.jpg)
Description
Balanus amphitrite (Striped Barnacle) is a member of the 'B. amphitrite' species complex, containing many similar species, which at times have been named as varieties of B. amphitrite. Currently, only two subspecies of B. amphitrite are recognized, B. amphitrite amphitrite, now distributed worldwide in warm waters, and B. amphitrite saltonensis, known from the Salton Sea and the Pacific Coast (CA) (Henry and McLaughlin 1975).
Potentially Misidentified Species - Barnacles occurring in or near Chesapeake Bay, and previously identified in the literature as varieties of B. amphitrite are listed below, with names of describers, (not in parentheses or in references):
Balanus subalbidus [known as B. amphitrite pallidus Henry 1954, in part (Henry and McLaughlin 1975)]; Balanus eburnus [known as B. amphitrite niveus Olivera 1941, in part (Henry and McLaughlin 1975)].
Balanus improvisus [known as B. amphitrite pallidus, in part, Nillson-Cantell 1932, B. amphitrite amphitrite Stubbings 1967 (Henry and McLaughlin 1975)].
Balanus venustus [known as B. amphitrite venustus Darwin 1854, B. amphitrite modestus Darwin 1854; B. amphitrite inexpectatus Nillson-Cantell 1933; B. amphitrite obscurus Darwin 1854; B. amphitrite niveus Pilsbry 1916; B. amphitrite denticulata Stubbings 1961; (Henry and McLaughlin 1975)]. Balanus venustus is predominantly subtidal, down to depths of 55 m, while B. amphitrite is mostly intertidal (Zullo 1966).
Specimens of 'B. a. pallidus' from Solomons and St. Marys MD in United States National Museum of National History collections are probably B. improvisus, but possibly B. subalbidus. 'B. a. niveus' from Martha's Vineyard, Narragansett Bay, and NC, are probably B. venustus.
br/>
Pitombo (2005) raised the 'Balanus amphitrite group, including B. amphitrite to the status of a genus, Amphibalanus.
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Animalia | Crustacea | Cirripedia | Thoracica | Balanidae | Balanus |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1967 | Established | Stable | Introduced | Regular Resident | Unknown-Marine | Western Pacific | Shipping(Ballast Water,Fouling Community) |
History of Spread
Amphibalanus amphitrite (Striped Barnacle) is a cosmopolitan barnacle in tropical to warm-temperate waters, whose movements have been difficult to interpret because of its complex taxonomy. The Indo-Pacific is the likeliest region of origin (Cohen and Carlton 1995). In the West Pacific and Indian Ocean, it ranges from Vladivostok, Russia, to Southeast Africa (Henry and McLaughlin 1975). It is 'extremely common on ship's bottoms' (Darwin 1854), and appears to have been introduced over much of its present range, including most or all of the Atlantic Basin (Bishop 1950; Zullo 1966; Zullo 1992) (Carlton et al. 1969; Cohen and Carlton 1995; Zullo et al. 1972). Specimens were collected in England as early as 1917 (Bishop 1950), but this species is confined to the warmer south coast, and is abundant in thermal effluents (Raymont 1976). A. amphitrite was first collected in HI in the early 1900's and on the coast of CA (La Jolla) in 1921 (Zullo et al. 1972), and is abundant from Mexico to San Francisco (and probably beyond) (Cohen and Carlton 1995; Henry and McLauglin 1975).
Amphibalanus amphitrite may have been introduced to the Caribbean, including FL before the mid-19th century (Darwin 1854), and is abundant as far south as Argentina (Calcogno et al. 1997). Darwin believed he had found barnacles intergrading from 'A. a. communis' (A. amphitrite) to 'A. a. niveus', (A. venustus), from the West Indies and FL (Darwin 1854, p. 246). However, A. amphitrite apparently was not found on the Atlantic Coast of the United States by Pilsbry (1916). 'Evidence for the invasion of A. a. amphitrite is purely circumstantial, but nonetheless convincing. Pilsbry did not identify it in any of the collections either at the United States National Museum of Natural History or the Academy of Natural Sciences of Philadelphia, and examination of the National Museum failed to uncover any specimens collected prior to World War II. Other evidence was obtained from examination of Pliocene and Pleistocene fossils from the Atlantic Coastal Plain of FL in the United States Geological Survey collection. Amphibalanus amphitrite amphitrite was not found, although A. venustus niveus was common. Not as much weight can be given to this negative evidence, since the predominantly intertidal habits of A. a. amphitrite might detract from its preservation' (Zullo 1966). Northwest Atlantic records of A. a. amphitrite are summarized below:
Gulf of Mexico - Tampa Bay FL 1954; Panama City 1964; Boca Ciega Bay 1955; Veracruz Mexico 1965 (Henry and McLaughlin 1975; United States National Museum of Natural History collections). It was collected at Pass Christian MS and probably also at Port Aransas TX. (Zullo 1966).
