J. mar. biol. Ass. India, 1997, 39 (I & 2) : 89 - 96

MATURATION AND SPAWNING BIOLOGY OF SIRM FROM PARANGIPE'ITAI, SOUTHEAST COAST OF INDIA

N. VEERAPPAN,M. RAMANATHAN AND V. RAMA~YAN Centre of Advanced Study in Marine Biology, Annamalai University, Parangi~ettai- 608 502, Tamil Nadu

ABSTRACT Studies on the maturation and spawning biology of the trenched sardine Amblygaster sirm (Walbaum) from Parangipettai coast revealed three distinct stages of ova viz. immature, mature and matured ttapc?Eti*ly with ova diameter of 0-19 mm, 0.19-0.42 and above 45 mm. Running gonad8 indicated a peak spaw ng during September-November nod another spawning during February-April. Also females were abunznt during these peak spawning period (September-November). Females attain maturity at length of 160 mm and males at 150 mm. Fecundity ranged from 21,800 to 1,24,800 and was directly proportional to length and weight of the fish.

Since the spawning habit has to be studied through indirect methods, the method of analysis of growth of ova by measuring their diametexs FISHESexhibit a periodic or cyclic reproductive as developed by Thompson (1915) and behaviour. The success of any species is suc(3essfully employed by subsequent workers ultimately determined by the ability to reproduce like Clark (1934), Hickling and Rutenberg successfully in a fluctuating environment and (1936) and De Jong (1940) was followed. The thereby to maintain variable populations. A ovaries were preserved in modified Gilson's thorough knowledge of maturation cycle and fluid (Simpson, 1951). ~easurkmentswere depletion of gonads will help to understand taken as described by Clark (1934), June (1953) and predict the annual changes that population and .Yeun (1955). A total of 600 ova drawn undergoes. with equal representation from the three regions of both the lobes were examined for frequency 'There is very little information available distribution. Ova of 0.14 mm size and above on the breeding biology of Amblygaster sinn were measured for all the stages except stages (Ronquillo, 1%0; Chacko and Gnanamekalai, I and 11. The different stages of maturity were 1963; Gnanamekalai, 1963a, 1963b; Lazarus, distinguished following the scale adapted by 1973, 1987a, 1987b, 1990; Bennet et al., 1986), International Council for the Exploration of the With a view to supplementing this, a detailed Seas (Lovern and Wood, 1937) with suitable investigation was undertaken along Parangipettai modificatin- coast on the breeding biology of A.sinn. The gonado-s ndex (GSI) for the MATERIAL AND ~&THoDs i~ndividual fish was ned as dt :scribed by Bhaskara Raju et al., (1986-87). Fresh specimens were collected from the For the fecundity studies, the method fish landing centres along the Parangipettai described by Grimes and Huntsman (1980) wq coqt during January to December 1994. After followed, by which counting the number of recording the total length, weight, sex and state mature ova (used only IV and V stages) in a of maturity the gonads were dissected out, portion of known weight and then calculating weighed and preserved for further analysis. the total numbers of mature ova by the formula 90 N. WERAPPAN, M. RAMANATHAN AND V. RAMAtYAN Weight of the ovary Fecundity x - Weight of the sub-sample No. of matarc ova in sub-sample Relationship between total length and fecundity, total weight and fecundity were established.

Ova6 was classified into 7 stages as in 'conformity with those recommended by ICES scale (Lovern and Wood, 1937). Development of ova to maturity Ovaries of seven stages were selected for the ova diameter frequency polygon. Three portions of the left ovary, ie. anterior, middle and posterior regions were removed and teased on micro~lides.~Thldiameter measurements of ova in each part were noted separately and the frequencies we= plotted (Fig. la). The frequency curves showed a similar pattern of distribution of the ' immature, matuting;l and mature ova. Similarly the distniution of ova in the right ovary was \also found uniform. The frequencies from all the &me regions of one OVA DIAMETER (MICRON) ovary wen? then pookd and plotted @g. lb). FIG. 1 a. OM dhmetcl fnsuency polygons of the aterior, ' The same type of distribution of ova was middle and posterior regioae of matun ovary apparent in the three different portions. of Amblygmfn sirm. The ova diameter frequency polygon of b. Combined ova diameter frequmcy polygon of a mature ovary (Fig. lb) showed the presence the Ulree regiom of three distinct groups of ova. The first group, faster rate and go distinctly separate off from which might be knned, the immature stock, the maturing group of eggs and another group varied in sjze upto a maximum of 0.19 mm. which has undergone about half of the The second group, which might be called the maturing ova ranged in size between 0.19 and maturation process immediately following it, 0.42 mm. The third group of ova which were leading to fwo spawning in a season. The fish considered to be mature, measured more than with running gonads (Stage VI) occurred during 0.45 mm. Ova diameter measurements of as September, October and November. The high many as 100 ovaries in different stages of values of gonado-somatic index obtained for maturity showed three groups of ova depending these months also testified this fact. Actually, on their stage of maturity. two spawning season occur vu., February to Spawning frequency and spawning 'season April and September to November. The latter was the peak spawning period (Table 1). The study of ova diameter frequencies of mature ovaries of A. sinn indicated that they Size at first maturity contained the early sqes of mapation. As the fish approaches the spawning season, the The percentage occurrence of mature mature group of eggs-appeared to grow at a females and males in each size group of A. MATURATION AND SPAWNING BIOLOGY OFAMBLYGASER SIRM 91 sinn was calculated for different stages of male and female increased steadily with the maturity (Fig. 2 and 3). length. From the nlaturity curve it is seen that 50% of males were mature at 150 mm length and 50% of the females attained maturity at 160 mm length. When compared with females, males matured at a smaller length. In majority, of fishes, males have been found to mature at a smaller length than females (Royce, 1972).

