E. Karimian et al. / Environmental Resources Research 5, 1 (2017) 101 Environmental Resources Research Vol. 5, No. 1, 2017 GUASNR The influence of environmental parameters on the abundance of monkey goby, Neogobius pallasi (Berg, 1916), in Kaboodval and Shirabad Streams, Golestan Province, Iran E. Karimian1, R. Ghorbani*2, A. Kamali2, A. Salmanmahiny2 1Graduate Student for M.Sc., Department of Fisheries and Environment, Gorgan University of Agricultural Sciences and Natural Resources 2 Department of Fisheries and Environment, Gorgan University of Agricultural Sciences and Natural Resources Received: February 2015 ; Accepted: July 2016 Abstract1 The aim of this study was to determine the influence of environmental parameters on the abundance of monkey goby Neogobius pallasi. A total of 526 and 163 individuals of monkey goby specimens were caught by electro-shocker in the Kaboodval and Shirabad Streams, respectively. The ranges of total length of the specimens in Kaboodval and Shirabad Streams were respectively 22-137.55 mm and 32.64-137.97 mm. All the specimens of both streams belonged to the 5th age group (0+-4+). The morphological, hydrological, biological and physicochemical parameters were investigated in both streams. The results showed that the hydrological parameters and vegetation coverage in the Kaboodval Stream and also, water velocity and depth in the Shirabad Stream had significant relationship with the monkey goby abundances (P<0.05). There was no significant difference between physicochemical parameters and monkey goby abundances in both streams. Moreover, the positive effect of elevation and negative influence of distance to road were observed but they were not significant. Keywords: Environmental parameters, Monkey goby, Kaboodval Stream, Shirabad Stream. * Corresponding author; [email protected] 102 E. Karimian et al. / Environmental Resources Research 5, 1 (2017) Introduction water (Berg, 1964; Barimani, 1977; Abdoli, Rivers and streams as one of the most 1999). One of the fresh water species in this important habitats for inland water aquatics, family is monkey goby, Neogobius pallasi have not received due attention in relevant (Berg, 1964), which has been reported as an studies. Studying the ecology of rivers and endemic species in the Caspian Sea in some streams needs information about their studies (Kiabi et al., 1999) and as a physical structure, national and topographical none-native and invasive species from situation and also, biotic and abiotic Europe in some other studies (Biro, 1972; parameters. Streams are located in different Skora and Stolarski, 1993). climates, vegetation coverage, topography In the study conducted in the non- and geology and their biological communities Iranian coasts of the Caspian Sea are also affected by human activities and (Rahimov, 1986), it is found that creation of regional and global climate changes. Different sub-species and native populations in the environmental parameters are effective in Caspian Sea depends on the differences in the density and diversity of biological climate, depth, salinity, water temperature, communities, such as hydrological parameters kind of substrate and other environmental (Marchetti and Moyle, 2000; Lamouroux parameters in different areas. In addition, in and Cattane´o, 2006), physical parameters other research performed in the Lake e.g. the kind of substrate and vegetation Balaton (Keresztessy, 1996), the presence coverage (Growns et al., 2003) as well as of monkey gobies has been reported in the chemical parameters (Matthews, 1998; rocky-pebbly substrates with the high Lappaleinen and Soininen, 2006). It is vegetation coverage. Patimar and Abdoli important to understand the effects of (2009) investigated the sensitivity of environmental parameters on the fish monkey goby population in relation with density and diversity and fish conservation. ecological parameters (flood) in the On the other hand, fish diversity modeling Zaringol Stream, Golestan Province of Iran. is very important in ecology (Guisan and In this study, the influences of different Thuiller, 2005) and the influences of environmental parameters on the abundance environmental parameters can helo in of monkey gobies populations in two prediction of the species frequency. These Kaboodval and Shirabad Streams were models are usually utilized for better studied towards better conservation and conservation and management of natural management of this species living in fresh resources and ecosystems (Kennard et al., waters. 2006). The biological and ecological studies of different fish species are necessary for Materials and Methods stock conservation and recreation and The study was performed in the provide an appropriate ecological recognition Kaboodval and Shirabad Streams located in of the ecosystems (Kazancheev, 1981). 