Int. J. Aquat. Biol. (2023) 11(1): 30-33 ISSN: 2322-5270; P-ISSN: 2383-0956 Journal homepage: www.ij-aquaticbiology.com © 2023 Iranian Society of Ichthyology Short Communication Length-weight relationships of three endemic fish species of the Arabian Peninsula Amir Hassan Masoumi1, Saud M. Al Jufaili2, Fereshteh Pourhosseini1, Hamid Reza Esmaeili1 1Ichthyology and Molecular Systematics Research Laboratory, Department of Biology, School of Science, Shiraz University, Shiraz, Iran. 2Department of Marine Science and Fisheries, Sultan Qaboos University, Muscat, Oman. Article history: Received 30 October 2022 Accepted 29 December 2022 Available online 2 5 February 2023 Keywords: Growth coefficient, Cube law, Population dynamics, Oman. Abstract: Length-weight relationships (LWRs) were evaluated for three endemic fish species collected from the north and south of inland waters of Oman in 2022 including Garra sindhae, G. smartae, and Oxyurichthys omanensis by using foldable shrimp and crab fishing traps (mesh size of 3*3mm) and hand nets (mesh size of 3*3mm). The parameter of b for all three species was between the estimated ranges of 2.5-3.5 as proposed for different other fish species, and there was high and significant coefficient of determination for all three species (0.87-0.984). Introduction Parameters of length-weight relationships (LWRs) for marine and freshwater fishes have a historical background in ichthyology and fisheries science; hence, these relationships have been estimated for many commercial and noncommercial species (Esmaeili et al., 2014, 2015; Keivany et al., 2015; Sadeghi and Esmaeili, 2018). At the beginning of the 20th century, length-weight relationships were implemented to evaluate fish population conditions in fish farms (Froese, 2006; Jellyman et al., 2013; Purrafee Dizaj et al., 2020). LWRs play a significant role in fisheries science (Esmaeili and Ebrahimi, 2006; Esmaeili et al., 2014, 2015; Hossain and Sultana, 2014; Sadeghi and Esmaeili, 2018; Mouludi-Saleh and Eagderi, 2019; Al-Jufaili et al., 2021). LWRs can be used to estimate unmeasured length or weight. As the LWRs data are the most available information in fisheries sciences, therefore, these parameters make a backbone in population dynamic investigations such as sex ratio, age at first maturity, longevity, and fecundity (Esmaeili et al., 2014, 2015; Sadeghi and Esmaeili, 2018; Mouludi- Saleh and Eagderi, 2019). To date, LWRs for many endemic fishes of the Correspondence: Hamid Reza Esmaeili DOI: https://doi.org/10.22034/ijab.v11i1.1789 E-mail: hresmaeili@shirazu.ac.ir DOR: https://dorl.net/dor/20.1001.1.23830956.2023.11.1.4.4 Middle East, including the Arabian Peninsula, have been reported; these parameters have not been estimated for several other endemics, especially those restricted to the Arabian Peninsula. However, biological information, especially LWRs for three endemic fishes: Garra sindhae Lyon, Geiger and Freyhof, 2016, Garra smartae Krupp and Budd, 2009 (Cyprinidae: Labeoninae); and eyebrow goby Oxyurichthys omanensis Zarei, Al Jufaili and Esmaeili, 2022 (Gobiidae: Gobionellinae). Garra sindhae is found in the south of Oman near Salalah in the Wadi Andhur. Garra smartae have been recorded from two localities, including the Wadis Hadhabram and Laggashalyon. Oxyurichthys omanensis is restricted to the Yeti estuary, Oman (Esmaeili et al., 2022; Zarei et al., 2022). This study aims to provide LWRs for these three species of the Arabian Peninsula. Materials and Methods Specimens of G. sindhae, G. smartae, and O. omanensis were collected from the Wadis Andhur; Hadhabram and Laggashalyon, and Yeti, respectively, using foldable shrimp and crab fishing traps (mesh size of 3*3 mm, 3 nets for overnight) 31 Int. J. Aquat. Biol. (2023) 11(1): 30-33 (Fig. 1). The sampling was conducted twice in winter and summer 2022. The total length (TL), Standard length (SL), and fork length (FL) of the individuals were measured to the nearest 0.1 mm using digital calipers, and total weight (TW) to the nearest 0.01 g using a digital electronic balance. The parameters of length and weight relationships were computed with the formula W=aLb and expressed by linear regression of the log- transformed length and weight which gives the linear equation (Koutrakis and Tsikliras, 2003): Log W = Log a + b Log L, where W= total weight in grams, L= length (total, standard and fork) in cm, a = a constant being the initial growth index, and b= growth coefficient. Prior to regression analysis, log– log plots of length and weight values were performed for visual inspection of outliers (Froese, 2006). The significance of the regression between length-weight relationships of fishes was tested by ANOVA. Bailey's t-test was used to determine whether b value significantly deviated from the expected cube value of 3. Data were analyzed