Rahway River migrations. Fish ladders are inundated structures with small underwater steps that allow fish to navigate around a dam and continue their migration. Other approaches include removing obstructions that are inoperative or no longer serve their purpose, or improving water quality and reducing debris that obstructs passage. The fish targeted for upstream passage at the Rahway River Water Supply Dam are alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), gizzard shad (Dorosoma cepedianum), white perch (Morone Americana) and the endangered American eel (Anguilla rostrate). Alewife and blueback herring are collectively referred to as river herring due to their similarity in appearance, range,
Chaca (genus) Chaca (genus) Chaca is the only genus in the catfish family Chacidae. These fish are commonly known as squarehead catfishes, frogmouth catfishes, or angler catfishes. These unusual fish have a sedentary lifestyle and spend much of their time motionless. The name "Chaca" is because, when removed from the water, they will rapidly repeat the sound "chaca". Only "C. chaca" makes these sounds; the other species do not. The four currently recognized species in this genus are: "Chaca" species are found in fresh water from eastern India to Borneo. "C. chaca" is found in rivers, canals, and ponds of grassland, scrubland,