Interciencia ISSN: 0378-1844 [email protected] Asociación Interciencia Venezuela

Carrasco, Claudio A.; Navarro, Jorge M.; Leiva, Germán E. Biochemical composition and tissue weight of giganteus (: ) exposed to different diets and temperatures during reproductive conditioning Interciencia, vol. 31, núm. 5, mayo, 2006, pp. 376-381 Asociación Interciencia Caracas, Venezuela

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How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative BIOCHEMICAL COMPOSITION AND TISSUE WEIGHT OF Chorus giganteus (GASTROPODA: MURICIDAE) EXPOSED TO DIFFERENT DIETS AND TEMPERATURES DURING REPRODUCTIVE CONDITIONING

Claudio A. Carrasco, Jorge M. Navarro and Germán E. Leiva

SUMMARY

A study was made of the effects of temperature and diet on Reloncavi Sound using the same diets, in order to provide a the dry soft tissue weight and biochemical composition of the comparative group of specimens exposed to environmental gastropod Chorus giganteus (trumulco) over a 133 day period temperatures (11.0-15.4ºC). The results show that all tissues of of reproductive conditioning. Adult specimens measuring 9- the fed with T. dombeii increased in dry weight and in 13cm in total length obtained from the subtidal habitat at biochemical components, while the second group of snails Chaihuin (Valdivia, Chile) were maintained in seawater tanks showed low preference for M. chilensis and no tissue gains. at 13, 15 and 18ºC, and fed ad libitum in parallel systems with The most favourable temperatures for the reproductive either , Mytilus chilensis, or razor , Tagelus conditioning were 13 and 15ºC, as well as the ambient dombeii. Two groups of snails were simultaneously installed in temperature, with no significant differences among these suspended culture at Metri Bay on the eastern shore of treatments.

RESUMEN

Se realizó un estudio para determinar los efectos de la tem- Reloncaví, utilizando las mismas dietas, con el fin de tener un peratura y dieta sobre el peso y composición bioquímica de los grupo comparativo de especímenes expuestos a la temperatura tejidos blandos del gastrópodo Chorus giganteus durante un ambiente (11,0-15,4ºC). Los resultados demuestran que todos periodo de acondicionamiento reproductivo de 133 días. los tejidos de los caracoles alimentados con T. dombeii aumen- Especímenes adultos obtenidos desde la zona submareal de taron su peso y componentes bioquímicos, mientras que el gru- Chaihuin (Valdivia, Chile), con tamaños entre 9 y 13cm de lon- po de caracoles alimentados con M. chilensis mostró una baja gitud total, fueron mantenidos en estanques de agua de mar a preferencia por esta dieta, sin presentar ganancia de tejidos. 13, 15 y 18ºC y alimentados ad libitum en sistemas separados Las temperaturas más favorables para el proceso de acondicio- con el bivalvo Mytilus chilensis o con la navajuela Tagelus namiento reproductivo fueron 13 y 15ºC, al igual que la tempe- dombeii. Otros dos grupos de caracoles fueron instalados en ratura ambiental, sin diferencias significativas entre estos dife- cultivos suspendidos en la bahía de Metri, al Este del seno de rentes grupos.

