NATURAL DIET OF FOUR FISH SPECIES FROM THE EUPHRATES RIVER AT ASH-SHAMIYAH, IRAQ

Abstract

A total of 401 fish belonging to four fish species were collected from the Euphrates River near Ash-Shamiyah (40km west of Ad-Dewaniyah). These fish were Hemrri, Barbus (Carasobarbus) luteus (Heckel, 1843) Khishni, Liza abu (Heckel, 1843), Lassaf, Alburnus caeruleus Heckel, 1843 and Carassuan carp Carassius carassius (Linnaeus, 1758). The stomach contents of the fish were evaluated by using ranking index (%R), occurrence method (%O) and approximate volumetric method (%V). The study showed that detritus (plant in origin) (56.84%, 25.34%& 42.84%), sand, zooplanktons and green & blue green algae were the main food items taken by L. abu, according to above methods respectively. Plant in origin materials formed 69.46% of fish consumed diet according to ranking index. On other hand, Barbus luteus was found mainly feeding on aquatic plants (31.44%, 15.15% & 30.0%), as well as detritus and zooplanktons. The fish was also found to have a greater plant in origin diet (71.36%). The study showed that zooplankton ranked first in the foregut contents of Alburnus caeruleus. It formed 25.20%, 22.64% and 18.25% of fish diet; it came with close percentages with detritus and sand. Plant in origin materials formed 45.62% of fish diet, according to ranking index, i.e. it's an omnivorous fish. Carassius carassius were also an omnivorous fish. Detritus ranked first in its foregut contents (39.35%, 16.56% and 31.59%), followed by sand, green and blue green algae, plant tissues and zooplanktons in close percentages, according to the above three methods of analysis respectively. Plant in origin materials formed 61.32% of fish diets. Sand as a food was not assessed in this study