Invasion History

First Non-native North American Tidal Record: 1875
First Non-native West Coast Tidal Record: 1948
First Non-native East/Gulf Coast Tidal Record: 1875

General Invasion History:

Chelura terebrans is a wood-boring amphipod first described by Philippi from Trieste, Italy in 1839, and redescribed by Allman (1847) from Ireland. Its native range is uncertain, as it has a wide global distribution being found from 18°N – 61°N in the northern hemisphere and 30ºS – 44ºS in the southern hemisphere. In the Eastern Atlantic, it ranges from Norway to Spain, and through the Mediterranean and Black Seas (Kuhne and Becker 1964). Chelura terebrans has been reported from the Northwestern Atlantic (Maine to Long Island; Wallour 1960), South Africa (Mead 2011b), the Northeastern Pacific (Washington to California; Wallour 1960; Carlton 1979), Australia and New Zealand (Kuhne and Becker 1964). It was likely transported to many locations in the hulls of wooden ships (Kuhne and Becker 1964). Chelura terebrans usually co-occurs with the wood-boring isopods of the genus Limnoria (Barnard 1955; Kuhne and Becker 1964) and is largely dependent on these borers for shelter and food, due to Limnoria's superior wood-eating ability.

North American Invasion History:

Invasion History on the West Coast:

Chelura terebrans was first collected in 1948 at the Hunters Point Naval Shipyard in San Francisco Bay, California (Cohen and Carlton 1995). It was subsequently found in several locations in the central bay, at Sausalito in 1949 (Barnard 1950); Tiburon in 1949 (Barnard 1950); and Lake Merritt, in Oakland (Carlton 1979). In 1950, C. terebrans was found at Cabrillo Beach, Los Angeles, San Pedro Bay, and in sample blocks placed in Los Angeles-Long Beach Harbors (Barnard 1950). It was also found in Long Beach Harbor in a survey in 2000 (Cohen et al. 2002). North of San Francisco Bay, C. terebrans was found in Humboldt Bay, California in 2000 (Boyd et al. 2002) and Grays Harbor, Washington (Wallour 1960, Carlton 1979).

Invasion History on the East Coast:

Chelura terebrans was first found at Woods Hole, Massachusetts (MA) in 1875 by Smith (1879): 'I have repeatedly made careful search of Chelura at many different points along our eastern coast from New Jersey to Nova Scotia, and have examined many pieces of Teredo and Limnoria-bored timber from other parts of the coast, but until 1875, I was not able to discover an individual of the genus.' (Smith 1879). Chelura terebrans was abundant at Provincetown, MA in 1879 (Smith 1879) and also found at Portland Harbor, Maine (ME), Boston Harbor, MA in 1951-52 (Brown 1953; Wallour 1960) and earlier (Atwood 1935, cited by Kuhne and Becker 1964). The southern limits are less clear. Chelura terebrans was collected in Long Island Sound around 1935 (Atwood 1935, cited by Kuhne and Becker 1964; Brown 1953; Wallour 1960). Bousfield (1973) gives the range of C. terebrans as 'south to Chesapeake Bay and northern Florida'. However, no specific records were given in the Clapp Laboratory's wood-borer surveys (Brown 1953; Wallour 1960), museum collections, or local amphipod surveys (Feeley and Wass 1971). We have not found reports of C. terebrans in adjacent estuaries to the north and south e.g. Watling and Maurer (1972) for Delaware Bay, or Fox and Bynum (1975) for North Carolina. The limited range of this species in the Northwest Atlantic and Smith's (1879) early difficulty in locating populations, support the case for introduced status.

