BioInvasions Records (2019) Volume 8, Issue 2: 400–409 CORRECTED PROOF Rapid Communication First record of introduction of Metacarcinus magister Dana, 1852 (Crustacea: Decapoda: Cancridae) and range extension of Eriocheir sinensis Milne-Edwards, 1853 (Crustacea: Decapoda: Varunidae) in the Long Island Sound David M. Hudson1,2,3,*, Sandi Schaefer-Padgett1, Barrett L. Christie1 and Richard Harris4 1The Maritime Aquarium at Norwalk, 10 N. Water St., Norwalk, CT 06854 USA 2Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, CT 06269 USA 3Southern Connecticut State University, New Haven, CT 06515 USA 4Copps Island Oysters, 7 Edgewater Place, Norwalk CT 06855 USA Author e-mails: [email protected] (DMH), [email protected] (SS-P), [email protected] (BLC), [email protected] (RH) *Corresponding author Citation: Hudson DM, Schaefer-Padgett S, Christie BL, Harris R (2019) First record Abstract of introduction of Metacarcinus magister Dana, 1852 (Crustacea: Decapoda: Invasive crustacean species have been present in the Long Island Sound, Cancridae) and range extension of northwestern Atlantic Ocean, for over two centuries. Three new records of Eriocheir sinensis Milne-Edwards, 1853 introduction are recorded here from collections by local fishermen. Two records are (Crustacea: Decapoda: Varunidae) in the for male Dungeness crabs, Metacarcinus magister (Dana, 1852), collected in the Long Island Sound. BioInvasions Records 8(2): 400–409, https://doi.org/10.3391/bir. Western Long Island Sound (2017) and Cape Cod Bay (2018). The other record is 2019.8.2.21 that of a range extension documented by a single male Chinese mitten crab, Eriocheir sinensis (Milne-Edwards, 1853), found in New Haven Harbor, Connecticut. Received: 4 September 2018 Both species could potentially harbor nonnative epibionts and endoparasites. Accepted: 13 February 2019 Additionally, E. sinensis may be more likely to establish, as it has in numerous Published: 24 April 2019 locations in the region and worldwide. Handling editor: Darren Yeo Thematic editor: April Blakeslee Key words: introduced species, invasive species, Brachyura, Dungeness crab, Copyright: © Hudson et al. Chinese mitten crab, Connecticut, Massachusetts This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International - CC BY 4.0). Introduction OPEN ACCESS. Invasive crustaceans are common in the Long Island Sound, northwestern Atlantic Ocean, with both the European green crab, Carcinus maenas (Linnaeus, 1758) and the Asian shore crab, Hemigrapsus sanguineus (De Haan, 1835), already established in the region and interacting with one another for decades (Lohrer and Whitlatch 2002). Invasive crabs have historically caused problems for ecological communities in intertidal and subtidal systems worldwide. Though not an exhaustive list, some of the most damaging crustacean invaders are the European green crab, Carcinus maenas, Chinese mitten crab, Eriocheir sinensis (Milne-Edwards, 1853), two members of the genus Hemigrapsus, H. sanguieneus, and H. takanoi (Asakura and Watanabe, 2005), the Harris mud crab, Rhithropanopeus harrisii (Gould, 1841), the blue crab, Callinectes sapidus (Rathbun, 1896), and the Asian paddle crab, Charybdis japonica (Milne-Edwards, 1861) Hudson et al. (2019), BioInvasions Records 8(2): 400–409, https://doi.org/10.3391/bir.2019.8.2.21 400 Metacarcinus magister and Eriocheir sinensis in the Long Island Sound (reviewed in Brockerhoff and McLay 2011; McLay 2015). This list of first records for invasions is growing ever larger with the addition of a first record of an eastern Pacific Ocean spider crab, Amphithrax armatus (de Saussure, 1853) to southern Taiwan (Ng et al. 2018). Two species that are regularly consumed by humans have recently appeared in the northwestern Atlantic region: Dungeness crab and Chinese Mitten crab. Dungeness crabs Metacarcinus magister (Dana, 1852) are native to the northeastern Pacific Ocean, and are a major fishery in that region, with the United States fishery landing over 29,000 metric tons worth over $222 million US dollars in the last year on record (National Marine Fisheries Service 2017). They are part of a male-only fishery for which some individuals are shipped live throughout the United States. While there are no reported established populations in the northwestern Atlantic Ocean, an individual was caught off Thatcher Island, Massachusetts in 2006 (Cohen 2006), and another in Cape Ann, Massachusetts in 2009 (Judith Pederson, Ph.D., MIT Sea Grant College Program, pers. comm.). Here, we report the first record of M. magister in the Long Island Sound and an additional record in Massachusetts. Chinese mitten crabs, E. sinensis, are already documented in the general vicinity of the Long Island Sound (Schmidt et al. 2009; reviewed in Dittel and Epifanio 2009). Here, we report an individual record of this species in the Long Island Sound. Materials and methods The Long Island Sound is an estuary in the northwestern