Length-weight relationship, condition factor and relative condition factor of Alosa braschnikowi and A. caspia in the southeast of the Caspian Sea (Goharbaran) Hasan Fazli*, Gholamreza Daryanabard, Mehdi Naderi Jolodar, Hassan Mollaei, Hosein Taleshian, Faramarz Bagherzadeh Caspian Sea Ecology Research Center (CSERC), Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research, Education and Extension Organization (AREEO), Sari, Mazandaran, Iran * Corresponding author’s E-mail: hn_fazli@yahoo.com; fazlihasan@gmail.com ABSTRACT The main objectives of the present study were to determine the species composition of Caspian shad, genus Alosa and to estimate the LWR, CF, and Kn of A. braschnikowi and A. caspia during different months in the southeastern coast of the Caspian Sea. Two fishing methods, small mesh size beach seine and gillnet were used from December 2013 through July 2014. A. braschnikowi and A. caspia, were distinguished in the southeastern part of the Caspian Sea (Goharbaran), consisting of 57.1% and 42.9% of the Alosa catch, respectively. The slopes (b values) of the length-weight regression were 3.241 and 2.844 which were significantly different from 3 (P<0.05), indicating positive and negative allometric growth, respectively. The average CF of A. braschnikowi and A. caspia were calculated as 0.72 ± 0.12 and 0.83 ± 0.13, respectively. The average CF for both species were significantly different among months (P<0.001). There was a significantly negative correlation between size classes and CF of A. caspia. The Kn was greater than 1 for A. braschnikowi and lower than 1 for A. caspia indicating good wellbeing of A. braschnikowi as opposed to A. caspia in the southeastern Caspian Sea. Keywords: Shad, Length, Condition factor, Relative condition factor, Caspian Sea. INTRODUCTION Over the past three decades various factors, such as sea-level fluctuations, pollution (Salmanov 1999; Ivanov 2000; Nasrollahzadeh 2010) and the introduction of exotic species have changed significantly the environment of the largest inland water body in the world, the “Caspian Sea”. The new invasive species (Ctenophora, Mnemiopsis leidyi) which was first observed in November 1999 (Ivanov et al. 2000) has subsequently affected the distribution and abundance of plankton species (Ganjian et al. 2010; Roohi et al. 2010), kilka stocks (Karimzadeh 2010; Fazli et al. 2007, 2009) and communities, habitats and ecosystem functioning of the Caspian Sea (Pourang et al. 2016). The Clupeidae is one of the world’s most commercially-important families of fish. Alosa species belong to family Clupeidae and comprise seven genera and 31 species (Whitehead 1985). These species are widely distributed in the Caspian, Black and Mediterranean seas, and also the Atlantic Ocean. Five species of genus Alosa (Caspian herrings) have been reported in Iranian waters of the Caspian Sea, including Caspian marine shad A. braschnikowi (Borodin 1904), Caspian shad A. caspia (Eichwald, 1838), Caspian anadromous shad A. kessleri (Grimm 1887), shad A. saposchnikowii (Grimm 1887) and Agrakhan shad A. sphaerocephala (Berg 1913) (Abdoli & Naderi 2008; Abbasi 2017; Esmaeili et al. 2018). During the last century, genus Alosa has been a major item of the Caspian and herring fisheries in almost the entire coast of the Caspian Sea. In the years 1885-1963, the maximum catch of herrings was higher than 300000 metric tons and averaged 104000 metric tons (Malkin & Andrianova 2008), but during the last two decades, their annual catch declined sharply to less than 6000 metric tons in the Caspian Sea. Caspian J. Environ. Sci. Vol. 19 No. 1 pp. 105~113 DOI: ©Copyright by University of Guilan, Printed in I.R. Iran Received: May 3. 