The average annual estimated catch of lizardfishes off Visakhapatnam is 229 t,

which formed 5.3% of the total landings during the period 1990-2001. Five species

of lizardfishes are landed of which, Saurida undosquamis and S. tumbil

are the dominant and contributed 88% to the total lizardfish landings of small

trawlers. The fishery, biology and some aspects of population dynamics of S.

undosquamis are studied. The estimated asymptotic length (L

) and growth

constant (K) in S. undosquamis are 395 mm and 0.31 year –1 respectively. The

fish attained maturity at 230 mm, with spawning period extending from October

to March. The estimated mortality rates Z, F, and M in the species are 1.81,

1.05 and 0.76 respectively. The exploitation rate (E) of S.undosquamis is 0.58

Kingsly, H Jose

Rajkumar, U

Rao, K Narayana

Sivakami, S

CMFRI Digital Repository

149Indian J. Fish., 50(2) : 149-156, Apr.-Jun., 2003Lizardfish fishery, biology and population dynam-ics of Saurida undosquamis (Richardson) offVisakhapatnamU. RAJKUMAR, S. SIVAKAMI, K.NARAYANA RAO ANDH. JOSE KINGSLYCentral Marine Fisheries Research Institute, Kochi-14, IndiaABSTRACTThe average annual estimated catch of lizardfishes off Visakhapatnam is 229 t,which formed 5.3% of the total landings during the period 1990-2001. Five spe-cies of lizardfishes are landed of which, Saurida undosquamis and S. tumbilare the dominant and contributed 88% to the total lizardfish landings of smalltrawlers.  The fishery, biology and some aspects of population dynamics of S.undosquamis are studied. The estimated asymptotic length (L ) and growthconstant (K) in S. undosquamis are 395 mm and 0.31 year –1 respectively.  Thefish attained maturity at 230 mm, with spawning period extending from Octo-ber to March.  The estimated mortality rates Z, F, and M in the species are 1.81,1.05 and 0.76 respectively. The exploitation rate (E) of S.undosquamis is 0.58.IntroductionLizardfishes are one of the importantdemersal resources off Visakhapatnam,caught by small trawlers and sona boats.Detailed information is available on vari-ous aspects of fishery and biology of S.tumbil, and S. undosquamis (Rao, 1981,1982, 1983 a &b, 1984; Kuthalingam,1959 and Sivakami, 1999). Similar stud-ies on S. undosquamis, especially on thepopulation dynamics are limited. SinceS. undosquamis is the dominant speciesaccounting for 54% of the lizardfish fish-ery off Visakhapatnam, an attempt wasmade to study the fishery and some as-pects of population dynamics.Materials and methodsData on catch and effort were col-lected twice a week from commercialsmall trawlers off Visakhapatnam dur-ing 1990-2001. The monthly and annualestimated catches were determined asper the procedure adopted by Fishery Re-source Assessment Division of CentralMarine Fisheries Research Institute.Size at first maturity (L50) was de-termined by plotting the percentage ofmature specimens (stage IV and above)against length.  Percentage distributionof gravid and running females (V&VI)over time was considered for determin-ing the spawning season (Pauly, 1983a).Length-weight relationship was esti-mated from W = a Lb by logarithmictransformation. The difference betweenthe slopes of the regression lines of malesand females were tested by ANCOVA150(Snedecor and Cochran, 1961).The von Bertalanfy growth param-eters were estimated using FiSAT(Gayanilo Jr. et al., 1995). The data forthe period 1998-2001 were pooled andanalysed for the estimation of growth pa-rameters. The total mortality rate (Z) wasestimated from the length convertedcatch curve method (Pauly, 1983b), whilenatural mortality rate (M) was estimatedfrom Pauly’s empirical formula. The t0was considered as 0 (Sparre et al., 1989).Log 10 M = -0.0066 - 0.279 log 10 L+0.6543 log 10 K +0.4634 log 10 TWhere L8 and K are von Bertalanfygrowth parametersT= Surface sea water temperature(27 0C)The fishing mortality rate F was ar-rived at by Z - M.  