Journal of Coastal Development ISSN : 1410 - 5217 Volume 10, Number 2, ebruary 2007 : 89 - 103 Accredited : 23a / Dikti/Kep/ 2004 G OWT( DETE MINATION O, T OPI.AL LIMPET Cellana testudinaria (Linnaeus, 1758) LI/ING ON T(E O.01 S(O E O, O(OIWAIT, SO2T(EAST MOL2..AS, INDONESIA Abraham S Khow*) Faculty of Fisheries and Marine Sciences, Pattimura University, Ambon 9712 Indonesia Received : June, 21, 2006 ; Accepted : ecember, 12 , 2006 ABSTRACT Monthly shell-length fre(uency distributions were used to analyse the si)e and age structure of the limpet population inhabiting the rocky shore of Ohoiwait, Southeast Moluccas. The lengths of the collected specimens ranged from ..0 to 31.. mm. The analysis of the successive fre(uency distributions suggested that the population consisted of 0 to 1 distinct age groups 2cohorts) at any given time, and that two new cohorts recruited during the one-year investigation period. An analysis to determine growth pattern using 3iSAT software showed that the longevity of C. testudinaria e5tended up to 2 years. The values of von 6ertalanffy growth parameters 27, K and t0), estimated from si)e-fre(uency distributions, were 33.1 mm, 1.0 yr-1, and 0.08, respectively. The highest growth increments were 219 and 1.9 of the asymptotic length during the first 3 and 6 months, respectively. The effects of environmental variables on the growth rates showed important seasonal variations, with the highest increment of 2.6 mm/month during dry season. Here, growth parameter of C. testudinaria limpet shows the same value as other tropical limpets and depends on environmental variables. Key Words: Shell-length frequency distributions, Growth determination, Cellana testudinaria. () Correspondence: Phone *62-81 , 0,,29., E-mail0 as1houw2web.de INTRODUCTION The tropical limpet C. testudinaria is A burst of theoretical contributions reasonably well 1nown from systematic and regarding estimation of growth parameters geographical distribution aspects 56ilson, from growth data 5Lotze, 19987 Khouw, 199 7 Attrill et al., 2001), but there are little 2002) has led to the clarification of the published studies regarding its growth or concept of the effects of environmental other aspects of its biology. Many variables on the growth of limpets 56illiam investigations about growth rates of various 8 Morritt, 199.7 Liu 8 Morton, 1998). Patellacea have been carried out focusing on Iwasa1i 51998) examined growth rates of several factors affecting growth, such as some tropical gastropods in an attempt to tidal height 5Ta1ada, 19977 6illiams et al., determine whether life spans were under 1999), water temperature 56illiam 8 primary temperature control as suggested by Morritt, 199.7 Saad, 1997), seasonal changes and food availability 59r:thes et al., 199,7 Ruiz Sebasti=n et al., 2002). Growth Determination Of Tropical Limpet Cellana testudinaria (Linnaeus, 1758) Living On The ocky Shore Of Ohoiwait, Southeast Moluccas, Indonesia 89 Journal of Coastal Development ISSN : 1410 - 5217 Volume 10, Number 2, ebruary 2007 : 89 - 103 Accredited : 23a / Dikti/Kep/ 2004 Levins 51968) or whether some other Therefore, this research would present features of the milieu of these animals information on the growth rates of C. determined their longevity. In a review of testudinarai and some factors presumably the physiological variation among intertidal affecting them. Moreover, the results are molluscs, Aunmore 8 Schiel 52000) compared it with those of similar limpets concluded that on the whole southern from temperate regions. hemispheres, species have shorter life span and attain smaller final size than northern ones. The evidence from the north Atlantic ATERIALS AND ETHODS and Pacific coasts of North America M M indicated that this generalization also holds Study site within species with broad latitudinal distribution 5Aunmore 8 Schiel, 2000). These findings imply that differences of The study was carried out monthly on the intertidal roc1y shore of Ohoiwait growth parameters between limpets in 0 0 different regions can be explained either by 5latitude . ,.E1.F S, longitude 1 2 .7E20F a single primary environmental effect or E), 9ig Kai Island, Southeast Mollucas, may result from a combination of interaction Indonesia Fig. 1) from October 2001 to September 2002. The intertidal region between environmental and other factors. 2 C. testudinaria is an excellent investigated is about 0.2. 1m 51 1m long species to study growth, as they are present and 0.2. 