statistically by using IBM SPSS (Version 22) statistical software package. Results The parameters of length-weight relationships are given in Table 1. LWRs were significant for all three species (P<0.001) with a high coefficient of determination (r2≥0.870). The b values of 2.627- 3.285, 2.772-2.965, and 2.999-3.362 were estimated for Garra sindhae, G. smartae, and O. omanensis respectively, based on standard length. Bailey's t-test reveals that the b values significantly deviated from 3. Discussion Length and weight measurements are generally recorded in fisheries surveys as these parameters make a foundation for other research and management investigations in fisheries sciences. The b-value of LWR is an exponent commonly different among fish species being 2.5 to 4. The slope parameter, b, is used to describe the growth pattern of a fish: allometric growth (b ≠ 3) represents a fish that has less girth as length increases (b < 3) or has an increase in plumpness as length increases (b > 3) and occurs more commonly among fish species compared to isometric growth. Isometric growth (b = 3) describes a fish that grows with an unchanging body form. Therefore, the b value represents the well-being and general morphology of fishes (Esmaeili et al., 2014, 2015; Sadeghi and Esmaeili, 2018; Mouludi-Saleh and Eagderi, 2019). LWRs of some Garra species in Oman are available e.g. b- Figure 1. Collection sites of three endemic fish species in the Arabian Peninsula (Oman). 32 Masoumi et al./ Length-Weight relationships of three endemic fish species value of G. barreimiae Fowler and Steinitz, 1956, and G. longipinnis Banister and Clarke, 1977, estimated for TL, FL, and SL are 3.441, 3.470, 3.269, and 3.104, 3.098, and 3.253, respectively (Al Jufaili et al., 2021). Compared with the studied G. sindhae, G. smartae in this paper, they have a higher b value. This can be due to the habitat characteristics of these two studied fishes being restricted to small ponds or streams with no co-existing species and low vegetation. For the genus Oxyurichthys, the b values have been reported to be 2.677 and 3.057 for O. microlepis (Bleeker, 1849) from the Pulicat lagoon in India and O. petersi (Klunzinger, 1871) from the eastern Mediterranean coast of Turkey respectively (Taskavak and Bilecenoglu, 2001; Nallathambi et al., 2020). The b value of 2.999-3.362 reported here for O. omanensis is close to O. petersi. Previous studies suggested that variation in b- value in fishes might be because of several factors like season, species, habitat, sex, gonad maturity, diet, stomach fullness, health, preservation techniques, and locality (Le Cren, 1951; Esmaeili, 2001; Sadeghi and Esmaeili, 2018). One or more of the above factors could be the reason for variation in the LWRs in studied species. In conclusion, this study provides basic information about the LWRs of three endemic fishes, including two Garra species and a goby from the Arabian Peninsula (Oman), which will be useful in their fisheries and future conservation management. Acknowledgments This research results from the scientific collaboration between Sultan Qaboos and Shiraz Universities. References Al Jufaili S.M., Sayyadzadeh G., Jawad L., Esmaeili H.R. (2021). Length-weight relationships of five fish species from the inland waters of Oman. Iranian Journal of Ichthyology, 8(1): 63-67. Esmaeili H.R., Al Jufaili S.M., Masoumi A.H., Zarei F. (2022). Ichthyodiversity in southeastern Arabian Peninsula: Annotated checklist, taxonomy, short description and distribution of Inland fishes of Oman. Zootaxa, 5134(4): 451-503. Esmaeili H.R., Ebrahimi M. (2006). Length-weight relationships of some freshwater fishes of Iran. Journal of Applied Ichthyology, 22(4): 328-329. 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Morphometric characters and length-weight relationship of Bele, (Glossogobius giuris) from Mithamoin haor, Kissorgonj, Species N Characters TL/SL range (cm) TW range (g) a 95% CI of a b 95% CI of b r2 Garra sindhae 30 TL 5.37-9.66 1.1-10.7 0.01288 0.00567-0.0293 2.886 2.454-3.318 0.87 30 SL 4.1-7.73 1.1-10.7 0.02182 0.01259-0.03793 2.956 2.627-3.285 0.924 30 FL 4.74-8.69 1.1-10.7 0.175 0.00837-0.03656 2.886 2.475-3.296 0.881 Garra smartae 142 TL 2.79-8.05 0.29-5.445 0.01534 0.01285-0.01832 2.914 2.792-3.035 0.941 142 SL 2.27-6.65 0.29-5.445 0.03 0.02667-0.03396 2.868 2.772-2.965 0.961 142 FL 2.5-7.3 0.29-5.445 0.02037 0.01774-0.0234 2.911 2.81-3.012 0.958 Oxyurichthys omanensis 23 TL 4.7-9.03 0.483-4.083 0.00387 0.00195-0.00769 3.128 2.767-3.49 0.939 23 SL 3.28-6.26 0.483-4.083 0.01096 0.0083-0.01449 3.18 2.999-3.362 0.984 N: number of specimens; TL: total length; FL: fork length; SL: standard length; TW: total weight; a: intercept; b: regression slope; CI: confidence Interval; r2: coefficient of determination. 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