Invasion History Elsewhere in the World:

Chelura terebrans has become widely distributed in the world, presumably, by burrowing into the hulls of wooden ships. It appears to have become established primarily in temperate waters (Kuhne and Becker 1964). It was established in South Africa by 1889 (Kuhne and Becker 1964; Robinson et al. 2005), New Zealand by 1911 (Cranfield et al. 1998), eastern Australia by 1921 (Kuhne and Becker 1964), Egypt (at the Red Sea terminus of the Suez Canal) by 1928 (Kuhne and Becker 1964), and Hong Kong by 1911 (Kuhne and Becker 1964). It is also established in Bermuda (1903, Kuhne and Becker 1964; Yale Peabody Museum of Natural History 2015). Records of C. terebrans from Hawaii and the Virgin Islands probably refer to the Indo-Pacific species Tropichelura insulae (Barnard 1959; Wallour 1960; Carlton and Eldredge 2009).


Description

The body of Chelura terebrans is depressed and cylindrical, and the posterior margins of its segment are lined with setae. Pleosome segment 3 is produced into a rearward-curving dorsal spine, which is especially large in males. The uropods are large, especially Uropod 3, in which the outer ramus is huge and paddle-like. In males, Uropod 3 is nearly as long as the body.

The head is broad and rounded, and a rostrum is absent. The eye is large and black, and located laterally. The antennae are short. Antenna 1 has a flagellum of 5-6 segments, with a 2-segmented accessory flagellum. Antenna 2 is longer and thicker than Antenna 1, and densely covered with setae. The flagellum consists of a single large, scale-like segment, and two minute segments.

Gnathopod 1 is not greatly enlarged in males or females, but is somewhat thicker, compared to Gnathopod 2. The 6th segment of Gnathopod 1 is longer than segment 5. Segments 2, 5 and 6 of Gnathopod 2 are lined with plume-like setae. As noted above, the rearward-projecting spine on the last pleosome segment is much larger in males than females. Each of the 3 pairs of uropods are dissimilar and also vary between males and females. Uropod 1 has a peduncle 2X the length of the rami, with the inner ramus expanded distally. In females, the peduncle and rami are stouter than in males. Uropod 2 is short, with a wing-like inner lobe on the margin of the peduncle with short rami. In males, the wing-like lobe is larger with more setae than in females. Uropod 3 has a short, broad peduncle, but a very long outer ramus, paddle-like in females, long and rudder-like in males. The telson is small and triangular. The body length is 3.5-6 mm, and the color is pale brown, mottled with pink. Description based on Allman 1847, Smith 1879, Barnard 1950, Bousfield 1973, Lincoln 1979, and Chapman 2007.


Taxonomy

Taxonomic Tree

Kingdom:   Animalia
Phylum:   Arthropoda
Subphylum:   Crustacea
Class:   Malacostraca
Subclass:   Eumalacostraca
Superorder:   Peracarida
Order:   Amphipoda
Suborder:   Gammaridea
Family:   Cheluridae
Genus:   Chelura
Species:   terebrans

Synonyms

Potentially Misidentified Species

Nippochelura brevicauda
Misaki, Onagawa and Kominato, Japan (Barnard 1959)

Tropichelura insulae
Indo-Pacific Islands from Christmas Island, Indian Ocean to Honolulu; Caribbean from Costa Rica to Puerto Rico and Trinidad (Barnard 1959)

Ecology

General:

Chelura terebrans is an amphipod which usually lives within the burrows of wood-boring isopods of the genus Limnoria spp. (gribbles). Gammarid amphipods have separate sexes, brooded embryos, and direct development. Males and females mature at about 3.5 mm. Copulation takes place within burrows. Broods average about 4 embryos, but can range to up to 15, with as many as 5 broods in a lifetime. Embryo development takes ~47 days at 14C, and 18 days at 26C (Becker 1971), Juveniles develop in their parents' burrow and cannot burrow on their own. Young C. terebrans take ~70-84 days to mature at 20C (Bourdillon 1958a; Bourdillon 1958b; Kuhne and Becker 1964; Becker 1971).