The exploitation ratewas estimated by the ratio of fishingmortality / total mortality.E= F/ F +MYield/recruit was estimated from therelative yield / recruit model of Bevertonand Holt (1957).Results and discussionFisheryLizardfishes are one of the majordemersal fishery resources caught bysmall trawlers and sona boats offVisakhapatnam coast. The details of thecatch and effort and percentage contri-bution to the total landings are presentedin Table 1. Though there was a reduc-tion in the number of units, the relativeeffort in hours increased. The reducednumber of units and increased effort inhours indicate the extended fishing voy-ages in the later years of the study pe-riod. The average annual estimated land-ings of lizardfishes is 229 t, forming 5.3%of the small trawler landings. The annualestimated catch was highest (476 t) in1990 and below 300 t in the subsequentyears. The catch was lowest (57 t) in 1999and after that the catches showed an in-creasing trend from the year 2000. Thecatch rate also followed similar trend asthat of the annual landings. The averageU. Rajkumar et al.TABLE 1: Catch and effort data of lizardfishes off Visakhapatnam during 1990-2001 in smalltrawlersYears Units Hours Catch CPUE Cph percent in(t) (kg/unit) (kg/hr) total catch1990 19699 314519 476.2 24.2 1.5 9.81991 21188 306836 270.4 12.8 0.9 5.11992 14180 220867 160.4 11.3 0.7 4.21993 14088 191701 200.6 14.2 1.0 5.31994 14232 205933 271.5 19.1 1.3 6.51995 10170 176454 163.0 16.0 0.9 4.91996 8998 146893 194.7 21.6 1.3 7.01997 10746 159491 258.5 24.1 1.6 9.01998 11602 240786 156.7 13.5 0.7 3.61999* 8215 225977 57.3 7.0 0.3 2.22000* 13874 507579 234.9 16.9 0.5 3.52001* 10702 292569 297.2 27.8 1.0 4.4Average 13141 249134 228.4 17.4 0.9 5.3* The data for the year is for 11 months since May is declared as closed season from 1999onwards151catch rate was 0.9 kg/hr. The catch rate(Cph) and percentage contribution to thefishery ranged from 0.3 (1999) to 1.6 kg/hr (1997) and 2.2 (1999) to 9.8 percent(1990) respectively (Table 1). The fisheryin the later parts of the period was pooras indicated by the decreased landings,Cph and percentage contribution to thetotal landings. The annual landings de-creased during the study period com-pared to that of eighties (Luther et al.,1988) when it was 625 t per year.Seasonal abundanceThe Cph of lizardfishes in differentmonths during the period 1990-2001(monthly average) is presented in Table2.  The Cph ranged from 0.6 in March to2.2 kg in May.  During May fishing banwas imposed by local authorities from1999 onwards as a measure of conserva-tion. During May the average number ofunits operated were more but, the effortput in (trawling hours) was less andhence the sharp rise in Cph. Constantcatch rate was observed from September(1.2) to January (0.9) and this period maybe considered as the peak period of abun-dance for lizardfishes.Species compositionFive species of lizardfishes werelanded during 1990-01.  S. undosquamis(54%) was the dominant followed by S.tumbil (34%), S. micropectaralis (8%),Trachynocephalus myops (3%) and S.longimanus (1%). S. tumbil and S.undosquamis contributed to the fisherythroughout the year. The dominance ofthese two species along Indian coast wasreported by Rao (1983) and Nair et al.(1992). Luther et al. (1988) reported thedominance of S. tumbil (65%) and S.undosquamis (35%) in trawl landings offVisakhapatnam during 1980s. Rao (1984)reported the dominance of S. tumbil innorthwestern Bay of Bengal and S.tumbil and S. undosquamis together con-tributed up to 90% of the catch from thatregion.Biology of S.undosquamisFood and feeding : A total of 502specimens collected from January 2000to December 2001 were examined for gutcontents. The stomach contents were di-vided into empty/little, half full, full andgorged based on the fullness of the stom-Lizardfish fishery off VisakhapatnamTABLE 2: Average monthwise catch during 1990-01 in small trawlersMonths Units Hours Catch CPUE Cph percent in(t) (kg/unit) (kg/hr) total catchJan. 