الفهرس 
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Abstract
Summary
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6- Summary
This study was conducted to investigate the effect of transportation in
freshwater and water containing 5gL-1 and 10gL-1 NaCl on O. niloticus
resistance. 200 Fish with average body weight 53±3 g were subdivided into 4
equal groups. The 1st was a control group (P1), the 2nd was PT2 group
transport in water without salt, the 3rd was PT3 group transported in water
containing 5gL-1 salt, the 4th was PT4 group transported in water containing
10gL-1 salt.
The results of this study revealed that water pH did not change,
Dissolved oxygen non significantly decreased while total ammonia
significantly increased in the PT3 and PT4 groups transported in water
containing 5 & 10gL-1 salt. The survival rate of O. niloticus after
transportation revealed that; the fish group transported in water without salt
(PT2) showed 90 % survival rate, while the PT3 group recorded 96 %
survival rate and PT4 group showed 94 % survival rate. Concerning the
Bacterial translocation, the PT2 group had progressively and significantly
increased total bacterial count in the liver and spleen post transportation
comparing with the other fish groups.
The serum cortisol at 0 h post transport and in comparison to the
control group, a significant increase was reported in PT2 group and non-
significant increase was reported in the PT3 and PT4 groups it was
significantly decreased in PT3 and PT4 group comparing with PT2 group at
12 and 24 h post transportation and it significantly dropped in the three
transported groups (PT2, PT3 and PT4) comparing to its level in the control
group.
Summary
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The serum glucose at 0 h post transport was significantly higher in the
PT2 group and no significance difference was recorded in the PT3 and PT4
groups transported in water containing 5 &10 gL-1 salt comparing with the
control group, while it significantly dropped in the three transported groups
(PT2, PT3 & PT4) at 12 and 24h post transportation comparing with the
control group.
The MUC2 gene expression of the O. niloticus in the PT2 group
significantly up-regulated at 0, 12 and 24 h post transportation and down
regulated in PT3 and PT4 groups at 0 h then significantly up regulated at 12
and 24 h post transport in comparison to PT1 group. MUC2 gene expression
of PT3 and PT4 fish groups were significantly down regulated comparing
with the PT2 fish group at 0, 12 & 24 h.
βD-1 and βD-2 antimicrobial peptides genes expression significantly
down-regulated in PT2 group at 0, 12 & 24h post transportation. The Dβ -1
and Dβ-2 genes expression in skin of O. niloticus P3 and P4 groups
transported in water containing 5 and 10 gL-1 salt first significantly up
regulated at 0 h post transportation then down regulated at 12 & 24h post
transportation. The IL-1β gene expression of PT2 group transported in water
without salt was significantly up-regulated at 0, 12 & 24 h post transport. The
IL-1β down regulated in PT3 and PT4 groups at 0h followed by progressive
up regulation at 12 and 24h post transportation. The TNF alpha gene
expression of O. niloticus in the PT2 fish group was significantly and
progressively up regulated at 0, 12 and 24 h post transport comparing with the
P1 group. Oppositely, it down regulated in the PT3 and PT4 groups at 0 h
post transportation then up regulated at 12 h and 24 h post transport.
The histopathological study revealed marked differences in the PT2,
PT3 and PT4 O. niloticus groups to the skin of the control P1 group. Skin
Summary
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tissue sections from O. niloticus of PT2 group showed moderate
inflammatory reaction in the form of melanocytes aggregation under dermis,
atrophied and loosen muscle bundles, vacuolated hypodermis and absence of
goblet cells. In PT3 group, the skin sections showed to some extent normal
epidermis layer with goblet cells, dermis with tight fibrous connective tissue,
melanocytes filled with melanin pigment and normal hypodermis. PT4 group
showed thin flattened epithelial cells with goblet cells, tight fibrous
connective tissue in the dermis infiltrated with lymphocytes, hypodermis
showed cystic dilatation and more or less muscle fibers and normal
melanocytes and mucous degeneration in hypodermis.