Invasion History

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

General Invasion History:

Scylla serrata is widely distributed in the Indian and tropical Western Pacific Ocean, from South Africa, the Red Sea, and southern Japan east to New Zealand and Tahiti. It inhabits estuaries and mangrove swamps, ranging from marine to fresh waters (Keenan et al. 1998). In an attempt to start a fishery, S. serrata was intentionally released to the Gulf coast of Florida and Hawaii. Populations in Florida never established, but S. serrata is now abundant in the Hawaiian Islands.

North American Invasion History:

Invasion History on the Gulf Coast:

In 1962, approximately 30 pairs of Scylla serrata were introduced into Pumpkin Bay, Collier Co., Florida, on the Gulf of Mexico, in an attempt to establish a commercial crab fishery. There are no further records of this crab from Florida waters (Park 1969, personal communication from R. P. Hutton to R. M. Ingle, USGS Nonindigenous Species Program 2009).

Invasion History in Hawaii:

Beginning in 1926, in Kanehoe Bay, Oahu, until 1935, 98 Scylla serrata from Samoa were released in Hawaiian waters. All but one of these releases was on Oahu, one was near Hilo, on the island of Hawaii (Brock 1960). By 1940, S. serrata was ascending far up major rivers on Oahu, and by 1960, it was established on all of the main islands of Hawaii, and 'brought a good price in the markets' (Brock 1960, Carlton and Eldredge 2009).

Invasion History Elsewhere in the World:

Two specimens of Scylla serrata were collected in Brazil, one in Santos, Sao Paulo State in 1983 (Melo 1983, cited by Tavares 2011), and one on Sepetiba Bay, Rio de Janeiro, in 2011. These occurrences could be either releases of live seafood or ballast water introductions (Tavares and Medonca 2011).


Scylla serrata is a swimming crab with an oval carapace. The carpace bears four triangular frontal teeth between the eyes and nine anterolateral teeth on each side. The chelipeds (claw-legs) are massive and smooth, and longer than the other legs. The palm of the chela (claw) has two spines on the dorsal margin and two more spines at the insertion of the dactyl (movable finger). The carpus (wrist) bears two prominent spines on the outer margin, and the merus (forearm) bears three large spines on the anterior border and two smaller spines on the posterior border. The legs are stout and moderately compressed, with the 4th pair modified for swimming. The male's abdomen is narrow, with segments 3-5 fused. The female's abdomen is broadly oval. The color of S. serrata is variable, from purple through green and brownish or black. Adult crabs can reach up to 186 mm in size (Keenan et al. 1998).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Arthropoda
Subphylum:   Crustacea
Class:   Malacostraca
Subclass:   Eumalacostraca
Superorder:   Eucarida
Order:   Decapoda
Suborder:   Pleocyemata
Infraorder:   Brachyura
Superfamily:   Portunoidea
Family:   Portunidae
Genus:   Scylla
Species:   serrata


Cancer olivaceus (Herbst, 1796)
Cancer serratus (Forskål, 1755)
Lupa tranquebarica (H. Milne-Edwards, 1834)
Portunus tranquebaricus (Fabricius, 1798)
Scylla oceanica (Estampador, 1949)
Scylla serrata paramamosain (Estampador, 1949)
Scylla tranquebarica var. oceanica (Dana, 1852)

Potentially Misidentified Species



Life History- In crabs of the family Portunidae, the male attends the female before molting, and carries the female around, underneath his carapace. He releases the female, allows her to molt, and then copulates with her, inserting the first pair of pleopods, carrying sperm, into the female's seminal receptacles. The eggs are fertilized internally, and then extruded as a 'sponge' or a mass of eggs brooded between the abdomen and the body (Barnes 1983). The eggs hatch into zoeae, larvae about 1 mm long, armed with long spines, which drift in the plankton. Each zoea molts four to seven times before metamorphosing into a megalopa, which has partially developed legs and prominent eyes. The megalopa is capable of crawling on the bottom and active, directed swimming. It settles and molts into a miniature 'first crab' stage which has all the features of an adult crab (Barnes 1983).

