Pinctada margaritifera

Invasion History

First Non-native North American Tidal Record: 1990
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 1990

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General Invasion History:

Pinctada margaritifera has a broad native distribution in the Indo-Pacific, spanning from the Red Sea and Madagascar to southern Japan, Hawaii, northern Australia, and the Line and Pitcairn Islands (Zenetos et al. 2003; Florida Museum of Natural History 2009; Museum of Comparative Zoology 2009; US National Museum of Natural History 2009). It also occurs on the tropical Pacific coast of North and South America, from Baja California to Peru, where it was known by the synonym P. mazatlanica (Tëmkin 2010). This oyster is widely cultivated and harvested for its pearls, so it is possible that its Indo-Pacific range has been extended by humans. This mussel was introduced to Calabria, Italy, around 1860 for pearl-culture, but did not persist (Zenetos et al. 2003). In the 1970s, a population was found to be established near Alexandria, Egypt (Hasan 1974, cited by Zenetos et al. 2003). In 1990, and in subsequent years, a few specimens of P. margaritifera were found off southern Florida and in the Bahamas (Carlton and Ruckelshaus 1997; Frank, in Lee 2003, http://www.jaxshells.org/910.htm; Florida Museum of Natural History 2009), but there is no evidence of establishment.

North American Invasion History:

Invasion History on the East Coast:

In 1990, P. margaritifera was collected 80 km off Boca Raton, Florida (FL) in the Atlantic Ocean (Carlton and Ruckelshaus 1997). Another collection occurred off Boynton Beach, FL in deep sublittoral waters on coral reefs (1994, Carlton and Ruckelshaus 1997). There have been at least three additional specimens collected off the south Florida Coast (Frank, in Lee 2003, http://www.jaxshells.org/910.htm). The Florida Museum of Natural History has an undated specimen (FLMNH 18933) from off of Key West, and another (FLMNH 14911) from New Providence Island in the Bahamas (Florida Museum of Natural History 2009). However, there is no evidence of reproduction. Ballast water and vessel hull fouling are the most likely vectors of introduction.

Invasion History Elsewhere in the World:

An early attempt (~1860) was made to introduce P. margaritifera to Calabria, Italy. These animals are reported to have reproduced, and produced pearls, but did not persist (Zenetos et al. 2003). An established population was found before 1974 in Abou-Kir Bay, Alexandria, Egypt (Mediterranean) (Hasan 1974, cited by Zenetos et al. 2003). References to an introduction in Greece involve a misidentification of P. imbricata radiata (Serbetis 1963, cited by Zenetos 2003).

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Description

Pinctada margaritifera has a large shell, with the two valves almost equal. They are mostly circular but asymmetrical, between the anterior and posterior halves, with the dorsal edge straightened. The beaks are located toward the anterior end, with a triangular projection near the hinge. The shell is roughly sculptured with concentric ridges, and radial ridges. The hinge lacks teeth, and the ligament is in a single, triangular depression. The shell is externally colored grayish green with white or yellowish radial rows of scales, and brown to black margins. The inside of the shell is pearly with a pale blue or violet cast. The shell reaches 200-250 mm in height. Larvae have been described by Doroudi and Southgate (2003). The veligers settle at a size of 230-266 µm. (Description from: International Commission for the Scientific Exploration of the Mediterranean Sea 2001-2011, Zenetos et al. 2003).

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Taxonomy

Ecology

General:

Pinctada margaritifera is a protandric hermaphrodite, changing from male to female as it grows. Females start to appear at about 20 mm diameter, varying with habitat, and dominate size classes above 30-60 mm (Kimani and Mavuti 2002). Eggs are released into the water column, and when fertilized, develop into a trochophore larva, and within 24 hours, a veliger. The veligers remain in the plankton for 20-23 days before settling at a size of 230-266 µm (Doroudi and Southgate 2003).

