Invasion History

First Non-native North American Tidal Record: 1916
First Non-native West Coast Tidal Record: 1916
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

The Scissor Date Mussel (Leiosolenus aristatus) was described from Senegal by Dillwyn in 1817 (Turner and Boss 1962). It has a fossil record in the Caribbean, and ranges from North Carolina to Venezuela. In the Eastern Atlantic, it has been found from the Algarve, Portugal to Angola, and in the Mediterranean, from Spain to Tunisia. It has been variously treated as native to the Caribbean, but introduced or cryptogenic in the Eastern Atlantic and Mediterranean (Turner and Boss 1962; Gofas and Zenetos 2003; Pestana net al. 2019; Lopez-Soriano 2019). Leiosolenus aristatus has been observed as a recent, well-documented invader on Cape Verde Island (Lopes 2011) and in bays on the coast of Brazil (Simone and Goncalves 2006; Ignacio et al. 2010; Cavallari et al. 2012).   

Carlton et al. (2019) regard L. aristatus as widely introduced in the East Pacific, probably before the mid-19th century.  It now ranges from southern California (Los Angeles, La Jolla, establishment unknown) to Ecuador. (Soot-Ryen 1955; Turner and Boss 1962). Genetic analysis of Pacific and Eastern Atlantic populations of L. aristatus is desirable. This bivalve was collected from Cocos Island, Costa Rica (Soot-Ryen 1955, cited v=by Hertlein 1963).

North American Invasion History:

Invasion History on the West Coast:

The Scissor Date Mussel (Leiosolenus aristatus) ris known from scattered locations in Calfiornia at La Jolla ((1916,ANSP 114118, Academy of Natural Sciences of Philadelphia 2021) and Los Angeles County (' White's Point ,Los Angeles County/CA/Pacific Ocean (1975, ANSP A473372, Academy of Natural Sciences of Philadelphia 2021).  It is established in the Gulf of California, and the southern Pacific Coast of Mescio (Turner and Boass 1962).

Invasion History Elsewhere in the World:

Leiosolenus aristatus (Scissors Date Mussel) iwas described from Senegal, west Afriva, but has a fossil record in the Caribbean. (Turner and Boss 1962)..  Thie eearly distirubtion of this species may have been infuluencesdby the African-Caribbean slave trade.  This mussel bores into shells of bivalves and corals, and has great potntial for transport in ship fouling  'Certianly, ships badly fouled with oysters are a perfect measns of transport for these mollusks (Turner and Boss 1962).  In Jalsico state, Mexico, it was studies as a commensal of a native inative Rock Oyster (Striostrea prismatica))  (Sanchez-Telumbre et al. 2021).  It has been long estblishe³d in the Eastenr Pacific, with first records in the Galapgos in 1898, in Panama in 1944, and Cccos Island Costa Rica before 1955  (Soot-Ryen 1955, cited by Hertlein 1963);

Leiosolenus aristatus  is regarded as a recent invader in Brazli, where it was first reported in Sao Paulo and  and Santa Catarins (~30³25³S), Simone andCavallari et a. 2012,-127 S) states in 2005.   In 2019, it was found much furhter north in Bahia state (13³S) (Cavallari et a. 2012). Leiosolenus aristatus is believed to thave been introduced to Brazil form the Caribbean (Simone andCavallari et a. 2012).


Leiosolenus aristatus (Scissors Date Mussel) is one of a subfamily (Lithophaginae) of mussels which use acid secretions to bore into shells, corals, and other calcareous material. The shells are narrow and elliptical and thin and fragile. The periostracum is largely covered with calcareous deposits. Curved calcareous projections extend posteriorly and cross, giving a scissor-like view when seen from above. The interior of the shell is purplish and iridescent. The shell can reach 52 mm in length. The synonyms Lithophaga aristata and Myoforceps aristatus are still widely used in the literature (Turner and Boss 1962; Simone and Goncalves 2016).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Bivalvia
Subclass:   Pteriomorphia
Order:   Mytiloida
Family:   Mytilidae
Species:   aristatus


Mytilus aristatus (Dullwyn, 1817)
Fistulanus ropan (Blainville, 1820)
Modiola caudigera (Lamarck, 1824)
Lithphagus caudigeus (Lamarck & Gibbs, 1848)
Lithodomus forficatus (Ravenel, 1861)
Myoforcepa aristatus (Fischer, 1886)
Lithophaga aristata (Caprenter, 1856)

Potentially Misidentified Species

Leiosolenus plumula
Native, southern California to Peru (Soot-Ryen 1955)



Reproduction has not been described in Leiosolenus aristatus, but sexes are probably separate as in other mussels, and larvae are probably planktonic larvae (e.g., Mytilus galloprovincialis, Geukensia demissa).


