Iran. J. Ichthyol. (September 2019), 6(3): 218-225 Received: December 12, 2018 © 2019 Iranian Society of Ichthyology Accepted: June 1, 2019 P-ISSN: 2383-1561; E-ISSN: 2383-0964 doi: 10.22034/iji.v6i3.355 http://www.ijichthyol.org

Research Article

Reproductive biology of suppositus (Troschel, 1840) (Teleostei: ) in coastal waters of the Persian Gulf

Faezeh IZADIFAR1, Mohsen SAFAIE*1, 2, Mohammad MOMENI3

1Fisheries Department, University of Hormozgan, Bandar Abbas, P.O.Box:3995, Iran. 2Mangrove Forest Research Center, University of Hormozgan, Bandar Abbas, P.O.Box: 3995, Iran. 3Persian Gulf and Oman Sea Ecological Research Center, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Bandar Abbas, Iran. *Email: [email protected] Abstract: This study was conducted to determine reproductive biology of Spotfin flathead Grammoplites suppositus for a period 16 months from November 2016 to April 2018 in coastal waters of the Persian Gulf. Sampling was carried out by shrimp bottom trawl net as bycatch and a total of 635 were examined during the study period. The recorded results showed that the sex ratio between male:female was not significantly being 1:1 throughout the study period with 55.28% of fish was female. Analysis of morphological maturity stages of ovary was showed that G. suppositus can spawn in throughout the year with a peak from November to March. Also, the GSI was uptrend in November to February and then declined from March in the region. The minimum size of the female G. suppositus that reaches the sexual maturity was observed in the size classes 160-179 mm of total length. The Lm50% was estimated at 199.4 mm of total length for this flathead fish.

Keywords: Spotfin flathead, Sex ratio, Spawning season, LM50%, Persian Gulf. Citation: Izadifar, F.; Safaie, M. & Momeni, M. 2019. Reproductive biology of Grammoplites suppositus (Troschel, 1840) (Teleostei: Platycephalidae) in coastal waters of the Persian Gulf. Iranian Journal of Ichthyology 6(3): 218-225.

Introduction Gulf and Oman Sea (Valinassab et al. 2006). It is The family Platycephalidae includes 85 species ecologically important because of this species belonging to 18 genera that found in benthic habitat, essentially is benthic predator and feeding on benthic often burying in the mud or sand bottoms, occurring crabs, penaeid prawns and (Abdurahiman et al. from about 10–300m in marine (some brackish 2007). water) environments (Fischer & Bianchi 1984; The present study has been undertaken to Nelson et al. 2016; Fricke et al. 2019). In the Persian investigate some aspects of reproductive biology of Gulf, 8 species of this family have been reported G. suppositus in the northern Persian Gulf as the first (Carpenter et al. 1997; Eagderi et al. 2019), with only experience time to be used for further resource the indicus (Linnaeus, 1758) having a management on this species. good food fish in the Iranian waters, while others are as discards in the shrimp bottom trawl net in the area. Materials and Methods The spotfin flathead, Grammoplites suppositus Study area, sampling and measurements: Sampling (Troschel, 1840) is a one of the common flathead fish was carried out using shrimp bottom trawling nets exploited (as bycatch) in the shrimp bottom trawl net with a 20mm cod end mesh size. The study area was E׳N, 56◦52׳in the Iranian coast. The previous study in the Iranian restricted in an area extending from 26◦55 E, and the biological data were׳N, 56◦05׳waters showed that this species accounts for 0.33% to 26°59 of the total biomass of aquatic in the Persian collected monthly within 16 months from November