Introduction tioning may be measured by and due to favourable charac- reproductive cycle, with the increase in body weight teristics of its biology has asynchronic maturation (Jara- Optimal conditioning of and tissue biochemical compo- shown promise as a potentially millo and Garrido, 1990). molluscan broodstock is re- sition, as these parameters re- cultivable marine resource Eggs are laid in capsules and quired for the production of spond to treatments for short (Gutiérrez and Gallardo, 1999; provided with nutritive eggs as high quality gametes for inten- periods, of weeks or months Navarro et al., 2002). This an extra-embryonic source of sive culture. Adequate storage (Barber and Blake, 1981). species is endemic to the Chil- nutrition (González and Gallar- of energetic reserves and go- The subject of the present ean coast, inhabiting waters do, 1999). The eggs hatch af- nad development has been ob- study, Chorus giganteus, is a between 8 and 30m in depth ter about 80-87 days in the tained by optimization of hold- commercially valuable (Amín et al., 1984) on sandy capsule and the larvae have a ing temperature (Uki and which is undergoing overex- bottoms (Gallardo, 1981). It 2-5 day lecithotrophic period Kikuchi, 1984; Chaparro, ploitation in its natural habitat. occurs (Osorio et al., 1979) in the plankton (González and 1990; Navarro et al., 2000) Despite increasing efforts, the from Antofagasta (23º48'S, Gallardo, 1999). Competent and diets (Uki and Kikuchi, landing of C. giganteus de- 70º32'W) to Valdivia (39º25'S, larvae are sensitive to meta- 1984; Chaparro, 1990). Re- creased from 2800 metric tons 73º10'W). The reproductive morphic induction with 20mM sponses of broodstock to ex- in 1980 to less than 100 tons characteristics of this species KCl, showing a greater per- perimental attempts at condi- in 1997 (Ram et al., 2000), include a continuous annual centage of postlarval survival

KEYWORDS / Biochemical Composition / Chorus giganteus / Muricidae / Reproductive Conditioning / Received: 06/28/2005. Modified: 03/16/2006. Accepted: 03/23/2006.

Claudio A. Carrasco. Marine Bi- Jorge M. Navarro. Ph.D. Memo- “Dr. Jürgen Winter”, Univer- Germán E. Leiva. Marine Biolo- ologist, Universidad Austral de rial University of Newfound- sidad Austral de Chile, Val- gist (UACH), Chile. Biologist, Chile (UACH), Chile. land, Canada. Professor, divia, Chile. e-mail: Austral, Servicios & Tecno- (UACH), Chile. Address: [email protected] logía Marina, Chile. Instituto de Biología Marina

376 0378-1844/06/05/376-06 $ 3.00/0 MAY 2006, VOL. 31 Nº 5 RESUMO

Realizou-se um estudo para determinar os efeitos da temperatura utilizando as mesmas dietas, com o fim de ter um grupo comparati- e dieta sobre o peso e composição bioquímica dos tecidos brandos vo de especímenes expostos à temperatura ambiente (11,0-15,4ºC). do gastrópode Chorus giganteus durante um período de acondicio- Os resultados demonstram que todos os tecidos dos caracóis ali- namento reprodutivo de 133 dias. Especímenes adultos obtidos des- mentados com T. dombeii aumentaram seu peso e componentes de a zona submareal de Chaihuin (Valdivia, Chile), com tamanhos bioquímicos, enquanto que o grupo de caracóis alimentados com entre 9 e 13cm de longitude total, foram mantidos em estanques de M. chilensis mostrou uma baixa preferência por esta dieta, sem água de mar a 13, 15 e 18ºC e alimentados ad libitum em sistemas apresentar ganho de tecidos. As temperaturas mais favoráveis para separados com o bivalve Mytilus chilensis ou com a almeja Tagelus o processo de acondicionamento reprodutivo foram 13 e 15ºC, ao dombeii. Outros dois grupos de caracóis foram instalados em culti- igual que a temperatura ambiental, sem diferenças significativas en- vos suspendidos na bahía de Metri, ao Leste do seno de Reloncaví, tre estes diferentes grupos.