1m wide). Thus, it is small enough in high numbers, range freely on all roc1y that atmospheric conditions may be substrata, and the shells of these animals assumed, for most purposes, to be uniform show distinct dimensions, suggesting a over the whole area. The shore consisted of possibility for determining growth. The shingles, pebbles, medium and big boulders notion that environmental stress is generally of about 90G of covering substrate. The an important factor which directly or physical conditions in the tidal zones are indirectly influences the population quite different7 the higher shore is wetted dynamics of common intertidal animals almost exclusively by tidal sea level rise, but 5Lohse, 199 7 Aelany et al., 19987 9rey, the lower shore receives considerable wave 200 7 Clar1e et. al., 200,) has led this study action. to further examine the same hypothesis. Growth Determination Of Tropical Limpet Cellana testudinaria (Linnaeus, 1758) Living On The ocky Shore Of Ohoiwait, Southeast Moluccas, Indonesia 90 Journal of Coastal Development ISSN : 1410 - 5217 Volume 10, Number 2, ebruary 2007 : 89 - 103 Accredited : 23a / Dikti/Kep/ 2004 N 5°18' * Banda Sea 5°26' 5°34' 5°46' Ohoiwait 5°54' Arafura Sea S 132°34' 132°42' 132°50' 132°58' E Fig 1. Map of study site of Ohoiwait located at the 9ig Kai Island. Growth measurements mean sizes of cohorts were followed through time. The population of C. testudinaria was sampled periodically and the mean size Analyses of the individuals within distinct age cohorts was calculated from polymodal size- Population structure. The frequency distributions 5Tablado et. al., population structure of C. testudinaria was 199,7 Turon et al., 199.7 Murray, 2002). analysed using the Modal class Progression Age classes were defined through analysis Analysis, MPA 5Gayanillo et al., 1996) by of length frequency distributions to the aid of FiSAT software 5Sparre 8 decompose monthly size-frequency into Henema, 1998). This methodology infers their component normal curves 59r:thes et growth from the apparent shift of the modes al., 199,). The estimate of growth used the or means in a time series of length frequency monthly size of frequency data, whereby the samples. It was then applied to the Growth Determination Of Tropical Limpet Cellana testudinaria (Linnaeus, 1758) Living On The ocky Shore Of Ohoiwait, Southeast Moluccas, Indonesia 91 Journal of Coastal Development ISSN : 1410 - 5217 Volume 10, Number 2, ebruary 2007 : 89 - 103 Accredited : 23a / Dikti/Kep/ 2004 frequency histograms of the limpetsE shell 9artlettEs test 5So1al 8 Rohlf, 199.) was lengths to divide them into distinctive used to chec1 the assumption of cohorts. homogeneity of the residual variances Growth. The growth of limpets was before using ANCOHA. analysed by using the most widely used being that developed by von 9ertalanffy 519 8) that has been 1nown as the RESULTS AND DISCUSSION - K 5t > to) 9ertalanffy equation0 7t I 7 [1 J e ] where 7t is the length at age t, 7 is the ,opulation structure asymptotic length 5representing the maximum theoretical length of animal), K The size structure of the population the growth coefficient 5describing the rate of of C. testudinaria was examined through the growth of the animal to its maximum size), analysis of percentage size frequency and to the theoretical age at length 0 5the distribution Fig. 2). The overall specimen start of growth of the settled larva)7 the sizes ranged from 8.0 to 1.8 mm, intercept between the curve and the t axis. representing 6 cohorts. The first cohort Statistical analysis. Seasonal consists of juvenile limpets with an average variation in the growth of cohorts was length of L 10.. mm, representing 1 G of assumed to be negligible in the present the total population. The second cohort study, because growth rates calculated at encompasses the limpets with lengths of different times could confound an analysis 10.. J 1... mm, accounting for ,8 G of the of seasonal variability. As a consequence, I total population. This sub-population proceeded with the comparison of regression generally presents the group of limpets with lines resulting from the relationships the highest growth rates. The remaining between shell length and the number of cohorts consist of limpets with an average months, using an analysis of covariance length of 1... J 20.. mm, 20.. J 2... mm, ANCOHA 5So1al 8 Rohlf, 199.). This test 2... J 0.. mm, and M 0.. mm, accounting determines the level of similarity between for 22 G, 9 G, 7 G, and 1 G of the total the samples, and, in case of heterogeneous population, respectively. relationships, obtained the nature of the source of the differences 59axter, 198 ). 20 18 16 14 12 10 8 6 4 PercentageFrequency (%) 2 0 8,5 9,5 10,5 11,5 12,5 13,5 14,5 15,5 16,5 17,5 18,5 19,5 20,5 21,5 22,5 23,5 24,5 25,5 26,5 27,5 28,5 29,5 30,5 31,5 Mean length (mm) Fig 2. Cellana testudinaria. Mean percentage frequency of each size class category. Hertical lines represent standard deviation 5SA). Growth Determination Of Tropical Limpet Cellana testudinaria (Linnaeus, 1758) Living On The ocky Shore Of Ohoiwait, Southeast Moluccas, Indonesia 92 Journal of Coastal Development ISSN : 1410 - 5217 Volume 10, Number 2, ebruary 2007 : 89 - 103 Accredited : 23a / Dikti/Kep/ 2004 Growth 8.