Ecology- In Scylla serrata, the life cycle is typically marked by migration through a range of environments. Mating can occur in brackish habitats, but the female migrates offshore for spawning, where the eggs hatch, and the zoeae develop. The megalopae tend to move up estuaries, a movement continued by the juveniles (Keenan et al. 1998; Eldredge and Smith 2001).


Crustaceans; Molluscs; Plant Matter; Detritus


fishes, humans

Trophic Status:




General HabitatGrass BedNone
General HabitatUnstructured BottomNone
General HabitatMangrovesNone
General HabitatCoral reefNone
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone
Vertical HabitatNektonicNone

Tolerances and Life History Parameters

Minimum Temperature (ºC)3Islam M.J., and A.L. Bhuiyan, cited by Smithsonian Marine Station 2007
Maximum Temperature (ºC)45Islam M.J., and A.L. Bhuiyan, cited by Smithsonian Marine Station 2007
Minimum Salinity (‰)1Chen and Chia (1997)
Maximum Salinity (‰)42Chen and Chia (1997)
Minimum Reproductive Temperature23Experimental (Hamasaki 2003)
Maximum Reproductive Temperature32Experimental (Hamasaki 2003)
Minimum Reproductive Salinity17.5Experimental (Hill 1974)
Maximum Reproductive Salinity35Experimental (Hill 1974)
Minimum Duration22Experimental, 22 C (Hamasaki 2003)
Maximum Duration43Experimental, 22 C (Hamasaki 2003)
Maximum Width (mm)216Carlton and Eldredge 2009
Broad Temperature RangeNoneWarm temperate-Tropical
Broad Salinity RangeNoneOligohaline-Euhaline

General Impacts

The one known introduction of Scylla serrata in continental US waters (on the Gulf coast of Florida) was unsuccessful. The stocked population in Hawaii is now abundant and a popular food item. This crab may have ecological impacts as an abundant predator in Hawaiian estuaries, but its impacts are unstudied (Eldredge and Smith 2001).

Regional Impacts

SP-XXINoneEconomic ImpactFisheries
The stocked population of Scylla serrata in Hawaii is now abundant and a popular food item (Carlton and Eldredge 2009).
HIHawaiiEconomic ImpactFisheries
The stocked population of Scylla serrata in Hawaii is now abundant and a popular food item (Carlton and Eldredge 2009).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
EA-IV None 0 Native Estab
EA-III None 0 Native Estab
EA-II None 0 Native Estab
GAden Gulf of Aden 0 Native Estab
RS-3 None 0 Native Estab
RS-2 None 0 Native Estab
RS-1 None 0 Native Estab
OM None 0 Native Estab
AG-5 None 0 Native Estab
AG-4 None 0 Native Estab
AG-1 None 0 Native Estab
IP-1 None 0 Native Estab
CIO-I None 0 Native Estab
CIO-II None 0 Native Estab
CIO-V None 0 Native Estab
CIO-III None 0 Native Estab
EAS-I None 0 Native Estab
CIO-IV None 0 Native Estab
EAS-III None 0 Native Estab
EAS-VI None 2013 Crypto Estab
EAS-VIII None 0 Native Estab
EAS-II None 0 Native Estab
NWP-2 None 0 Native Estab
AUS-XIV None 0 Native Estab
AUS-I None 0 Native Estab
AUS-XII None 0 Native Estab
AUS-XI None 0 Native Estab
AUS-X None 0 Native Estab
AUS-II None 0 Native Estab
SP-I None 0 Native Estab
EAS-IV None 0 Native Estab
SP-IV None 0 Native Estab
SP-III None 0 Native Estab
SP-V None 0 Native Estab
SP-VII None 0 Native Estab
SP-IX None 0 Native Estab
SP-XVI None 0 Native Estab
NZ-IV None 0 Native Estab
SP-XXI None 1926 Def Estab
EA-V None 0 Native Estab
SP-XIII None 0 Native Estab
NWP-3a None 0 Native Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 1962 Def Failed
G030 North Ten Thousand Islands 1962 Def Failed
NWP-3b None 0 Native Estab
WA-V None 0 Native Estab
SP-XII None 0 Native Estab
SA-II None 1983 Def Failed
EAS-VII None 0 Native Estab
CAR-III None 2013 Def Unk