at Coihuin (41º29'S, 72º54'W) 1.0L·min-1. To control for the and mussels (Mytilus chilensis) effects of temperature, snails in from suspended cultures in two other tanks were each fed Metri Bay. These species were with the corresponding bivalve selected because the razor diet but maintained in open clams were common natural tray cultures, in Metri Bay, prey in the habitat of C. gigan- where ambiental temperatures teus (Osorio et al., 1979) and during the test period, between the mussels appeared to be a June and November of 1998, potentially useful prey species fluctuated between 11.0 and for mass snail culture, due to 15.4ºC (Table I). their ready availability in large Over the experimental period quantities and low cost. of 133 days, sampling for analyses included 6 snails from Experimental design the natural population prior to conditioning, 6 snails at the Prior to reproductive condi- time conditioning was begun (1 tioning tests, the snails were week of post-acclimation) and 6 measured, separated by sex, snails per each temperature/diet and randomly allocated in eight combination in each of 4 sam- 75L plastic aquaria for accli- plings made over the time pe- mation to test temperatures for riod of conditioning (Table II). a one-week period. Snails in At each sampling, male and fe- one set of three tanks, with male groups of C. giganteus water at 13, 15 and 18ºC, were were randomly selected from fed ad libitum with T. dombeii each experimental temperature (>3cm length). Snails in a sec- and diet treatment, as well as Figure 1. Study area. : Collection place of Chorus giganteus (39º52'S, 73º25'W). ♦: Intertidal flat of Coihuín (41º29'S, 72º54'W), collection place ond set of three tanks, also from the field tests. Because of of Tagelus dombeii. +: Bay of Metri (41º36'S, 72º42'W), collection place of kept at 13, 15 and 18ºC, were logistic reasons (i.e. remote lo- Mytilus chilensis and experimental laboratory. fed with M. chilensis (>3cm cations of this research and lim- length). Water in all tanks was ited laboratory space) little con- (González, 1997) and greater Material and Methods constantly replaced with 50µm trol was exerted over the experi- rates of growth as juveniles filtered seawater at a rate of mental design and no true repli- (Muñoz and Leiva, 1994). Experimental specimens Some research has been done TABLE I on broodstock conditioning un- 300 adult specimens of C. MONTHLY TEMPERATURE (ºC) AVERAGES der different regimes of diet and giganteus measuring 9-13cm AT METRI BAY (JUN - NOV 1998) temperature (Navarro et al., in total length were obtained 2002); however, no studies have by diving in the subtidal zone Jun Jul Aug Sep Oct Nov evaluated the effects of different at Chaihuin (39º52'S, 73º25'W; 11.5 11.0 11.0 11.5 14.0 15.4 methods of conditioning on dry Figure 1) and transported to Data from Aquaculture and Marine Sciences Center, Metri. soft tissue weight and biochemi- the Aquaculture and Marine cal components of the adult tis- Sciences Center of the TABLE II sues. The present study evalu- Universidad de Los Lagos on SAMPLING DATES ates the effects on these param- Metri Bay (41º36'S, 72º42'W), eters of four experimental tem- near Puerto Montt, Chile, in Date Conditioning time (days) Sample peratures (three fixed, plus am- April 1998. April 21 0 Natural population biental), and two different diets, Prey species for use as ex- June 19 0 Starting conditioning a knowledge required for opti- perimental diets for C. gigan- August 4 40 Conditioning mal reproductive conditioning of teus included razor clams September 7 74 Conditioning this species prior to mass cul- (Tagelus dombeii) obtained October 9 105 Conditioning ture. from intertidal sand/mud flats November 6 133 End of conditioning

