See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/320044059 Growth and survival of the winged pearl oyster Pteria sterna (Gould, 1851) in suspended culture in the tropical Eastern Pacific: Influence of environmental factors Article in Aquaculture Research · September 2017 DOI: 10.1111/are.13514 CITATIONS READS 9 272 7 authors, including: Cesar Lodeiros Daniel Rodriguez Pesantes Universidad Técnica de Manabí (UTM) Escuela Superior Politécnica del Litoral (ESPOL) 215 PUBLICATIONS 2,855 CITATIONS 10 PUBLICATIONS 55 CITATIONS SEE PROFILE SEE PROFILE Adrian Marquez Esteban Revilla Escuela Superior Politécnica del Litoral (ESPOL) Universidad Católica del Norte (Chile) 27 PUBLICATIONS 107 CITATIONS 11 PUBLICATIONS 47 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Sustainable aquaculture View project Transferencia tecnologica del cultivo de la ostra de mangle View project All content following this page was uploaded by Stanislaus Sonnenholzner on 12 March 2018. The user has requested enhancement of the downloaded file. DOI: 10.1111/are.13514 ORIGINAL ARTICLE Growth and survival of the winged pearl oyster Pteria sterna (Gould, 1851) in suspended culture in the tropical Eastern Pacific: Influence of environmental factors Cesar Lodeiros1,2 | Daniel Rodrıguez-Pesantes1 | Adrian Marquez 1 | Jormil Revilla1 | Luis Freites2,3 | Carla Lodeiros-Chacon 4 | Stanislaus Sonnenholzner1 1Escuela Superior Politecnica del Litoral, ESPOL, Centro Nacional de Acuicultura e Abstract Investigaciones Marinas, CENAIM, The growth, survival and influence of environmental factors were analysed in two Guayaquil, Ecuador cohorts of cultured Pteria sterna in Ayangue Bay, Province of Santa Elena, Ecuador 2Instituto Oceanografico de Venezuela, Universidad de Oriente, Cumana, Venezuela (tropical Eastern Pacific). Juveniles representing cohorts I and II (8.4 Æ 0.54 and 3Universidad Estatal Penınsula de Santa 5.0 Æ 0.17 mm in dorso-ventral axis) were deployed in November 2015 and Febru- Elena (UPSE), Santa Elena, Ecuador ary 2016, and grown in pearl nets suspended in a long line for 12 and 10 months 4Master Interuniversitario en Acuicultura, Universidades de Santiago de Compostela, respectively. The stocking density was monthly and bi-monthly reduced during sam- ~ ~ La Coruna, Espana pling of individuals to determine growth in dorso-ventral shell axis, dry mass of Correspondence shell, soft tissues and dry mass of fouling on shell. Water temperature, salinity, total Cesar Lodeiros, Escuela Superior Politecnica seston and phytoplankton biomass (chlorophyll a) were determined at the culture del Litoral, ESPOL, Centro Nacional de Acuicultura e Investigaciones Marinas, site. Results showed that P. sterna reached ~100 mm in length during the first year CENAIM, Guayaquil, Ecuador. of culture. Although little negative influence of environmental factors was detected, Email: [email protected] high temperatures during the reproduction period can be the most negative influen- tial trait. The highest tissue mass (6 g), which occurred at the 10th month of cultiva- tion, as well as a high availability of spat by artificial collectors in the coastal waters, showed that the species can be considered a good candidate for aquaculture in the tropical eastern Pacific. KEYWORDS American Pacific, aquaculture, growth, pearl oyster, tropics 1 | INTRODUCTION regions, including tropical areas, are suitable for the cultivation of pearl oysters, particularly for P. sterna (Serna-Gallo et al., 2014). In In the tropical and subtropical American Pacific, there are several equatorial waters, it has been observed a high, although periodic, species of bivalve mollusks with potential to produce pearls, but only availability of P. sterna spat through natural catch using artificial col- two (the mother pearl oyster Pinctada mazatlanica and the winged lectors (up to 4–5 juveniles of 10 mm in 5 cm2 of sardine fishing net pearl oyster Pteria sterna) produce an iridescent nacre suitable for -personal observation), which could support a growing industry, with quality pearls (Kishore, Southgate, Seeto & Hunter, 2015; Southgate interest in the production of pearls and/or food, as well as byprod- et al., 2008). Although some pearl production trials have been con- ucts that can be made with its shell. ducted in the American Pacific, only Mexico has promoted a low- Although P. sterna has a distribution from Morro Santo Domingo, scale pearl industry in the subtropical zone of Baja California Sur in Baja California (28.2°N), to Ancon, Lima, Peru (11.8°S) (Coan & and Sonora, and certain information has been produced on this sub- Valentich-Scott, 2012), and has commercial importance, there are ject (Lodeiros, 2014; Monteforte, 2013; Saucedo, Castillo-Domınguez few studies on its aquaculture feasibility in tropical areas. Only & Melgar-Valdes, 2015; Southgate et al., 2008). However, many Serna-Gallo et al. (2014) demonstrates the feasibility of P. sterna 832 | © 2017 John Wiley & Sons Ltd wileyonlinelibrary.com/journal/are Aquaculture Research. 