218

Izadifar et al.- Reproductive biology of Grammoplites suppositus

Fig.1. Study area for Grammoplites suppositus in the Persian Gulf, Iran 2016 to April 2018 in coastal waters of Hormozgan Computing b value estimated with 3 was tested by Province in the northern Persian Gulf, Iran (Fig. 1). using the t- test (Pauly 1983): At least 30 specimens were taken per month, each s.d (L) b 3 fish was measured and recorded for its sex, total t    n  2 s.d (w) 1 r2 length and its body weight, and reproductive aspects. Where: s.d. (L) is the standard deviation of the ln The maturity stages of ovaries were grouped into TL values, and s.d. (W) the standard deviation of the five main classes following the procedure adopted by ln W values, n being the number of fish used in the Biswas (1993). The Gonado-Somatic Index (GSI) computation. The value b is different from 3 if t is were calculated as following formula: Drained ovary weight greater than the table value for t in n - 2 df. (Pauly GSI (%) = * 100 Total live weight 1983). Data Analysis: Using size frequency distribution of The sex ratio analysis was carried out by monthly total length, for male and female fish was depicted in data sets of the total number of male and female fish. each month. To establish the length-weight Chi-square (X2) statistical was performed to test the relationship, the commonly used relationship W = a difference between ratios in both sexes. Spawning Lb was applied (Pauly 1983), Where: W is the weight season of this species was forecast from the (g.), L is the total length (cm), a is the intercept percentage of ovary stage 4 and monthly GSI index (condition factor) and b is the slope (growth trend. The Lm50% was estimated by using following coefficient). formula (King 2007) and least square method (Solver A linear equation (ln W = ln a + b ln TL) was fitted Tools in Microsoft Excel ver. 2013): for log-transformed data. The Parameters a and b P = L/ [1+exp (- rm (L- Lm50))] were estimated using power regression and the Where: rm is the slope of curve, Lm is the mean coefficient of determination (R2) to show the total total length (cm) at sexual maturity, L is mean total length-weight relationship. The parameter b is a length (cm) and P is probability of presence mature shape parameter for the body form of the fish species. fish. In theory, one might expect that the exponent b would have a value of roughly b = 3 because the volume of Results a 3- dimensional object is roughly proportional to the Descriptive statistics and total length-weight cube of length for a regularly shaped solid. relationship: The results showed that the total length

219 Iran. J. Ichthyol. (September 2019), 6(3): 218-225

Table 1. Total length -weight relationships of Grammoplites suppositus in the Persian Gulf.

Sex Total length-weight Equation R2 N Sig. Male W = 0. 00009×TL3.35 0.83 284 P<0.05 Female W = 0. 00002×TL3.21 0.86 351 P<0.05 Total W = 0. 00002×TL3.18 0.86 635 P<0.05

Fig.2. The changes in total length (Mean±SE) for Grammoplites suppositus in the study area.

Fig.3. Sex ratio between male and female of Fig.4. All maturity stages of female Grammoplites Grammoplites suppositus from the Oman Sea, Iran. suppositus sampled from the Oman Sea, Iran. (TL) of 284 males and 351 females, ranged from 12.2 The total length-weight relationship (Table 1) of to 27.2cm and 13.5 to 32.3cm, respectively (Fig. 2). G. suppositus had a high R2 value and the exponent The mean (±SE) TL was 17.67±1.56 for males and (b=3.18) was significantly different from 3 (P<0.05), 20.14±1.62cm for females. Also, the marketable size indicating that growth in this species is positively of males and females G. suppositus were dominated allometric. throughout the study area with its peak during Sex-ratio: The overall sex ratio between male and January to March. Whereas, the juvenile fishes was female individuals of G. suppositus throughout the dominant from April to July. year was significantly different from 1:1(P<0.05), 220 Izadifar et al.- Reproductive biology of Grammoplites suppositus

Fig.5. Monthly fluctuation GSI index of Grammoplites suppositus in the study area.

