MEPS 368:197-207 (2008)  -  DOI:

Effect of oxygen conditions on intracapsular development in two calyptraeid species with different modes of larval development

Antonio Brante1,2,5,*, Miriam Fernández1,2,5, Frédérique Viard3,4,5

1Departamento de Ecología Costera, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile
2Estación Costera de Investigaciones Marinas, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
3UPMC Univ Paris 06, UMR 7144, Equipe Evolution et Génetique des Populations Marines, Station Biologique de Roscoff, 29682 Roscoff, France
4CNRS, UMR 7144, Station Biologique de Roscoff, 29682 Roscoff, France
5International Associated Laboratory ‘Dispersal and Adaptation in Marine Species’ (Station Biologique de Roscoff and Center for Advanced Studies in Ecology and Biodiversity [CASEB])

ABSTRACT: Oxygen availability in the aggregation of offspring has been shown to be a critical factor affecting the survival and development of embryos in aquatic systems. It is not yet known, however, to what extent the capacity to provide O2 to embryo aggregations may act on the time of parental protection (here encapsulation), ultimately determining indirect and direct embryonic development. We assessed O2 conditions during encapsulation, the factors determining those conditions, and the consequences on embryo survival in 2 gastropod species with contrasting developmental modes: Crepidula fornicata, an indirect developer, and Crepidula coquimbensis, a direct developer showing adelphophagy. Results showed that intracapsular O2 conditions decreased to almost hypoxic conditions throughout development in C. fornicata, in contrast to the oxygenated conditions observed in C. coquimbensis during the entire encapsulation period. These contrasting patterns between species were explained by: (1) differences in metabolic rate of the embryos, (2) differences in total metabolizing material per capsule throughout development, and (3) differences in wall thickness and rates of decay throughout development, which may affect O2 diffusion. Moreover, when the low O2 conditions observed at the end of the encapsulation period were maintained after hatching by artificially extending encapsulation for 3 d, a dramatic negative effect on embryonic survival was observed in the indirect developer. In contrast, no effect on juvenile survival was observed in the direct developer. We suggest that hatching at intermediate stages of embryonic development in C. fornicata may be a response to increased O2 constraints during the encapsulated period.

KEY WORDS: Parental protection · Oxygen limitation · Developmental mode · Larvae · Crepidula · Encapsulation

Full text in pdf format 
Cite this article as: Brante A, Fernández M, Viard F (2008) Effect of oxygen conditions on intracapsular development in two calyptraeid species with different modes of larval development. Mar Ecol Prog Ser 368:197-207.

Export citation
Mail this link - Contents Mailing Lists - RSS
- -