IMPORTANCE OF PROTOZOA AS FOOD TO ZOOPLANKTON AND SOME FISH SPECIES IN LAKE QAROUN, EGYPT | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 4, Volume 6, Issue 2, April 2002, Pages 59-74 PDF (907.25 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2002.1740 | ||
| Authors | ||
| Ade Mageed1; Amaal Mohammadein2; Mahmoud Desouky2 | ||
| 1National Institute of Oceanography and Fisheries, El Kanater El Khayria Research Station, Egypt. | ||
| 2Zoology Department, Faculty of Science, Zagazig University, Egypt | ||
| Abstract | ||
| The relationship between the protozoan organisms and zooplankton in addition to fish predation of Lake Qaroun were herby studied. An experiment was conducted in the aquatic laboratory of Shakshouk Station-Fayoum close to Lake Qaroun using cylindrical fiberglass enclosures of 1000 liters capacity that were filled with water pumped from 0.5m depth of Lake Qaroun. The numbers and net population growth and production of the dominant protozoan organisms in absence and presence of small and large- sized zooplankton as well as two native fishes namely, Mitgil cephalus and Tilapia zillii were described. The average air and water temperatures were 27.7±2.1 and 22.6±l.lsC (mean ±SD) respectively. PH values ranged from 7.39 to 8.00 (7.74±0.13, mean±SD) while ammonium ranged from 64.39^gf 1 to 1.05mgmrl during the experiment At the start, the protozoan organisms, constituted numerically 48.12% of total zooplankton organisms that dominated by three species; Tintinnopsis kofoidi, Helicostomella subulata, and Euplots vannus. In the presence of the small-sized organisms (SS), the total protozoan number was decreased. In the presence of small and large sized organisms (SLS) the protozoan number returned to the control level The impact of the fishes was more pronounce in presence of M. cephalus than T. zilli compared to the control enclosure. Protozoan organisms were observed in the gut contents of M cephalus and T. zilli, representing 1429% and 4.69% respectively. The net population growth (NPG) was higher in control. (1.18 day ), while its lowest level was recorded in presence of M cephalus (0.63 day"1;.(2.15 day"') followed by SLS (2.10 day1). NPGR of T. kofoidi was the highest especially in presence of the SLS | ||
|
Statistics Article View: 330 PDF Download: 817 |
||
