World Journal of Fish and Marine Sciences 4 (4): 426-429, 2012 ISSN 2078-4589 © IDOSI Publications, 2012 DOI: 10.5829/idosi.wjfms.2012.04.04.63123

Morphometric and Meristic Studies of Snow Trout zarudnyi (Nikolskii, 1897) as A Threatened Endemic Fish

Ahmad Gharaei

Department of Fisheries, Hamoun International Wetland Research Institute, University of Zabol, Zabol, Iran

Abstract: Schizothorax zarudnyi is one of the endemic and economical species in southeastern of Iran. In order to study the morphometric and meristic characteristics of this species, a total number of 89 specimens (including 25 female and 64 male), ranging from 14.70-32 cm total length and 101.91-176.28 g body weight, were captured from Chahnimeh water reservoirs in Sistan-Iran. The results showed that all morphometric data were not significantly different in both sexes (P>0.05). Based on meristic data, the fin formula can be written as D. IV 8, A. III 5, P. 18, V. 9 and Ll. 96-115. The length-weight relationship in both sexes (female and male), relative length of gut (RLG) and condition factor (K) for the species are y = 0.0118x3.2177, y = 0.0035x3.3349, 1.71 and 1.09±0.03, respectively. These results suggest that the species has allometric growth and characterized as an omnivore in good condition. These finding may provide useful information for the conservation and fishery management in Hamoon International Wetland in future.

Key words: Schizothorax zarudnyi % Length-Weight Relationship % Condition Factor % Allometric Growth

INTRODUCTION in Hamoon Lake and Helmand River system and distributed east southern Asian in Iran, Afghanistan and Fish are one of the cheapest sources of protein in the Pakistan [6]. There is no report on morphometry details world which contains necessary and essential nutrition and length-weight relationship from Sistan waters till now. for body [1]. According to increasing of population in all This species belongs to the subfamily countries, fish may play an important role in economic Schizothoracinae. The genus Schizothorax is included in development of countries in both aquaculture and the primitive Schizithoracinae group. According to some production of ornamental fish [2, 3]. systematic specialists, 39 species and sub-species can be Morphometric and meristic study are vigorous tools included in the genus that is the largest genus of the for measuring discreteness of the same species [4]. subfamily. Schizothorax zarudnyi is endemic of Sistan Indeed, a mathematical data of length-weight relationship and it is common in Helmand River and Hamoun Lake gained from investigation of different sexes and sizes from before dry period, both in Iran and Afghanistan [7]. a specific area is very beneficial tool for research of Considering the need for a research, the present study biology, physiology, ecology, stock assessment, health was undertaken to provide the morphometric and meristic management and population dynamics [5]. characteristics and identify the main factors that threaten The Schizothoracine fish are one of the largest and the species S. zarudnyi and making suggestions of the most diverse groups of the Asian area and its patterns of remnant isolated population in the lower part of Helmand evolutionary mechanism and biogeography are very River and nearby areas. complex. They are specialized for high elevation rivers and show wonderful adaptations. They dominate the torrential MATERIALS AND METHODS mountain streams and plateau lakes of central Asia, the Himalayas and Tibetan plateau. Snow trout Schizothorax Samples of fish were collected from the Chahnimeh zarudnyi [5] (Teleostomi/ / water reservoirs that located at Zahak city, Zabol, Iran. A / ) is one of the most commercial and important total number of 89 specimens of S. zarudnyi (female=25,