MAY 2006, VOL. 31 Nº 5 377 cations were included. This did tal standard length (11.5cm), LE not allow to test the tank ef- and WE: actual total length and fects, reducing the accuracy of dry tissue weight, respectively, the measurements. of the snail, and b: weight ex- ponent of the relation between Dry soft tissue weight the length and weight. and biochemical composition Analysis of variance For determination of the dry (ANOVA) and an a posteriori soft tissue weight and subsequent Scheffe test were used to detect biochemical analysis, individual significant differences among snails of each sex were dissected treatments defined by diets, from the shell and the soft tis- temperatures, sexes, and condi- sues separated into foot, gonad tioning times. Kruskal-Wallis and rest of the tissue. Separate tests were used in cases where tissues were dried at 60ºC for the distribution of variables was 48h, weighed and grounded in a significantly different from nor- ball mill for biochemical analy- mal. All statistical tests were carried out at the 5% level (p ses. The gonadosomatic index ≤ was calculated as the percentage 0.05), and the data was pro- of the gonad dry weight over the cessed using the “S-plus 4.0” total dry soft tissue weight. package for Windows. Figure 2. Chorus giganteus. Fluctuation of the dry weight of the foot for Protein, carbohydrates and a standard individual of 11.5cm total length. Values represent means ±SE. lipids were determined on Results : males, : females. subsamples of dried, homog- enized tissue. Protein was deter- Dry soft tissue weight mined in 3-5mg of tissue using the Pierce Laboratories BCA The dry weight of the foot in method, which uses a C. giganteus showed a slight bicinchoninic acid solution for tendency to increase over the colorimetric determination of experimental period when fed total protein. Carbohydrates with T. dombeii, compared with were extracted by boiling 8- specimens fed with M. chilensis 10mg of homogenized tissue in which demonstrated a slight de- trichloroacetic acid with silver crease (Figure 2). This observa- sulphate (Barnes & Heath, tion was more pronounced dur- 1966) and quantified with glu- ing the latter months of condi- cose as the standard using the tioning. Over the entire study, phenol-sulphuric acid method the dry weight of the foot was (Dubois et al., 1956). The gravi- significantly greater in snails fed metric method of Bligh and with the razor clams than with Dyer (1959) was used for deter- mussels. Significant differences mination of lipids in 40-50mg were also observed in dry weight of the foot with the time- of foot tissue, while gonad tis- Figure 3. Chorus giganteus. Fluctuation of the dry weight of the gonad for sue was assayed using the diet interaction. This showed that the conditioning time used ac- a standard individual of 11.5cm total length. Values represent means ±SE. method described by Marsh and : males, : females. Weinstein (1966) on 1-3mg centuated the difference in samples using tripalmitin as a weight of the foot between the of the conditioning experiment nificantly greater in snails fed T. dombeii standard. The latter method was snails on the two diets. the values for this index were with than those fed with M. chilensis. The employed due to the very small The dry weight of the foot 3.33 +2.1% in males and 2.10 amounts of gonad tissue present showed no significant differ- +0.6% in females. By the end tendency of the protein curves in the samples during the test ences with regard to experi- of the conditioning period these (eight combinations of diet and temperature) were similar, period. mental temperature used in the values had increased to 9.70 laboratory and ambient tem- +9.5% in males fed with T. repeating the same pattern of Statistical analysis perature in the field (Figure 2). dombeii at ambient tempera- higher values in August, de- A significant effect was ob- ture, and 6.30 +1.2% in fe- crease in September, rise in All data were standardized to served of diet on the weight of males at 13ºC and fed on the October and stabilization a specimen of 11.5cm in total the gonad, where greater gonad same diet (Figure 4). There nearing the end of the experi- length, which represented the weight was achieved on a diet were no significant differences mental period. Foot protein mean size of individuals used of T. dombeii (Figure 3). observed either between sexes varied over time with signifi- in the experiment. This stan- nor among the different treat- cant differences between the dardization was done, accord- Gonadosomatic index (GI) ments of diet and temperature. samples of August-September ing to Bayne et al. (1987), as and September-October (Fig- W = (L / L )b × W The GI evaluated the relation Biochemical composition ure 5). The protein content of S S E E between weight of the gonad the gonad also showed sig- where WS: standardized dry and total soft tissue weight of Proteins. Protein content of nificant differences between weight of the specimen, LS: to- the individual. At the beginning the foot (Figure 5) was sig- diets, with an increase in this

