Combined effects of temperature and salinity and induced stress on some hematological parameters of tra catfish (pangasianodon hypophthalmus) fingerlings

AGU International Journal of Sciences – 2019, Vol 7 (3), 37 – 46<br /> <br /> <br /> <br /> <br /> COMBINED EFFECTS OF TEMPERATURE AND SALINITY AND INDUCED STRESS ON<br /> SOME HEMATOLOGICAL PARAMETERS OF TRA CATFISH (Pangasianodon<br /> hypophthalmus) FINGERLINGS<br /> <br /> Dang The Luc1<br /> 1<br /> An Giang University, VNU - HCM<br /> <br /> Information: ABSTRACT<br /> Received: 17/10/2018<br /> Three separate experiments were carried out to assess combined effects of<br /> Accepted: 08/07/2019<br /> temperature and salinity and induced stress on blood variables of Tra catfish<br /> Published: 11/2019<br /> (Pangasianodon hypophthalmus) fingerlings. Some hematological parameters<br /> Keywords: included Haemoglobin concentration, glucose and pH levels which were tested<br /> Pangasianodon hypophthalmus, in different conditions. The experiment 1 aimed to test how blood variables<br /> temperature, salinity, change in different temperature (24, 28-30, 32 oC) and salinity (0, 6 and 12<br /> Haemoglobin, glucose, stress ppt) while the experiment 2 induced catfish fingerlings to different stress time<br /> (5, 15 and 30 min.). Additionally, combined effects of all factors (temperature,<br /> salinity and induced stress) on fish blood parameters were also determined in<br /> the experiment 3. Results showed that in normal condition, the mean Hb<br /> concentration and glucose levels of blood varied from 4.36 – 4.90 g/dL, and<br /> from 3.83 – 5.23 mmol/L, respectively and mean pH ranged from 7.73 – 8.20.<br /> The concentration of Hb, glucose and pH levels changed when temperature<br /> increased from 24 to 32oC. After 30 stress minutes, there was only glucose<br /> levels influenced. Moreover, there were significant interaction effects among<br /> temperature, salinity and stress level on blood variables. The findings revealed<br /> that the physiology of Tra catfish fingerling could be affected after 5 stress<br /> minutes at temperature of 24oC and 32oC with salinity of 6 and 12 ppt. All data<br /> of experiments showed that a positive correlation between Hb concentrations<br /> and glucose levels and negative correlation between Hb concentrations and pH<br /> levels were found. Results also showed that changes in blood variables could<br /> cause stress for aquatic animal, especially Tra catfish fingerlings.<br /> <br /> <br /> 1. INTRODUCTION levels and the interaction between temperature<br /> Catfish is one of the most important species and salinity on fishes (Kemp, 2009; Wright and<br /> cultured in the MeKong Delta, which brings the Tobin, 2011; Nguyen et al., 2015). These studies<br /> main income to An Giang farmers. However, have all concluded that fish health including<br /> despite of climate change, there are some negative growth rates, survival rates and physiological<br /> impacts on catfish farming, especially when responses could be negatively affected by<br /> temperature and salinity have changed. significant changes.<br /> <br /> Many previous studies have been carried out to The increase of temperature could affect the<br /> assess effects of rising temperatures, salinity metabolism of aquatic animals as well as the<br /> <br /> <br /> <br /> <br /> 37<br /> AGU International Journal of Sciences – 2019, Vol 7 (3), 37 – 46<br /> <br /> growth rate of fish (Kemp, 2009). Modified The study was carried out from December 2016 to<br /> salinity is a factor causing stress and affecting fish October 2017 at the wetlab of An Giang<br /> physiology (Fashina-Bombata & Busari, 2003; University, Long Xuyen city, An Giang province.<br /> Konstantinov & Martynova, 1993; Partridge & 2.2 Experimental design<br /> Jenkins, 2002; Sink, 2010). Stress is a popular<br /> The experiment 1: A two-factor designs, where<br /> physiological status in fish or other species in<br /> three temperature (T) levels (24°C, 28°C – 30°C<br /> order to deal with changes of the environment to<br /> and 34°C) and three salinity (S) levels (0 ppt, 6<br /> survive and maintain internal balance of animals<br /> ppt and 12 ppt) were tested in triplicate<br /> (Fuzzen et al., 2011).<br /> combinations (TxS).<br /> Previously, stress indicators included changes in<br /> In this experiment, with a density of 30<br /> plasma glucose and pH levels in fish, especially<br /> individuals/tank, fish fingerlings were accustomed<br /> Tra catfish, were examined (Kirchhoff et al.,<br /> gradually to required salinity rates by replacing<br /> 2014; Nguyen et al., 2014). In addition,<br /> freshwater in each tank with saline water in a<br /> Haemoglobin concentration is also considered as<br /> stepwise fashion, which was 2‰ per day to<br /> an indicator to evaluate overall physiology and<br /> prevent shock to fish, until all tanks had reached<br /> general health in fish (Houston, 1997). However,<br /> their target salinities. Individuals were then kept<br /> it is necessary to fully collect more data on blood<br /> within 24 hours to be stable.