2020 Accepted: Oct. 17. 2020 Article type: Research 106 Length-weight relationship, condition… For example, in the years 1993–2012, the catch ranged from 144 to 932 (averaged 530) metric tons in Iran and ranged from 72 to 4710 (averaged 1220) metric tons in other neighboring countries of the Caspian Sea (data source: Fishstat Plus, FAO Fisheries Department, Fishery Information, Data and Statistic Unit; FISHSTAT Plus: Universal software for fishery statistical time series). Knowledge of length-weight relationship, condition factor, growth, and recruitment are important tools for the adequate management of any fish species (King 2007). The length-weight relationship (LWR) can give information on the stock condition, condition indices and several aspects of fish population dynamics (Bagenal & Tesch 1978; Gonçalves et al. 1997). The condition factor (CF) is used to compare the condition, fatness or well-being of the fish (Bagenal & Tesch 1978) and the relative condition factor (Kn) is influenced by many environmental and biological factors (Le Cren 1951). Despite the commercial importance of Caspian shads, knowledge on the life history parameters of these fishes is limited to the spatiotemporal habitat preferences of Alosa (Haghi Vayghan et al. 2016), length-weight relationships (Ghotbi-Jokandan et al. 2015), length, weight, age and sexuality (Taghavi et al. 2016), feeding habits (Abbasi & Sabkara 2004; Abdollahpour et al. 2007; Afraei Bandpei et al. 2012; Jalili et al. 2013; Azizov et al. 2015) as well as biology and stocks (Malkin & Andrianova 2008). Therefore, the main objectives of the present study were to determine the species composition of genus Alosa and to estimate the LWR, CF, and Kn of A. braschnikowi and A. caspia in the southeastern coast of the Caspian Sea. MATERIALS AND METHODS The sampling area, Goharbaran is located beside the Amirabad port and Neka Power Plant in the southeastern part of the Caspian Sea. Two fishing methods, small mesh size beach seine (SBS) in depths ≤ 2 m and multi-mesh gill net (MGN) (30 m length and 4 m height, with 22, 26, 33, 40, 45 and 56 mm mesh sizes, knot to knot) in three depths 5, 7 and 10 m were used during December 2013 to July 2014. The total length (TL) was measured to the nearest 1 mm and total weight to the nearest 1 g. The length-weight relationship was derived by applying an exponential regression as the following equation: 𝑊 = 𝑎𝑇𝐿𝑏 where W is the total weight (g), TL, the total length (cm), and a and b are parameters to be estimated (Ricker 1975). Parameters estimation was conducted by least-squares linear regression on log-log transformed data: ln (W) = ln (a) + b × ln (TL). T-test for departure from isometry (b = 3) was carried out using the following formula (Pauly 1984): 𝑠. 𝑑. ln⁡(𝑇𝐿) |𝑏 − 3| 𝑡= × × √𝑛 − 2 𝑠. 