ASST The Migratory Pattern and Condition of Tiny Scale Barb, Thynnichthys thynnoides (Bleeker, 1852) at Rui River, Perak, Malaysia A.M. Radhi1, H. Rohasliney1,*, M.N.A. Amal2 and H.H. Zarul3 1 Department of Environmental Management, Faculty of Environmental Studies, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia 2 Biology Department, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia 3 School of Biological Sciences, Universiti Sains Malaysia, 11800 USM Minden, Penang, Malaysia * Corresponding author: [email protected] Submission: 6 May 2018 Revised: 14 January 2020 Accepted: 17 February 2020 ABSTRACT A study on the migratory behavior and condition of potamodramous Thynnichthys thynnoides and its environmental attributes was studied from May to October 2015 in Rui River, the main tributary of Perak River. The migration pattern and condition of T. thynnoides were examined by using two catch techniques which are active (scoop net) and passive (gill net) sampling, while water quality parameters were determined by using standard methods. Thynnichthys thynnoides were caught between August and October as the migration season began, with peak migration occurring in September and October. The longest observed migration from the refugee habitat to the possible spawning ground was 52 km. There was a significant variation in turbidity concentration between spawning and non–spawning seasons (F = 13.23, P < 0.05). The length–weight relationships of T. thynnoides exhibited isometric body growth, and the condition of T. thynnoides declined over the spawning migration. From these results, it was concluded that the migration of T. thynnoides was dependent on environmental conditions. Keywords: Freshwater, Thynnichthys thynnoides, behavior, environmental factors, Perak River Thai J. Agric. Sci. (2020) Vol. 53(1): 19−31 INTRODUCTION Ali, 2001), Pahang River in Maran and Temerloh districts (Zulkafliet al., 2015; Zulkafliet al., 2016) The tiny scale barb, Thynnichthys and in Chini Lake, Pahang (Kutty et al., 2009). This thynnoides is a relatively small riverine cyprinid species also scattered around Brunei, Cambodia, species inhabiting river basins and lakes (Ali and Indonesia, Laos, Myanmar, Thailand and Vietnam Lee, 1995; Thuok and Sina, 1997; Vidthayanon et (Ambak et al., 2010). Furthermore, T. thynnoides is al., 1997). This species inhabits large river canals recognized as an important fish species for human of Perak River and moves to small tributaries (i.e. consumption in both Khone Falls, Cambodia and Rui River) during spawning season. Although this Chenderoh Reservoir, Perak, Malaysia (Ali and migratory species has been spotted spawning in Lee, 1995; Bishop, 2002). Rui River, the details of distribution and spawning Currently, IUCN Red List Status reports activity have not been adequately assessed (Amal that T. thynnoides is categorized as a species of et al., 2015). Thynnichthys thynnoides can be found least concern (LC) (Vié et al., 2008). However, in Chenderoh Reservoir, Perak (Kah–Wai and Chong et al. (2010) classifiedT. thynnoides as being Thai Journal of Agricultural Science Volume 53 Number 1 January−March 2020 19 THE AGRICULTURAL SCIENCE SOCIETY OF THAILAND under medium threat due to overfishing and water the migratory pattern and condition of this species, pollution. It is anticipated that fishing pressure on and also environmental attributes that influence the T. thynnoides is increasing since this fish is high in well–being of the species. commercial value and selectively targeted during the spawning season. In 2014, an occurrence of fish MATERIALS AND METHODS kill in Rui River has became a concern to regarding food safety of fishes caught there, particularly Study Location T. thynnoides (Dolasoh, 2014). Tin mining activity This study was conducted in Perak River, affects the water quality of Rui River based on Perak, including one of the main tributaries, the Rui its water treatment compound, particularly in the River, which is located in Kenering dam. With a water of Kepayang River, a tributary of Rui River. surface area of 40 km2, mean depth of 15 m, and The mining company directly introduces lime into water volume of 352 million m3, Kenering Reservoir the river water to reduce the water pH from acidic was built mainly for hydropower generation and to normal range (pH 6 – 8). During heavy rainfall, flood control (Zarul, 2013). Kenering Reservoir the accumulated lime sediment is then flushed has the second largest surface area in Perak River into Rui River. It is therefore necessary to provide after Temenggor (152 km2) followed by Chenderoh information on the condition factor (length–weight (21 km2) and Bersia (10 km2) Reservoirs. Eight relationship (LWR)) and migratory pattern of sampling sites were selected based on the T. thynnoides in order to assist the stakeholders’ suggestions from local villagers