IBN AL- HAITHAM J. FOR PURE & APPL. SCI VOL.23 (1) 2010 Observations on the Age and Growth of Shank (Acanthopagrus latus (Houttuyn, 1782)) from Al-Razzazah Lake H.A.M. Dauod, R. A. Al-Aamery, A. I. Ali*,*F. M. Chabuk* and *K. M. Abbas* Department of Biology, College of Education Ibn Al-Haitham,Universty of Baghdad *General Board for Fish Resources Development, Al-Wazeria Abstract From February 2007 to January 2008, monthly samples of shank (Acanthopagrus latus) were taken from three stations at Al-Razzazah lake,by using a range of gill nets and seine nets. A total of 318 fish were taken from all stations. The age data determined from the scales showed that there were eight age classes present in station 1 and 2 and seven age classes in station 3. The increment in length of A. latus at the area of study showed a tendency to decrease with the increase in age after the fourth year of life. The length- weight relationships of both sexes specimens are expressed by the following equations: Log  = -1.93 + 2.67 Log ….. for station (1) fish Log = -2.08 + 2.74 Log  …. For station (2) fish Log = -2.02 + 2.39 Log  …. For station (3) fish It seems from the above equations that the growth of A. latus in the area of study is allometric. Introduction Decreased catches of different fish species from Al-Razzazah lake have caused anxiety among the General Board for Fish Resources Development (GBFRD) during the year 1996. The (GBFRD) suggested to introduce some fish species from Shatt Al-Arab, south of Iraq, in an attempt to cultivate Mugil sp ., in the lake, since then A. latus which was introduced randomly with Mugil sp . became the most abundant fish species available in the lake [1]. A. latus is one of marine fish belonging to the family Sparidae, which is represented by more than 120 species. It is an economic fish in west Indian ocean countries. It is represented in Arabian Gulf by several species including the species under investigation [1,2]. The present paper reports part of an extensive study which was carried out in an attempt to study the biological aspects of the species under investigation. One of the major drawbacks with the current investigation is almost the lack of the scientific data about the age and growth of this fish in Al-Razzazah lake with the exception of the preliminary data reported by Mansour[1] who used the length frequency distribution to determine the age. It is hoped that the information obtained would be of interest to ichthyologists who are looking to cultivate suitable species of fish in Al-Razzazah lake as it is subjected to sever water level fluctuation which affects the hydrological condition in the lake and community structures of the contained macro invertebrates. Area of Study Al-Razzazah lake is one of the largest water body in Iraq. It is situated in North west of Karbala city at 4354 & 4322' E, and 3213 & 339' N. The maximum length of the lake IBN AL- HAITHAM J. FOR PURE & APPL. SCI VOL.23 (1) 2010 is about 76Km from the beginning of Al-Majarah channel to the white valley near Karbala city, while the maximum width is about 40Km[3]. The area of the lake is in between (1050-1700)Km 2, and the capacity of the lake is (4.85-250.25)Km3. The