928. In fact WIMPENNY e TITTERINGTON (1936) reported that the zooplankton of the oligohaline lake Qarun consisted mainly of brackish water species, at that time dominated by Diaptomus salinus (Copepoda) and Moina salinarum (Cladocera). NAGUIB (1958) and GRIGIS (1959), twenty years after, noticed that there was no more evidence of D. salinus and M. salinarum, while the marine neritic copepod P. latisetosa was detected in high numbers. BOULOS (1960) stated that the permanent zooplankton in lake Qarun was composed mainly of copepods (P. latisetosa) and Protozoa. DOWIDAR (1981) reported P. latisetosa as dominant (about 88.4% of the total zooplankton annual mean). He added that this species was highly abundant in spring, common in summer and autumn and rarely appeared in winter. On the contrary, AHMED (1994) recorded the highest standing crop of this species (2,500 specimens/m -3 ) in winter and the lowest yield in summer (825 specimens/m -3 ). The aim of the present study is to confirm the presence and the seasonality of the Paracartia latisetosa population in the lake Qarun studying different years (1994,1995 and 1999-2000) to understand its environmental exigencies.

RIS (EndNote, Reference Manager, ProCite, RefWorks)
BibTex (BibDesk, LaTeX)

[Back to search]