Atlantic Ocean located between the glacial moraine of Long Island to the south and the state of Connecticut to the north. Rhode Island Sound and Cape Cod are to the east, and the New York City metropolitan area is on the Long Island Sound’s western end. It is a highly seasonal estuary, with southern migratory species moving in during summer and northern species in winter. The Long Island Sound and surrounding estuaries are historically commercial fishing areas and have seen an impact from European development since the 1600s. On 26 July 2017, a local fisherman captured a Dungeness crab, M. magister, in a lobster trap due south of Norwalk Harbor, Connecticut, on Copp’s Island Oysters’ Lot 006 in over 60 meters of water (41.014833°N; 73.394250°W). The 1.13 kg (male, 180.59 mm carapace width) individual was transported to The Maritime Aquarium at Norwalk (TMA) for identification. The staff at TMA identified it as M. magister, with some spots of shell disease, and reported the finding to the Connecticut Department of Energy and Environmental Protection (CT DEEP). In November 2018, another individual was caught by fisherman Kevin Scola and submitted to Massachusetts Division of Marine Fisheries. That individual was another male, measuring 217.68 mm carapace width, caught in Cape Cod Bay Hudson et al. (2019), BioInvasions Records 8(2): 400–409, https://doi.org/10.3391/bir.2019.8.2.21 401 Metacarcinus magister and Eriocheir sinensis in the Long Island Sound (42.03833°N; 70.38500°W). With concerns of confounding the specimens with the Atlantic rock crab Cancer irroratus, for which the authors have had a number of false alarms, the identification of these individuals was checked against Mary Wicksten’s (2011) most recent key for the Pacific Ocean. In April of 2018, a captain from Copps Island Oysters collected a Chinese mitten crab, E. sinensis, in an oyster dredge on the southern side of the Lot 12 lease in New Haven Harbor, Connecticut (41.248389°N; 72.934833°W). That individual, a male (56 g after freezing, 58.91 mm carapace width), was transported to Copps Island Oysters, in Norwalk, Connecticut and identified by Richard Harris as E. sinensis, who reported the finding to the CT DEEP. This specimen was submitted to the Yale Peabody Museum of Natural History in New Haven, CT (Specimen number: YPM IZ 103488); the M. magister specimen was accessioned in the Maritime Aquarium’s living collection (accession no. Norwalk-00348), but upon death was preserved and was also deposited at Yale Peabody Museum of Natural History (Specimen number: YPM IZ 103916). Results and discussion The Long Island Sound animals were captured using commercial fishing gear in areas of high commercial shipping traffic (mid-Long Island Sound off Norwalk and New Haven, Figure 1C), and in an area of Cape Cod Bay that is an approved shellfishing area due west of Provincetown, Massachusetts (Figure 1B). The most likely vector of introduction of both species is the live seafood trade, since port seizures of E. sinensis imports continue to happen every few years and M. magister can be found at markets both locally and throughout the United States. Humans have long been considered a vector for accidental introduction of invertebrates in the western North Atlantic via shipping (Carlton 2003; Chapman et al. 2003), but import of live animals for seafood and fishing bait is also an important documented vector for introductions in marine systems (Weigle et al. 2005; Fowler et al. 2016). Purchase of live animals at seafood markets and online, and their release in the wild, is probably how both of these crabs ended up in the Long Island Sound. Crustaceans that are involved in fisheries are easily the subject of illegal transportation, selling and potential release (Carlton 2003). The M. magister fishery is all male, making the likelihood of establishment of this species by the live seafood vector, barring a mistake, near zero. All the respective regulatory agencies of the states and provinces in the range of this animal (Alaska, British Columbia, Washington, Oregon, and California) do not permit anything but mature male fishery. Reflective of this vector, both the Long Island Sound (2017) and Cape Cod Bay (2018) specimens are male (Figure 2) and both of the individuals collected in Massachusetts in 2006 and 2009 were also male (Judith Pederson, Ph.D., MIT Hudson et al. (2019), BioInvasions Records 8(2): 400–409, https://doi.org/10.3391/bir.2019.8.2.21 402 Metacarcinus magister and Eriocheir sinensis in the Long Island Sound Figure 1. (A) Collection locations of introduced crabs. The two Dungeness crabs, M. magister, were collected in (B) Cape Cod Bay (triangle, 42.03833°N; 70.38500°W) and (C) in deeper water off of Norwalk (triangle, 41.014833°N; 73.394250°W). The non-native Chinese mitten crab, E. sinensis, was collected in (C) the Long Island Sound in New Haven Harbor (circle, 41.248389 °N, 72.934833°W). Sea Grant College Program, pers.