2018;49:832–838. LODEIROS ET AL. | 833 cultivation in the Bay of Acapulco, Mexico (16°N), but dependent on 2.3 | Fouling and environmental factors spat production in the laboratory. Some preliminary studies (Jara, Gregori & Freites, 2016; Trevino~ & Figueroa, 2009) show high In order to estimate the impact of environmental factors (including growth rate in equatorial waters (0° and 2°S). At this moment, more fouling) on the growth of the pearl oyster, water samples (in triplicate) studies are necessary to examine growth and survival in tropical were collected weekly between 0.5 and 1 m of sea surface with 12 L waters to determine the feasibility of P. sterna cultivation. These plastic bottles. Sub-samples of water were obtained for the determina- studies must be accompanied by records of environmental factors, tion of salinity (with a refractometer, 0.1 of precision), as well as seston to estimate, from an integrated eco-physiological point, the possible and phytoplankton biomass. For the latter, water samples previously causes that could influence the growth and survival, in order to filtered with 153-lm pore size mesh to eliminate macroplankton, were establish cultivation strategies. For instance, food availability and transferred to dark plastic bottles (2 L) to be transported to the labora- temperature should be considered, since it has been determined that tory, in order to estimate the phytoplankton biomass by the concen- they are the main factors controlling the growth and reproduction of tration of chlorophyll a, and total seston. These analyses were tropical pearl oysters (Freites et al., 2017; Pouvreau, Bacher & Heral, performed by retaining the sample particles in Whatman GF/C filters 2000; Pouvreau & Prasil, 2001; Serna-Gallo et al., 2014; Tomaru, (1.2 lm pore diameter) using Millipore vacuum filtration equipment. Kumataba, Kawabata & Nakano, 2002). For the determination of chlorophyll a the spectrophotometric method The present study evaluates the growth and survival of two was used and the seston method was performed using gravimetric P. sterna cohorts under suspended cultivation conditions and the techniques following Strickland and Parsons (1972). The temperature influence of environmental factors associated to equatorial waters of was continuously recorded every 30 min or 1 hr using an electronic the Eastern Tropical Pacific Ocean. thermograph (Hobo, Onset, MA, USA). Shell fouling (organisms and material deposited on shell) was scraped and its weight determined as dry mass with an analytical 2 | MATERIALS AND METHODS balance (0.001 g of precision), after a dehydration process by heat treatment (60°C until reaching constant weight). The fouling index 2.1 | Experimental culture was estimated as the % in dry mass of fouling in relation to the dry The study was carried out in Ayangue Bay, Province of Santa Elena, mass of shell. Ecuador (1°5901.59″S; 80°45035.15″W). Two lots of juveniles that recruited on sardine fishing net collectors at two time periods of the 2.4 | Statistical analysis year, were suspended (2–4 m in depth) from an experimental long line, and identified as cohort I to those juveniles for which the The contrasts of the means of each growth variables between succes- experimental culture started in November 2014, and cohort II in sive samples in each cohort, or between cohorts in a particular sample, February 2015. The juveniles measured 8.4 Æ 0.54 mm (cohort I) were made by Student’s t-test at a probability of .05. To evaluate the and 5.0 Æ 0.17 mm (cohort II) in dorso-ventral length. The juveniles effect of environmental factors on growth of the pearl oyster, we exam- (>2,000 in each cohort) were confined in several pearl nets (initially ined the relationship of changes in body components to environmental 3 mm mesh size, increasing it as the crop evolved) maintaining a factors using a stepwise multiple regression procedure applied to Log density equivalent to 25%–30% coverage of the basket base. (X + 15) transformed data, following Hair, Black, Babin and Anderson Monthly or bi-monthly samplings were made on the pearl nets, (2014). The probability of entry of the variables in the models was .05. decreasing the number of individuals per basket according to the cri- The regression analysis was performed between the daily specific teria established. Lots of four to six baskets were protected with a changes