Page 1 - Scuderi_Balistreri_Germanà_2019

Biodiversity Journal, 2019, 10 (4): 415–426 https://doi.org/10.31396/Biodiv.Jour.2019.10.4.415.426
MONOGRAPH

Are Pinctada radiata (Leach, 1814) and Pinctada fucata (Gould,
1850) (Bivalvia Pteriidae) only synonyms or really different

species? The case of some Mediterranean populations

1*
2
Danilo Scuderi , Paolo Balistreri & Alfio Germanà 3
1 I.I.S.S. “E. Majorana”, via L. Capuana 36, 95048 Scordia, Italy; e-mail: danscu@tin.it
2 ARPA Sicilia Trapani, Viale della Provincia, Casa Santa, Erice, 91016 Trapani, Italy; e-mail: requin.blanc@hotmail.it
3 Via A. De Pretis 30, 95039, Trecastagni, Catania, Italy; e-mail: alfiogermana@virgilio.it
* Corresponding author

ABSTRACT The earliest reported alien species that entered the Mediterranean after only nine years from
the inauguration of the Suez Canal was “Meleagrina” sp., which was subsequently identified
as the Gulf pearl-oyster, Pinctada radiata (Leach, 1814) (Bivalvia Pteriidae). Thereafter, an
increasing series of records of this species followed. In fact, nowadays it can be considered
a well-established species throughout the Mediterranean basin. Since the Red Sea isthmus
was considered to be the only natural way of migration, nobody has ever doubted about the
name to be assigned to the species, P. radiata, since this was the only Pinctada Röding, 1798
cited in literature for the Mediterranean Sea. Taxonomy of Pinctada is complicated since it
lacks precise constant morphological characteristics to distinguish one species from the oth-
ers. Thus, distribution and specimens location are particularly important since different
species mostly live in different geographical areas. Some researchers also used a molecular
phylogenetic approach, but the results were discordant. This taxonomic conundrum was re-
examined this time applying morphological taxonomy. Increasing vessel traffic and records
of vast amounts of Pinctada specimens with morphologically different shells led us to for-
mulate the hypothesis that a separate Pinctada population of different geographical prove-
nance could be present. Specimens were grouped according to the site of collection in the
Mediterranean basin. Results from these morphological studies confirmed that, according
to us, there were two distinct species, P. radiata and P. fucata (Gould, 1850). Morphological
comments and interpretations on the taxonomical status of both species together with auto-
ecological notes and a literature review of the molecular phylogenetic studies conducted
will be here presented.

KEY WORDS Pinctada imbricata complex; Pteriidae; pearl oyster; Recent; Mediterranean Sea.

Received 10.07.2018; accepted 12.09.2018; published online 20.12.2019
Proceedings of the 4th International Congress on Biodiversity “Man, Natural Habitats and Euro-Mediterranean Biodiversity”,
November 17th-19th, 2017 - Malta

INTRODUCTION first time “Meleagrina” sp. for the Mediterranean
Egypt (Alexandria), where it was so abundant that
Just only nine years after the inauguration of the it was sold in the local fish markets.
Suez Canal, Monterosato (1878) reported for the He admitted not to know whether it was a local