tailieunhanh - Báo cáo khoa học: "Site adaptations of Acanthogyrus (Acanthosentis) tilapiae: Observations through light and scanning electron microscopy"

Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Site adaptations of Acanthogyrus (Acanthosentis) tilapiae: Observations through light and scanning electron microscopy | J. Vet. Set. 2006 7 4 339-342 JOURNAL OF Veterinary Science Site adaptations of Acanthogyrus Acanthosentis tilapiae Observations through light and scanning electron microscopy Mahmoud E. Bayoumy Osman K. Abd El-Hady Hussein . Osman Hydrobiology Department National Research Center Giza Egypt Acanthogyrus Acanthosentis tilapiae parasites were collected from the intestines of 300 fish belonging to three tilapia species sourced at the River Nile Giza Egypt. The proboscis of the parasite was characterized by three rows of hooks that curved towards the posterior of the body. The first row is supported by unmodified hooks. The parasite tegument has a series of alternative folds and a large number of pores. Sensory ganglia are located on the surface of the proboscis and body. Acanthogyrus Acanthosentis tilapiae provokes an aggressive host response indicated by hyperplasia of the intestinal goblet cells and focal eosinophil infiltrations. This acanthocephalan parasite shows a highly modified adaptation to its site of host infection. Key words Acanthocephala Acanthogyrus Acanthosentis tilapiae adaptation parasites scanning electron microscopy Introduction The phylum Acanthocephala includes at least 1 150 species of relatively small vermiform endoparasites. The adult members of the phylum locate and feed on the intestinal walls of fresh and marine water vertebrate fishes 1 . They are well adapted parasites with low specificities to their intermediate definitive and transport hosts. A broader envfronmental tolerance of these parasites might account for the high degree of morphologic variability often found in species of this group 25 . Adult members are highly specialized heterosexual parasites that locate in the intestines and take up their nutrition through theft teguments since they have no intestine. These parasites are harmful to theft host 6 20 . In general many studies have been carried out on the fish parasites typical of Egypt but few have focused on the .