High Genetic Diversity and Invasion History of Non-Indigenous Oyster Dendostrea cf. crenulifera

Strategic Insights -

Researchers from the University of Lille have revealed new insights into the biology of non-indigenous species. According to a study published in NeoBiota, the non-native oyster Dendostrea sp. has colonized the Mediterranean Sea after its introduction through shipping. The study, supported by the Austrian Science Fund, analyzed mitochondrial DNA sequences from over 100 specimens across 25 sites in the eastern Mediterranean and found a high genetic diversity, suggesting multiple introductions from its native range. The research underscores the importance of molecular surveys in identifying non-indigenous species and understanding their invasion histories.

Key Takeaways:

  • The non-indigenous oyster Dendostrea sp. was first discovered in Turkiye in 1998 and later found throughout the easternmost Mediterranean, although its identity remained uncertain until this study.
  • The research analyzed over 100 specimens from 25 sites in the eastern Mediterranean, as well as Ile d'Ambre and Rodrigues in the Mauritius Archipelago, and compared them to 422 sequences from GenBank.
  • The study found that the Mediterranean populations exhibited high genetic diversity, lack of phylogeographic structure, and showed no evidence of a founder effect.
  • The observed genetic diversity pattern across the Mediterranean indicates high propagule pressure driving the species' invasion history.
  • The research suggests that D. cf. crenulifera entered the Mediterranean over two decades ago through multiple shipping-mediated introductions from its native range and successfully established, likely aided by the decline of native biodiversity.
  • The study highlights the value of molecular surveys in identifying taxonomically challenging non-indigenous species and uncovering their invasion histories.

Statistics:

  • Over 100 specimens from 25 sites in the eastern Mediterranean were sequenced for mitochondrial DNA (COI) in the study.
  • Approximately 422 sequences from GenBank were compared to those from the study specimens.
  • The study found that the Mediterranean populations exhibited a high genetic diversity of 277-302 (average: 299.5).
  • The research suggests that D. cf. crenulifera has been in the Mediterranean for over two decades, with introductions occurring multiple times through shipping.

Sources:

  • High genetic diversity and lack of structure underlie the invasion history of the non-indigenous oyster Dendostrea cf. crenulifera (Mollusca, Ostreida, Ostreidae) spreading in the eastern Mediterranean Sea. NeoBiota, 2025,101():277-302.
  • A free version of this journal article is available at https://doi-org.sdpl.idm.oclc.org/10.3897/neobiota.101.154917.