Fig.6. A logistic curve for estimation Lm50% of Grammoplites suppositus from Oman Sea, Iran. with 55.28% of the fish were female. An inspection females (Fig. 5). of the monthly sex ratio revealed that there was also Calculating monthly percentage of the ovary a female bias in sex ratio in most months of the year development in G. suppositus, reveals that mature (Fig. 3). females were actively in the breeding condition Gonad Development and Size at Sexual Maturity throughout the year. In addition, concerning the (LM50%): All five stages of the ovarian development percentages of fish in the maturity stage 4 and GSI of G. suppositus were observed throughout the year value, this species had a spawning peak from (Fig. 4). The abundance of mature fish (stages 3 to 5) November to March in the region. The minimum size had relatively high percentage and young fish (stages of the female G. suppositus that reaches the sexual 1 and 2) showed the same trend, indicating this maturity was observed in the size classes 160-179mm species have continuous spawning in throughout the of total length. Figure 6 shows a logistic curve fitted year. Monthly GSI estimations for both sex had the estimation of length at which 50% of female fluctuation in different months, showing upswing fishes were in stage 4 (adult ones) with the estimated trend from November to February with the maximum TL50%=19.94cm of total length. GSI value of 7.29±1.01 observed in February 2017 in 221 Iran. J. Ichthyol. (September 2019), 6(3): 218-225

Discussion Ricker (1975) believed the length-weight The study on spotfin flathead, G. suppositus stocks is relationships can be found the condition of fish and ecologically important in the area because of this determine whether growth is isometric or allometric. species almost feeds on high-value benthic Also, Negative allometric growth implies the fish invertebrates such as crabs and penaeid prawns, thus becomes more slender as it increase in weight while its population size may affect benthic community in positive allometric growth implies the fish becomes the area. relatively stouter or deeper-bodied as it increases in In the present study, the total length for males and length (Riedel et al. 2007). Variation in estimated b- females G. suppositus ranged from 12.2 to 27.2cm value from cube law reported by other authors may and 13.5 to 32.3cm, respectively. Also, based on the be due to difference in the number and ranged of size monthly size frequency data of G. suppositus, the classes of samples used for t-test and the females were always larger in size than males. The environmental conditions of the study area. There are total length of this species has been reported at a sometimes remarkable differences between different range of 15-30.7cm in the Khuzestan coastal waters, populations of the same species, or between the same Iran (Hashemi et al. 2013). In another study, populations in different years, presumably associated Abdurahiman et al. (2007) measured a size range of with their nutritional condition (Ricker 1975). 14.1-29 cm for this species landed at the southeast In this study, the overall sex ratio M:F = 0.81:1 Arabian Sea. The previous studies on another species was significantly different from the expected 1:1; and of this family in the Persian Gulf, Iran including female bias in sex ratio in most months of the year. P. indicus (Linnaeus, 1758)) and P. fuscus Cuvier, Studies on a , P. indicus in the Persian 1829, showed that the males and females have a Gulf indicated that males population was dominate different size range and females were always larger (Hashemi et al. 2014; Mousavi-Sabet et al. 2015), than males (Gray & Barnes 2008; Hashemi et al. whereas, the results on dusky flathead P. fuscus in 2014; Mohammadikia et al. 2014; Mousavi-Sabet et estuaries of Australia, was confirmed with our al. 2015). Also, the recorded results revealed that the research results (Gray & Barnes 2008). juvenile G. suppositus individuals were dominant The recorded results showed that the females from April to July. Whereas, the adult population G. suppositus have a spawning peak from November were found throughout the year demonstrating high to March in the region. Also, the Lm50% was peak during January to March. The abundant adult estimated at 19.94 cm of total length. Mohammadikia fishes were found from mentioned period, which et al. (2014) reported that high GSI in both sexes of might be due to the presence of mature fishes being P.indicus was observed from December to March in gathered for spawning behavior. coastal waters of the Persian Gulf. Gray & Barnes The estimated b-values as b=3.35, 3.21 and 3.18 (2008) noted that the female dusky flathead, P. fuscus for males, females and total fishes, respectively were reproductively active primarily for 5 months derived from length-weight relationship of between November and March in the New South G. suppositus in which was significantly different Wales, Australia. They also reported that the size at from 3, implying this species have positive allometric 50% maturity in female P. fuscus was occurred at growth. Hashemi et al. (2014) reported the negative 56.75 cm in total length. While, the spawning peak allometric growth (with b=2.95) for this species in for P. speculator Klunzinger, 1872 in the south coast the north of the Persian Gulf. While, a different of Western Australia has been reported from summer growth pattern has been reported for other species and early autumn (Hyndes et al. 1992). Bani et al. (P. indicus) of this family in the Persian Gulf (2009) found that the P. bassensis Cuvier, 1829 (Hashemi et al. 2014; Mousavi-Sabet et al. 2015). actively spawned from October to March in the 222 Izadifar et al.- Reproductive biology of Grammoplites suppositus

