Potimirim potimirim

Invasion History

First Non-native North American Tidal Record: 1960
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 1960

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General Invasion History:

Potimirim potimirim is a freshwater shrimp native to Brazil from Rio Itajai, Santa Catarina north to Rio Gurjau, Recife, Pernambuco State, Brazil, and from Atlantic drainages in Central America (Abele 1972; de Almeida et al. 2008). Two collections, made in 1972, of shrimp identified as this species, from the Caribbean island of Guadeloupe, are in the National Museum of Natural History collections (USNM 169709; USNM 169710, US National Museum of Natural History 2009). These appear to represent introductions from Brazil, if identified correctly. This shrimp is tolerant of salinities of at least 23 PSU (Gore et al. 1978), but natural dispersal to the Caribbean and Florida is unlikely.

North American Invasion History:

Invasion History on the East Coast:

In 1960, Potimirim potimirim was collected in freshwater canals in the Indian River Lagoon drainage near Jupiter, Florida. An additional collection was made nearby in 1971 (Abele 1972). In 1977, P. potimirim was collected again in freshwater canals draining into the Indian River Lagoon (Gore et al. 1978), about 100 km north, near Vero Beach (Gore et al. 1978). A third collection was made in Reed Canal, draining the Halifax lagoon, near Daytona Beach (Beck 1979). All of these collections included ovigerous females, suggesting that a reproductive population was established. However, we are not aware of captures of this shrimp since 1979, so it is possible that it may have died out due to cold weather or another cause. Likely vectors include strays from the tropical fish or aquatic plant industry, which operates many fish and plant farms in the area (Abele 1972; Gore et al. 1978).

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Description

Potimirim potimirim is a freshwater caridean shrimp. As is typical of this group, the lower part of the 2nd abdominal segment is expanded and overlaps the 1st and 3rd segments. The rostrum is comparatively short, and smooth on the dorsal surface, while the ventral surface bears two small teeth. The antenna is relatively short, about equal to the length of the carapace, and bears an unsegmented flagellum of about equal length. The first two walking legs have chelae (movable claws). This shrimp is brown, with scattered yellowish areas. A longitudinal stripe runs along the median dorsal surface. The telson has bands of brown and gold. Live specimens turn blue when excited. The largest specimen found in Florida waters was an ovigerous female at 28.5 mm total length (Abele 1972; Gore et al. 1978; de Almeida et al. 2008).

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Taxonomy

Ecology

General:

Life History- In caridean shrimps, the copulating pair is usually oriented at right angles to one another, with the genital regions opposing each other. The modified first and second pairs of pleopods are used to transfer a spermatophore to a receptacle between the thoracic legs of the female (Barnes 1983). After mating, female palemonid and atyid shrimps carry broods of fertilized eggs on their abdomen. These hatch into planktonic larvae with feathery appendages, called zoeae. Zoeae of shrimps lack the prominent spines seen in brachyuran crabs, and look quite shrimplike (Johnson and Allen 2005). They go through several molts and metamorphose into postlarvae, which have well-developed walking legs and pleopods (swimmerets). After a subsequent molt, the body takes on the adult shape. Larvae of P. potimirim were raised by Gore et al. (1978) through stage III zoeae, but did not reach metamorphosis. To our knowledge, the larvae have not been described.

Ecology- Potimirim potimirim is a freshwater shrimp, inhabiting small freshwater streams and vegetated edges of rivers (de Almeida et al. 2008). It is known from estuaries (Teixera and Helio 1998) and its larvae tolerate salinities as high as 23 PSU (Gore et al. 1978).

Trophic Status:

Omnivore

Omni

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Habitats

General Habitat	Nontidal Freshwater	None
General Habitat	Canals	None
General Habitat	Fresh (nontidal) Marsh	None
General Habitat	Grass Bed	None
General Habitat	Coarse Woody Debris	None
General Habitat	Swamp	None
General Habitat	Tidal Fresh Marsh	None
General Habitat	Salt-brackish marsh	None
General Habitat	Unstructured Bottom	None
Salinity Range	Limnetic	0-0.5 PSU
Salinity Range	Oligohaline	0.5-5 PSU
Salinity Range	Polyhaline	18-30 PSU
Tidal Range	Subtidal	None
Vertical Habitat	Epibenthic	None
Vertical Habitat	Nektonic	None

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Tolerances and Life History Parameters

Minimum Salinity (‰)	0	This is primarily a freshwater shrimp (Abele 1972)
Maximum Salinity (‰)	23	Highest salinity tested for lab-reared zoeae (Gore et al. 1979)
Maximum Length (mm)	28.6	Florida (Abele 1972)
Broad Temperature Range	None	Subtropical-tropical
Broad Salinity Range	None	Nontidal Limnetic-Polyhaline

General Impacts

Potimirim potimirim appears to have briefly established breeding populations in Florida canals, but did not persist. It had no reported ecological or economic impacts.

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References

Abele, Lawrence E. (1972) Introductions of two freshwater decapod crustaceans (Hymenosomatidae and Atyidae) into Central and North America, Crustaceana 23(3): 209-218

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

Beck, J. Thomas (1979) A third occurrence of the introduced atyid shrimp, Potimirim potimrim, in Florida., Florida Scientist 42(4): 256

de Almeida, Alexandre Oliveira and 5 authors (2008) Decapod crustaceans in fresh waters of southeastern Bahia, Brazil, International Journal of Tropical Biology 56(3): 1225-1254

Gore, Robert H.; Kulczycki, George R.; Hastings, Philip A. (1978) A second occurrence of the Brazilian freshwater shrimp, Potimirim potimirim, along the central eastern Florida coast, Florida Scientist 41: 57-60

Johnson, William S.; Allen, Dennis M. (2005) <missing title>, Johns Hopkins Press, Baltimore. Pp. <missing location>

Teixeira, Rogério L.; Sá, Hélio S. (1998) [Abundance of decapod macrocrustaceans occupying the shallow waters of a tropical estuary], Revista Brasileira da Biologia 58(3): 393-404

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