Monthly trends in the gonado-somatic index are given in Fig. 4. High values are seen

U TOTAL LENGTH (mm)

PM:2 Size at first mahuity of males

MONTHS 1944 -*o

Fro. 4 Monthly variations in the gonado-somatic index (0) for both males and females during the months February to April coinciding with the months of spawning. Fmm September to November there is an increase in the gonado-somatic index values. This sugge!sts that tile increase in gonad weight is associa~ted wit1h the progress of maturity in this species. Fu rther, the fish starts -. spawning during c ter the South West monsoon post-mo ~ndthere appear to be a pre- monsoon ~g,just 15y the end of Northea~~IIIUIWVUII. Sex Ratio

There are no secondary sexual characters. 'During this study, a total of 320 specimens TOTAL LENGTH (mm) comprising 116 males and 204 females of A. Ra. 3 Sbat first maturity of fanales sirm were examined covering a wide range of sizes to determine the sex ratio. The sex ratio The minimum size at which A. sirm attains was calculated tbr various months and for maturity was determined for both male and different length group during January to female. The percentage occurrence of mature December, 1994. The percentage occurrence of 92 N. VEERAPPAN, M. RAMANATHAN AND V. RAMAlYAN male and female was calculated by employing the chi-square test 02-test) to test the homogeneity of the distribution of female and male and the details are presented in Tables 2 and 3. Fecundity The relationship between total length and fecundity, total weight and fecundity and ovary length and fecundity of A. sinn we= estimated by least square method. The fecundity varied from 21,800 to 1,24,800 based on 30 ovaries (only mature and ripe stages) of fishes ranging in total length from 191-226 mm and weight 68-118 g. The relationship between total length and fecundity of A. sinn is logarithmically expressed by the equation. Lo9 total length Log weight Pro. 5. a. Pecuadity - mi ksgth nlatimshfp and Log R .= a + b Log L. b. Fecundity - total weight rclatiomhp in A. sirm where The correlation coefficient (r = 0.6241) F = Fecundity between total weight and fecundity was found L = Total length aqd 'a' and 'b' are two to be significant at P < 0.001 level. Hence, it constants examined by the method of least can be concluded from the pEsent obsexvation that the fecundity appeaxs to imase with square and expressed by the following equation. increasing body weight of the fish. Log F = - 3.7720 + 3.6676 log L, Relatiomhip between ovary length (OL) and Based on this fonrmla, the expected (F) fecundity values were calculated for different fecundity lengths and a linear relationship is evident as shown in fig. 5a. The correlation co-efficient The relationship between ovary length and (r = 0.7676) between total length and fecundity fecundity showed a linear relationship as was found to be significant at P c 0.001 level. represented in fig. 6. Hence, the present study suggests that the fecundity increase with increasing length of the Logarithmically the relationship between fish. the two variables was calculated by the method of least square and can be expressed by the Relationship between total weight (W) and regression equation as given below. fecundity (F) The relationship between total weight (W) Log F. = - 0.9352 + 3.0664 log OL. and fecundity (F) showed a linear relationship as represented in fig. 5b. Logarithmically the relationship between the two variables was The correlation coefficient (r = 0.9858) calculated by the least square method as value between ovary length and fecundity was expressed by the regression equation. found to be significant at P < 0.001 level indicating a high degree of relationship between Log F = 2.7385 + 1.5094 log W these two variables. MATURATION AND SPAWNING BIOLOGY OFAMBLYGASZERSIRM 93

Relationship between ovary weight (OW) and relationship between these two variables was fecundity (F) calculated by the method of least square and can be expressed by the regression equation as given below. Log F = 1.9309 + 0.7582 Log OW. The correlation coefficient (r) value between wary weight and fecundity was found to be 0.9219 (P ,< 0.001) indicating a high degree of relationship between these two variables.

