Research Article
Effects of Water Type (River and Well) on Hematological Parameters in Juvenile Siberian Sturgeon (Acipenser baeri)
Genetic and Breeding Research Center for Coldwater Fishes, Shahid Motahari Yasouj, Yasouj, Iran
Water quality and quantity is a limiting factor in intensive fish production (Kucuk, 2010). Many of the negative chemical and environmental factors associated with most operations have their origins in the source of water selected. Final site selection has to be made based on both the quality and quantity of water available. The most common sources of water used for aquaculture are wells, springs, rivers and lakes. Of the sources mentioned, wells and springs are considered to be the best sources of water to use for aquaculture. Rivers have variable chemical and physical characteristics. Well and river sources were studied in this experiment.
There are optimum water quality requirements for each species. Several biotic and abiotic factors influenced the fish growth and survival (Kucuk, 2010). Many studies were attentioned to see the effect of one parameter individually, likes temperature and oxygen on the fish (Townsend et al., 2003; Hammond et al., 2006; Adhikari et al., 2007; Handeland et al., 2008; Sahoo et al., 2008; Blanksma et al., 2009). However it is important to consider the effects of quality parameter within interactions.
Iran is one of the main countries in sturgeon industry; the total sturgeon catches and caviar production in 1993 were 1710 and 106 t, declining in 2006 to 330 and 31.3 t, respectively (IFO, 2007). The natural stocks of all species of sturgeon has depleted because of over-exploitation, alterations of the habitats and pollution (Beamesderfer and Farr, 1997; Waldman and Wirgin, 1998; Chebanov et al., 2002; Williot et al., 2002). Sturgeon culture has been carried out to stock enhancement and caviar or meat production. Culture of sturgeon fish is an important industry for those countries where wild stocks are declining or have been exterminated. Sturgeon has mainly been farmed for caviar production but in the last decade there has been increased interest in farming for flesh production, because of the need to expand production by introducing new species (Palmegiano et al., 2005). Several species of sturgeon are now considered attractive candidates for aquaculture such as Siberian sturgeon. High growth rate in different types of production systems (Williot et al., 1993; Arndt and Mieske, 1994) and ability to attain sexual maturity in captivity (Ronayi et al., 1989; Ronayi and Peteri, 1990) make it a candidate species for aquaculture. Siberian sturgeon (Acipenser baeri) has been introduced to Iran in 2004. Physiology, growth and feeding performance of the species under different rearing conditions should be studied. There have been previous investigations in which some blood parameters of sturgeons were studied (Alyakrinskyaya and Dolgova, 1984; Bahmani et al., 2001). However, there are a few studies focused on blood characteristics of Siberian sturgeon under different environmental conditions, especially water sources. Thus, this study comprises the quantitative assessment of some blood indices in Siberian sturgeon after rearing at different water types such as well and river.
Rearing conditions: The experiment was conducted at the International Sturgeon Research Institute of Rasht (Iran) in October 2009. Siberian sturgeon juveniles were obtained from Shahid Beheshti Sturgeon Rearing Center, Rasht (Iran) and transported to an indoor system at the Institute. Prior to the beginning of the trail, fish were acclimatized to experimental conditions for a 10-day period. During acclimation, fish were fed to apparent satiation four times daily using a feed formulated at the institute for sturgeon rearing (containing 45% crude protein, 18% crude fat, 10% ash and 8% moisture). Ninty fish with weights of 19.3±0.62 g were randomly distributed in six circular fiber glass tanks with per 500 capacity (15 fish per replication). Two experimental groups with three replicate were used in this study. First group, the tanks water was continuously supplied throughout the experiment using Sefid-Rood River after filtration at a flow rate of approximately 5 L min-1. Second group, the tanks water was continuously supplied throughout the experiment using a well at a flow rate of approximately 5 L min-1. The rearing water in each tank was permanently saturated (up 92%) with oxygen by supplying air continuously through air-stone from an air-blower. Water parameters were controlled and recorded every week.
Water quality parameters: Throughout the experiment, the following water quality parameters were measured using the inflow and outflow of each experimental tank: pH using commercial test kit (Aquamerck; Merck, Darmstadt, Germany), orthophosphates (PO4-P), ammonia (NH3), nitrite (NO2), nitrate (NO3) and total iron by photometer (Model Pc22; Tintometer, GmBH, Dortmund, Germany). Dissolved Oxygen (DO), Temperature (T) and Oxygen Saturation (OS) were also measured daily by oxymeter (WTW oxi 330i, Weilheim, Germany). Samples of water were collected from each tank at a fixed hour of the each day (1000 h) for determination of different kinds of nitrogen compounds and iron (ammonia-N, nitrite-N and nitrate-N) and other water quality parameters (temperature, pH, DO) according to the standard methods (Anonymous, 1994; APHA, 1998).
