taxonID	type	format	identifier	references	title	description	created	creator	contributor	publisher	audience	source	license	rightsHolder	datasetID
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424204	https://doi.org/10.3897/zse.101.161784.figure2	Figure 2. Habitus images of Gammarus fasciatus, A. Topotype male (USNM 1694137), 13.12 mm, Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA; B. Topotype female (USNM 1694138), 5.91 mm, Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. Scale bar: 1 mm.	Figure 2. Habitus images of Gammarus fasciatus, A. Topotype male (USNM 1694137), 13.12 mm, Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA; B. Topotype female (USNM 1694138), 5.91 mm, Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. Scale bar: 1 mm.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424205	https://doi.org/10.3897/zse.101.161784.figure3	Figure 3. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Antenna 1 (aesthetasc enlarged); B. Antenna 2; C. Left mandible; D. Right mandible (palp omitted, lacinia mobilis enlarged). Scale bars: 0.25 mm (A, B), 0.1 mm (C, D).	Figure 3. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Antenna 1 (aesthetasc enlarged); B. Antenna 2; C. Left mandible; D. Right mandible (palp omitted, lacinia mobilis enlarged). Scale bars: 0.25 mm (A, B), 0.1 mm (C, D).	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424206	https://doi.org/10.3897/zse.101.161784.figure4	Figure 4. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Upper lip; B. Lower lip; C. Maxilla 1, left (outer plate apical serrate setae enlarged); D. Maxilla 1, right palp; E. Maxilla 2; F. Maxilliped (apical margin of inner plate enlarged). Scale bars: 0.1 mm.	Figure 4. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Upper lip; B. Lower lip; C. Maxilla 1, left (outer plate apical serrate setae enlarged); D. Maxilla 1, right palp; E. Maxilla 2; F. Maxilliped (apical margin of inner plate enlarged). Scale bars: 0.1 mm.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424207	https://doi.org/10.3897/zse.101.161784.figure5	Figure 5. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Gnathopod 1 (palmar margin and dactylus enlarged); B. Gnathopod 2 (palmar margin and dactylus enlarged; C. Pereopod 3. Scale bar: 0.25 mm.	Figure 5. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Gnathopod 1 (palmar margin and dactylus enlarged); B. Gnathopod 2 (palmar margin and dactylus enlarged; C. Pereopod 3. Scale bar: 0.25 mm.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424208	https://doi.org/10.3897/zse.101.161784.figure6	Figure 6. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Pereopod 4; B. Pereopod 5; C. Pereopod 6; D. Pereopod 7; E. Pleopod 1 (coupling spines enlarged); F. Pleopod 2 (coupling spines enlarged, rami omitted); G. Pleopod 3 (coupling spines enlarged, rami omitted). Scale bar: 0.25 mm.	Figure 6. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Pereopod 4; B. Pereopod 5; C. Pereopod 6; D. Pereopod 7; E. Pleopod 1 (coupling spines enlarged); F. Pleopod 2 (coupling spines enlarged, rami omitted); G. Pleopod 3 (coupling spines enlarged, rami omitted). Scale bar: 0.25 mm.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424209	https://doi.org/10.3897/zse.101.161784.figure7	Figure 7. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Epimera; B. Uronites; C. Uropod 1; D. Uropod 2; E. Uropod 3; F. Telson. Scale bars: 0.25 mm.	Figure 7. Gammarus fasciatus topotype male, 13.12 mm (USNM 1694137), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Epimera; B. Uronites; C. Uropod 1; D. Uropod 2; E. Uropod 3; F. Telson. Scale bars: 0.25 mm.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424210	https://doi.org/10.3897/zse.101.161784.figure8	Figure 8. Gammarus fasciatus topotype female, 5.91 mm (USNM 1694138), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Gnathopod 1 (palmar margin and dactylus enlarged); B. Pereopod 7; C. Uropod 3. Scale bars: 0.25 mm.	Figure 8. Gammarus fasciatus topotype female, 5.91 mm (USNM 1694138), Schuylkill River at Flat Rock Park, Montgomery County, Pennsylvania, USA. A. Gnathopod 1 (palmar margin and dactylus enlarged); B. Pereopod 7; C. Uropod 3. Scale bars: 0.25 mm.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424211	https://doi.org/10.3897/zse.101.161784.figure9	Figure 9. Principal component analysis (PCA) scatterplot based on 19 morphological variables collected from populations of G. fasciatus sens. lat. Principal component 1 (Epimera 2 ventral setae) and principal component 2 (Antenna 2 peduncular segment 4 posterior setae) explain 58 % and 21 % of variation, respectively. Asterisks indicate populations not conspecific with G. fasciatus sens. str. Convex hulls indicate individuals from the same population; convex hull shades vary to provide contrast for overlapping populations.	Figure 9. Principal component analysis (PCA) scatterplot based on 19 morphological variables collected from populations of G. fasciatus sens. lat. Principal component 1 (Epimera 2 ventral setae) and principal component 2 (Antenna 2 peduncular segment 4 posterior setae) explain 58 % and 21 % of variation, respectively. Asterisks indicate populations not conspecific with G. fasciatus sens. str. Convex hulls indicate individuals from the same population; convex hull shades vary to provide contrast for overlapping populations.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
656A57E9E6305F3A95910FF3C8AD8E19.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://binary.pensoft.net/fig/1424203	https://doi.org/10.3897/zse.101.161784.figure1	Figure 1. Recorded distribution of Gammarus fasciatus sens. lat., including introduced regions in the Laurentian Great Lakes and Mississippi River basins, and records currently identified as G. fasciatus from the southern United States, which may represent cryptic or pseudocryptic species. Distributional data presented here were collected from a variety of sources, including personal collections, museum records, literature searches, and iNaturalist observations.	Figure 1. Recorded distribution of Gammarus fasciatus sens. lat., including introduced regions in the Laurentian Great Lakes and Mississippi River basins, and records currently identified as G. fasciatus from the southern United States, which may represent cryptic or pseudocryptic species. Distributional data presented here were collected from a variety of sources, including personal collections, museum records, literature searches, and iNaturalist observations.	2025-09-25	Cannizzaro, Andrew G.;Berg, David J.		Zenodo	biologists	Cannizzaro, Andrew G.;Berg, David J.			