FL, Atlantic Coast - It was reported from Miami in 1963 (Henry and McLaughlin 1975; United States National Museum of Natural History collections). Settlement was recorded on fouling plates from the 1950's onward, but identification of A. amphitrite may have been uncertain before 1962 (Moore et al. 1974). It was reported from Fernandina Beach and the Jacksonville area (Zullo 1966).
NC - It was collected in Beaufort NC in 1955, (Henry and McLaughlin 1975; United States National Museum of Natural History collections) and described as 'a conspicuous element in the mid and low intertidal at Beaufort' (Henry 1959), Morehead City, and Wrightsville Beach, NC (Zullo 1966).
Chesapeake Bay - It was collected in Norfolk VA at Lynnhaven Inlet in 1967 (Henry and McLaughlin 1975). It was reported for the lower Chesapeake Bay, 'scarce' (Van Engel et al. 1972). In 2004, Amphibalanus amphitrite was identified from several fouling plates from Lynnhaven Bay, collected in 2000-2004 (Ruiz et al. unpublished data; Jana Seeger, personal communication).
Cape Cod - Four individuals were collected from pilings in West Bay, Hyannis MA on the south side of Cape in 1963. Two of these were maintained in a running seawater system, but died in December when the temperature reached 1.5 C (Zullo 1966). 'These specimens probably represented the spat of individuals carried north from warmer waters' (Zullo 1966).
History References - Bishop 1950; Calcogno et al. 1997; Carlton et al. 1969; Cohen and Carlton 1995; Darwin 1854; Henry 1959; Henry and McLaughlin 1975; Moore et al. 1974; Pilsbry 1916; Van Engel et al. 1972; Zullo 1966; Zullo et al. 1972; Zullo 1979; Zullo 1992
Invasion Comments
History of Spread - Records of 'Amphibalanus amphitrite niveus' from Cape Henry VA, 1959, and 'A. a. pallidus', from Solomons and St. Marys MD (United States National Museum of Natural History collections) refer to A. venustus and A. subalbidus respectively.
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | 1.5 | 32.0 | 15.0 | 32.0 |
| Salinity (‰) | 10.0 | 44.0 | 10.0 | 44.0 |
| Oxygen | ||||
| pH | ||||
| Salinity Range | poly-eu |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | 5.5 | 5.5 |
| Typical Adult Size (mm) | 9.0 | 9.0 |
| Maximum Adult Size (mm) | 15.0 | 15.0 |
| Maximum Longevity (yrs) | 5.5 | 5.5 |
| Typical Longevity (yrs | 1.0 | 1.0 |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
|||
| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
|||
| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Amphibalanus amphitrite (Striped Barnacle) is apparently too scarce to have significant econmic impacts in the Chesapeake region.
Economic Impacts Outside of Chesapeake Bay
Amphibalanus amphitrite (Striped Barnacle) is an important fouler of ships and marine structures worldwide in warm waters (Shkedy et al. 1995), and in heated discharges in England, and probably elsewhere (Raymont 1976).
References- Raymont 1976; Shkedy et al. 1995
Ecological Impacts on Chesapeake Native Species
Impacts of Amphibalanus amphitrite (Striped Barnacle) are considered minor because of this barnacle's scarcity in the Chesapeake region. In areas with suitable temperature regimes, it is a major colonizer of artificial structures in England and Israel (Bishop 1950; Shkedy et al. 1995), areas affected by thermal plumes, in England (Raymont 1976), and estuaries affected by sewage discharges, Argentina (Calcogno et al. 1997). At each of these sites, A. amphitrite is rare outside disturbed areas, and is the dominant form within them, suggesting that it may outcompete native barnacles in disturbed environments. As temperature decreased in a heated dock in England, the native Balanus crenatus appeared, and was presumed to be competing with A. amphitrite (Raymont 1976).
References- Bishop 1950; Calcogno et al. 1997; Shkedy et al. 1995; Raymont 1976
Ecological Impacts on Other Chesapeake Non-Native Species
Amphibalanuss amphitrite (Striped Barnacle) is apparently too rare in the Chesapeake Bay region to affect other fouling biota. However, in regions affected by thermal plumes, it could compete for space and food with other introduced organisms (Raymont 1976).
References- Raymont 1976