378 MAY 2006, VOL. 31 Nº 5 component in specimens fed similar results: each individual observed in Thais haemastoma, ity of the experimental speci- with T. dombeii (Figure 6). of C. giganteus fed on average which discarded non-muscular mens was observed in the last upon 0.77 to 1.32, 3 to 5cm tissues of (Gunter, month of the experiment. In a Carbohydrates. A high de- long mussels per month. These 1979). According to Hughes concurrent study carried out gree of variation was observed results may be due to the fact (1986), when high quality by Merino (2000) with this in carbohydrate content in the that in its natural habitat, C. preys are abundant, selective species, only 15% of the or- foot tissue of C. giganteus. giganteus does not prey on M. ingestion would maximize the ganisms survived at 18°C. The T. dombeii diet produced chilensis, which occupies a net energy gain acquired by the Thus, it seems that adults of a larger increment in this com- different habitat. Cristian predators, which could ingest C. giganteus are unable to sur- ponent, with significant differ- Manque (personal communica- the most favourable organs vive for a long time in water ences found in comparison tion) found a contrasting (those least difficult to ingest, at >17°C, as they would lose with the M. chilensis diet. Sig- behaviour in C. giganteus en- with the highest energetic and/ their capacity for thermal nificant differences were found closed in the laboratory and or nutritional value). compensation outside their in the diet-time interaction in fed on prey species that did The temperature of 18ºC zone of tolerance (Newell and the last two months of the ex- not occur in its typical habitat; was deleterious to the snails Branch, 1980). In a great vari- periment (Figure 7). The go- the snails were first fed with as, in addition to failure to ety of marine organisms the nad tissue also showed signifi- Semimytilus algosus and then gain weight, a massive mortal- maximum temperature limit cant differences in carbohy- with M. chilensis, and after drates related to diet. Again, four months of feeding with the T. dombeii diet produced the latter, each snail consumed greater levels of carbohydrates. about 3.8 individuals of M. In contrast, the M. chilensis chilensis per month. diet showed highly reduced Tagelus dombeii was well carbohydrate values in the go- accepted as diet of C. gigan- nad at the end of the experi- teus, leading to increment in ment (Figure 8). the weight of the snail tissues. Lipids. The lipid content of Navarro et al. (2002) found the foot showed significant that one individual of C. differences related to diet (Fig- giganteus reached monthly ure 9), with greater values consumptions between 5.24 produced when feeding T. and 7.26 T. dombeii of 4-6cm dombeii. Significant differ- in length. Conversely to M. ences were also found be- chilensis, T. dombeii is a com- tween temperatures, with mon bivalve species in the greater lipid accumulations re- habitat of C. giganteus (Osorio corded for the snails main- et al., 1979), representing a tained at 13ºC. In gonad tissue common prey species in the Figure 4. Chorus giganteus. Fluctuation of the gonadosomatic index for (Figure 10) snails fed T. diet of this snail. The higher a standard individual of 11.5cm total length. Values represent means ±SE. dombeii showed lipid content rate of food consumption with : males, : females. values significantly greater T. dombeii than with M. than those fed with M. chilen- chilensis may be related to the sis. Lipids in gonad tissue fact that the soft tissues of T. demonstrated some significant dombeii are not totally en- differences with regard to tem- closed by the shell, allowing perature; when maintained at the snail to consume this bi- ambient temperatures snails valve without spending energy developed significantly greater in penetrating the shell. Thus, amounts of gonad lipids than feeding on this prey would when maintained at 18ºC. No imply a low energy cost for significant differences in lipid the snail by the optimal forag- content were observed be- ing theory (Hughes, 1986), as tween snails of different sex in compared to M. chilensis, a any of the tissues examined. prey that closes its valves tightly. Discussion When T. dombeii was used, C. giganteus mainly consumed When C. giganteus was fed the gonad and digestive gland with M. chilensis, the dry of the clams, discarding foot weight of all its tissues de- and siphons. Hughes and creased gradually during the 8 Dunkin (1984) describe a simi- months of the conditioning pe- lar behavior in the gastropod riod, which reflects the low Nucella lapillus, which con- preference of the snail for this sumes the digestive gland and species. The study of Navarro discards the mantle and foot Figure 5. Chorus giganteus. Fluctuation of the protein content of the foot et al. (2002), under similar ex- when preying on mytilids. Se- for a standard individual of 11.5cm total length. Values represent means ±SE. perimental conditions, yielded lective consumption was also : males, : females.