Conand (1991) from New Caledonia have obsewed that the spawning season of A. sim is from October to December, before the hot, rainy season. There are probably several spawnings. Jayasuriya (1989) observed that the spawning occured twice a year viz., AprilIMay and AugustBeptember in Sri Lankan waters. Milton et al. (1994) in obsewed I, 1 0 + N protracted spawning in A. sinn with periods of f ? 4 m N intense spawning activity and fish spawned LOG OVAR? LENGTK from August to October and also during May FIO..6 Panmdity - my length relatiomhip h A. sbm and June. Lezarus (1990) based on the presence The,nlatiollship between ovary weight of more than two distinct batches of ova in ad fecundity in A. sinn showed a linear the ovaries suggested that the fsh spawns twice relationship (Fig. 7). Logarithmically the in a season. The spawning season extended from December to February off Vizhinjam. In the pEsent study also the two distinct batches of ova indicated that the spawning occur twice in a year viz., February to April and September to November along Parangipettai coast. The study indicates two recruitment and spawning pulses separated by an interval of two months. These periods were coinciding with the beginning and latter part of the northeast monsoon. The earlier authors have reported that the fish attains sexual maturity at a slightly smaller .length of 140-150 mm (Chacko and Gnanamekalai, 1963). According to Conand (-1991) first maturity is attained when fish attains one year of age and is about 175-179 mm and 180-184 mm for males and females respectively. However, based on the present study the size Fh7 Fdty- ovry weight relationship in A. sinn at 50% maturity for males and females were 94 N. VEERAF'PAN, M. RAMANATHANAND V. RAMAIYAN

150 and 160 mm respectively. These variations with the earlier observation by Jayasuriya (1989) in length at first maturity may perhaps be from . Lazarus's (1990) observation TAME1. Seasonal changes in stages of maturity for A. sinn

related to ,ecological factom, food supply and reveals the same sex ratio and the predominance assimilation. of females from 105 mm size onwards. But Lazarus (1990) has observed the monthty in the present study the predominance of females trends in the gonado-somatic index showing was obsetved from 150 mm onwards. low values for both males and females in the The proportion of females was months of January and February. According to significantly higher between September to James (1967) the gonado-somatic index varied November. This may be due to the active significantly between months in fish with short movements of the females during spawning

TAME2. Sex ratio and chi-square values of Adygaster sinn in different months during January, 1994 to December, 1994

spawning period. During these investigations season. Lazanrs's (1990) observation in Vizhinjam, high values are seen for both males and females south west coast of India, confirms this. toin theNovember. of Febnury to and September According lo Lazarus (1990) the fecundity of A. sirm varies from 21,050 to 1,35900 eggs. From Tables 2 and 3 it is clear that Milton et al. (1994) observed a mean of 20000 females are abundant than males. This coincides eggs per batch and individuals probably spawn MATURATTON AND SPAWNING BIOLOGY OFAMBLYGASlERSlRM 95

more than one batch of eggs (Conand, 1988). probably be due to a number of factors such However, in the present study- the fecundity as abundance of food, density (Bagenal, 1966) TABU 3. Sex ratio and Chiquare values of Ambfygaster sirm in relation to various length groups

increases not only with length but also with and age (Hanson and Wickwire, 1967; Winten, weight of the fish. Fecundity ranged from 1971) but so far no definite reason could be 21,800 to 1,24,800 eggs with wide variation indicated for the fluctuation in fecundity. among individuals of the same size. This may

