Download Food and feeding habits of lessepsian fish Etrumeus teres (Dekay

Food and feeding habits of lessepsian fish Etrumeus teres (Dekay,
1842) from the Egyptian Mediterranean waters.
By
Alaa G. M. Osman1, El Sayed H. Kh. Akel2, Mahmoud M. S. Farrag1*, Mohsen A. Moustafa1
1Department
2National
of Zoology, Faculty of Science, Al-Azhar University (Assiut Branch), 71524 Assiut, Egypt
Institute of Oceanography and Fisheries, Alexandria, Egypt
Keywords: Round herring; lessepsian fish; food; feeding habits; Mediterranean Sea.
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*corresponding author
E mail [email protected]
ABSTRACT
In the present work, food and feeding habits of lessepsian fish, Etrumeus teres (Dekay, 1842)
were studied to know its feeding habits and its preferibilty for food items with the variations in sex,
length and season. Fish samples were collected monthly from Alexandria landing centers during two
years 2008 & 2009, then a total of 490 stomachs were used for this study. Our results indicated that
round herring Etrumeus teres feeds on avariety of food items, mainly on crustaceans which dominated
by shrimp, isopods and amphipods; fish larvae were represented by Engraulidae, Mugilidae and
Labridae; mollusca were represented by a little of gastropods and cephalopods and food remains. A
remarkable seasonal variation in the feeding intensity was observed. The highest percentage of fullness
index was recorded during winter (82 %) and the lowest one was in autumn (50.6 %). Round herring
shifted their diet composition as they grew, the lowest value of fullness index was recorded for length
group 9-15cm and the highest value was recorded for length group15–20cm. According to the modified
food index (MFI), crustaceans were the first preferable food item followed by fish larvae. Based on
diversity index (H') of food items for males, it was higher than females; For length groups, the small size
group (9 – 15 cm) was higher than other size groups suggesting that fishes of smaller sizes seemed to be
more active for capturing different food items.while the value of diversity index (H') of autumn was
higher than other seasons. For overlap test (T), there were no obvious differences between male and
female both sexes and different length groups where the value was found to be (1), this means that
both sexes and all the selected size groups have the same resource of food items supported by light
from purse-seine using light.