Corresponding Author: Ahmad Gharaei, Department of Fisheries, International Hamoun Wetland Research Institute, University of Zabol, Zabol, Sistan and Balouchestan, Iran, P. O. Box: 98615-538. Tel/Fax: +98 542 2232600 426 World J. Fish & Marine Sci., 4 (4): 426-429, 2012 male=64) were caught by means of gill net gears with As comes in table 1: measured factors, the maximum value mesh size 20 mm knot to knot and cast net from July 2010 recorded for intestinal length which alters between 30-64 to February 2011. Fresh fish samples transferred to the cm in female and 24-56 cm in males and the minimum value laboratory of Fisheries Department, University of Zabol, recorded for eye diameter which alters in 0.40-0.90 cm where all morphometric and meristic characteristic were between females and 0.41-0.81 cm in males. Table 2 shows measured according to Ali and McNoon [8]. The that the scale along lateral line alters between 96-115. This Morphometric characters of specimens were measured species is characterized by the large barbels (2 pairs) and with a varnier clliper up to the nearest 0.1 cm and they enlarged scales around the anal fin. The scale sheath weighted with a sensitive electric analytical up to the around the anal papilla and anal fin extends about one nearest 0.01 g (AND, FX-100). Sex was recorded by third to half way between the anal fin origin and the pelvic examination of gonad tissue either with eye or with the aid fin base [11]. The mouth is usually slightly subterminal of a binocular (25×40x). The length-weight relation in both but can be terminal or have the lower jaw projecting sexes were provided by exponential cure fitting as per the slightly. The length-weight relationship for both sexes formula W= aLb [2]. The weight method was used to (female and male) of S. zarudnyi were measured y = analyze the stomach contents [9]. The length of gut was 0.0118x3.2177 and y = 0.0035x3.3349, respectively (Figure 1). measured with the accuracy of 0.5 cm in order to obtain The analysis of covariance shows that the length-weight the Relative Length of Gut (RLG) and the same value was relationship between sexes was not significant (P<0.05). recorded. The Relative Length of Gut (RLG) was The regression coefficient values in both sexes were calculated base on method that explained by [10]. 3.21female and 3.33 male for length-weight relationship Condition factor (k) resulting from feeding habit was suggests positive allometric growth for both sexes. Naeem calculated base on specific formula [11]. and Salam [4] reported that b=3.32 for Aristichthys nobilis. They suggested that increasing of weight in this RESULTS AND DISCUSSION species compared to its cube of length. In many researches, it is proved that b is close to 3 or a bit more of In this study, morphometric and meristic it in fish species of natural waters which indicates that the characteristics were measured in total of 89 samples of S. growth tends to be isometric. But Mohamed and Rao [12] zarudnyi ranging from 14.70-32 cm total length and 101.91- reported that b=2.1052 for Loligo duvauceli and they 176.28 g body weight. All data of Morphometric and suggested the allometric growth pattern for it. Because it meristic factors are listed in Table 1 and 2, respectively. is demonstrate that the values more than three indicate

Table 1: Morphometric measurement of the Schizothorax zarudnyi specimens (n= 89; Female=25, male=64) captured from Chahnimeh water reservoirs, southeastern Iran Female Male pooled ------Measurement (cm) Min Max Mean±SD Min Max Mean±SD Min Max Mean±SD TL (%) / Mean Total length (TL) 20.50 32.00 25.36±3.20 14.70 26.70 21.22±2.99 14.70 32.00 22.57±3.60 Standard length (SL) 15.50 27.20 21.34±3.24 12.00 24.10 17.77±2.92 12.00 27.20 18.93±3.44 83.87% TL Head length (HL) 3.80 6.50 5.15±0.76 2.70 5.60 4.41±0.72 2.70 6.50 4.65±0.80 20.60% TL Pre-ventral length (PV) 5.00 14.5 11.48±4.03 4.7 11.00 8.83±1.89 4.7 14.5 9.58±2.94 42.44% TL Pre-dorsal length (PL) 8.10 13.20 10.84±1.47 6.30 11.40 9.20±1.38 6.30 13.20 9.73±1.60 43.11% TL Postdorsal length (PdL) 10.61 15.41 12.02±1.78 7.02 11.41 9.81±1.29 7.02 15.41 10.53±0.63 46.65% TL Snout length (SL) 1.20 2.50 1.91±0.33 0.80 2.80 1.69±0.41 0.80 2.80 1.76±0.40 7.79% TL Eye diameter (ED) 0.40 0.90 0.76±0.13 0.41 0.88 0.70±0.12 0.40 0.90 0.72±0.12 3.19% TL Body width (BW) 3.60 5.50 4.35±0.65 2.30 4.55 3.57±0.56 2.30 5.50 3.83±0.69 16.96% TL Dorsal fin height (DH) 2.10 3.90 3.26±0.56 1.90 3.90 3.12±0.60 1.90 3.90 3.17±0.59 14.04% TL Dorsal fin base (DB) 1.60 3.10 2.51±0.38 1.40 2.90 2.21±0.37 1.40 3.10 2.31±0.39 10.23% TL Pectoral fin base (PB) 2.40 3.80 2.92±0.33 2.00 3.25 2.66±0.37 2.00 3.80 2.75±0.38 12.18% TL Anal fin height (AH) 2.20 4.10 3.08±0.52 1.60 3.80 2.62±0.53 1.60 4.10 2.77±0.56 12.27% TL Anal fin base (AB) 0.90 1.90 1.51±0.24 0.80 2.40 1.36±0.38 0.80 2.40 1.41±0.31 6.24% TL Intestinal length (IL) 30 64 43.93±10.21 24 56 36.32±8.39 24 64 38.80±9.60 171.90% TL * There is no significant difference (p>0.05) between measured characteristics.