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Baars, Jan-Robert; Caplice, Martina B. ; Flynn, Oscar; O’Leary, Kate; Swanwick, Heather; Minchin, Dan (2022) The Ponto-Caspian quagga mussel, Dreissena rostriformis bugensis Andrusov, 1897, is established in Ireland, BioInvasions Records 11: in press

Barnes, Robert D. (1983) Invertebrate Zoology, Saunders, Philadelphia. Pp. 883

Brock, Vernon E. (1960) The introduction of aquatic animals into Hawaiian waters, Internationale Revue der Gesamten Hydrobiologie 45(4): 463-480

Brockerhoff, Annette; McLay, Colin (2011) In the wrong place- Alien marine crustaceans: Distribution, biology, impacts, Springer, Dordrecht. Pp. 27-106

Carlton, James T.; Eldredge, Lucius (2009) Marine bioinvasions of Hawaii: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago., Bishop Museum Bulletin in Cultural and Environmental Studies 4: 1-202

Chen, Jiann-Chu; Chia, Peng-Gek (1997) Osmotic and ionic concentrations of Scylla serrata (Forskal) subjected to different salinity levels, Comparative Biochemistry and Physiology 117A: 239-244

Coles S. L., DeFelice R. C., Eldredge, L. G. (1999a) Nonindigenous marine species introductions in the harbors of the south and west shores of Oahu, Hawaii., Bishop Museum Technical Report 15: 1-212

Coles, S. L.; DeFelice, R. C.; Eldredge, L. G.; Carlton, J. T. (1999b) Historical and recent introductions of non-indigenous marine species into Pearl Harbor, Oahu, Hawaiian Islands., Marine Biology 135(1): 147-158

Eldredge, L. G.; Smith, C. M. (2001) Introduced marine species of Hawaii, Bishop Museum Technical Report 21: 1-60

Hamasaki, Katsuyuki (2003) Effects of temperature on the egg incubation period, survival and developmental period of larvae of the mud crab Scylla serrata (Forskal) (Brachyura: Portunidae) reared in the laboratory, Aquaculture 219: 561-572

Hill, B. J. (1974) Salinity and temperature tolerance of zoeae of the portunid crab Scylla serrata, Marine Biology 25(1): 21-24

Huang, Zongguo (Ed.), Junda Lin (Translator) (2001) Marine Species and Their Distributions in China's Seas, Krieger, Malabar, FL. Pp. <missing location>

Keenan, Clive P.; Davie, Peter, J. F.; Mann, David L. (1998) A revision of the genus Scylla de Haab 1833 (Crustacea: Decapoda: Brachyura: Portunidae)., Raffles Bulletin of Zoology 46(1): 217-245

Lemaitre, Rafael; Campos, Néstor H.; Maestre, Efraín A. Viloria; Windsor, Amanda M. (2013) Discovery of an alien crab, Scylla serrata (Forsskål, 1775) (Crustacea: Decapoda: Portunidae), from the Caribbean coast of Colombia, Bioinvasions Records 2: in press

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

MacKenzie, Richard Ames; Bruland, Gregory L. (2012) Nekton communities in Hawaiian coastal wetlands: the distribution and abundance of introduced fish species, Estuaries and Coasts 35: 212-226

Park, John R. (1969) A preliminary study of portunid crabs in Biscayne Bay, Quarterly Journal of the Florida Academy of Sciences 32(1): 1-20

Paulay, Gustav; Kropp, Roy; Ng, Peter, K. L.; Eldredge, Lucius G. (2003) The crustaceans and pycnogonids of the Mariana Islands, Micronesica 35-36: :56-513

Smithsonian Marine Station at Fort Pierce 2007-2022 Indian River Species Inventory.

Tavares, Marco (2011) In the wrong place- Alien marine crustaceans: Distribution, biology, impacts, Springer, Dordrecht, Netherlands. Pp. 251-268

Tavares, Marcos; Mendonça, Joel B. Jr. (2011) The Occurrence of the Indo-pacific swimming crab Scylla Serrata (Forskål, 1775) in the Southwestern Atlantic (Crustacea: Brachyura: Portunidae), Aquatic Invasions 6(Supplement 1): S49-S51

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database.

USGS Nonindigenous Aquatic Species Program 2003-2024 Nonindigenous Aquatic Species Database.