Figure 10 1 A caddis larva Psychoglypha subborialis

Figure 10. 1 A caddis larva, Psychoglypha subborialis, and snail, Vorticifex effusa. The caddis larva is 1 cm long, and the snail is 0. 5 cm long. Both are from Mare’s Egg Spring, Oregon. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 2 Example freshwater cnidarians and structures (AD) and sponges and structures (E and F). Organisms and structures and their approximate lengths are as follows: (A) Hydra, B 5 mm; (B) discharged and undischarged Hydra cnidocysts, the microscopic stinging structures that contain venom; (C) Craspedacusta medusa, B 1 cm; (D) Cordylophora colony, 20 mm; (E) a sponge colony growing on a stick, 20 cm; (F) spicules made of silicon from several species of sponges (about 50 μm each). A and CF reproduced with permission from Thorp and Covich (2001); B original. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 3 Cordylophora individual. Photo by N. Rorem, provided by US Geological Survey.

Figure 10. 4 Lake jellyfish (A) Mastigias, a jellyfish abundant in a saline lake in Palau, and (B) Craspedacusta an invasive freshwater jellyfish. Images from Creative Commons, (A) taken at the Monterey Bay Aquarium and (B) courtesy Alexander Mrkvicka. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 5 Representative rotifers (AE), gastrotrichs (F and G), flatworms (HI), and a nemertean (J), a nematode (K), and a nematomorphan (L). Organisms shown and their approximate lengths are as follows: (A) Gastropus, 0. 3 mm; (B) Kellicottia, 0. 6 mm; (C) Limnias, a tube-building rotifer, B 0. 15 mm; (D) a colony of Sinantherina, colony diameter 2 mm; (E) Epiphanes, 0. 6 mm; (F) Chaetonotus, 0. 4 mm; (G) Stylochaeta, 0. 4 mm; (H) Macrostomum, 2 mm; (I) Girardia (Dugesia), 10 mm; (J) Protostoma with proboscis extended, B 20 mm; (K) a nematode, 1 mm; and (L) a horsehair worm, Nematomorpha, 10 cm. A, B, DH, and KL reproduced with permission from Thorp and Covich (2001) and C and J from Smith (2001). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 6 Change in body form (cyclomorphosis) of the planktonic rotifer Karatella quadratica in successive generations in laboratory culture after Hutchinson (1967). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 7 Some representative mollusks (AF) and annelids (GJ). Organisms shown and their approximate lengths are as follows: (A) a unionid mussel, Quadrula, 7 cm; (B) the Asiatic clam, Corbicula, 3 cm; (C) a zebra mussel, Dreissena on a stick, 3 cm; (D) Pomacea, 4 cm; (E) Planorbella, 3 cm; (F) the freshwater limpet, Ferrissia, 4 cm; (G) Branchiura, 10 cm; (H) Ceratodrilus, 3 mm; (I) Aeolosoma, B 6 mm; and (J) Placobdella, 16 mm. AH and J reproduced with permission from Thorp and Covich (2001). I reproduced with permission of Smith (2001). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 8 Spread of the zebra mussel from 1988 to 2005. Images courtesy

Figure 10. 9 Zebra mussels foul a current meter that has just been removed from a lake. Image courtesy US National Oceanic and Atmospheric Administration. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 10 A red-eye bass (Micropterus coosae) “attacking” the lure of a freshwater mussel (Lampsilis cardium). (A) View of the gravid mantle that serves as a lure. The fish approaches the lure (B). After the fish bites the mantle (C), the glochidia are released in a cloud and the fish rapidly leaves (D). The mussel is about 6 cm long. From Haag and Warren, Jr. (1999). Images courtesy of Wendell R. Haag, U. S. Forest Service. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 11 Pearl shell buttons and a Megalonaias nervosa mussel shell from the Mississippi River that was drilled for buttons. Photograph by J. W. Grubaugh. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 12 Some representative bryozoans and structures (AD), a tardigrade (E), and water mites (FH). Organisms and structures shown and their approximate lengths are as follows: (A) Hyalinella colony, B 2 cm wide; (B) bryozoan statoblast, 1. 4 mm; (C) Urnatella colony, 5 mm; (D) heterotardigrade, 0. 3 mm; (E) generalized adult water mite, 1 mm; (F) generalized larval water mite, 0. 5 mm; A reproduced with permission of Smith (2001). BF reproduced with permission from Thorp and Covich (2001). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 13 Statoblast of Pectinatella magnifica. Courtesy of Wikimedia Commons, photo by Josef

