Crassostrea praia

Ferreira, João Paulo Ramos, Legat, Angela Puchnick, Lazoski, Cristiano, Freire, Thais Brito, Gomes, Carlos Henrique Araújo de Miranda & de Melo, Claudio Rodrigues Manoel, 2023, A historical and integrative taxonomic account of mangrove oyster species native to the Atlantic American coast: A re-evaluation of Brazilian Crassostrea species, Zoologischer Anzeiger 305, pp. 52-81 : 77

4.4. Incertae sedis species: Crassostrea praia

C. praia is a species currently recognized in the revision of Crassostrea of Brazil, being an elevation of O. parasitica subsp. praia to a species category. The species is mainly known for its holotype (solely the lef valve, Amaral and Simone, 2014, Fig. 11A–B ), which is mainly defined morphologically by its elongate SF and MSF and deep UCC. The early concept of this taxon, however, was developed by Ihering and carried more of an ecological approach to species than a morphological approach.

When O. parasitica was the only species recognized in Brazil (see Table 3), the conceptual view of this entity included species occurring in mangrove vegetation. A group of native oysters in Brazil (within the genus Crassostrea ) was found in Rio Grande do Sul State where no mangrove vegetation is found. The mangrove border is located in Laguna County, Santa Catarina State, Brazil. Ihering (1907) highlighted that specimens of O. parasitica occurring beyond the southern mangrove vegetation border were to be named O. parasitica subsp. praia Ihering (1907) ( Lamy, 1928).

Previous studies interpreted O. parasitica sub praia as a synonym of C. rhizophorae , with a distribution ranging from USA to Uruguay ( Huber, 2010; Ríos, 2009), since the species would not be limited to mangrove areas (see our seventh point in subsection 4.3.2).

According to their morphology, some C. gasar specimens have the same shell conformation described for C. praia (elongate SF, MSF, and deep UCC), with a strong correlation between this configuration of shells and C. gasar instead of C. rhizophorae ( Fig. 21 ).

Because the present study does not include specimens sampled with this shell morphology collected beyond mangrove areas, we may not confidently rule out C. praia as a species. Further studies are needed to determine the identity of this taxon.

Figures

Fig. 11. The χ2 test of independence of Species, IC and IMC, based on the permutation distribution.

Fig. 21. The χ2 test of independence of Species, SF, MSF and UCC, based on the permutation distribution. Legends for MSF (E Elongate, O - Ovate, R – Reniform) and UCC (S – Shallow, D – Deep).