- Scientific name: Faxonius quinebaugensis
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
Description
The Quinebaug River crayfish was recently described from the Quinebaug River as possible endemic native crayfish species to southern New England (Mathews et al. 2008, Mathews and Warren 2008). Individuals are brown to olive green with paired brown spots on abdominal segments. In larger individuals, chelae (claws) are blue with orange-yellow tips and tubercles. The rostrum (a projection between the eyes) is concave with no median carina (ridge) and has a distinctly pointed acumen. Males and females are distinguished by the presence in males of highly modified pleopods (abdominal appendages) on the first two abdominal segments. The pleopods are unmodified in females. The tips of the first pair of pleopods or gonopods in reproductive males (form 1 males) are divergent.
This species is closely related and morphologically similar to the nonnative and invasive virile crayfish (Faxonius virilis). Definite identification requires examination of form 1 male gonopods (reproductive males) where the central projection and mesial process are strongly recurved, unlike virile crayfish. See Mathews and Warren (2008) for detailed description and illustration of defining morphological features.
Life cycle and behavior
Little is known of the life cycle of Quinebaug River crayfish. Mature females are holding eggs in April and May with juveniles present in summer months. Juveniles grow through the summer and undergo several molts. Reproductive males are present from August to December (Mathews and Warren 2008) with breeding occurring in October to January. Form 2 males (non-reproductive) are present during summer months (Warren et al. 2009). Not all fully grown males can engage in sexual activity at a specific time because males of all species in the family Cambaridae undergo cyclic changes in the reproductive morphology. During the inactive phase, the sexual organs of the male are reduced and become non-functional.
Distribution and abundance
The Quinebaug River crayfish may be endemic to southern New England and has only been recorded in Massachusetts since its description (Mathews and Warren 2008). The species has been mostly found in watersheds east of the Connecticut River including the Quinebaug, Swift, Ware, Millers and Blackstone River watersheds (Mathews et al. 2008).
The status of the Quinebaug River crayfish is uncertain. Recent effort has documented possible introgressive hybridization between F. quinebaugensis and its closely related invasive sister species F. virilis in the Blackstone River watershed (Buchenan et al. 2012). Hybridization in other watersheds remains uncertain.
Habitat
This species inhabits small to medium sized streams and shallow ponds. Substrates range from silt and mud to gravel and cobble (Mathews and Warren 2008).
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Low gradient, moderate-sized stream habitat for Quinebaug River crayfish
Threats
Threats to Quinebaug River crayfish include invasive crayfish species (F. virilis, Procambarus clarkii) via competition and hybridization, chemical pollutants, accelerated eutrophication, road salts, channelization, and habitat fragmentation by dams.
Conservation
Survey and monitoring
Standardized surveys are needed to determine the status of this species in Massachusetts. Efforts should target waterbodies in the Ware, Quaboag, Swift, Millers, Blackstone, and Quinebaug watersheds.
Management
Preventing the introduction and spread of invasive crayfish and protecting historical stream habitat is critical for this species. Controls over invasive species vectors including live fish bait shops, improper storage and disposal in educational environments (i.e., school classrooms), and the pet trade, should be put into place for Massachusetts. Preservation of riparian forests, restoration of channelized stream reaches, dam removal (in some cases), and reduction of chemical runoff from roads and industrial discharge will benefit this species.
Research needs
Baseline distribution and trend data does not exist for this species. Standardized surveys should target occupied but also new streams to better understand its distribution and population status in Massachusetts. Further, surveys are needed to understand the distribution of non-native and potentially invasive crayfish species that co-occur with Quinebaug River crayfish including F. virilis. Population-level genetics will also help to determine the level of hybridization with nonnative F. virilis. Data can inform species risk assessments.
References
Buchenan, A., H. Dutia, and E. Scott-Solomon. 2012. Introgressive hybridization between Orconectes quinebaugensis and Orconectes virilis in the Blackstone River Valley. Worcester Polytechnic Institute, Major Thesis, 72 pp.
Mathews, L.M., L. Adams, E. Anderson, M. Basile, E. Gottardi, M.A. Buckholt. 2008. Genetic and morphological evidence for substantial hidden biodiversity in a freshwater crayfish species complex. Molecular Phylogenetics and Evolution 48:126-135.
Mathews, L.M., and A.H. Warren. 2008. A new crayfish of the genus Orconectes Cope, 1872 from southern New England (Crustacea: Decapoda: Cambaridae). Proceedings of the Biological Society of Washington 121(3):374-381.
Warren, A.H., L. Saltzman, M. A. Buckholt, and L.M. Mathews. 2009. Agonistic interactions differ by sex and season in the crayfish Orconectes quinebaugensis. Journal of Crustacean Biology 29(4):484-490.
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| Date published: | April 10, 2025 |
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