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NEW YORK SPECIES
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Hand-colored lithograph of
a green crab (Carcinus maenas)
from DeKay 1843
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Due to the paucity of information on the distribution of decapods in the state prior to the 1950s, it is impossible to provide definitive numbers for native species, exotic species, extinct or extirpated species, or the status of each species in specific drainages. It is clear that the decapod fauna of New York was depauperate. DeKay (1844) noted only one species of crayfish in inland waters, Astacus bartonii (= Cambarus bartonii), although his description indicates that he is referring to both C. bartonii and C. robustus. He specifically noted that he had searched for a second species, Astacus affinis (= Orconectes limosus) because it was reported from neighboring states. He failed to find specimens in New York, but he does not provide information on the effort put into the search. Cheney (1896) mentioned that four crayfishes inhabited the state; unfortunately, he did not identify the species beyond common name. His assessment is based on observations, not synoptic survey work. Early surveys by Faxon (1898, 1914) provide little additional information. Changes in taxonomy also add to the confusion. At best, the numbers and the assessment of status provided here are judgements.
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Big river crayfish
(Cambarus robustus)
Photo by Ron Gill
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Five species of crayfish were widely distributed in the state and had few disjunct populations in the 1950s. I argue that these are native species and, despite the fact that DeKay (1844) did not record them, they gained access to the inland waters of the state using natural dispersal mechanisms and routes. These species are Cambarus bartonii, C. robustus, Orconectes limosus, O. obscurus, and O. propinquus (Table 1: List of NYS Decapods). Three other species are restricted geographically and are likely to be native. Cambarus carinirostris is found in the Allegheny River drainage. Gall and Jezerinac (1998) first reported C. diogenes around Buffalo; this species may be a recent migrant into the state or it just simply may have been overlooked in early surveys. The presence of C. diogenes could be the result of an introduction, however. Procambarus acutus was first collected on Long Island and downriver sites along the Hudson River; it was present at these sites early in the twentieth century, but curiously was not collected by DeKay (1844) or Paulmier (1905). It also may be a relatively recent migrant into the state, or overlooked in earlier surveys, or it may be introduced. The conservative approach is to regard these three species as native until additional information suggests otherwise.
Two species have been in the state at least during the entire twentieth century. Orconectes immunis and O. virilis were reported by Faxon (1914) and early museum specimens date to the 1920s. Both species are regarded as native in the Saint Lawrence River system in Ontario (Crocker and Barr 1968) and Wisconsin (Hobbs and Jass 1988). Interestingly, in the 1950s (Crocker 1957), these two species were present in the state in several disjunct populations. Records describing abundance are even rarer that those delimiting range. However, O. immunis was comparatively rare in Oneida Lake in the early years of the twentieth century, whereas O. propinquus was found in abundance throughout the shallows of the lake (Baker 1918). The Saint Lawrence River system populations should be treated as native, but those in the Hudson and Susquehanna river systems may be exotic. Three crayfish species are clearly exotic: O. rusticus was first collected in 1969 (Crocker 1979); O. neglectus in 1997 (Daniels et al. 2000); and P. clarkii appears in museum collections from the 1980s. The introduction of these three species is well documented.
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Hand-colored lithograph of a sevenspine
bay shirmp (Crangon septemspinosa)
from DeKay 1843
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Palaemonetes kadiakensis, the only obligate freshwater shrimp in the state, was collected in the 1930s in Lake Ontario and its tributaries and is still taken in this drainage. This species is likely native. The other shrimp and crab species are essentially marine strays in the Hudson River, although P. pugio, P. vulgaris, Crangon semptemspinosa, Callinectes sapidus, and Rhithropanopeus harrisi are consistently and frequently taken in the river as far upriver as Albany at river km 247. The shrimp and crab species in Table 1 (List of NYS Decapods) are native to the coastal Atlantic Ocean and native to the Hudson River. The exceptions are the green crab, Carcinus maenas, and the Japanese shore crab, Hemigrapsis sanguineus. The green crab was introduced into North America during the nineteenth century (Grosholz and Ruiz 1996) and occurs in the East River and is likely to be found in coastal streams on Long Island and the lower Hudson River. Hemigrapsis sanguineus, which was first discovered on the Atlantic coast in 1988 (Williams and McDermott 1990), has since spread into the Hudson River.
The decapod fauna of New York is not diverse or rich because even the native fauna is relatively new. New York was covered by glaciers until about 10,000 years ago, which has allowed crayfishes relatively little time to disperse into the state naturally from ice age refugia. Although New York’s decapod fauna is considerably less diverse than that of the states of the upper Mississippi River drainage and the mid-Atlantic, it is richer than that of the New England states. Only the Hudson River can be regarded as having a relatively diverse decapod assemblage and that is due to the large number of marine strays and exotic forms (Table 1: List of NYS Decapods). Coastal streams on Long Island and in Westchester County may also have a relatively rich decapod assemblage, but this is also due to the marine strays. The native decapod assemblages in the other inland drainages are low, with fewer than five species (Table 1: List of NYS Decapods).
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