842 19691 17.3 20.5 0.9 5.8Feb. 957 18998 14.9 15.5 0.8 4.3Mar. 1083 17843 10.2 9.5 0.6 3.3Apr. 1345 11332 8.3 6.2 0.7 3.0May* 1906 11173 24.0 12.6 2.2 6.9Jun. 1007 20701 14.6 14.5 0.7 4.8Jul. 1363 34479 32.1 23.6 0.9 6.5Aug. 1227 25338 21.0 17.1 0.8 5.7Sep. 1162 28151 32.4 27.9 1.2 6.6Oct. 900 19983 19.7 21.9 1.0 5.1Nov. 781 16867 15.2 19.5 0.9 4.6Dec. 1046 27373 24.8 23.7 0.9 5.7Pooled 13618 251927 234.5 17.4 0.9 5.3* The data for May is for 9 years only since May is declared as closed season from 1999onwards152ach.  S. undosquamis is a carnivore, feed-ing predominantly on fishes, crustaceansand cephalopods. Fishes formed the ma-jor food item forming about 70% of thestomach contents. The major fish speciesobserved in descending order of occur-rence were Sardinella spp, Stolephorussp., Pentaprion sp., Rastrelligerkanagurta, Upeneus spp., Leiognathusspp., Nemipterus japonicus, Apogon sp.etc.  The crustaceans were prawns suchas Acetes, Metapenaeus sp., Solenocerasp., and juvenile crabs. The squid, Loligoduvacelli was the common cephalopod.Similar observations on the gut contentsof S.undosquamis were made by Rao(1981) and Sivakami (1999).Length at first maturity : A totalof 278 female specimens collected during2000-01 were used to determine thelength at first maturity (L50).  The lengthat first maturity of S. undosquamis was230 mm (Fig. 1). Rao (1983) observed thesize at first maturity of S. undosquamisas 240 mm, which was almost similar toSpawning : A total of 276 femaleswere studied for determining the spawn-ing season. The spawning season ex-tended from October - February with apeak in December. Rao (1983) reportedsimilar spawning season for S.undosquamis (October-March) with peakin November – December in the north-western part of Bay of Bengal.  Sivakami(1999) observed the spawning periodfrom September to December fromCochin waters.Length -Weight Relationship : Atotal of 466 (170 male and 296 female)specimens in the range of 90-240 mm oftotal length and 26-174 g weight wereused for determining the length-weightrelationship. The relationship for maleand female are:Male: log W= log - 5.4255 + 3.1155 xlog L  orW= 0.000003754 x L 3.1155.  (r = 0.94)Female: log W= log - 5.311 + 3.0689x log L   orW= 0.000004887 x L 3.0689.  (r = 0.96)The two regression lines were testedby ANCOVA for difference in slopes.Since there is no significant differencebetween the slopes, a combined relation-ship was considered for male and female(Table 3).log W= log - 5.1025 + 3.1025 x log LorW= 0.000003754 x L 3.1025.  (r = 0.96)Rao (1983) reported the lengthweight relationship in S. undosquamis asW= 0.005811 x L 3.038.Population dynamicsAge and growth : A total of 1650fishes in the range of 110-310 mm in to-tal length were used for estimation ofgrowth parameters. The estimated VBGFU. Rajkumar et al.Fig. 1. Length at first maturity of S.undosquamisthe present study.  Rao et al. (1988) alsoreported similar findings (240 mm) offMangalore coast, whereas Sivakami(1999) reported lower length (200 mm)at first maturity. The fish attains matu-rity in the middle of the third year of life.153parameters of S. undosquamis were as-ymptotic length (L) 395 mm and growthconstant K= 0.31 year –1 (Fig. 2).The VBGF for S. undosquamis isLt = 395 (1-e –0. 31(t) )The fish at-tained a size of105 and 182 mmat the end of 1stand 2nd years re-s p e c t i v e l y .Chakraborty etal. (1994) andMuthaiah (1996)reported fastergrowth rates, viz.,0.51 and 0.64year-1 respectively for S.undosquamisfrom Maharashtra and Karnataka coasts(Table 4). Ingles and Pauly (1984) ob-served L and K for the species to be 305mm and 0.80 year-1  from Philippine wa-ters.  Tsi-Shiang et al. (1987) reportedslower growth rate 0.13 and 0.12 yr-1 formale and female respectively from Aus-tralian waters.  