Elsevier

Aquaculture

Volume 468, Part 1, 1 February 2017, Pages 545-548
Aquaculture

Short communication
Effects of salinity on fertilization and larviculture of the mangrove oyster, Crassostrea gasar in the laboratory

https://doi.org/10.1016/j.aquaculture.2016.11.016Get rights and content

Highlights

  • The manuscript presents original research on the main native oyster species cultured in Brazil (Crassostrea gasar).

  • To the best of our knowledge, this is the first article on species larviculture.

  • The results indicate the optimal salinity for fertilization, embryonic and larval development, and settlement for a species that occurs between salinities 0-40 in natural environment, providing guidance for hatcheries.

Abstract

The mangrove oyster Crassostrea gasar is the main native oyster species cultivated in Brazil. C. gasar culture is based on seed and juvenile capture from the environment. However, its capture using artificial collectors is difficult due to overlapping settlement periods with other oyster species. Therefore, research on seed production techniques of C. gasar in hatcheries is needed. This study evaluated the effect of salinity on fertilization and larviculture of C. gasar in salinities 7, 14, 21, 28 and 35 from December 2013 to April 2014. Fertilization and larva-D development occurred between salinities 21 and 35. Larval development from larva-D to umbo occurred with no significant differences in length and height between salinities 14 and 35. Only larvae cultivated in salinities 28 and 35 reached the settlement stage by the end of the experiment, after 25 days of larviculture. Fertilization, embryonic and larval development presented best results in salinity 28.

Introduction

According to the Food and Agriculture Organization of the United Nations, Latin America, Africa and the Caribbean present high and increasing potential for bivalve production. However, cultivation in these areas is limited mainly due to the small number of hatcheries and the lack of proper methodologies for domesticating native species (FAO, 2014).

Brazil is a representative example of the Latin America scenario. Along its 7.370 km of coastline, Brazil has only two established hatcheries and another two under construction. Furthermore, laboratory techniques for native species seed production are still under development, and studies to determine optimal conditions for each culture stage are required.

Brazilian oyster culture focuses on Pacific oyster, Crassostrea gigas, with smaller scale production of the native oysters, Crassostrea gasar (= Crassostrea brasiliana) and Crassostrea rhizophorae. Since higher seawater temperatures can compromise growth and survival rates of C. gigas (Poli, 2004), the expansion of oyster farming in the Brazilian tropical regions is linked to the domestication of native species. Among indigenous oysters, C. gasar is the most cultivated species because it reaches greater size than C. rhizophorae (Christo and Absher, 2006) and presents satisfactory performance at cultivation sites (Baldan and Bendhack, 2009, Galvão et al., 2009, Lopes et al., 2013).

The use of artificial collectors to obtain C. gasar seeds from the environment is difficult due to the occurrence of overlapping settlement periods with other oyster species. In South Brazil, Paraná State, 31% of the individuals collected by Montanhini-Neto et al. (2012) were Crassostrea sp., 36% C. rhizophorae and 33% C. gasar. When obtaining seeds from the environment using artificial collectors is not viable, production in hatcheries is the most efficient approach, and offers the additional advantage of minimal impact on natural populations (Ferreira and Oliveira-Neto, 2007).

The present study evaluated the effects of salinity on fertilization and larval development of the native oyster C. gasar aiming to contribute for the development of hatchery techniques for seed supplies of this species.

Section snippets

Materials and methods

The broodstock of C. gasar used for the fertilization (1) and larviculture (2) experiments was produced (sixth generation) at the Laboratory of Marine Molluscs of the Federal University of Santa Catarina (LMM-UFSC) (27°35′S, 48°26′O). The animals were kept in lantern-net floating systems at the experimental culture area of LMM, at Sambaqui Beach, Florianópolis (27°35′S, 48°32′O). From December 2013 to April 2014 adult animals were transported from the culture area to the laboratory in thermal

Effects of salinity on fertilization and embryonic development

Fertilization conducted in salinity 28 resulted in a significantly (p < 0,0001) higher number of normal shape D-larvae in comparison to other salinities (7, 14, 21 and 35) (Fig. 1). There was no difference in numbers of normal D-larvae between the salinities 21 and 35, although this last treatment (salinity 35) presented significantly more deformed shaped D-larvae in comparison to the other treatments.

Successful embryonic development did not occur in salinities 7 and 14, in these salinities there

Discussion

Regarding the influence of salinity on embryonic development of C. gasar in the laboratory, results presented in this study indicate that fertilization and D-larvae development occurs from salinity 21 and optimal conditions occur around salinity 28. At higher salinity (35) the success of fertilization declines. Optimal salinity ranges for fertilization in other oyster species of the genus Crassostrea are presented in Table 2.

In fertilization tests conducted at LMM-UFSC (unpublished data) using

Acknowledgments

The authors would like to thank Paul Gailey, Paola Tomaselli and Leticiaà Legat for reviewing the English version of the manuscript. To Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), for scholarship granted to the last author.

References (25)

  • L. Paixão et al.

    Effects of salinity and rainfall on the reproductive biology of the mangrove oyster (Crassostrea gasar): implications for the collection of broodstock oysters

    Aquaculture

    (2013)
  • S.H. Tan et al.

    Effect of salinity on hatching, larval growth, survival and settling in the tropical oyster Crassostrea belcheri (Sowerby)

    Aquaculture

    (1996)
  • M.C.P. Albuquerque et al.

    Influência da temperatura e da salinidade na sobrevivência e crescimento de larvas da ostra perlífera Pteria hirundo

    Boletim do Instituto de Pesca, São Paulo

    (2012)
  • A.P. Baldan et al.

    Sustainable Mariculture in Paraná Coast, Brazil: Updates and Perspectives

    (2009)
  • S.W. Christo et al.

    Reproductive period of Crassostrea rhizophorae (Guilding, 1828) and Crassostrea brasiliana (Lamark, 1819) (Bivalvia: Ostreidae) in Guaratuba Bay, Paraná, Brazil

    J. Coast. Res.

    (2006)
  • H.C. Davis et al.

    Combined effects of temperature and salinity on development of eggs and growth of larvae of M. mercenaria and C. virginica

    Fish. Bull.

    (1964)
  • M.S. Doroudi et al.

    The combined effects of temperature and salinity on embryos and larvae of the black-lip pearl oyster, Pinctada margaritifera (L.)

    Aquac. Res.

    (1999)
  • FAO

    The State of World Fisheries and Aquaculture

    (2014)
  • J.F. Ferreira et al.

    Cultivo de moluscos em Santa Catarina

  • M.S.N. Galvão et al.

    Desempenho da criação da ostra do mangue Crassostrea sp. a partir da fase juvenil em sistema suspenso, no estuário de Cananéia e no omã de Ubatuba (SP, Brasil)

    B. Inst. Pesca

    (2009)
  • E. His et al.

    Combined effects of temperature and salinity on fed and starved larvae of the Mediterranean mussel Mytilus galloprovincialis and the Japanese oyster Crassostrea gigas

    Mar. Biol.

    (1989)
  • Z. Huo et al.

    Effects of salinity on embryonic development, survival, and growth of Crassostrea hongkongensis

    J. Ocean Univ. China

    (2014)
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