Evolutionary Pressures
{"Image DocumentName": "Evolutionary Pressures", "Image ImageDescription": "Gas exchange. Water movement over gills. Opercular and pharyngeal muscles pump water in most fishes. Ram ventilation in elasmobranchs and open-ocean bony fish. Gas exchange surfaces. Visceral arches support gills. Gill filaments and pharyngeal lamellae. Countercurrent exchange mechanism. (figure 18.16)", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}