and fishermen on decision–making process. The informed decision the locations of T. thynnoides. The selected sites from stakeholders will ensure the well–being of at Rui River were: S1 (Alai), S2 (Kg Baharu), S3 T. thynnoides in Rui River, Gerik, Perak. as well as (Kg Plang), S4 (Kerunai), S5 (Kuala Rui), while S6 to safeguard the spawning habitat of this species (Kg Perah), S7 (Air Ganda) and S8 (Bersia) were and introduction of sustainable fisheries to the local located in Perak River, named from upstream to community. Thus, this study aimed to determine downstream (Figure 1). Figure 1 Location of sampling sites at Rui River, Gerik, Perak 20 Thai J. Agric. Sci. (2020) Vol. 53 (1) ASST Fish Collection Environmental Data The primary data collection was conducted Temperature (°C), dissolved oxygen (DO) in selected months: May, August, September and (mg/L), pH and electrical conductivity (EC) (μS/cm) October 2015. Samples were collected at eight were measured with a multi–probe metre (YSI 556 sampling sites along the Rui River and Perak River MPS, USA). Turbidity measurement was conducted according to season, which are normal season using the light extinction spectrophotometer (May and August), and wet season (September (HACH 2100P, USA), and in compliance with the and October). Active (scoop net) and passive (gill Hach procedure. All in–situ physico–chemical net) gears were both used in this study for fish parameters involving: (1) pH, (2) temperature, sampling based on the locations of T. thynnoides, (3) DO and (4) turbidity were measured three as informed by the local fishermen and villagers at times on the surface water (10 cm) at littoral zone Rui River and Perak River. During normal season, of each sampling site. Total Suspended Solid the population of T. thynnoides is expected at the (TSS) analysis was carried three times out based lower stream area (S5, S6, S7 and S8), thus, gill on Eaton et al. (2005). nets (passive samples) were used for the study. Four gill nets with mesh sizes of 2.5 cm, 5.0 cm, Data Analyses 7.6 cm and 10.0 cm were used at the littoral areas LWR was calculated by using log of all sampling sites (N = 4 sampling months × 3 W = log a + b log L, where W is the weight of the days × 1 year × 3 replicates × 4 gill net sets = 144 fish (g), L is the total length of the fish (cm), samplings/river). The gill nets were set up from 8.00 a is the intercept, and b is the growth coefficient. am to 6.00 pm before the samples were collected The condition factor (K) was estimated from after three continuous 24 hour intervals (72 hours). K = 100 (W/L3) based on Froese (2006) where W During spawning season, the scoop net was used is the weight of an individual fish specimen as the gill net is not suitable due to the fast water (g), L is the total length (cm), and 100 is a constant. current at sampling sites S1, S2, S3, S4 and S5 One–way ANOVA test was performed by using (N = 2 sampling months × 1 hour × 1 day × 20 IBM SPSS Statistics 21 to distinguish variance replicates × 1 scoop net = 40 samplings/river). The of regression coefficients (b value) and K value length of the net handle was 371 cm, and the net between different group sizes (small, medium and circumference was 97 cm with a depth of 74 cm large). and mesh size of 2.5 cm. The gill net was first set The selected physicochemical parameters up during spawning season at sampling sites S6 data are subjected to descriptive statistics and and S7 from 8.00 am to 12.00 pm, and the samples one–way ANOVA to test the variance of temperature were then collected after three continuous 24 hour and dissolved oxygen between sampling sites. intervals (72 hours). Sampling site S8 was not in- The Pearson’s correlation is performed to cluded because the main objective was to record investigate the correlation among: (i) physicochemical the migration activity upstream of Rui River during parameters (ii) fish condition, and (iii) body weight. the spawning season. Subsequently, the sampling For habitat assessment parameters, non–parametric activity proceeded with scoop net technique from independent–samples Kruskal–Wallis test is used 12.00 pm to 6.00 pm at S1, S2, S3, S4 and S5. to compare and relate the distribution of score The total length of individual fish in cm across all sampling sites. Mann Whitney U test is was taken from the tip of the snout to the extended also used to compare the median between each tip of the caudal fin, using a measuring board. group of sampling sites. Body weight was taken to the nearest gram using an electronic balance (Smith LT2002, China). Thai Journal of Agricultural Science Volume 53 Number 1 January−March 2020 21 THE AGRICULTURAL SCIENCE SOCIETY OF THAILAND RESULTS AND DISCUSSION stream of Rui River and was caught at S2 and S3 (Figure 2). Migration Pattern Among 238 fishes recorded in this study, A total of 238 specimens of T.