W, S., S. LAunus, R. ~~UOARAIANAND G. DB JONO~J.K. 1940. A preliminary investigation Luntg~ 1986. Present status of our knowledge on the of the spawning habits of some fishes of Java Sea. Treubia, leaser tiardincs, of Indian waters. CMHU Spbcial 17 .: 307-330. Publicafion, 28 r 43 pp. G~,uwmum,A.G. 1%3a. Studies on the age Beow T.B. 1966. The ecological and and growth of the Kareemccnchalai., sinn. geographical ~pcctaof fecundity of plaice. J. mar. biol. Madras J. Fish., l(1) : 25-33. jss. UX.,44 : 161-186. - 1%3b. Aa instance of gonadal BHAS~CARARMJ, M. M.S. KASUMA AND B. abnormality in Sardinella sim Ibid. l(1) : 40. N~EWLWTAN1986-87 On nome aspects of the maturation and spawning of the pearl spot Etrqlus GRIMBF,B. AND HUNTSMAN 1980 Reproductive ,sura&~b@lo&) from the Kali eshury. Karwar. Matsya, biOio~ the snapper, R~$ihauro~~~ 112 & 13 : 34-38. from North Carolina and South Carolina. Fish. Bufl., 78 : 137-146. CHMXo P.I. AM) A.G. GNANAMBKAW1%3. Preliminary observation on the age, growth, maturity and HANSON, J.A. AND R.H. WI~WDU 1967. Fecundity of sardinelh ~irmoocurring in the Gulf of and age at maturity of lake Trout Salrarinus mmayeush Mannar off Tuticorin. Pm. 50h Indian Sci. Congt, Part (Wdbaum) in lake Tanoe. Calif: Fish. Ga"% 53(3) : nI, 506 (Abstract). 154-164. Cwur, EN. 1934. Maturity of California sardine Iir~c~euo,C.P. AND E. Rmmo 1936. The ovary (SadiM aacrulES) determind by ova as an indicator of spawning period of fishes. J.mar. biol. measurements. Fish Bull., 42 : 1-49. Ass., U.K., 21 : 31-1-317. CONAND, F. 1988. Biologie et ecologie dea JAMBS,P.S.B.R. 1967. The ribbon-fishes 9f lhe poimion pelagiquar du de Nou VelleCalcdonie family Trichiuridae of India. Mem Mar. bid. Ass. India, utiliaabla armme amt- - thonier. Paris: ORSTOM. Etudes : et Theses, 239 pp. JAYASUR~YA,P.M.A. 1989. Some aspects of the 1991. ~i~l~~~and pheno~oU of biology and population dynamics of Ambfygaster inn Adyga.~tersirm () in New Caledonia. A Sardine (Walbaum) from the West Coast of Sri Lanka. J. at. of the coral environment. Bull. mar. Sci., 48 (1) : 137-149. Sci. Cmn. Sri LMka.,17(1) : 53-66. % N. VEERAPPAN, M. RAMANATHAN AND V. RAMAIYAN

Ju?q F.C. 1953. Spawning of yellowfin in species of Clupeidae from Kiribati, tropical Pacific. Fish Hawaiian waters. U.S. Fish. Wddlife. Serve. Fish Bull., Bull., 92 : 102-121. 54 : 47-64. Roruounm, LA. 1%0. Synopsis of biological data LAURVS, S. 1973. On some gonadial on Philippine sardines (Sardinella perforata, S. funbriata, abnormalities in Sardinella dayi (Regan), S. clupeoides S. sirm and S. longiaps). In : Roceedinga of the world (Bleeker) and S. sirn 3. mar. tiof. Ass. India, 15(1) : scicntifz dngon the biology of sardines and related 446-447. species., 2 : 453-495. FAO, Rome. - 19878. Studies on the early life history ROY- W.F. 1972. Inbodrtctim to the firhay of Saniinclla sim (Walbaum) from Vizhinjam. Southweat sdcncs. Acadcnic Rcas, New York adLordon, 351 pp coast of India. Indim J. Fish., 34(1) : 28-40. SIMPSON, A.C. 1951. The fecundity of plaice - 1987b. Studies on the age and growth (Pleuronectcs platasa I;.) Fishery Inllcrt. Loud., 2(17) : of benched sardine Sardinella sinn (Walbaurn) from 1-27. Vizhinjam, Southwest Coast of India. Ibid, 34(2) : 178-187. lMm,W.F. 1915. A preliminary report on - 1990. Studies on the apawniug biology the life history of the halibut. British Columbia. Comm. of the benched sardine. SardineIla sirm (Walbaum), from Fish Rep. for 1914. pp. N76-N99. Vizhinjam, Southwast Coast of India. Ibid., 37(4) : 335-346. Wm,G.H. 1971. Fecundity of the left ad ~VB~W,J.A. m H.,WOOD. 1937. Variatiolg in right ovaries of the grand bank capelin (Mallom ullanu). the Chemical composition of herring. J. mar. biol. Ass. J. Fish. Res. Board Canada, 28(7) : 1029-1033. UK, h : 281-293. Yew, H.S.H. 1955. Maturity and fecundity of Mnm, D.A., SJ.M. BLABBRAM) N.J.F. hwmso~ bigcye Tuna in the Pacific Spec Sci. Rep. U.S. Fi 1994 Reproductive biolhgy and egg production of three Wildl. Sew., 150 : 30 pp