𝑑. ln⁡(𝑊) √1 − 𝑟 2 where s.d.ln (TL) and s.d.ln (W) are standard deviations’ natural logarithm of the total length (cm) and weight, respectively; a and b are regression parameters and R2 is correlation coefficient between length and weight and n is sample size. The condition factor (CF) was calculated as the following equation (Froese 2006): 𝑊 𝐶𝐹 = 3 × 100 𝑇𝐿 where W (g) is weight and TL (cm) is the total length. The relative condition factor (Kn) compensates for changes in form or condition with an increase in length and was calculated using the following equation (Froese 2006): 𝑊 𝐾𝑛 = 𝑎𝑇𝐿𝑏 where W is weight (g), TL is the total length (cm), and a and b are the exponential form of the intercept and slope, respectively, of the logarithmic length-weight equation. The Pearson correlation coefficient was calculated to investigate the relationship of Kn and CF length. The comparison between the average values for months was carried out through analysis of variance (ANOVA). The Tukey pairwise test for multiple comparisons was used to assess differences between the months (Zar 2010). Statistical analyses were performed using SPSS 18 and Excel 2013 software packages. RESULTS A total of 308 caught specimens belonged to two species of A. braschnikowi and A. caspia, consisting of 176 (57.1%) and 132 (42.9%) of the catch, respectively. The specimens of A. braschnikowi were caught during December 2013 and January-April 2014, while those of A. caspia in December 2013, May and July 2014 (Fig. 1). Caspian J. Environ. Sci. Vol. 19 No. 1 pp. 105~113 DOI: ©Copyright by University of Guilan, Printed in I.R. Iran Received: May 3. 2020 Accepted: Oct. 17. 2020 Article type: Research Fazli et al. 107 The length frequency of the two species shows that the smallest specimen was caught by SBS (Figs. 2 - 3). Fig. 1. Monthly species composition of Alosa in catches in the southeastern Caspian Sea. Fig. 2. Length frequency of Alosa braschnikowi in two fishing methods (small mesh size beach seine and gill net) in the Southeast Caspian Sea. Given the whole samples, the total length and weight of A. braschnikowi ranged from 51 to 440 mm and 1.0 to 736.0 g by averaged (± SD) 144.0 (± 65.9) mm and 44.5 (± 90.0) g, while in the case of A. caspia, it ranged from 31 to 220 mm and 0.3 to 87.7 g by averaged (± SD) 110.8 (± 38.0) mm and 14.8 (± 14.7) g, respectively. Length-length relationships and the coefficient of determination (R2) for A. braschnikowi was calculated as W = 0.0038 × FL3.241 (R2 = 0.989, n = 176) while for A. caspia it was W = 0.0119 × FL2.844 (R2 = 0.98, n = 132). The estimations of “b” were 3.241 and 2.844 which were significantly different from 3.0 (t-test; t = 6.9, p < 0.001 and t = 4.4, p < 0.001), indicating positive and negative allometric growth for the two species, respectively (Fig. 4). The average CF of A. braschnikowi was 0.72 ± 0.12. Monthly variations of CF was significantly different (F = 19.1, P < 0.001; Table 1). The Kn was 1.10 ± 0.141 and a significant difference was found among months (F = 4.0, P < 0.004; Table 1). The highest values of CF and Kn were 0.85 and 1.21 in February, respectively. The correlation between TL and CF was not statistically significant (R2 = 0.36, P > 0.05; Fig. 5). A perusal of the data on the Kn values showed that the parameter was higher than 1 in all size classes except the size class of 371-410 mm. In the size class of 291-330 mm, Kn was the highest (1.39). The average CF and Kn of A. caspia were 0.83 ± 0.13 and 0.87 ± 0.12, respectively. There were statistically significant differences in both parameters among the months (F = 10.4; P < 0.001 and F = 8.7, P < 0.001, respectively; Table 2). The highest values of CF and Kn were 0.88 and 0.91 in July, respectively. The correlation between TL and CF was statistically significant (R2 = 0.42, P < 0.05; Fig. 6). The Kn values showed that the parameter was lower than 1 in all size classes. In the size class of 211-230 mm, Kn was the highest (0.95). Caspian J. Environ. Sci. Vol. 19 No. 1 pp. 105~113 DOI: ©Copyright by University of Guilan, Printed in I.R. Iran Received: May 3. 