Aquatic Insects of Michigan

by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment
University of Michigan

Aquatic Isopoda (Sowbugs) and Amphipoda (Scuds, Side swimmers) of Michigan

Order: Isopoda Latreille, 1817 - Aquatic Sowbugs

ASELLIDAE Rafinesque, 1815

Caecidotea Packard, 1871
Caecidotea forbesi (Williams, 1970) Asellus (orig.) - Williams 1970, 1972
Caecidotea intermedius (Forbes, 1876) Asellus (orig.) - Williams 1970, 1972
Asellus militaris Hay, 1878
Caecidotea racovitzai racovitzai (Williams, 1970) Asellus (orig.) - Williams 1970, 1972
Asellus communis Say, in Racovitza, 1920

Lirceus Rafinesque-Schmaltz, 1820
Lirceus lineatus (Say, 1818) Asellus (orig.)- Williams, 1972
(syn.) Mancasellus danielsi Richardson, 1902
(syn.) Mancasellus tenax (Smith, 1871 as Asellus)

Order: Amphipoda

CRANGONYCTIDAE Bousfield, 1973 (Suborder Gammaridea)

Bactrurus Hay, 1902
Bactrurus mucronatus (Forbes, 1876) Crangonyx (orig.) - Berrien Co., Monroe Co.(Holsinger, 1970, Subterranean Amphipod Database [accessed Nov.27.2012])

Crangonyx Bate, 1859
Crangonyx forbesi (Hubricht and Mackin 1940) Eucrangonyx (orig.) - record from Monroe Co., also found in cave streams and springs from AK to PA and WV (Zhang and Holsinger 2003).
(misid.) Crangonyx gracilis Smith, in Hay, 1882
(syn.) Crangonyx shoemakeri (Hubricht & Mackin, 1943), in part
Crangonyx gracilis Smith, 1871 - Zhang and Holsinger 2003
Crangonyx minor Bousfield 1958 - IL, OH, ON - small streams, sloughs, ditches, drains, springs, and ponds (Zhang and Holsinger 2003)
(syn.) Eucrangonyx shoemakeri (Hubricht & Mackin, 1940), in part
(syn.) Crangonyx shoemakeri (Hubricht & Mackin, 1943), in part
Crangonyx pseudogracilis Bousfield, 1958 - Zhang and Holsinger 2003
(misid.) Crangonyx gracilis Smith, in Hines, 1955
(misid.) Eucrangonyx gracilis (Smith), in Hines, 1951
Crangonyx richmondensis Ellis, 1940 - most widely distributed species of Crangonyx (Zhang and Holsinger 2003)
(syn.) Crangonyx occidentalis Hubricht & Harrison, 1941
(syn.) Crangonyx alpinus Bousfield, 1963
Crangonyx rivularis Bousfield, 1958 - Zhang and Holsinger 2003
Crangonyx setodactylus Bousfield, 1958 - Zhang and Holsinger 2003
(syn.) Crangonyx shoemakeri (Hubricht & Mackin, 1943), in part

GAMMARIDAE Latrielle, 1802 (Suborder Gammaridea)

Echinogammarus Stebbing, 1899
Echinogammarus ischnus (Stebbing, 1899) Gammarus (orig.) - native of the Dnieper River Delta region of the Ukraine, this species was introduced in 1995 to the Detroit River via ballast water release and is becoming a dominant benthic amphipod, competing with native amphipod species (especially Gammarus fasciatus). It is now widespread in the Great Lakes.
(comb.) Chaetogammarus ischnus
(syn.) Gammarus tennulus
(syn.) Gammarus sowinskyi
(syn.) Chaetogammarus tenellus var. behningi morpha sowinskyi

Gammarus Fabricius, 1775
Gammarus fasciatus Say, 1818 - widely distributed through most Michigan; Herdendorf et al. 1986: 166
Gammarus lacustris sensu latu Sars, 1863 - (Holsinger 1972)
Gammarus pseudolimnaeus Bousfield 1958 - (Holsinger 1972)

HYALELLIDAE Bulycheva 1957 (Suborder Gammaridea)

Hyalella Smith, 1874
Hyalella azteca sensu latu (Saussure 1858) - widely distributed through most of Michigan; Herdendorf et al. 1986: 166



PONTOPOREIIDAE Dana, 1853 (Suborder Gammaridea)

Monoporeia
Monoporeia affinis (Lindstrom, 1855) Pontoporeia? (orig.) - Herdendorf et al. 1986: 166

Updates

22-Dec-2017: Removed Gammerus tigrinus Sexton, 1939 from the list. Specimens collected from the Great Lakes that were attributed to this species appear to be misidentifications of G. fasciatus (Gerald Shepard, pers. comm. 2017).

References

Herdendorf CE, Raphael CN, Jaworski E. 1986. The ecology of Lake St. Clair wetlands: a community profile. U.S. Fish and Wildlife Service Biological Report 85 (7.7).
Holsinger JR. 1972. The freshwater amphipod crustaceans (Gammaridae) of North America. Biota of Freshwater Ecosystems, Identification Manual U.S. No. 5 (for the Environmental Protection Agency): xiii + 89 p.
Williams WD. 1972. Freshwater isopods (Asellidae) of North America. Biota of Freshwater Ecosystems, Identification Manual 7, Environmental Protection Agency, Project 18050 ELD: ix + 45 p.
Zhang J, Holsinger JR. 2003. Systematics of the freshwater amphipod genus Crangonyx (Crangonyctidae) in North America. Virginia Museum of Natural History Memoir 6. 274 p.