Phytoplankton, detritus

Trophic Status:

Suspension Feeder



General HabitatOyster ReefNone
General HabitatMarinas & DocksNone
General HabitatCoral reefNone
General HabitatVessel HullNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone

Life History

Leiosolenus aristatus is widely distributed in shallow warm-temperate to tropical marine waters. This mussel is a suspension-feeder but can have adverse impacts on shelled mollusks and corals by boring into shells and coral skeletons. Despite the former genus name Lithophaga, this mussel does not bore into non-living rock (Turner and Boss 1962). The mussels are known from oysters, scallops, chitons, conchs, whelks and limpets where they reside (Turner and Boss 1962; Simone and Goncalves 2006; Alvarez-Cerrillo et al. 2011). 

Tolerances and Life History Parameters

Maximum Length (mm)52Turner and Boss 1962
Maximum Height (mm)16.5Turner and Boss 1962
Broad Temperature RangeNoneWarm-temperate-Tropical
Broad Salinity RangeNonePolyhaline-Euhalibe

General Impacts

This mussel bores into other molluscan shells and corals. In Brazil, the invasion of Leiosolenus aristatus has been promoted by the spread of the cup corals Tubastraea coccinea and T. tagusenisis, whose calcareous bases provide habitat. The increasing abundance of L. aristatus is considered a threat to native corals and reefs (Vinagre et al. 2017).

Regional Impacts

SEP-ZNoneEcological ImpactHabitat Change
The Scissors Date Mussel (Leiosolenus aristatus) wwa an abundant internal borer of live coral Porites lobata, together with the native L.laevigatusa (Reaka-Kudla et al. 1996).
NEP-VIINoneEconomic ImpactFisheries
The boring mussel Leiosolenus aristatus abundantt in the shells of the native Rock Oyster (Striostrea prismatica), which supports an artisanal fishery (Sanchez-Telumbre et al. 2021).
SA-IINoneEcological ImpactHabitat Change
The invasive cup corals Tubastraea coccinea and T. tagusensis have provided increased habitat for the boring mussel Leiosolenus aristatus, posing a threat to native corals (Vinagre et al. 2017).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
SEP-Z None 1902 Def Estab
CAR-III None 0 Native Estab
WA-II None 1817 Crypto Estab
CAR-VI None 0 Native Estab
CAR-VII Cape Hatteras to Mid-East Florida 0 Native Estab
SEP-H None 0 Def Estab
CAR-III None 0 Native Estab
NEP-VI Pt. Conception to Southern Baja California 1916 Def Failed
CAR-II None 0 Native Estab
CAR-IV None 0 Native Estab
WA-III None 0 Crypto Estab
NEP-VIII None 0 Def Estab
NEP-VII None 1934 Def Estab
SA-II None 2005 Def Estab
SA-III None 2011 Def Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 0 Native Estab
MED-II None 0 Crypto Estab
MED-I None 0 Crypto Estab
MED-III None 0 Crypto Estab
P016 _CDA_P016 (San Diego) 1916 Def Unk
P050 San Pedro Bay 1975 Def Unk
WA-III None 1969 Crypto Estab
NEA-V None 0 Crypto Estab
CMAR1 Isla del Coco / Cocos Island 1955 Def Estab
SEP-B None 0 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Academy of Natural Sciences of Philadelphia 2002-2016a Malacology Collection Search.

Alvarez-Cerrillo. Laura Regina; Valentich-Scott, Paul; newman, William A. (2017) A remarkable infestation of epibionts and endobiontsof an edible chiton (Polyplacophora: chitonidae) from the mexican tropical pacific, Nautilus 131(1): 87-96

Antit, M.; Gofas, S.; Salas, C.; Azzouna, A. (2011) One hundred years after Pinctada: an update on alien Mollusca in Tunisia, Mediterranean Marine Science 12(1): 53-73

Breves, A.; ; Junqueira, A. O. R. (2017) Intertidal vermetid reef as a shelter for invasive bivalves in a tropical bay, Aquatic Ecosystem Health and Management 20(4): 383-392