inshore region of Tasmania, Australia. Gray, C.A. & Barnes L.M. 2008. Reproduction and Given GSI trend and ovary maturity stages, the growth of dusky flathead () in results of the present study indicated that the NSW estuaries, NSW Department of Primary G. suppositus have two peak of spawning season in Industries, Fisheries Final Report Series, No. 101. 26 the area, so that the exploitation of this resource p. Hashemi, S.A.; Taghavimotlagh, S.A. & Vahabnezhad, should be properly managed. A. 2014. Stock assessment of bartail flathead (Platycephalus indicus Linnaeus, 1758) in northwest Acknowledgments of Persian Gulf, Iran. Environmental Studies of We would like to thanks to several members of the Persian Gulf 1(1): 59-66. fishing cooperative at Hormozgan Province for Hashemi, S.A.; Taghavimotlagh, S.A.; Eskandary, G. & providing sampling opportunities and their Hedayati, A. 2013. Length-weight relationships of cooperation and assistance during sampling. five species of demersal fish from north of Persian Gulf, Iran. Journal of Fisheries Sciences 8(2): 153- References 160. Abdurahiman, K.P.; Zacharia, P.U.; Nayak, T.H. & Hyndesf, G.A.; Neira, J. & Potter, C. 1992. Reproductive Kolliyil, S.M. 2007. Trophodynamics of the Spotfin biology and early life history of the marine Flathead Grammoplites suppositus (Troschel 1840) Klunzinger from the Southeast Arabian Sea. Asian Fisheries (Platycephalidae) in a temperate Australian estuary. Science 20: 125-143. Journal of Fish Biology 40: 859-874. Bani, A.; Moltschaniwskyj, N. & Pankhurst, N. 2009. King, M. 2007. Fisheries biology, assessment and Reproductive strategy and spawning activity of sand management. Oxford, UK, fish. New. Blackwell flathead, Platycephalus bassensis (Platycephalidae). Science Ltd. 382 p. International Journal of Ichthyology 33(2): 151-162. Mohammadikia, D.; Kamrani, E.; Taherizadeh M.R.; Biswas, S.P. 1993. Manual of methods in fish biology. Soleymani, A.; Farokhi, E. & Momeni, M. 2014. Age Delhi, South Asian Publisher. Pvt. Ltd. 157 p. and growth of flathead, Platycephalus indicus from Carpenter, K.E.; Krupp, F.; Jones, D.A. & Zajonz, U. the Persian Gulf (Bandar Abbas, Iran). Journal of the 1997. FAO species identification guide for fishery Marine Biological Association of the United purposes. The living marine resources of Kuwait, Kingdom 94(5): 1063-1071. Eastern Saudi Arabia, Bahrain, Qatar, and the United Mousavi-Sabet, H.; Heidari, A. & Fekrandish, H. 2015. Arab Emirates. Rome, FAO. 293 p. Population structure, length-weight and length-length Eagderi, S.; Fricke, R.; Esmaeili, H.R. & Jalili, P. 2019. relationships of six populations of the Bartail Annotated checklist of the fishes of the Persian Gulf: Flathead Platycephalus indicus (: Diversity and conservation status. Iranian Journal of Platycephalidae) along the Persian Gulf coastal Ichthyology 6(Suppl. 1): 1-171. waters. Journal of Threatened Taxa, 7(1): 6810-6814. Fischer, W. & Bianchi, G. 1984. FAO species Nelson, J.S.; Grande, T.C. & Wilson, M.V.H. 2016. identification sheets for fishery purposes. Western Fishes of the World. 5th Edition, John Wiley and Indian Ocean (Fishing Area 51). Prepared and printed Sons, Hoboken.752 p. with the support of the Danish International Pauly, D. 1983. Some simple methods for the assessment Development Agency (DANIDA). FAO, Rome. Vol. of tropical fish stocks. FAO Fisheries and 5. Aquaculture Technical Papers, 234: 52 p. Fricke, R.; Eschmeyer, W.N. & Van der Laan, R. (eds). Ricker, W.E. 1975. Computation and interpretation of 2019. Eschmeyer's catalog of fishes: genera, species, biological statistics of fish populations. Bulletin of references. Electronic version accessed dd mmm. the Fisheries Research Board of Canada, 191. 382 p. (http:// researcharchive.calacademy.org/research/ Riedel, R.; Caskey L.M. & Hurlbert S.H. 2007. Length- ichthyology/ catalog/fishcatmain.asp. weight relations and growth rates of dominant fishes