Chelura terebrans tolerates a wide range of temperature (-2 to 26C), and occurs through the euhaline-polyhaline salinity range (Nair and Leivestad 1959; Kuhne and Becker 1964; Becker 1971). It has been found with L. lignorum, L. tripunctata, L. quadripunctata and Limnoria carinata (Bourdillon 1958a; Kuhne and Becker 1964; Borges 2010). The diet of C. terebrans consists largely of Limnoria fecal pellets. The feeding of C. terebrans helps keep the burrows clean, and its movements increase water circulation in the burrows. It prefers fungus-infected wood, and its boring activities mostly involve enlarging Limnoria's borrows (Kuhne and Becker 1964; Becker 1971). Green Extabe (2013) found that C. terebrans could be cultured indefinitely on Scots Pine wood, in the absence of Limnoria, and are capable of producing enzymes to digest wood, without depending on gut bacteria. Chelura terebrans disperses by swarming, usually in the spring, and also when their wooden habitat disintegrates (Bourdillon 1958a; Kuhne and Becker 1964; Becker 1971).

Food:

Bacteria; Protists; Decaying Wood

Trophic Status:

Herbivore

Herb

Habitats

General HabitatCoarse Woody DebrisNone
General HabitatMarinas & DocksNone
General HabitatVessel HullNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone


Tolerances and Life History Parameters

Minimum Temperature (ºC)-2Experiments (Nair and Leivestad 1959)
Maximum Temperature (ºC)26Field Data (Kuhne and Becker 1964)
Minimum Salinity (‰)18Experiments (Nair and Leivestad 1959)
Maximum Salinity (‰)40Field Data (Kuhne and Becker 1964)
Minimum Reproductive Temperature15Experimental, lowest tested (Becker 1971)
Maximum Reproductive Temperature26Experimental (Becker 1971)
Minimum Length (mm)3.5Adults, Bourdillon 1958; Kuhne and Becker 1964
Maximum Length (mm)6Adults, Bourdillon 1958; Kuhne and Becker 1964
Broad Temperature RangeNoneCold temperate-Warm temperate
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

Chelura terebrans is an amphipod which usually lives in association with wood-boring isopods of the genus Limnoria spp. (gribbles), living in the Limnoria burrows (Becker 1971). This amphipod is capable of digesting wood on its own (Green Etxabe 2015) but its impacts on natural wood and human structures appears to be small compared to shipworms and Limnoria. Most of its boring activity consists of enlarging Limnoria burrows (Atwood 1922; Brown 1953; Becker 1971).

Economic Impacts

Shipping- Chelura terebrans is regarded as an important wood-boring pest, although it is usually only a significant borer in the presence of Limnoria spp., and its damage consists mostly of enlarging Limnoria's burrows and speeding the latter's destruction of wooden pilings (Barnard 1955; Becker 1971; Kuhne and Becker 1964). As destroyers of wooden structures, crustacean borers as a group are regarded as second in importance to shipworms (Atwood 1922; Brown 1953). In the NW Atlantic, substantial populations of C. terebrans were found between Boston and Fisher's Island New York, (near New London, Connecticut), and in Hamilton Harbor, Bermuda. However, boring activity due to C. terebrans was considered minor (Brown 1953).

Chelura terebrans was first collected on the west coast of North America in 1949 in San Francisco and Los Angeles harbors (Barnard 1950). In Los Angeles-Long Beach Harbors, and harbors in San Francisco Bay, these amphipods were 'very abundant' on pilings (Barnard 1950); apparently increasing the size of burrows and the erosibility of wood (Barnard 1955).

Ecological Impacts

Herbivory, Habitat Change- Chelura terebrans together with the isopods Limnoria spp. (gribbles) play an important role in the decomposition and recycling of wood. Limnoria spp. burrow much more rapidly than C. terebrans, and the amphipod normally depends on its tunnels for shelter, which it enlarges (Barnard 1959; Kuhne and Becker 1964). The relationship between the isopods and amphipods is mutualistic in part, since C. terebrans cleans feces from the burrows and improves water circulation, but high densities can interfere with Limnoria populations (Kuhne and Becker 1964; Becker 1971).