Capel, Kátia C. C.;Creed, Joel C ;Kitahara, Marcelo V. (2020) Invasive corals trigger seascape changes in the southwestern Atlantic, Bulletin of Marine Science 96(1): 217-218

Carlton, James T.; Keith, Inti; Ruiz, Gregory M. (2019) Assessing marine bioinvasions in the Galápagos Islands: implications for conservation biology and marine protected areas, Aquatic Invasions 14(1): 1-20

Cavallari, Daniel C.;Gonçalves, Eric P; do Amaral, Vanessa S. (2012) New occurrences of Myoforcepsaristatus (Bivalvia: Mytilidae) in the Brazilian coast, Strombus 19: 23-27

Coan, E. V.; Scott, Paul H. (1997) Checklist of the marine bivalves of the Northeastern Pacific Ocean, Santa Barbara Museum of Natural History Contributions 1: 1-28

Gofas, Serge; Zenetos, Argyro Z (2003) Exotic molluscs in the Mediterranean basin: Current status and perspectives, Oceanography and Marine Biology, an Annual Review 41: 237-277

Ignacio, Barbara L.; Julio, Luciana M.; Junqueira, Andrea O. R; Ferreira-Silva, Maria A. G. (2010) Bioinvasion in a Brazilian Bay: filling gaps in the knowledge of southwestern Atlantic biota, PLOS ONE 5(9): <missing location>

Lopes, Evandro P. (2011) Leiosolenus aristatus (Dillwyn, 1817), new to the Cape Verde Islands (Mollusca, Bivalvia, Mytilidae), Zoologia Caboverdiana 2(2): 71-73

Lopes, Rubens M. (Ed.) (2009) <missing title>, Ministry of the Environment, Brasilia, Brazil. Pp. 1-440

Lopez-Soriano, Joaquín López; Salgado, Sergio Quiñonero (2019) [First record of Leiosolenus aristatus (Bivalvia: Mytilidae) on the CatalanCoast, Spira 7: 93-95

Museum of Comparative Zoology 2008-2015 Invertebrate Zoology Collections Database

Pestana, Lueji Barros; Dias, Gustavo Muniz; Marquesa, Antonio Carlos (2017) A century of introductions by coastal sessile marine invertebrates in Angola, South East Atlantic Ocean, Marine Pollution Bulletin 125: 426-a432

Pilsbry, H.; Vanatta, E. G. (1902) Papers from the Hopkins Stnaford Galapagos Expedtion, 1898-1899, prceedings of the Washington Academy of Science 4: 549-560

Reaka-Kudla, M. L.; Feingold, J. S.; Glynn, W. (1996) Experimental studies of rapid bioerosion of coral reefs in the Galfipagos Islands, Coral Reefs 15: 101-107

Sanchez-Telumbre,, N. A.; Torreblanca-Ramírez, C.1 ; Padilla Serrato, J. G.1,2 , Flores Rodríguez, P.; , Flores-Garza, R.; , Kuk-Dzul. J. G (2021) Mollusks associated to the rock oyster Striostrea prismatica Gray, 1825 in Corrales Beach, Jalisco, Mexico, Revista Bio Ciencias 9: e1072.

Simone, Luiz Ricardo L.;; Gonçalves, Eric Pedro ERIC PEDRO GONÇALVES (2006) Anatomical study on Myoforceps aristatus, an invasive boring bivalve in s.e. Brazilian coast (mytilidae), Papeis Avulsos Zoologia de Sao Paolo 47(6): 57-65

Soot-Ryen T (1955) (1955) A report on the family Mytilidae (Pelecypoda)., Allan Hancock Pacific Expeditions 20: 1-175

Turner, Ruth D.; Boss, Kenneth (1962) The genus Lithophaga in the Western Atlanitc, Johnsonia 4(41): 81-116

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database. <missing description>

Vinagre, Catarina; Silva, Rodrigo; Mendonça, Vanessa; . Flore, Augusto A.V.; Baeta, Alexandra; Marques, João Carlos (2018) Food web organization following the invasion of habitat-modifying Tubastraea spp. corals appears to favour the invasive borer bivalve Leiosolenus aristatus, Ecological Indicators 85: 1204-

WoRMS Editorial Board (2021). 2021 World Register of Marine Species. Available from at VLIZ. Accessed 2021-09-07. doi:10.14284/170