This oyster is widespread on tropical rocky shores, lagoons and coral reefs, often in surge channels between reefs and reef edges. It appears to be limited to warm, high-salinity environments (Kimani and Mavuti 2002; Zenetos et al. 2003; Academy of Natural Sciences of Philadelphia 2010; US National Museum of Natural History 2010).

Food:

Phytoplankton

Consumers:

snails, crabs, fishes, humans

Trophic Status:

Suspension Feeder

SusFed

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Habitats

General Habitat	Marinas & Docks	None
General Habitat	Rocky	None
General Habitat	Coral reef	None
Salinity Range	Polyhaline	18-30 PSU
Salinity Range	Euhaline	30-40 PSU
Tidal Range	Subtidal	None
Tidal Range	Low Intertidal	None
Vertical Habitat	Epibenthic	None

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Tolerances and Life History Parameters

Maximum Salinity (‰)	40	Experimental, Southgate et al. 1999, cited by Zenetos et al. 2003
Minimum Reproductive Temperature	25	Experimental, Southgate et al. 1999, cited by Zenetos et al. 2003
Maximum Reproductive Temperature	30	Experimental, Southgate et al. 1999, cited by Zenetos et al. 2003
Minimum Reproductive Salinity	25	Experimental, Southgate et al. 1999, cited by Zenetos et al. 2003
Minimum Duration	20	Larval duration, fertilization to settling at 28-29 C (Doroudi and Southgate 2003)
Maximum Duration	23	Larval duration, fertilization to settling at 28-29 C (Doroudi and Southgate 2003)
Maximum Length (mm)	250	International Commission for the Scientific Exploration of the Mediterranean Sea 2001-2011, Zenetos et al. 2003
Broad Temperature Range	None	Warm temperate-Tropical
Broad Salinity Range	None	Poly-Euhaline

General Impacts

Pinctada margaritifera is highly prized for its pearls and nacre (pearly shell material), and supports extensive pearl fisheries and aquaculture in the Indo-Pacific (Zenetos et al. 2003). However, it has no reported economic or ecological impacts outside its native range.

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References

Academy of Natural Sciences of Philadelphia 2002-2024a Malacology Collection Search. <missing URL>



Academy of Natural Sciences of Philadelphia 2006-2014b OBIS Indo-Pacific Molluscan Database. <missing URL>



Carlton, James T.; Ruckelshaus, Mary H. (1997) Nonindigenous marine invertebrates and algae of Florida, In: Simberloff, Daniel, Schmitz, Don C., Brown, Tom C.(Eds.) Strangers in Paradise: Impact and Management of Nonindigenous Species in Florida. , Washington, D.C.. Pp. 187-201

Doroudi, Mehdi; Southgate, Paul C. (2003) Embryo and larval development of Pinctada margarifiera (Linnaeus 1758), Molluscan Research Molluscan Research 23: 101-107

Florida Museum of Natural History 2009-2013 Invertebrate Zoology Master Database. <missing URL>



Harvard Museum of Comparative Zoology 2008-2021 Museum of Comparative Zoology Collections database- Malacology Collection. <missing URL>



International Commission for the Scientific Exploration of the Mediterranean Sea (CEISM) (2001) <missing title>, <missing publisher>, <missing place>. Pp. <missing location>

Kimani, Edward N.; Mavuti, K. M. (2002) Abundance and population structure of the blacklip pearl oyster, Pinctada margaritifera L. 1758 (Bivalvia: Pteriidae), in coastal Kenya, Western Indian Ocean Journal of Marine Science 1(2): 169-179

Lee, Harry 2001-2015 Harry Lee's Florida Mollusca Checklists. <missing URL>



Tëmkin, Ilya (2010) Molecular phylogeny of pearl oysters and their relatives (Mollusca, Bivalvia, Pterioidea), BMC Evolutionary Biology 10: 342 published online

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database. http://collections.nmnh.si.edu/search/iz/

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