427 World J. Fish & Marine Sci., 4 (4): 426-429, 2012

Fig. 1: Length-weight relationship for female and male of Schizothorax zarudnyi.

Table 2: Meristic counts of the Schizothorax zarudnyi specimens (n= 89) Based on other studies that reported about Clarotes captured from Chahnimeh water reservoirs, southeastern Iran filamentosus (K= 0.77-0.81) [1], Ethmalosa fimbrata Meristic characters Number (0.85±0.015), Ilishia africana (0.96±0.061), Sardinella Dorsal fin rays III (IV)-8 maderensis (0.87±0.072) and Cynoglossus senegalensis Anal fin rays III-6 (0.62±0.011) [1], the condition factor obtained in this Pectoral fin ray 18 study varied slightly with them and showed that S. Ventral fin rays 9 zarudnyi was in good condition. Scale along lateral line 96-115 Recently after a decade of drought in the Gill filaments number 78-95 international wetland of Hamoon, in fact the Gill rakers number 33-41 distribution of S. zarudnyi is limit to Chahnimeh water Pharyngeal teeth rows 3 (2.3.5-5.3.2) reservoirs in Zahak-Iran. Unfortunately, the species population threading due to a combination of over- allometric growth and fishes having b value lower than fishing, environmental degradation, spread of three maintain their specific body shape throughout their disease, pollution and lack of proper management. life [13, 14]. Body scales are cycloid and the breast is Therefore, we hope that the findings of the current naked or sparsely scaled. The color is silvery, the back study will be of help to the environmental and and head darker with indistinct fine dots. The flanks may fishery officials, informing their Future decisions for be spotted with black and some small areas may be more there construction of the fish resources used for human lightly pigmented and appear as indistinct spots or consumption. blotches [7]. The gut of species is elongate and coiled ranging ACKNOWLEDGEMENTS from 24-64 cm. the average relative length of gut (RLG) in S. zarudnyi was measured as 1.71. Al-hussaini [10] stated The authors would like to thank the director manager that if RLG is more than 1, it tends to be herbivore. of Sistan Fishery Department and University of Zabol, Therefore, based on this theory and type of available food for providing the funds and facilities for this study. in its habitat, it can be categorized as an herbivore fish. But information to access type of diet of S. zarudnyi is REFERENCES unavailable. In fish, the condition factor (K) reflects, through its 1. Davies, O.A., 2009. Study of the length-weight variations, information on the physiological state of the relationship and condition factor of five fish species fish in relation to its welfare. From a nutritional point of from Nkoro River, Niger Delta, Nigeria. Curren. Res. view, there is the accumulation of fat and gonadal J. Biol. Sci., 1: 94-98. development [14]. From a reproductive point of view, the 2. Gharaei, A., A. Rahdari and M. Ghaffari, 2010. highest K values are reached in some species [9]. The Schizothorax zarudnyi as a potential species for amount of condition factor (K) is ranging from 0.62 to 1.41, aquaculture. Global conference on aquaculture 2010, averaging 1.09±0.03. Phuket, Thailand, pp: 9-10.

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