Effects of Salinity on Some Haematological and Biochemical Parameters in Nile Tilapia, &amp;lt;i&amp;gt;Oreochromus niloticus&amp;lt;/i&amp;gt;

Naglaa Elarabany

doi:10.11648/j.aff.20170606.13

Abstract

Any change in haematological and biochemical parameters could be a predictor of unfavorable environment or effect of different stress factors. The present study was designed to assess different salinity concentration induced changes in some haematological and biochemical parameters in 64 O. niloticus fishes captured from Manzala Lake (Egypt), they were acclimatized and fed with commercial fish diet for one week before starting the experiment for another 2 weeks. Fishes were divided into 4 equal groups assigned as; control, 4g NaCl\L, 8 g NaCl\L and 12 g NaCl\L. RBCs, HCT, Hb concentration, platelets count, superoxide dismutase activity, catalase activity, potassium level and serum total protein were estimated. The HCT, Hb concentration, platelets count and potassium levels were significantly higher in (4gNaCl\L, 8gNaCl\L and12gNaCl\L, respectively). The Superoxide dismutase activity (SOD), total protein, RBCs and catalase activit were significantly lower in (4gNaCl\L, 8g NaCl\L and 12gNaCl\L, respectively) compared to the control group. Other parameters such as WBCs, haematimetric indices (MCV, MCH, MCHC), malonedialdhyde (MDA) level, carbonyl protein (CP), glutathione reductase (GR) activity, as well as serum sodium, glucose, cortisol and IgM, did not show any significant differences in the estimated salinity concentrations.

Highlights

Fish aquaculture is essential to enhance food security, in addition to give another source of income, especially in Egypt that has high population density [1, 2].It is outstanding that oceanic life forms, including fishes, are influenced by both inside and outside components
The results revealed a decrease in both haemoglobin content, red blood cells count (RBCs) and haematocrit in 8g/l and 12g/l treated groups, These findings are in agreement with other researcher who found a significant effect of salinity on RBCs, HCT and Hb in different species, this result may be associated with osmoregulatory dysfunction induced by high salinity levels [25,26,27]
Low haematocrit percentages in fishes under stress could be explained by reduced volume of RBCs due to osmotic changes caused by ion leakage from the plasma [28]; while no significant differences were found in mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) values in treated groups, these results are in according with the findings of previous results [27, 29, 30]

Summary

Introduction

Fish aquaculture is essential to enhance food security, in addition to give another source of income, especially in Egypt that has high population density [1, 2].It is outstanding that oceanic life forms, including fishes, are influenced by both inside (e.g. hormones and compounds) and outside components (e.g. their condition). Stress is any change in the physical or systemic elements that affect body health leading to disease or many causes death [3]. It may cause disturbing homeostasis, stress reaction including many physiological changes including blood composition and immune mechanisms [4]. Fish response to any stressor could be achieved by many physiological changes to maintain homeostasis, osmolality and hematology [5, 6]. The physiological responses to high or low salinity levels in the aquatic environment have been studied in different fresh and marine species [9,10,11]

Methods

Results

Conclusion