Hematological parameters: In each tank, 30% of the fish were randomly sampled at the end of the experimental period in order to evaluate haematological variables. Fish were quickly captured and blood samples were taken from the caudal vein using a heparinized syringe and transferred to tubes that were kept on ice until analysis of selected biochemical parameters. Blood sampling was always completed within 1 min. Haematocrit was determined by centrifuging whole blood in heparinized microhaematocrit capillary tubes at 3500 g for10 min and then measuring the packed cell volume. Haemoglobin (Hb) was determined using a commercial kit (Cyanmethaemoglobin method; Sigma, St Louis, MO, USA). We also calculated number of White Blood Cells (WBCs), number of Red Blood Cells (RBCs), Mean Corpuscular Volume (MCV), mean corpuscular haemoglobin MCH and Mean Corpuscular Haemoglobin Concentration (MCHC) as other indices of haematology according to Sandnes et al. (1988).
Statistical analysis: SPSS 15.1 was used to assess statistical analysis of data. After normality of data was determined by Levene test, one-way ANOVA was used to estimate differences between various water types and where different were found, Tukey's test were used to compare the means difference. Presence or absence of a statistically significant difference was determined at 5% level. All data is presented as Mean±Standard Error (M±SE).
Water quality parameters: Water quality parameters, pH, total Fe, PO4, NO2, NH3, NO3 were measured (Table 1). There is any significant difference in two types of water.
Hematological parameters: Hematological indices of Siberian sturgeon reared in two water types (well and river) were measured, including Hb, Hct, WBC, RBC, MCV, MCH and MCHC (Fig. 1-7). According to the obtained results, two types of water were not significantly affected on the Hb, Hct, WBC, RBC, MCV, MCH and MCHC.
Table 1: | Water quality parameters of two type water sources (well and river) |
nd = Not detected |
Fig. 1: | Hemoglobin values of Siberian sturgeon reared in different water types. No significant differences observed in two groups |
Fig. 2: | Hematocrit values of Siberian sturgeon reared in different water types. No significant differences observed in two groups |
Fig. 3: | White blood cells count values of Siberian sturgeon reared in different water types. No significant differences observed in two groups |
Fig. 4: | Red blood cells count of Siberian sturgeon reared in different water types. No significant differences observed in two groups |
Fig. 5: | Mean corpuscle volume of Siberian sturgeon reared in different water types. No significant differences observed in two groups |
Fig. 6: | Mean corpuscle hemoglobin of Siberian sturgeon reared in different water types. No significant differences observed in two groups |
Fig. 7: | Mean corpuscle hemoglobin concentration of Siberian sturgeon reared in different water types. No significant differences observed in two groups |
Analysis of hematological and biochemical parameters is a commonly used diagnostic tool in the physiological status of fish. The hematological parameters of fish can be influenced by many biotic and abiotic factors such as age, sex of fish, water temperature, water quality, seasonal pattern and feeding status (Rehulka et al., 2004). Conservation biology, ecology and aquaculture are the most focused sections of sturgeon research (Bemis and Kynard, 1997), whereas a limited number of studies have focused on sturgeon physiology. During recent years, physiological aspects in sturgeon have been investigated by many studies in which the quantitative features in the blood have been used to assess the physiological responses of these fishes (Baker et al., 2005). However, hematological factors, particularly the cellular parameters, of sturgeon when these fishes are exposed to different environmental conditions have received only limited attention.
Water type is a main component in aquaculture. Some studies reported the effect of water quality such as hardness, alkality, oxygen dissolved and temperature (Townsend et al., 2003; Person-LeRuyet et al., 2004; Hammond et al., 2006; David, 2006; Adhikari et al., 2007; Bjornsson et al., 2007; Okamura et al., 2007; Kling et al., 2007; Handeland et al., 2008; Sahoo et al., 2008; Blanksma et al., 2009) and water quantity on the growth, hematological and biochemical parameters in teleosts. But there is no report available on the effect of water type on chondrostean fish. T herefore the objective of this study is to observe the effect of two water types (well and river) on water quality parameters and hematological indices in Siberian sturgeon.
Hematological parameters such as hemoglobin, hematocrit, WBC, RBC, MCV, MCH and MCHC, had no significant differences in the effect of two water types (well and river), indicating no change in homeostasis. It can also indicate a healthy immune system because white blood cells are key components of innate immune defense and leukocytes are involved in regulation of immunological function in the organism (Ballarin et al., 2004). It has been shown that the environment in which fish live and the conditions governing them influence the metabolite content in blood (Bullis, 1993). For example, in response to ecological and physiological conditions, major changes occur in the fish blood composition, such as fluctuations in the levels of red blood cells, white blood cells, hormones, hematocrit, hemoglobin concentration, leukocytes counts and other basic components. There were no significant differences between two water types regarding the water quality parameters like pH, total Fe, PO4, NO2, NH3 and NO3. It seems that no changes in hematological parameters can be due to similarity in main water quality parameters.
The present results indicated that two water types in this study (well and river) can be used to culture Siberian sturgeon. However, it is difficult to draw conclusions as more research is needed to expand knowledge and the demonstration of immunity and biochemical parameters would make for future works.