Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Subspecies Caecidotea racovitzai racovitzai

Great Lakes Waterslater - Caecidotea racovitzai - male Great Lakes Waterslater - Caecidotea racovitzai - male Great Lakes Waterslater - Caecidotea racovitzai
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Crustacea (Crustaceans)
Class Malacostraca (Malacostracans)
Superorder Peracarida (Marsupial Crustaceans)
Order Isopoda (Isopods)
Suborder Asellota (Asellotes)
Superfamily Aselloidea (Waterslaters)
Family Asellidae (Common Waterslaters)
Genus Caecidotea
No Taxon (forbesi group)
Species racovitzai (Caecidotea racovitzai)
Subspecies racovitzai (Caecidotea racovitzai racovitzai)
Synonyms and other taxonomic changes
Asellus racovitzai racovitzai Williams, 1970
Explanation of Names
Caecidotea racovitzai racovitzai (Williams, 1970)
Identification
Can be told from C. communis in the field by the male pleopod 1: the last segment is as wide at the tip as the base in communis vs narrower at the tip than at the base in this species. The tip of the male second pleopods' endopod is also different between the two species, with this species having a medial process that is absent in communis. The only other species that looks similar is laticaudus (reported from KY and LA, could reasonably occur over a large area in the interior southeast) which has on average a more rounded tip to the male first pleopod endite and lacks a medial process on the tip of the male second pleopod endopod.(1) Other species that may overlap with racovitai either have ovate pleopod 1 endites, have subquadrate endites with long plumose setae at the tip (simple setae in racovitai) or are cave-adapted. See also C. r. australis (details on seperating them are avaliable on the species page).
The newly described C. burkensis, endemic to Burkes Garden in western Virginia, is for all intents and purposes identical to this species except for some very minute differences in the male pleopod 2 endopod tip and conpsicous adaptations to subterranean life (lack of pigment, longer legs, etc.)(2)
Range
across the northeastern and north-central US and adjacent Canada down to at least Virginia
Habitat
Unlike other species in the genus, Caecidotea r. racovitzai is often abundantly found in deep lakes. It is the dominant species in the Great Lakes, with only one other species being once collected from Lake Huron (C. forbesi) out of the abundant collections from all of the Great Lakes. Otherwise, this species is a habitat generalist.(1)
Remarks
Will probably be split from C. r. australis in the near future(2)
See Also
Caecidotea communis
Works Cited
1.A revision of North American epigean species of Asellus (Crustacea: Isopoda)
W. D. Williams. 1970. Smithsonian Contributions to Zoology.
2.Caecidotea burkensis, new species, a unique subterranean isopod from Burke's Garden, with a synopsis of the biogeography and ...
Salisa L. Lewis, Julian J. Lewis and William Orndorff. 2021. Journal of Cave & Karst Studies.