36º 53ʹN-54º 54ʹ E and 36º 52ʹN-37º 57ʹE, Some researchers believe that in studies of respectively. These streams emanate from water resources, fish communities should the northern slopes of the eastern Alborz be considered more compared to other Mountains and then join the Gorganrood elements (Bagenal, 1978). River and finally empty into the Caspian Several species of family Gobiidae are Sea (Afshin, 1994). The sampling stations known as marine species and live in were determined according to their brackish and saline waters. Approximately accessibility and the kind of substrate. 37 species and sub-species of Gobiidae Because of the short length of Kaboodval exist in the Caspian Sea (Rahimov, 1986); and Shirabad Streams, 5 and 3 sites were however, there are some species of sampled from them in summer, respectively Gobiidae that permanently live in fresh (Figure 1). E. Karimian et al. / Environmental Resources Research 5, 1 (2017) 103 Figure 1. The study area and sampling stations (black squares) in Kaboodval and Shirabad Streams in Golestan Province, Iran. The substrates of the Kaboodval and invertebrates) and physicochemical parameters Shirabad Streams are composed of rock and (e.g. water temperature, dissolved oxygen, pebble. Therefore, the specimens were phosphate, water turbidity, pH, EC and collected by electro-shocker (1.7 KW; salinity). Physicochemical parameters were 100-200 V; 10 A. direct electricity) measured by Water Checker. (Bagenal, 1978; Copp et al., 2005). All specimens were fixed in 10% formalin and Fish Biomass transported to the laboratory. The body LeCren method which is based on catch mass was weighed for each specimen to 0.1 per unit effort (CPUE), was used for g accuracy. Total length of the individuals determining the frequency of monkey goby were measured to 0.01 mm accuracy using populations in different stations. The a vernier caliper. The age of specimens was specimens were collected two times in each determined based on otoliths through a station (Bagenal, 1978) and the number of binocular microscope that magnified the specimens was measured by the formula ring patterns for 15 times. below: The fish specimens were identified by 2 identification keys (Abdoli, 1999; Kottelat C1 N and Freyhof, 2007; Coad, 2012). It C C 1 2 should be noted that the scientific name of monkey goby has changed from Neogobius where C1 and C2 are the first and second fluviatilis (Pallasi, 1814) to Neogobius efforts of catching the specimens, pallasi (Berg, 1916) (Coad, 2012). Habitat respectively and N is the number of variables can be classified by means of specimens. describing the size and features of streams (Allan, 1995). These variables include Sampling of benthic macroinvertebrates parameters in the stream basin (e.g. the Different kinds of aquatic insects elevation of study area, distance to road, the (Diptera, Ephemeroptera and Trichoptera), slope of study area and drainage), Crustaceans and fish larvae (in older morphological parameters (e.g. the kind of specimens) have been mentioned as substrate and stream width), hydrological monkey goby nutrition in the inland waters parameters (e.g. the average of water of the southern Caspian basin (Abdoli, discharge and stream depth), biological 1999; Abdoli and Rahmani, 2001). parameters (the percentage of vegetation Therefore, the density of benthic coverage and the density of benthic macro macroinvertebrates can be an important 104 E. Karimian et al. / Environmental Resources Research 5, 1 (2017) biological parameter in the density of Results monkey gobies populations. The samples of Using several maps and applying benthic macroinvertebrates were collected necessary corrections and rectifications, by Surber sampler, fixed in 4% formalin different parameters of sub-catchments (e.g. and transported to the laboratory for elevation, slope, the mean distance to road counting and identification. The benthic and the density of drainages) were extracted macroinvertebrates were identified using and the influences of these parameters on the Atlas of Caspian Sea Invertebrates the abundance of monkey goby populations and other identification keys. Regression were investigated. The comparison of and correlation analyses were used for slopes in the Kaboodval and Shirabad investigating the relationship between sub-catchments showed that the slope environmental parameters and the abundance in Shirabad is higher than Kaboodval of monkey goby populations in the (Table 1). Kaboodval and Shirabad Streams. Table 1. Comparison of different environmental parameters between the Kaboodval and Shirabad Streams in Aug. 2008. Station 1 2 3 4 5 Parameter Stream K S K S K S K S K S Physicochemical parameters Water