2020 Accepted: Oct. 17. 2020 Article type: Research Length-weight relationship, condition… 108 Fig. 3. Length frequency of Alosa caspia in two fishing methods (small mesh size beach seine and gill net) in the Southeast Caspian Sea. Fig. 4. Length-weight relationship of Alosa braschnikowi (A) and Alosa caspia (B) in the Southeast Caspian Sea. Table 1. Monthly average condition factor (CF) and relative condition factor (Kn) of Alosa braschnikowi in the Southeast Caspian Sea. Parameter CF Kn Month (year) December (2013) January (2014) February (2014) March (2014) April (2014) Total December (2013) January (2014) n 14 115 5 36 5 175 14 115 Mean 0.82b 0.67a 0.85b 0.81b 0.76ab 0.72 1.15 1.07 S.D. 0.148 0.061 0.169 0.149 0.120 0.117 0.153 0.109 Min-Max 0.54-1.02 0.52-0.87 0.70-1.03 0.57-1.17 0.64-0.93 0.52-1.17 0.84-1.37 0.51-1.38 February (2014) 5 1.21 0.211 0.94-1.47 36 5 175 1.15 1.04 1.10 0.187 0.157 0.141 0.93-1.90 0.88-1.26 0.51-1.90 March (2014) April (2014) Total Fig. 5. Variation of mean condition factor (CF) and relative condition factor (Kn) of Alosa braschnikowi in size classes in the southeastern Caspian Sea. Caspian J. Environ. Sci. Vol. 19 No. 1 pp. 105~113 DOI: ©Copyright by University of Guilan, Printed in I.R. Iran Received: May 3. 2020 Accepted: Oct. 17. 2020 Article type: Research Fazli et al. 109 Table 2. Monthly average condition factor (CF) and relative condition factor (Kn) of Alosa caspia in the Caspian Sea. Parameter K Kn Month (year) December (2013) May (2014) July (2014) Total December (2013) May (2014) July (2014) n 44 18 70 132 44 18 70 Mean 0.78a 0.80a 0.88b 0.83 0.81a 0.80a 0.90b S.D. 0.111 0.049 0.132 0.129 0.127 0.048 0.124 Min-Max 0.40-1.07 0.71-0.88 0.60-1.30 0.40-1.30 0.44-1.19 0.72-0.88 0.65-1.35 Total 132 0.87 0.124 0.44-1.35 Fig. 6. Variation of mean condition factor (CF) and relative condition factor (Kn) of Alosa caspia in size classes in the Caspian Sea. DISCUSSION In the last century, genus Alosa has been a major item of the Caspian and herring fisheries in almost the entire coast of the Caspian Sea. Five species of genus Alosa have been reported in the Iranian waters of the Caspian Sea including A. braschnikowi, A. caspia, A. kessleri, A. saposchnikowii and A. sphaerocephala (Abdoli & Naderi 2008; Abbasi 2017; Esmaeili et al. 2018) . However, in the present study, only two species A. braschnikowi and A. caspia were found in the south-eastern part of the Caspian Sea (Goharbaran) and the slope (b) of the lengthweight relationships for the two species were within the expected range of 2.5–3.5 (Froese 2006), i.e., 2.844 and 3.241 for A. caspia and A. braschnikowi, respectively. In contrast, Taghavi Jelodar et al. (2016) and GhotbiJokandan et al. (2015) reported lower b values for A. braschnikowi (2.93 and 3.10 in the southern Caspian Sea, respectively). In other study, Taghavi Jelodar et al. (2016) and Patimar et al. (2011) reported lower values (2.385, 2.626 and 2.796, in the southern, south middle and south-western Caspian, respectively), while in the case of A. caspia, higher values (2.98 and 3.272, in the southern and southeastern Caspian Sea) were reported (Patimar et al. 2011; Ghotbi-Jokandan et al. 2015) (Table 3). According to Bagenal