<br /> variables in Tra catfish's fingerlings in the<br /> condition of climate change in Mekong Delta, Finally, the temperature levels were modified by<br /> Vietnam. ice and heaters in a stepwise fashion, which was<br /> not higher than 2°C per 3 hours until all tanks had<br /> Therefore, the study “Combined effects of<br /> reached their target temperature levels. Fish blood<br /> temperature and salinity and induced stress on<br /> was immediately collected from the caudal veins<br /> some hematological parameters of Tra catfish<br /> within 5 min. of sampling with 1 mL heparin-<br /> (Pangasianodon hypophthalmus) fingerlings”<br /> coated syringes after being anaesthetised at the<br /> was conducted to fully understand about Tra<br /> following time intervals: 0h, 1h and 24h.<br /> catfish fingerling’s health. This also contributes to<br /> establish some blood variables’ baseline for Tra The experiment 2: According to Lopez-Patino et<br /> catfish, which helps to determine and manage fish al. (2014), fish was stressed by chasing (using<br /> health status more effectively. As a result, the hand-nets to catch up fish) within 5, 15 and 30<br /> production cycle of Tra catfish could be enhanced minutes. After stressed time, fish blood was<br /> and sustainably developed in the condition of immediately collected from the caudal veins as in<br /> climate change in Mekong Delta. the experiment 1.<br /> 2. MATERIALS AND METHODS The experiment 3: Fish was challenged by a<br /> three-factor design which combined different<br /> 2.1 Experimental system and source of catfish<br /> temperature (T), salinity rates (S) and stress levels<br /> Catfish fingerlings (25.96 ± 0.67 g/fish) were (St) in triplication. This experiment included 27<br /> obtained from a hatchery farm located in Dong treatments. Temperature and salinity rates were<br /> Thap province. Fish were in good conditions and adjusted as the experiment 1 before fish was<br /> fed commercial feed (40% crude protein) during chased as in the experiment 2 After that, fish<br /> the experiment. Individuals were acclimated for a blood was immediately collected from the caudal<br /> month before transfered to 80L tanks in veins within 5 min. of sampling with 1 mL<br /> freshwater at 28-30°C (maintained by heaters) heparin-coated syringes after being anaesthetised.<br /> with a continuous supply of well-aerated water. 2.3 Sampling collection and analysis<br /> After the acclimatation period, fish were arranged<br /> Fish fingerlings were anaesthetised by 0.3 ppm of<br /> into different experiments.<br /> MS-222. Fish blood was collected from caudal<br /> veins. Each sample contained 2 mL in heparinised<br /> 38<br /> AGU International Journal of Sciences – 2019, Vol 7 (3), 37 – 46<br /> <br /> Vacutainer® tube (BD, USA). All samples were time) and their interactions on blood variables. All<br /> stored with ice before being analysed. variances were homogenous by Levene's test.<br /> Haemoglobin (Hb) concentration was determined Relationships between blood variables were<br /> by using a haemoglobin meter, ACON Mission® determined using all data and Spearman's rank<br /> Hb Plus Meter (ACON Laboratories Inc., USA). correlation coefficients. Homogeneity of variance<br /> Glucose concentration was determined by using a was tested with Levene’s test and the means of<br /> glucose meter test, ACON On Call Plus Meter blood variables were compared using Duncan test.<br /> (ACON Laboratories Inc., USA). Blood pH was 3. RESULTS<br /> determined by using a pH meter, Horiba 11<br /> 3.1 The experiment 1<br /> (LAQUAtwin, Japan).<br /> 2.4 Statistical analysis 3.1.1 Haemoglobin<br /> <br /> All data were analysed by SPSS 20.0 for There was an interaction between temperature and<br /> Windows (SPSS Inc., Chicago, IL, USA). Means salinity on Hb concentrations. Hb concentrations<br /> and standard errors were calculated for blood were unstable during this study, especially there<br /> variables including Hb concentration, levels of was an increase in Hb concentration at 24 0C, 0<br /> glucose and pH. The differences among ppt after 24 hrs (shown in Table 1) when Hb<br /> treatments within experiment were determined by concentration reached the highest concentration<br /> two-way and three-way analysis of variance (6.03 ± 0.45 g/dL). The lowest one (2.90 ± 0.10<br /> (ANOVA) at a significance α=0.05 for significant g/dL) was at 240C, 6 ppt, 0 hr. The Hb<br /> main effects (temperature, salinity or stressed concentration in a normal condition was in range<br /> of 4.36 – 4.90 g/dL.<br /> <br /> Table 1. Mean Hb concentrations (g/dL) between treatments in the experiment 1<br /> <br /> Treatment 0h 1h 24h<br /> <br /> 24C, 0 ppt 3.33 ± 0.35ab 3.33 ± 0.35ab 6.03 ± 0.45d<br /> <br /> 24C, 6 ppt 2.90 ± 0.10a 3.46 ± 0.45abc 3.36 ± 0.15ab<br /> <br /> 24C, 12 ppt 3.10 ± 0.30a 3.16 ± 0.32a 3.26 ± 0.35ab<br /> <br /> Control, 0 ppt 4.36 ± 0.65bc 4.16 ± 0.25c 4.90 ± 0.10c<br /> <br /> Control, 6 ppt 3.66 ± 0.85ab 3.93 ± 0.35bc 2.90 ± 0.10a<br /> <br /> Control, 12 ppt 3.86 ± 0.85ab 4.10 ± 0.40c 4.76 ± 1.15c<br /> <br /> 34C, 0 ppt 4.85 ± 0.55c 4.90 ± 0.45d 4.20 ± 0.20bc<br /> <br /> 34C, 6 ppt 3.30 ± 0.40ab 3.30 ± 0.30ab 4.25 ± 0.45bc<br /> <br /> 34C, 12 ppt 3.70 ± 0.50ab 3.63 ± 0.45abc 4.86 ± 0.95c<br /> <br /> Mean values having different letters within columns are significant difference (p