The varied growth ratesmay be due to the environmental condi-tions, availability and competition forfood and exploitation.  The regional dif-ferences in growth rate for the fish stockswere reported by Wright et al. (1989).Recruitment : The recruitment pat-tern obtained from FiSAT indicates anunimodal, protracted period from Aprilto August with a peak in July (Fig. 3).Peak spawning was observed in Decem-ber and recruitment to the fishery occursLizardfish fishery off VisakhapatnamTABLE 3: Comparison of regression lines of length-weight relationship of males and females ofS. undosquamis off VisakhapatnamSource df X2 XY Y2 b Deviation from Regression Fdf SS MSSWithinMales 169 1.7753 5.5309 19.5156 3.115 168 2.284 0.01360Females 295 5.6901 17.4613 57.7465 3.069 294 4.163 0.01416462 6.447 0.01393Pooled 464 7.4654 22.9922 77.2621 3.080 463 6.450 0.01393 0.21Between slopes 1 0.003 0.00297Between 1 1.1668 3.7894 12.3073Total 465 8.6322 26.7816 89.5694 3.103 464 6.479 0.01396 2.04Between adjusted means 1 0.028 0.02848* F value is not significant at 1% level.Fig. 2. Restructured growth curve of S. undosquamis off Visakhapatnamat the end of the first year.  Varying re-cruitment strengths result from year -to-year variations in reproductive effort orsuccess, as well as variations in the sur-vival or settlement of larvae and juve-niles. Recruitment patterns obtained bythe FiSAT programme give only approxi-mate results as it is based on several as-sumptions. The results however suggestthat recruitment pattern contain usefulinformation from which legitimate infer-ences on the dynamics of fish stock canbe drawn.Mortality : Estimation of mortality154U. Rajkumar et al.TABLE 4: Population parameters of S. undosquamisSr. Area L(mm) K/yr Z M F E AuthorNo.1 Maharashtra 420 0.51 2.52 1.10 1.42 0.56 Chakrabortyet al. 19942 Karnataka 360 0.64 2.62 1.31 1.31 0.5 Muthaiah, 19963 Philippines 305 0.80 4.07 1.54 2.53 0.62 Ingles and Pauly,19844 599 0.123 - - - -Australia (male) Tsi-Shiang et al.589 0.121 - - - - 1987.(female)5 Visakhapatnam 395 0.31 1.81 1.05 0.76 0.58 Present studyrates is an important criterionfor fisheries management.The estimated values of totalmortality (Z), fishing mortal-ity (F) and natural mortalityfor S.undosquamis are 1.81,1.05 and 0.76, respectively.Fig. 4 shows the length con-verted catch curve forS.undosquamis. Chakrabortyet al. (1994), Muthiah (1996)and Ingles and Pauly (1984)reported higher mortalityrates for the species (Table 4).Yield/Recruit : The ex-ploitation of the resource ismeasured in terms of exploi-tation rate (E=F/ F+M).  Theexploitation rate (E) in thepresent study is 0.58.  Thepresent exploitation rate ofthe resource is more than theE max 0.48.  The optimum yieldper recruit is 1.7 gm andbiomass per recruit is 0.27 g(Fig. 5).  The optimum yield& biomass per recruit can bemaintained by reducing theexploitation rate up to 0.3.Chakraborty et al. (1994) andMuthaiah (1996) reportedlower exploitation rates forFig. 3. Recruitment pattern of S. undosquamis offVisakhapatnamFig. 4. Length converted catch curve of S. undosquamis offVisakhapatnam (1998-2001)155Lizardfish fishery off VisakhapatnamS.undosquamis, while Ingles and Pauly(1984) reported higher E (Table 4) thanthe present study. The exploitation rateis on higher side, which may be detrimen-tal to the resource.  The reduction in thenumber of units and decrease in effortwill improve the status of the resource.AcknowledgementsThe authors are grateful to Dr.Mohan Joseph Modayil, Director, CMFRIand Dr. V. S. R. Murty, Former Head,Demersal Fisheries Division, CMFRI, fortheir continuous support and encourage-ment. Thanks are extended to Dr. G.Syda Rao, Officer-in- Charge, R. C. ofCMFRI, Visakhapatnam, Dr. G.Sudhakara Rao, Dr. G. Maheswaruduand Dr. A. K. V. Nasser for their help andencouragement.ReferencesBeverton, R. J. H and S. J. Holt 1957.  On thedynamics of exploited fish populations.Fish. Invest. Ser. London, 19: 553 pp.Chakraborty, S. K, V. D. Desmukh, M.Zaffarkhan, K. Vidyasagar and S. G. Raje1994.  