and Tesh (1978) and Froese (2006), the sampling gear, geographic location and the associated environmental conditions such as water temperature, which is the determining factor of feeding capacity, season, stomach fullness, disease and parasite loads can affect the value of b, hence the changes in this parameter. In the present study, the highest mean values of CF were 0.85 and 0.88 in February and July, respectively. According to Kumolu & Ndimele (2010), the condition factor reflects information on the physiological status of fish in relation to welfare, and higher values indicate favorable environmental conditions (Blackwell et al. 2000). Also, there was a significantly negative correlation between size classes and CF in A. caspia (Fig. 6). CF can be influenced by season, sex, type of food, age of fish, reserved fat and environmental conditions (Bagenal and Tesch 1978; Abowei 2009). The Kn indicates the suitability of the environment for fish growth and the general well-being of the fish. A Kn>1, indicates good well-being of the fish, while a value <1 reflects poor condition. In the present study, the Kn was greater than 1 for A. braschnikowi indicated that the well-being of the fish was good, while lower than 1 for A. caspia exhibited its low well-being in the Southeast Caspian Sea. Also, a seasonal/monthly variation of Kn can be influenced by maturity, gonad development, feeding activity and several other factors (Le Cren 1951; Bagenal & Tesch 1978; Simon et al. 2012). A. braschnikowi feed mainly on small clupeids, gobies, and atherinids (Vetchanin 1984; Whitehead 1985; Afraei Caspian J. Environ. Sci. Vol. 19 No. 1 pp. 105~113 DOI: ©Copyright by University of Guilan, Printed in I.R. Iran Received: May 3. 2020 Accepted: Oct. 17. 2020 Article type: Research Length-weight relationship, condition… 110 Bandpei et al. 2012). Vetchanin (1984) reported that the diet of A. braschnikowi in the Southeast Caspian Sea was composed of 85% anchovy (Clupeonella engrauliformis) as well as some gobies (genus Neogobius) and shrimps. However, in the years 2003-2004 the diet significantly shifted to atherinid fish (Atherina caspia) (Afraei Bandpei et al. 2012). In contrast, A. caspia in the southern Caspian Sea feed mainly on zooplankton (95.0%) and phytoplankton (Rhizosolenia and Sprirogyra) (4.5%) (Abbasi & Sabkara 2004; Abdollahpour et al. 2007). Table 3. The length-weight relationships in Alosa braschnikowi and A. caspia from different locations. Alosa braschnikowi Study area Southern Caspian Sea, Iran Southern Caspian Sea, Iran Southeastern Caspian, Iran Alosa caspia Southern Caspian Sea, Iran Southern Caspian Sea, Iran Southeastern Caspian, Iran South middle Caspian, Iran Southwestern Caspian, Iran Southeastern Caspian, Iran W (g) Min-Max 37-1085 91.3-700.8 1.0 – 736.0 b r2 147 54 176 TL (cm) Min-Max 17.4-47.0 21.0-42.5 5.1-44.0 3.10 2.93 3.241 0.977 0.98 0.989 Ghotbi-Jokandan et al. 2015 Taghavi Jelodar et al. 2016 Present study 113 60 159 97 145 132 11.6-27.6 23.0-31.0 ?? – 28.3 ?? – 27.7 ?? – 26.9 3.1-22.0 11-164 94.9-238.7 ?? – 171.8 ?? – 145.7 ?? – 138.3 0.3-87.7 2.98 2.385 3.272 2.626 2.796 2.844 0.97 0.946 0.872 0.777 0.933 0.980 Ghotbi-Jokandan, 2015 Taghavi Jelodar et al. 2016 Patimar et al. 2011 Patimar et al. 2011 Patimar et al. 2011 Present study N Author (s) Over the past three decades, the new invasive species (Ctenophora, Mnemiopsis leidyi) has affected the whole ecosystem of the Caspian Sea (Roohi et al. 