maximum depth is 17.0m, and the mean depth is (4.6-11.9)m [3]. The geology of the area is the sandstone underlying clay[4]. Several fish species occur in the lake, Barbus xanthopterus, B. grypus, B. esocinus, B. luteus, B. sharpeyi, Aspius vorax and Liza abu [3]. Al-Razzazah lake is subjected to water level fluctuation which leads to sever changes in the hydrological condition of the lake and the community structures of the contained macroinvertabrates. It is not possible to say how much damage has been caused to the flora and fauna by the fluctuating water levels nor is it possible to surmise neither or not community structures have altered. Materials and Methods Acanthopagrus latus fish was obtained from three stations at Al-Razzazah lake within Karbala province area Fig.( 1) Monthly samples were taken during the period from February 2007 to January 2008, by using gill & sein netting. The specimens were measured by using total length (TL) and wet weight of each fish were recorded to the nearest 1mm and 0.1g respectively. The numbers measured and aged fishes are listed in table (1). Scales of each fish were removed, cleaned, dried and fixed between two glass slides, and then the age read from them. Results and Discussion Age Distribution: The age structure of the population revealed that there were eight age classes at the area of study. These results agree with the data reported by Mansour [1] who used length- frequency distribution to determine the age. The results of the present study showed that the population of A. latus in the area of study was dominated by four and five years. The dominance of four and five years through the period of investigation, is difficult to explain but is though related to the fact that nets missed some of the small fishes which were able to escape by swimming under stones at some sites, or perhaps due to the gear selectivity [5, 6, 7]. Length and Growth: Treasurer [8] has indicated that the length measurements are more reliable indicator of growth than weight data since they are less susceptible fluctuation. The number of fish examined, the mean length per age class and their ranges at the sites of study are shown in tables (2,3 and 4). The average growth of fishes in the area of study is illustrated in figures (2,3 and 4). It seems from the above tables and figures that the highest increment in length appear during the 2 nd, 3rd and 4th years and then showed a tendency to decrease with the increase in age after the 4th year of life. It is important to note that there is no scientific data about the age and growth (increment of length) of A. latus in Al-Razzazah lake to discuss and compare the present results. The growth of A. latus in the area of study seems to be poor. This is not unexpected as the lake is oligotrophic (4). Several workers including [6, 9,10,11] agree that the best fish growth is achived in alkalin water. It is also generally accepted that where fishes are plentiful, as well as fast growing invertebrates are present in abundance[6,9,10]. The poor ionic content of water and the paucity of the invertebrate fauna are militate against Al-Razzazah fishes. One further complication in Al-Razzazah lake is the fluctuation