|Influence of ontogenetic and environmental changes in the otolith microchemistry of juvenile sole (Solea solea)|de Pontual, H.; Lagardère, F.; Amara, R.; Bohn, M.; Ogor, A. (2003). Influence of ontogenetic and environmental changes in the otolith microchemistry of juvenile sole (Solea solea). J. Sea Res. 50(2-3): 199-210. dx.doi.org/10.1016/s1385-1101(03)00080-7
In: Journal of Sea Research. Elsevier/Netherlands Institute for Sea Research: Amsterdam; Den Burg. ISSN 1385-1101, more
|Also published as |
- de Pontual, H.; Lagardère, F.; Amara, R.; Bohn, M.; Ogor, A. (2003). Influence of ontogenetic and environmental changes in the otolith microchemistry of juvenile sole (Solea solea), in: Geffen, A.J. et al. (Ed.) Proceedings of the Fifth International Symposium on Flatfish Ecology, Part I. Port Erin, Isle of Man, 3-7 November 2002. Journal of Sea Research, 50(2-3): pp. 199-210, more
Environmental factors; Estuaries; Juveniles; Nursery grounds; Ontogeny; Otoliths; Salinity effects; Solea solea (Linnaeus, 1758) [WoRMS]; ANE, France, Brittany, Vilaine Bay; ANE, France, Pays de Loire, Loire Estuary [Marine Regions]; Marine
|Authors|| || Top |
- de Pontual, H.
- Lagardère, F.
- Amara, R.
We analysed otolith composition, specifically Sr/Ca ratios, with the aim of determining whether metamorphosis and the transition to benthic life of Bay of Biscay sole occur in marine or estuarine conditions. Otoliths of wild juveniles (0-group) collected in two estuarine nurseries showed characteristic Sr/Ca chronologies, with a significant decrease of the Sr/Ca ratio from the core to the accessory growth centres. As the otolith Sr/Ca ratio decreases in respect of the ambient salinity, this could suggest a relative synchronism in the timing of estuarine nursery entrance. In order to validate this hypothesis, hatchery-produced larvae were reared in a tidal marsh mesocosm until they completed metamorphosis (around 1 month post-hatching) and settled on the bottom. The otoliths from these juveniles exhibited a similar Sr/Ca pattern, which could not be explained as a result of habitat changes, and especially salinity variations, but rather reflected an ontogenetic signal. Since both wild and reared soles achieved high growth rates during metamorphosis, this suggests a link between a high metabolic rate and the observed Sr/Ca drop. In addition, ontogenetic changes during this transitional phase could involve the setting of functional mechanisms, responsible for the regulation of free Sr2+ in either plasma or endolymph or both. Nevertheless, this common trend appeared to be modulated by environmental cues: Sr/Ca ratios were significantly higher for reared fish compared to wild fish during the larval period. A possible explanation is that experienced temperatures were much higher in the incubator than in the field. Furthermore, Sr/Ca values obtained in the otolith juvenile area, with the lowest ratios for soles from the Loire nursery, suggest that the salinity regime of estuarine nurseries could exert an environmental control on otolith Sr/Ca ratios, thus providing ecological records of up-estuary migration after metamorphosis.