Figure 10. 14 Some representative aquatic insects: (A) a semiaquatic springtail (Collembola), 1 mm; (B) Baetis mayfly nymph (Ephemeroptera), 1 cm; (C) adult Hexagenia mayfly (Ephemeroptera), B 3 cm; (D) a damselfly nymph (Odonata), Calopteryx, 1 cm; (E) a dragonfly nymph, Macromia (Odonata), B 5 cm; (F) an adult dragonfly, Macromia, B 8 cm; (G) a stonefly nymph, Isoperla (Plecoptera), 0. 7 cm; (H) an adult stonefly, Clioperla, B 3 cm; (I) an alderfly larvae, Sialis (Megaloptera), 2 cm; (J) a spongilla fly larvae, Climacia (Neuroptera), 0. 5 cm; (K) an adult backswimmer, Notonecta (Hemiptera), B 2. 5 cm; (L) an adult giant water bug, Lethocerus (Hemiptera), B 7 cm. A, B, and J reproduced with permission from Thorp and Covich (2001). C, E, F, H, and L reproduced with permission from Borror et al. (1989) and D, G, I, and K reproduced with permission of Hilsenhoff (1991). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 15 A dense mayfly hatch from the Mississippi River near La Crosse, Wisconsin indicated by Doppler weather radar. Image courtesy US National Weather Service. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 16 Exarate pupa of an eastern dobsonfly (Corydalus cornutus). Courtesy University of Florida, photo by D. W. Hall. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 17 Some representative aquatic insects (A) a midge larva, Chironomus (Diptera) 0. 5 cm; (B) a syrphid fly larvae, Eristalis (Diptera) with respiratory siphon extended, B 5 cm; (C) a mosquito larvae, Anopheles (Diptera), B 1. 5 cm; (D) a hydropsychid caddisfly larvae, Hydropsyche (Trichoptera), B 2 cm; (E) a caddisfly larva, Polycentropus, 1. 5 cm; (F) an adult caddisfly, Macronemum, B 2. 5 cm; (G) a whirligig beetle larva, Dineutus (Coleoptera), 1 cm; (H) a riffle beetle Stenelmis, 0. 5 cm; and (I) a hydrophilid beetle, Hydrophilus (Coleoptera), B 2. 5 cm. AC, E, and H reproduced with permission from Thorp and Covich (2001). D, F, and I reproduced with permission of Borrer et al. (1998); and G reproduced with permission of Hilsenhoff (1991). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 18 Caddisfly larvae cases illustrating diversity of materials used and form of construction, all about 1 cm long: (A) Philarctus, (B) Clostoeca, (C) Brachycentrus, (D) Helicopsyche, and (E) Platycentropus. Reproduced with permission from Wiggins (1995). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 19 Some representative Crustacea: (A) calanoid copepod and nauplii, adult 0. 5 mm; (B) the parasitic copepod, Lernaea, B 7 mm; (C) cyclopoid copepod and nauplii, adult 0. 5 mm; (D) the cladoceran, Leptodora, 3 mm; (E) Daphnia, 0. 5 mm; and (F) the ostracod, Candona with left valve carapace removed, 0. 5 mm. A and CF reproduced with permission from Thorp and Covich (2001). B reproduced with permission from Food and Agriculture Organization of the United Nations and Kumar (1992). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 20 Cyclomorphosis of adults of the cladoceran Daphnia retrocurva over a season in Bantam Lake, Connecticut, during 1945. Only body shape was traced. From Brooks (1946). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 21 Some representative Crustacea: (A) a cave shrimp, Palaemonias, 2 cm; (B) the isopod, Caecidotea, 2 cm; (C) the crayfish, Cambarus, 10 cm; (D) the opossum shrimp, Mysis, 1 cm; and (E) the amphipod Gammarus, 1 cm. Reproduced with permission from Thorp and Covich (2001). Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 22 Numbers of freshwater species in several phyla. Data from Balian et

Figure 10. 23 Some representative fishes: (A) lamprey, Petromyzon, 60 cm; (B) eel, Anguilla, 1 m; (C) bluegill, Lepomis, 20 cm; (D) bullhead, Ictalurus, 50 cm; (E) paddlefish, Polyodon, 2. 5 m; and (F) alewife, Alosa, 40 cm. Figures from Wikimedia Commons. C and D courtesy of Freshwater and Marine Image Bank, University of Washington. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019

Figure 10. 24 Some representative fishes: (A) walleye, Stizostedion, 90 cm; (B) gar, Lepisosteus, 1. 5 m; (C) sturgeon, Scaphirhynchus, 20 cm; (D) bowfin, Amia, 60 cm; (E) salmon, Salmo, 1 m; and (F) burbot, Lota, 90 cm. Images courtesy of Wikimedia Commons. C US Fish and Wildlife Service Karen Couch. D courtesy of Freshwater and Marine Image Bank, University of Washington. Freshwater Ecology: Concepts and Environmental Applications of Limnology © 2019