223 Iran. J. Ichthyol. (September 2019), 6(3): 218-225

of the Salton Sea: implications for predation by fish- eating birds. Lake and Reservoir Management 23: 528-535. Valinassab, T.; Daryanabard, R.; Dehghani, R. & Pierce, G.J. 2006. Abundance of demersal resources in the Persian Gulf and Oman Sea, Journal of the Marine Biological Association of the United Kingdom 86: 1455-1462.

224 Iran. J. Ichthyol. (September 2019), 6(3): 218–225 Received: December 12, 2018 © 2019 Iranian Society of Ichthyology Accepted: June 1, 2019 P-ISSN: 2383-1561; E-ISSN: 2383-0964 doi: 10.22034/iji.v6i3.355 http://www.ijichthyol.org

مقاله پژوهشی زیستشناسی تولیدمثل زمین کن خال باله ,Grammoplites suppositus (Troschel 1840( در آبهای ساحلی خلیج فارس

فائزه ایزدیفر1، محسن صفائی*1،2، محمد مومنی3 1گروه شیالت، دانشکده علوم و فنون دریایی، دانشگاه هرمزگان، بندرعباس، ایران. 2گروه علوم طبیعی و زیستمحیطی، پژوهشکده منطقهای جنگلهای حرا، دانشگاه هرمزگان، بندرعباس، ایران. 3پژوهشکده اکولوژی خلیج فارس و دریای عمان، موسسه تحقیقات علوم شیالتی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی )AREO(، بندرعباس، ایران.

چکیده: این مطالعه با هدف بررسی زیستشناسی تولید مثل ماهی زمین کن خالباله Grammoplites suppositus و بهمدت 16 ماه از آبان 1395 تا فروردین 1397 در آبهای ساحلی خلیج فارس انجام شد. نمونههای ماهی بهعنوان صید ضمنی میگو و در مجموع 635 ماهی جمعآوری و مورد زیستسنجی قرار گرفتند. نتایج نسبت جنسی نشان داد که نسبت فراوانی نر: ماده بهطور معنیداری 1:1 نبود و در کل دوره مورد مطالعه مادهها با 28/55 درصد غالب بودند. گستره درصد رسیدگی تخمدان ماهی زمین کن خال باله نشان داد که این گونه در تمامی طول سال میتواند تخمریزی داشته باشد و اوج آن در ماههای آبان تا اسفند بود. همچنین شاخص GSI در ماههای آبان تا بهمن ماه روند صعودی داشته و از اسفندماه این شاخص کاهش داشته است. براساس نتایج حداقل اندازه ماهیها که به اندازه بلوغ جنسی میرسند در کالس 179-160 میلیمتر طول کل بودند. طولی که 50% ماهیهای زمینکن خال باله به بلوغ جنسی میرسند در طول کل 4/199 میلیمتر برآورد شد. کلماتکلیدی: زمینکن خالباله، نسبت جنسی، فصل تخمریزی، LM50%، خلیج فارس.

225