Identification, distribution and fisheries ecology of the larvae of the deep-sea blue and red Shrimp Aristeus Antennatus in the Northwestern Mediterranean sea
- Autores: Marta Carreton Salvador
- Directores de la Tesis: Joan B. Company (dir. tes.), Guiomar Rotllant (codir. tes.), Lluís Cardona Pascual (tut. tes.)
- Lectura: En la Universitat de Barcelona ( España ) en 2021
- Idioma: inglés
- Tribunal Calificador de la Tesis: Enrique Macpherson Mayol (presid.), José María Landeira Sánchez (secret.), Beatriz Guijarro González (voc.)
- Programa de doctorado: Programa de Doctorado en Ciencias del Mar por la Universidad de Barcelona y la Universidad Politécnica de Catalunya
- Materias:
- Enlaces
- Tesis en acceso abierto en: TESEO
- Resumen
The study of larvae is a key stepping stone in bridging the knowledge gap of species connectivity in the field of fisheries monitoring and management. Together with population genetics and dispersal modelling studies, the gathering of observed data from plankton surveys is essential to use as input and validation of the results, and to explore ecological aspects of the larval phase in species of commercial interest. In particular, the ecological and fisheries aspects of the deep-sea blue and red shrimp Aristeus antennatus have been widely studied, but knowledge about its larvae was still scarce, thus hindering the development of new methods for stock assessment and fisheries monitoring.
In this thesis, we used different methods of identification of decapod crustacean larvae (observation at the stereomicroscope, Scanning Electron Microscopy, and DNA barcoding and metabarcoding) to study these communities along the eastern Spanish Mediterranean coast, within the management region of the Geographic Subarea 6 (GSA 6, from Cartagena to the Gulf of Lions). The sampling was carried out during the summer of 2016 with three different gears (a neustonic sledge, a bongo net, and a Multiple Opening/Closing Net with Environmental Sensor System, or MOCNESS), to ensure the coverage of the entire water colum from the surface down to 1200 m depth, with both horizontal and oblique tows.
We first clarify the identification of the larvae of the deep-sea blue and red shrimp Aristeus antennatus with both morphological and molecular methods, in order to ensure an accurate study of its distribution and of the decapod larval community that shares its habitat during its spawning period. All known larval stages of A. antennatus were identified and confirmed by molecular methods, and the description of the first protozoea of the species is presented for the first time. Then, the larvae of A. antennatus are presented both in the context of a small-scale study and in a meso-scale study, where we produce the first abundance and distribution map for the larve of this species and validate its larval dispersal model. The distribution maps in surface waters show that the larvae aggregate near submarine canyons, are influenced by hydrodynamic barriers such as density fronts and seasonal eddies , and are associated with the cold, low-salinity waters of the Gulf of Lions. The suggestion of dividing GSA 6 in three zones for fisheries management is reinforced by our observed data. Finally, we present an application of larval ecology as a tool for fisheries monitoring, producing the larval distribution of several species of commercial interest, and then using morphological studies in x combination with the technique of DNA metabarcoding, a promising method for the detection of larvae of commercial species. The use of molecular marker V9 18S rRNA proves successful in rapidly and accurately identifying larvae of commercial species, and opens the door for streamlining the identification process of decapod crustacean larvae.