Estimtes of growth, mortality, re-cruitment pattern and MSY of importantresources from the Maharashtra coast.Proc. Nat. Symp. Aquacrops, 1-39.Gayanilo, F. C. Jr., P. Sparre and D. Pauly1995.  FAO-ICLARM Stock AssessmentTools (FiSAT) User’s Manual. FAOComp. Info. Ser. (Fisheries), 8: 126 ppIngles, J. and D. Pauly1984.  An atlas of thegrowth, mortality andrecruitment ofPhiliphine fishes.ICLARM / Tech. Rep.,13: 127pp.Kuthalingam, M. D.K. 1959. Sauridatumbil (Bloch):  devel-opment and feedinghabits. J. Zool. Soc.India, 1(2): 115-129.Luther, G, T., S. AppaRao, Y. Rueben, M.V.Appanna Sastry,Somaraju and K.Radhakrishna 1988. Marine Fish Calen-dar. 20. Visakhapatnam. Mar. Fish.Infor. Serv., T. & E. Ser., 80: 1-21.Muthaiah, C. 1996. Studies on the fishery andbiology of lizardfishes Saurida spp., fromthe Karnataka coast. P.hd thesis,Karnataka University, Karwar. 185pp.Muthaiah C. and B. Neelakantan 1997.  Thelizardfish fishery along the Karnatakacoast. J. Mar. Biol. Ass. India, 39 (1&2): 97-107.Nair, K. V. and R. Reghu 1990.  Studies onthe threadfinbreams and lizardfish re-sources in the Exclusive Economic Zoneof India based on the demersal trawlingoperation of FORV Sagar Sampada.Proc. First Workshop Scient. Resul.FORV Sagar Sampada, 5-7 June, 1989,p. 239-255.Nair, K. V., D. Vinay, D. Deshmukh and S.G. Raje 1992.  Present status of exploi-tation  of fish and shell fish resources;lizardfish. Bull. Cent. Mar. Fish. Res.Inst., 45: 169-181.Pauly, D. 1983a. Some simple methods for theassessment of tropical fish stocks. FAOFish. Tech. Paper, No. 243, 52pp.Fig. 5. Yield/recruit and biomass/recruit of S. undosquamis offVisakhapatnam (1998-2001)156U. Rajkumar et al.Pauly, D. 1983b. Length converted catchcurves. A powerful tool for fisheries re-search in tropics (Part -I). ICLARMFishbyte, 1(2): 9-13.Rao, K.V., C. Muthaiah and Madan Mohan1988.  Marine fish calendar, Mangalore.Mar. Fish. Infor. Serv., T. & E. Ser., 79.Rao, K.V.S. 1981.  Food and feeding oflizardfishes (Saurida spp.) from northwestern part of Bay of Bengal. Indian J.Fish., 28(1&2): 47-64.Rao, K.V.S. 1982. Studies on the populationof Saurida tumbil (Bloch) from Indianwaters. Indian J. Fish., 29(1&2): 8-19.Rao, K.V.S. 1983 a. Maturation and spawn-ing of lizardfishes (Saurida spp.) fromnorthwestern part of Bay of Bengal. In-dian J. Fish., 30(1): 27-54.Rao, K.V.S. 1983 b.  Length weight in Sauridatumbil and S. undosquamis and relativecondition in S. tumbil. Indian J. Fish.,30(2): 296-305.Rao, K.V.S. 1984.  Age and growth oflizardfishes (Saurida spp.) from thenorth western Bay of Bengal. Indian J.Fish., 31(1): 19-30.Showers, P. A. T. 1996.  Comparative growthperformance for species of the familyclupeidae, of sierra Leone. NAGA, TheICLARM quarterly, 19 (4): 42-45.Sivakami, S. 1999.  Fishery of lizardfishes offCochin with a note on the biology ofS. undosquamis (Richardson).  Thefourth Indian fisheries Forum Proceed-ings, 24-28 November, 1996. Kochi. P.245-248.Sparre, P.,E.Ursine and S.C.Venema 1989.Introduction to tropical fish stockassessement. FAO Fisheries TechnicalPaper, 337pp.Snedecor, G. W. and W.G. Cochran 1967. Sta-tistical Methods. 593pp.Tai-Shiang Wen, His – Chiang Liu, andSheanya-yeh 1987. Age and growth oflizardfish Saurida undosquamis(Richardson) in the north-west shelf offAustralia. Acta Oceanographicataiwanica, 18: 1-15Wright, P. J, N. G. Willouby and A. J.Edwards 1989. Growth, size and agecomposition of Stolephorus heterolobys innorth central Java.  Tuna bait fish in theIndopacefic region. ACIAR proceedings,30: 142-146.

Lizardfish fishery, biology and population dynamics

of Saurida undosquamis (Richardson) off

Visakhapatnam

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Lizardfish fishery, biology and population dynamics of Saurida undosquamis (Richardson) off Visakhapatnam

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