IBN AL- HAITHAM J. FOR PURE & APPL. SCI VOL.23 (1) 2010 of water levels which lead to marked changes in the productivity of the water body [6, 11,12, 13]. In the present study, results obtained for the age and growth of A. latus showed low growth rate in comparison with the data reported from other water bodies [14,15,16]. This low growth rate may be related to the different environmental factor such as the temperature, availability of food and/ or the ionic content of water [6, 9,10]. The relationships between the length and weight of A. latus at the different stations, derived by fitting straight lines to the logarithms of the two variables, were expressed by the following equations: Log = -1.93 + 2.67 Log ….. for station (1) (Al-Shuaib) fish  = 0.99 Log w= -2.08 + 2.74 Log  …. For station (2) (Al-Rahalia) fish  = 0.78 Log w= -2.02 + 2.39 Log  …. For station (3) (Ain Temer) fish  = 0.93 It seems from the above equations that the growth of A. latus at Al-Razzazh lake is allometric as the regression coefficient (b) values are less than 3 [17]. The results of the present study differ numerically from that reported by Mansour [1]. Review of the literature showed that there are several factors affected the length- weight relationship such as age, maturity of gonads, sex and the time of catch [18,19]. It seems that the above factors may be militated agains the relationship in the present study in comparison with the data reported by Mansour[1]. In conclusion, it appears that A. latus fish have managed to maintain themselves naturally in Al-Razzazah lake, which means that they introduced to a suitable environment. Nevertheless it would provide better returns and should at least be given a trial as it is the only course of action which will improve the current situation until the fluctuating water levels are corrected. References 1.Mansour, R.H. (2004). Some biological characteristics of silver sheim (Shank) Acanthopagrus latus (Houttuyn, 1782) in Razzaza lake. M. Sc. Thesis, Technical College of Al-Mussayib. (In Arabic). 2.Al- Daham, N.K. (1979). Fishes of Iraq and Arabian gulf. Vol. 2. Al- Basrah University Press, 406 pp (In Arabic). 3.Anon (1985). State and prospective of fisheries in Razzazah lake. Polservice consulting engineers. A report of states fisheries organization. 4.Al- Saadi, H. A.; Al-Tamimi, A.A. and Al- Ghafily, A.A. (1995). Basrah J. Sci. 13(1): 41- 48. 5.Samuel, M.; Bawazer, A.S. and Matheus, C.P. (1984). Ann. Res. Kuwait Inst. Sci. Research. 1: 52-61. 6.Dauod, H.A.M. (1986). Studies on some aspects of the biology of brown trout (Salmo trutta L.), minnow (Phoxinus phoxinus (L.) and the three- sp ined stickleback (Gasterosteus aculeatus L.) from an upland reserovoir system, Co. Wiklow. Ph.D. Thesis, National University of Ireland. 7.Dauod, H.A.M.; Al-Rubai, R.K.S. and Al-Douri, T.Y. (1999). The Veternarian, 9(3): 64-79. 8.Treasurer, J.W. (1976). J. Fish Biol. 8: 241-253. 9.Kennedy, M. and Fitzmaurice, P. (1971).Proc. R. Ir. Acad. 71 B: 269-352. 10.O'Grady, M.F. (1981). A study of brown trout (Salmo trutta L.) populations in selected Irish lakes. Ph.D. Thesis, National University of Ireland. 11.Dauod, H.A.M. and Al-Rubai, R.K.S. (1996). J. Ibn Al-Haitham Pur. Appl. Sci. 7(2): 1-21. 