MAY 2006, VOL. 31 Nº 5 379 may be related to natural con- at 18ºC, it can easily survive giganteus, the biochemical (2000) in snails from the ditions in their habitat shorter periods of high tem- composition of the different tis- present study showed no sig- (Henderson, 1929 in Newell et peratures that can occur at sues was affected by variations nificant differences associated al., 1971). Based on this, and their natural environment. in the conditioning process. with the type of diet. Merino with the knowledge that C. Also, the high mortality of the The protein content, as well as (2000) reported that even giganteus inhabits the subtidal test specimens may be attrib- the content of the other bio- though fed with the diet of zone below 8m depth (Lépez, uted to the short period of ac- chemical components, showed lesser consumption, mature 1981 in Amín et al., 1984), it climation afforded to the snails that the diet had a significant snails deposited egg capsules is assumed that C. giganteus before experimentation. Newell effect on the foot and gonad: when held in the natural envi- never experiences temperatures et al. (1971) found in the high rates of consumption of T. ronment. It thus appeared that as high as 18°C during long prosobranchs Littorina littorea dombeii resulted in weight in- the group of snails fed with M. periods of time, and thus its and Monodonta lineata that crement of these structures. chilensis carried out the forma- upper compensation limit must the upper lethal temperature The relatively constant content tion of gametes primarily at the be below this value. However, was significantly affected by of protein in the muscular tis- expense of reserved energy it seems also reasonable to as- thermal acclimation. sue (foot) of specimens fed available from body tissues, sume that if this species is Similarly to results on the with mussels indicated that which was subsequently mea- able to survive near 8 months dry soft tissue weight in C. structural integrity of this body sured as a decrease in bio- tissue was maintained to the chemical components. In con- end of the experiment. This trast, snails fed with Tagelus situation was observed by Hol- dombeii could obtain sufficient land et al. (1975) in Littorina energy for the process of ga- littorea after 14 weeks without metogenesis, considering that feeding. These authors also ob- they were able to divert energy served that during the time the reserves as carbohydrates in the snails were maintained without foot tissues, in coincidence food, the lipid and carbohy- with observations made for L. drate contents of the tissues de- littorea (Holland et al., 1975). creased in greater proportion This study indicates that the than the protein. According to best reproductive conditioning these results, L. littorea as well for the snail C. giganteus will as C. giganteus prioritize the be strongly determined by suit- catabolism of carbohydrates able temperatures, no higher and lipids rather than proteins than those experienced in the when deprived of food. natural habitat, and by appropri- The gonad of C. giganteus ate diets represented by those contained greater quantities of bivalves which can be easily lipids than carbohydrates, in preyed upon. Thus, when C. gi- contrast to the foot tissues. This ganteus was fed with the bi- distribution of lipids and carbo- valve T. dombeii, it increased its Figure 6. Chorus giganteus. Fluctuation of the protein content of the gonad for a standard individual of 11.5cm total length. Values represent means ±SE. hydrates in gonad and muscular weight and the concentration of : males, : females. tissues holds as a characteristic the biochemical components in pattern in prosobranchs (Web- its tissues. Furthermore, greater ber, 1977). The results of go- amounts of carbohydrates than nad histology by Merino lipids were found in the foot tis-

Figure 7. Chorus giganteus. Fluctuation of the carbohydrate content of the Figure 8. Chorus giganteus. Fluctuation of the carbohydrate content of the foot for a standard individual of 11.5cm total length. Values represent means ±SE. gonad for a standard individual of 11.5cm total length. Values represent : males, : females. means ±SE. : males, : females.

380 MAY 2006, VOL. 31 Nº 5 sue, whereas the contrary was nel of CEACIMA-Metri for Exp. Mar. Biol. Ecol. 52: 121- lapillus (L.), feeding on mussels observed in the gonads, suggest- field and laboratory help. This 134. Mytilus edulis (L.), in laboratory. Barnes H, Heath J (1966) The extrac- J. Exp. Mar. Biol. Ecol. 77: 45- ing that the foot represents an study was financed by the 68. important energy reservoir in C. Aquaculture and Marine Biol- tion of glycogen from marine in- vertebrate tissues. Helgoländer. Jaramillo R, Garrido O (1990) Ciclo giganteus. The results obtained ogy Program 1 (97), Inverte- Wissenschafthiche reproductivo de Chorus giganteus are relevant to the development brate Subprogram, FONDAP, Meeresuntersuchungen 13: 115- (Gastropoda: Muricidae) en la of more efficient culture meth- Chile and for the DID-UACH. 117 Bahía de Corral, Valdivia. Biol. ods of this commercially valu- Bayne BL, Hawkins AJ, Navarro E Pesq., 19: 49-53. 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