Regional Impacts

P050San Pedro BayEconomic ImpactShipping/Boating
'Very abundant' in pilings (Barnard 1950); apparently increasing the size of burrows made by gribbles (Limnoria spp.) and the erosibility of wood (Barnard 1955)
P090San Francisco BayEconomic ImpactShipping/Boating
'Very abundant' in pilings (Barnard 1950); apparently increasing the size of burrows made by gribbles (Limnoria spp.) and the erosibility of wood (Barnard 1955)
NEP-VNorthern California to Mid Channel IslandsEconomic ImpactShipping/Boating
'Very abundant' in pilings (Barnard 1950); apparently increasing the size of burrows made by gribbles (Limnoria spp.) and the erosibility of wood (Barnard 1955)
NEP-VIPt. Conception to Southern Baja CaliforniaEconomic ImpactShipping/Boating
'Very abundant' in pilings (Barnard 1950); apparently increasing the size of burrows made by gribbles (Limnoria spp.) and the erosibility of wood (Barnard 1955)
CACaliforniaEconomic ImpactShipping/Boating
'Very abundant' in pilings (Barnard 1950); apparently increasing the size of burrows made by gribbles (Limnoria spp.) and the erosibility of wood (Barnard 1955), 'Very abundant' in pilings (Barnard 1950); apparently increasing the size of burrows made by gribbles (Limnoria spp.) and the erosibility of wood (Barnard 1955), 'Very abundant' in pilings (Barnard 1950); apparently increasing the size of burrows made by gribbles (Limnoria spp.) and the erosibility of wood (Barnard 1955)

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
AR-V None 0 Native Established
NEA-II None 0 Native Established
NEA-III None 0 Native Established
NEA-IV None 0 Native Established
NEA-V None 0 Native Established
MED-I None 0 Native Established
MED-II None 0 Native Established
MED-III None 0 Native Established
MED-IV None 0 Native Established
MED-VII None 0 Native Established
MED-VI None 0 Native Established
MED-V None 0 Native Established
MED-IX None 0 Native Established
MED-VIII None 0 Native Established
NA-ET3 Cape Cod to Cape Hatteras 1875 Non-native Established
NA-ET2 Bay of Fundy to Cape Cod 1879 Non-native Established
NA-ET4 Bermuda 1903 Non-native Established
WA-V None 1889 Non-native Established
WA-IV None 1921 Non-native Established
RS-3 None 1928 Non-native Established
NWP-2 None 1911 Non-native Established
AUS-X None 1921 Non-native Established
NZ-IV None 1914 Non-native Established
NEP-V Northern California to Mid Channel Islands 1948 Non-native Established
NEP-IV Puget Sound to Northern California 1960 Non-native Established
NEP-VI Pt. Conception to Southern Baja California 1950 Non-native Established
M040 Long Island Sound 1935 Non-native Established
P050 San Pedro Bay 1950 Non-native Established
M020 Narragansett Bay 1949 Non-native Established
M010 Buzzards Bay 1875 Non-native Established
P130 Humboldt Bay 2000 Non-native Established
M130 Chesapeake Bay 1973 Non-native Unknown
P090 San Francisco Bay 1948 Non-native Established
P280 Grays Harbor 1960 Non-native Established
N195 _CDA_N195 (Cape Cod) 1953 Non-native Established
N180 Cape Cod Bay 1879 Non-native Established
N170 Massachusetts Bay 1953 Non-native Established
N100 Casco Bay 1953 Non-native Established
AUS-XII None 1936 Non-native Established
CAR-VII Cape Hatteras to Mid-East Florida 0 Non-native Unknown
AUS-IV None 1971 Non-native Established
AUS-VIII None 1986 Non-native Established

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude

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