2010; Pourang et al. 2016). It feeds aggressively on zooplankton (Mutlu 1999) which has significantly reduced the abundance and distribution of zooplankton species and their predators, especially two main pelagic fish stocks of kilka, C. engrauliformis and C. grimmi (Fazli et al. 2007, 2009; Roohi et al. 2010; Pourang et al. 2016). Afraei Bandpei et al. (2012) concluded that A. braschnikowi displays an opportunistic feeding behavior and feeds on a variety of prey items as well as a wider range of food items and is adapted to the conditions, resulting in its good well-being. Due to the food competition of A. caspia with two species of kilka and especially M. leidyi, the well-being of the fish was not good in the southeastern Caspian Sea. ACKNOWLEDGMENT This work was funded by Iran Water and Power Resources Development Co. and Iranian Fisheries Research Organ-ization/IFRO which supported the Project Number: 4-76-12-95102. We wish to thank Dr. Salmanmahiny for improving the quality of the manuscript. 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Prentice Hall, Upper Saddle River, New Jersey, 946 p. Caspian J. Environ. Sci. Vol. 19 No. 1 pp. 105~113 DOI: ©Copyright by University of Guilan, Printed in I.R. Iran Received: May 3. 2020 Accepted: Oct. 17. 2020 Article type: Research ‫‪Fazli et al.‬‬ ‫‪113‬‬ ‫روابطه بین طول – وزن‪ ،‬ضریب چاقی و ضریب چاقی نسبی ‪ Alosa braschnikowi‬و ‪A.‬‬ ‫‪ caspia‬در سواحل جنوب شرقی دریای خزر (گهرباران)‬ ‫حسن فضلی*‪ ،‬غالمرضا دریانبرد‪ ،‬مهدی نادری جلودار‪ ،‬حسن مالئی‪ ،‬حسین طالشیان‪ ،‬فرامرز باقرزاده‬ ‫پژوهشکده اکولوژی دریای خزر‪ ،‬موسسه تحقیقات علوم شیالتی کشور‪ ،‬سازمان تحقیقات‪ ،‬آموزش و ترویج کشاورزی‪ ،‬ساری‪،‬‬ ‫ایران‬ ‫(تاریخ دریافت‪ 99/02/41 :‬تاریخ پذیرش‪)99/07/22 :‬‬ ‫چکیده‬ ‫هدف اصلی این مطالعه تعیین ترکیب گونهای شگ ماهیان خزر جنس ‪ Alosa‬و برآورد رابطه طول‪ -‬وزن‪ ،‬ضریب چاقی و‬ ‫ضریب چاقی نسبی گونههای ‪ A. braschnikowi‬و ‪ A. caspia‬در ماههای مختلف در سواحل جنوب شرقی دریای خزر‬ ‫(گهرباران) بود‪ .‬برای تهیه نمونه از دو روش صید‪ ،‬پرهریز چشمه و دام گوشگیر در ماههای آذر سال ‪ 4992‬الی تیر سال ‪4999‬‬ ‫استفاده شد‪ .‬دو گونه ‪ A. braschnikowi‬و ‪ A. caspia‬با فراوانی نسبی به ترتیب ‪ % 77/4‬و ‪ % 12/9‬از جنس ‪Alosa‬‬ ‫شناسائی شد‪ .‬مقدار شیب خط (مقدار ‪ )b‬رابطه طول‪ -‬وزن دو گونه به ترتیب ‪ 9/214‬و ‪ 2/411‬بود که با مقدار عدد ‪ 9‬اختالف‬ ‫معنیداری داشته (‪ ) P < 0.05‬و به ترتیب بیانگر رشد آلومتریک مثب و منفی بود‪ .‬میانگین ضریب چاقی گونههای ‪A.‬‬ ‫‪ braschnikowi‬و ‪ A. caspia‬به ترتیب ‪ 0/72 ±0/42‬و ‪ 0/49 ±0/49‬محاسبه شد‪ .‬ضریب چاقی هر دو گونه در ماههای‬ ‫مختلف دارای اختالف معنیداری بود (‪ .)P < 0.001‬همبستگی منفی معنیداری بین کالسهای طولی و ضریب چاقی گونه‬ ‫‪ A. caspia‬وجود داشت‪ .‬ضریب چاقی نسبی گونه ‪ A. braschnikowi‬بزرگتر از عدد ‪ 4‬و گونه ‪ A. caspia‬کمتر از ‪4‬‬ ‫بود که بیانگر به ترتیب وضعیت مطلوب و نامطلوب سالمت دو گونه در سواحل جنوب شرقی دریای خزر میباشد‪.‬‬ ‫*مولف مسئول‬ ‫‪Bibliographic information of this paper for citing:‬‬ ‫‪Fazli, H, Daryanabard, G, Naderi Jolodar, M, Mollaei, H, Taleshian, H, Bagherzadeh, F 2021, Length-weight‬‬ ‫‪relationship, condition factor and relative condition factor of Alosa braschnikowi and A. caspia in the southeast‬‬ ‫‪of the Caspian Sea (Goharbaran), Caspian Journal of Environmental Sciences, 19: 105-113‬‬ ‫‪Copyright © 2021‬‬ ‫‪Received: May 3. 2020 Accepted: Oct. 17. 2020‬‬ ‫‪Article type: Research‬‬ ‫‪Caspian J. Environ. Sci. Vol. 19 No. 1 pp. 105~113‬‬ ‫‪DOI:‬‬ ‫‪©Copyright by University of Guilan, Printed in I.R. Iran‬‬