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The Majorera macaw (Patella candei) is a historical, traditional resource and an endemic to the biodiversity of the Canary Islands. It is a Macaronesian endemism that in the Canary Islands is a traditional fishing resource and whose populations have decreased to the point of being reduced to a specific area of Fuerteventura.

In fact, its classification as “endangered” is aggravated by the lack of consensus on its taxonomy and distribution range. At present, the various morphometric, meristic and molecular approaches have not allowed a consensus about the significant evolutionary units that would make up the Patella candei complex.

According to the University of Las Palmas de Gran Canaria, the management and conservation of this organism inevitably requires the clarification of its phylogenetic and taxonomic position, and the estimation of genetic diversity throughout the distribution range of its populations. Likewise, the analysis of a reduced representation of its genome will provide the highly resolutive markers (SNPs), required to resolve these fundamental and critical issues in the implementation of initiatives for the conservation of the species with guarantees.

The general objective of the project has been to evaluate the taxonomy and genetic diversity in the endemic Majorera macaw based on genomic data for advice on the conservation of this endangered species.

The specific objectives were as follows:

• Manage the entity’s Patella candei tissue and DNA bank to provide the DNA samples required for genomic analysis.
• Sequencing a reduced representation of the Patella candei genome.
• To analyse the relationships between the Macaronesian populations from the Azores to Cape Verde of Patella candei.
• To implement the conclusions on taxonomy and structure of genetic diversity in Patella candei populations in a management and conservation plan for the resource.

• Quantitative and qualitative evaluation of the DNA available in the BioMol DNA and tissue bank of the University of Las Palmas de Gran Canaria and preparation of Patella candei DNA samples for analysis (using ddRAD methodology).
• Obtaining ddRAD libraries for a population sample of each Macaronesian subspecies and phylogenetically related species.
• Sequencing libraries on the Illumina platform.
• Analysis of sequencing data, determination of point polymorphisms (SNPs) and inference of population structure and phylogenetic relationships in the Patella candei complex.
• Definition of taxonomic and genetic diversity conclusions of impact for the conservation of the species and the ways of implementation in a conservation plan.
• Dissemination and communication of the project.

The SNPs4candei project has carried out the genetic study of the populations of the Patella candei complex from DNA samples obtained from the tissues and DNA of the species, available in the Macaronesian marine genetic bank BANGEMAC of the BioMol Laboratory of the University of Las Palmas de Gran Canaria. Genetic sequencing has been carried out after selecting 70 DNA samples from four ddRAD libraries plus one control library, with a group of 20 individuals per library. Subsequently, thanks to a principal component analysis (PCA), it has been possible to represent the genetic separation between the two subspecies of Patella candei: Patella candei candei and Patella candei crenata.

Thus, the phylogenetic results obtained for Patella candei candei and derived from the dendrogram and cluster analysis, show that there are evident genetic differences between the populations of this subspecies located in Fuerteventura and the populations of the same subspecies located in the Savage Islands. For this reason, the entity concludes that the measures for the recovery of the subspecies in Fuerteventura should not be carried out with repopulations of specimens from other Macaronesian islands, in particular, from the Savage Islands, since their execution could have a negative impact on the genetic biodiversity of the taxon.

In short, the entity has managed to clarify the taxonomic and phylogenetic position of the Patella candei complex, by demonstrating that there are genetic differences and divergences between the populations of Fuerteventura and the Savage Islands. For this reason, the entity has proposed establishing specific measures for the management of the resource in Fuerteventura, based on genomic results, based on the seed reproduction system with individuals from the island’s own population to ensure the restoration of their populations in the marine ecosystem of the Canary Islands. This action has been considered a priority and has been agreed upon by the participants of the interdisciplinary and institutional workshop organised within the framework of the project and in which both researchers and technical staff from the competent administrations have collaborated.

Finally, the results of the project have been transferred to the Ministry of Ecological Transition, Fight against Climate Change and Territorial Planning of the Government of the Canary Islands and to the Tenerife Territorial Center of the Spanish Oceanographic Institute (IEO) through an executive report, as well as to the scientific community through a poster presented at the AQUI Forum 2021, specialized in marine resources, and the publication of two scientific articles in the specialized press.