12.Grimas, U. (1961).Rep. Inst. Freshwat. Res. Drottingham, 42: 183-237. IBN AL- HAITHAM J. FOR PURE & APPL. SCI VOL.23 (1) 2010 13.Hynes, H. B. N. (1961).Verh. Internat. Verein. Limnol. 14: 652-656. 14.Jasim, F.K. (2002). A study on gonads histology and fecundity of Acanthopagrus latus (Houttuyn, 1782) in Iraqi sea water. M.Sc. Thesis, College of Agricultur, Basrah University (In Arabic). 15.Al-Aareky, M.K. (2001). Biology of Acanthopagrus latus (Houttuyn, 1782) in Iraqi sea water- M. Sc. Thesis, College of Agricultur, Basrah University. ( In Arabic). 16.Samuel, M. and Mathews.C.P. (1987).Bull. Mar. Sci. 9: 159-171. 17.Bagenal, T.B. and Tesch, F.W. (1978). Age and growth. In "Methods for assessment of fish production in freshwater". (Ed. T.B. Bagnal). I.B.P. No. 3: 101-136. 18.Le Cren, E.D. (1951). J. Anim. Ecol. 20: 201-219. 19.Bagenal, T.B. (1978). Methods for assessment of fish production in freshwaters. 3 rd ed. Blackwell Scientific publication Oxford, London. I.B.P. Hand book No. 3: 365. Table (1): Numbers of fish caught and aed on each sampling data at each site Month Station (1) (Al- Shuaib) Number aged Station (2) (Al- Rahalia) Number aged Station (3) (Ain Tamr) Number aged February 2007 10 11 9 March 10 12 10 April 12 11 10 May 13 11 12 June - - - July 12 13 13 August - - - September - - - October 7 12 9 November 14 15 12 December 13 12 14 January 2008 14 14 13 Total 105 111 102 IBN AL- HAITHAM J. FOR PURE & APPL. SCI VOL.23 (1) 2010 Table (2): Mean(…) and range of length of A.Latus at the end of each growth period (Station 1- Al- Shuaib). Age Number of fish Length at age 1 2 3 4 5 6 7 8 8 2 (5.25) 4.4-6.0 (8.75) 5.5-12 (14.0) 11.0- 15.0 (19.0) 14.5- 23.5 (23.0) 20.5- 25.5 (26.5) 24.0- 29.0 (29.5) 28.0- 31.0 (32.0) 30.5- 33.5 7 5 (5.5) 4.5-7.0 (9.2) 7.5-12.5 (13.5) 12.0- 17.5 (18.5) 17.0- 24.0 (23.2) 22.0- 25.0 (26.2) 23.5- 28.0 (29.7) 27.0- 31.5 - 6 9 (5.5) 4.5-8.5 (10.22) 8.0-13.0 (14.5) 11.5- 17.0 (19.5) 16.0- 22.5 (23.5) 21.0- 25.0 (26.3) 23.5- 28.5 - 5 25 (6.0) 4.0-9.0 (10.0) 7.5-12.0 (16.5) 12.5- 19.5 (21.5) 18.0- 24.0 (24.0) 22.0- 26.5 - 4 34 (6.25) 4.5-8.0 (10.5) 7.0-12.0 (17.5) 11.5- 19.5 (22.5) 17.5- 24.0 - 3 22 (5.5) 5.0-8.0 (10.5) 7.0-12.5 (16.25) 12.0- 17.5 - 2 8 (5.25) 5.0-7.5 (10.0) 7.0-13.0 - 1 - - - - - - - - - Over all 105 (5.8) 4.0-9.0 (9.9) 5.5-13.0 (15.4) 11.0- 19.5 (20.2) 14.5- 24.0 (24.3) 21.0- 26.5 (26.3) 23.5- 29.0 (29.6) 27.0- 31.5 (32.0) 30.5- 33.5 Increment of mean Length (cm) 5.8 4.1 5.5 4.8 4.1 3.0 3.3 2.4 Table (3): Mean(…) and range of length of A.Latus at the end of each growth period (Station 2- Al-Rahalia) Age Number of fish Length at age 1 2 3 4 5 6 7 8 8 1 (4.0) 4.0-4.0 (7.5) 7.5-7.5 (10.5) 10.5- 10.5 (16.2) 16.2- 16.2 (21.5) 21.5- 21.5 (24.5) 24.5- 24.5 (26.5) 26.5- 26.5 (29.0) 29.0- 29.0 7 3 (6.0) 5.5-6.5 (10.0) 6.0-12.0 (14.5) 9.5-18.0 (19.7) 17.5- 24.0 (23.36) 23.0- 27.0 (26.3) 25.5- 28.0 (29.0) 27.0- 30.0 - 6 7 (5.78) 5.0-6.5 (10.36) 6.0-14.5 (15.36) 13.0- 18.0 (20.36) 18.0- 27.5 (24.17) 24.5- 30.0 (27.8) 26.0- 32.0 - 5 29 (5.97) 4.5-8.0 (11.0) 7.0-15.0 (15.5) 14.5- 16.0 (20.0) 14.5- 26.5 (24.0) 23.0- 29.5 - 4 33 (6.5) 5.0-8.5 (11.5) 8.0-14.5 (14.5) 13.0- 15.5 (19.5) 14.5- 27.0 - 3 25 (5.5) 4.5-8.0 (11.5) 7.5-15.0 (15.5) 14.0- 21.0 - 2 12 (5.4) 4.5-10.0 (10.3) 9.5-14.0 - 1 - - - - - - - - - Over all 111 (5.6) 4.0-10.0 (10.3) 6.0-15.0 (14.3) 9.5-18.0 (19.2) 14.5- 27.5 (23.3) 21.5- 30.0 (26.2) 24.5- 32.0 (27.7) 26.5- 30.0 (29.0) 29.0- 29.0 Increment of mean Length (cm) 5.6 4.7 4.0 4.9 4.1 2.9 1.5 1.25 Table (4): Mean(…) and range of length of A.Latus at the end of each growth period (Station 3- Ain-Tamr) Age Number of fish Length at age 1 2 3 4 5 6 7 8 8 - - - - - - - - - 7 2 (6.5) 5.0-8.0 (9.5) 7.5-12.0 (14.5) 11.0- 18.0 (20.25) 16.5- 24.0 (24.0) 23.0- 25.0 (26.5) 25.0- 28.0 (28.75) 27.5-30.5 - 6 11 (5.8) 4.5-8.5 (8.5) 7.0-11.5 (14.12) 10.0- 17.5 (20.27) 16.0- 23.0 (24.12) 21.0- 26.0 (27.89) 24.0- 29.0 - 5 24 (5.97) 4.5-8.0 (9.48) 7.5-13.0 (15.21) 12.5- 19.0 (20.48) 18.0- 23.0 (24.2) 22.0- 26.0 - 4 36 (5.79) 4.5-9.0 (10.28) 9.5-13.0 (15.38) 12.5- 19.0 (20.73) 17.0- 25.5 - 3 15 (5.93) 5.0-8.0 (10.2) 6.5-13.5 (15.47) 11.0- 19.5 - 2 14 (5.87) 5.0-9.0 (10.5) 9.5-12.5 - 1 - - - - - - - - - Over all 102 (5.9) 4.5-10.0 (10.6) 6.5-13.5 (14.9) 10.0- 19.5 (20.1) 16.5- 25.5 (24.2) 21.0- 26.0 (27.2) 24.0- 29.0 (28.75) 27.0-30.5 - Increment of mean Length (cm) 5.9 4.7 4.3 5.2 4.1 3.0 1.5 Fig. (1): Location of study area. * sampling station Fig.(2) : Mean length and increment of mean length in A. latus at station (1). (Al-shuaib) 0 5 10 15 20 25 30 35 1 2 3 4 5 6 7 8 Mean length Increment of mean length T .L . ( cm ) IBN AL- HAITHAM J. FOR PURE & APPL. SCI VOL.23 (1) 2010 at station (2). A. latus(3) : Mean length and increment of mean length in Fig. (Al-Rahalia) Fig. (4) : Mean length and increment of mean length in A. latus at station (3).(Ain Tamr). 0 5 10 15 20 25 30 35 1 2 3 4 5 6 7 8 Mean length Increment of mean length 2 3 4 5 6 7 Mean length Increment of mean length T .L . ( cm ) T .L . ( cm ) T .L . ( cm ) 2010) 1( 23مجلة ابن الھیثم للعلوم الصرفة والتطبیقیة المجلد مالحظات عن العمر والنمو في سمكة الشانك Acanthopagrus latus (Houttuyn, 1782) في بحیرة الرزازة وكامل محمد *د جابك، فراس مجی*عیسى علي حسین عبد المنعم داود، رنا عالء العامري، علي *عباس - ، جامعة بغداد، كلیة التربیة ابن الهیثم ة قسم علوم الحیا الهیئة العامة لتنمیة الثروة السمكیةالوزیریة* الخالصة ألســماك ) سـمكة 318(جمــع عینـات شـهریة 2008الـى كـانون الثـاني 2007ة الممتـدة مــن شـباط یـتم خـالل المـد مـن ثــالث محطـات علــى بحیـرة الـرزازة، واســتخدمت فـي عملیـة الصــید شـباك خیشــومیة Acanthopagrus latusك الشـان ـة القشــور لحســاب العمــر إن هنــاك ثمـــان لاج الدراســة الحالیـــة ومــن خــالل اســتعمأظهــرت نتــائ. مختلفــة الســعة وشــباك كرفـ ).عین تمر(مجامیع في المحطة الثالثة ، وسبع)الشعیب والرحالیة(لثانیة مجامیع عمریة في المحطتین االولى وا ة مـن العمـر تـم التعبیــر . أظهـرت معـدالت الزیـادة فـي الطـول إشـارة إلـى النقصـان مـع زیـادة العمـر بعـد السـنة الرابعـ -:یةعالقة الطول بالوزن بالمعادالت اآلتعن Log  = -1.93 + 2.67 Log ….. أسماك المحطة األولى Log = -2.08 + 2.74 Log  أسماك المحطة الثانیة .… Log = -2.02 + 2.39 Log  أسماك المحطة الثالثة .… ـــي ــــ ــــ ـــر قیاســــ ــــ ــــ ــــ ـــــوًا غی ــــ ــــ ـر نمـــ ــــ ــــ ــــ ــا یؤشــ ــــ ــــ ــــ ـــــو مـ ــــ ــــ ـــل ال(Allometric) لوهــ ــــ ــــ ــــ ـاط اقـ ــــ ــــ ــــ ــــــل االرتبــ ــــ ــــ ن معامـ ).3(من