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Changes in diet, prey size and feeding habit in Bagrus bayad, and possible interactions with B. docmac in a Nile canal


Bagrids in Bahr Shebeen Nilotic canal depend mainly on fish, insects and shrimp as well as fish embryos for food and their stomachs included runoff materials (e.g. plant foliage, glass, black crystals, coloured gravel). B. bayad maximised its efficiency of catching prey catfish by face to face attack to avoid damage by the prey's pectoral and dorsal spines. In the size classes of 10 to 30 cm standard length, B. bayad and B. docmac show diet overlap and interact with each other especially with respect to tilapias as prey. After this length, B. docmac, aided by its relatively larger mouth, shifted to larger size of tilapias to coexist with B. bayad.

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Khallaf, E.A., Authman, M.N. Changes in diet, prey size and feeding habit in Bagrus bayad, and possible interactions with B. docmac in a Nile canal. Environ Biol Fish 34, 425–431 (1992).

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Key words

  • Freshwater catfish
  • Bagrus ecology
  • Predator and prey
  • Trophic adaptation
  • Diet overlap
  • Feeding behaviour
  • Interspecific interaction