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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: a cladoceran

Taxonomy: available through www.itis.gov

Identification: This cladoceran has an elongated body and rectangular head. Its swimming antennae do not reach the posterior margin. Antennal setae 4-8/0-1-4. The ventral margin of the valves lacks inflexion, and are armed with several setae and a row of 4–6 spinules between each two setae. One dorsal spine is present near the posterior margin of the valve. The postabdomen has a wide dorsal proximal prominence and three spines on base of claw. Claws are armed with a line of fine denticles (Elías-Gutiérrez et al., 2001).  Care should be taken to distinguish this species from similar natives Diaphanosoma birgei and Diaphanosoma brachyurum.

Size: Length: females 0.78-0.92 mm, males 0.65-0.75 mm (Korovchinsky, 1992)

Native Range: South America, Central America, and the Caribbean

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: This species is parthenogenetic, with offspring developing from unfertilized eggs (López et al. 2008). Diaphanosoma fluviatile feeds predominantly on tiny particles (bacteria and detritus) and algal food consisting mainly of green algae (Oocystis), and likely consumes nanoplanktonic algae as well (Cisneros et al. 1991b). Diaphanosoma fluviatile tended to be present in higher numeric proportions during the peak of the rainy season (June-September) in its native habitat (Cisneros et al. 1991a). Fernandes et al. (2012) report the “time to hatchling” of D. fluviatile as 6 days.

This may be a riverine species which is only occassionally flushed into the open waters of the Great Lakes (Personal Communications Hudson 2019).

Means of Introduction: This species most likely arrived in the Great Lakes from the southern US populations as a hitchhiker with recreational boats, gear, bait or ornamentals. Ballast water is also a major vector of other species of North American Diaphanosoma (birgei and brachyurum) (Gray et al., 2007) which are in the same size range as D. fluviatile (Balcer et al., 1984).

Status: Established in Florida, Louisiana, and Texas, as well as the Great Lakes region (Lake Erie and Lake Michigan).

Impact of Introduction: Several very similar native species are present in the Great Lakes, suggesting limited potential for dramatic ecosystem disturbances, but this species may compete with native zooplankton for resources (Associated Press, 2018).

Remarks: Diaphanosoma fluviatile has been found in The Maumee River and two locations in western Lake Erie in 2015 samples. EPA’s Great Lakes National Program Office and Cornell University recently confirmed the presence of Diaphanosoma fluviatile during routine zooplankton monitoring in the open waters of Lake Erie as part of the GLNPO Long-term Biology Monitoring Program. On May 30, 2018, Cornell University researchers and Dr. Kay VanDamme of Senckenberg Research Institute identified two adult Diaphanosoma fluviatile among other zooplankton in a sample collected in September 2015 from the Maumee River in the western basin of Lake Erie. The Maumee River samples were taken for the purposes of developing a method for detecting exotic and/or rare zooplankton species. On June 25, 2018, Cornell University researchers identified eight adult female Diaphanosoma fluviatile collected in August 2015 from GLNPO monitoring stations in the western basin of Lake Erie. Out of 50 individuals removed for ID out of the Maumee River, all were D. fluviatile. The initial 2 Maumee River D. fluviatile specimens were confirmed by a recognized cladoceran expert (Dr. Kay VanDamme of Senckenberg Research Institute). The finding of a large population in the Maumee River and two small populations in Western Lake Erie confirm that this is an established reproducing population. Ongoing analyses of samples collected in summer 2015 from other stations in the western basin of Lake Erie are being conducted (US Fish and Wildlife, 2018).

References: (click for full references)

Associated Press. 2018. Two new zooplankton species found in Lake Erie. The Pittsburgh Post-Gazette. Created on: August 10, 2018.

Balcer, M. D., N. L.  Korda, and S. I. Dodson. 1984. Zooplankton of the Great Lakes: a guide to the identification and ecology of the common crustacean species. Univ of Wisconsin Press.

Brito, S. L., P. M. Maia-Barbosa, and R. M. Pinto-Coelho. 2011. Zooplankton as an indicator of trophic conditions in two large reservoirs in Brazil. Lakes & Reservoirs: Research and Management 16:253-264.

Cisneros, R., E. I. Mangas, and M. Van Maren. 1991a. Qualitative and quantitative structure, diversity and fluctuations in abundance of zooplankton in Lake Xolotlán (Managua). Hydrobiological Bulletin 25(2):151-156.

Cisneros, R., E. Hooker, and L. E. Velasquez. 1991b. Natural diet of herbivorous zooplankton in Lake Xolotlán (Managua). Hydrobiological Bulletin 25(2):163-167.

Debastiani-Júnior, J. R., L. M. Elmoor-Loureiro, and M. G. Nogueira. 2016. Habitat architecture influencing microcrustaceans composition: a case study on freshwater Cladocera (Crustacea Branchiopoda). Brazilian Journal of Biology 76(1):93-100.

Elías-Gutiérrez, M., N. N. Smirnov, E. Suárez-Morales, and N. Dimas-Flores. 2001. New and little known cladocerans (Crustacea: Anomopoda) from southeastern Mexico. Hydrobiologia 442:41-54. 10

Fernandes, A. P. C., L. S. M. Braghin, J. Nedli, F. Palazzo, F. A. Lansac-Tôha, and C. C. Bonecker. 2012. Passive zooplankton community in different environments of a neotropical floodplain. Acta Scientarium 34(4):413-418.

Korovchinsky, N. M. 1992. Sididae & Holopedidae. Guides to the identification of the microinvertebrates of the continental waters of the world 3. SPB Academic Publishing, The Hague, The Netherlands.

López, C., L. M. Soto, L. Dávalos-Lind, and O. Lind. 2008. Occurrence of Diaphanosoma fluviatile Hansen 1899 (Cladocera: Sisidae) in two reservoirs in central Texas. The Southwestern Naturalist 53(3):412-414.

Panarelli, E. A., A. M. Güntzel, and C. N. Borges. 2013. How does the Taquari River influence in the cladoceran assemblages in three oxbow lakes? Brazilian Journal of Biology 73(4):717-725.

Pecorari, S., S. José de Paggi, and J. C. Paggi. 2006. Assesment [sic] of the urbanization effect on a lake by zooplankton. Water Resources 33(6):677-685.

Sanders, S., C. Castiglione, and M. H. Hoff. 2018. Risk Assessment Mapping Program: RAMP. U.S. Fish and Wildlife Service.

Other Resources:
Great Lakes Waterlife

US Fish and Wildlife Service Ecological Risk Screening Summary for Diaphanosoma fluviatile

Author: Lower, E., Daniel, W.M.

Peer Review Date: 9/6/2019

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.