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The nacre (
Pinna nobilis
) is a bivalve endemic to the Mediterranean Sea endangered by the attack of the parasite Haplosporidium pinnae, a protozoan. For this reason, the organization points out that achieving their reproduction in captivity is a priority and could become an essential tool to avoid the extinction of the species.

The entity indicates that treatments with reproductive neuropeptides (molecules formed by amino acids with action on the nervous system) considerably accelerate the gonadal maturation of bivalves in captivity, but that the type and dosage must be adjusted to the different species.

Currently, the scientific team of Fundación Universidad Católica de Valencia San Vicente Mártir is conducting experiments on the gonadal maturation of P. nobilis The present project aimed to study the experimental application of reproductive neuropeptides to improve and accelerate gonadal maturation in nakras. Given its scarcity, these methodologies were proposed using as a model the species P. rudis, much more abundant at present, and then applied to the species P. nobilis.

The main objective of the project has been to study the experimental application of reproductive neuropeptides to improve and accelerate reproduction in captivity of the nacre(Pinna nobilis).

Specific objectives include:

• Identification of neuropeptides (relative literature and available genome).
• Collection of specimens of nobilis and P. rudis species.
• Gonadal maturation in nobilis and P. rudis in captivity.
• Use of reproductive neuropeptides to stimulate spawning in captive nobilis and P. rudis.

• Identification and production of neuropeptides in literature. Conducting bibliographic searches in different phases of the project: beginning, process and end, after obtaining results to consider reorienting the knowledge needs after this compilation.
• Transcriptomics of gonad and ganglia (study of RNA molecules in a cell) of nobilis and P. rudis for the specific identification of reproductive neuropeptides of both species.
• Campaigns to collect wild specimens of nobilis and P. rudis.
• Application of reproductive neuropeptide treatments in nobilis and P. rudis for the induction of gonadal maturation. (Bioassay 1).
• Use of reproductive neuropeptides to stimulate spawning in captive nobilis and P. rudis. (Bioassay 2).
• Dissemination and communication of the project.

The Neupinna project has enabled important advances in the captive reproduction of the Pinna nobilis nacre, a species that is “in danger of extinction” according to the Spanish Catalog of Threatened Species as a result of a parasitic disease caused by the protozoan Haplosporidium pinnae.

The nacre is the largest bivalve in the Mediterranean and the second largest in the world. It has a high ecological and environmental value as it filters thousands of liters of water per day, which contributes to water clarity and quality. In addition, the large surface area of its shell makes it a nucleus of biodiversity, since a multitude of other invertebrates and algae grow on it.

Due to its ecological importance and its threatened status in the Mediterranean, this project has studied its reproduction in captivity, with the long-term objective of its regeneration in the wild. In previous projects, such as PinnaSpat, it was possible to develop a method for the maturation of nacra in captivity through the development of temperature and feeding protocols.

In this initiative, we have contributed to the development of a new methodology that has led to an advance in gonadal maturation, improving reproduction in captivity outside the natural laying cycle of this species, which could allow in the future to obtain several clutches throughout the year, even in periods where natural reproduction does not occur in the environment.

This project has achieved results that allow the use of a species very close to Pinna nobilis, called Pinna rudis, as a model species in breeding studies through its genetic similarities. In total, 14 identical reproductive neuropeptide precursors were identified in the transcriptomes of both species.

In addition, with a view to future projects, an important bibliographic compilation is available that can serve as a basis for the approach to the different questions that still need to be investigated about this species. Likewise, the knowledge generated in this research will contribute to the survival of the species under conservation, as well as other similar species.