The Sonora Sucker, Catostomus insignis, is a medium-sized catostomid fish with 16 other species in the genus scattered throughout North America. This species is remarkably similar in appearance to the Yaqui Sucker.
Description
Sonora suckers have a fusiform body, with large heads and chubby figures. They have generally large lower lips, with no fleshy lobes. Sonora suckers have unique square dorsal fins, and relatively large scales. Their coloration is distinctly bi-colored, with a yellow underside and brownish dorsal side. Each scale has discrete outlines to form a definite spot. Adults can reach a length of 80 cm, and can weigh to about 2 kg.
The Sonora sucker can live in an array of habitats, varying from trout streams to warm water rivers. However, these fish prefer rocky, relatively deep, and quiet waters. During daylight, adult Sonora suckers tend to take cover and stay in the shade.
Diet
The Sonora sucker's main diet consists of tiny crustaceans, protozoans, and macroinvertebrates. Adult fish are omnivorous, and feed in the early morning and late evening.
Reproduction
Two males usually follow a female Sonora sucker during breeding season. Females lay their eggs in riffles, or a patch of waves or ripples, and are incubated in the spaces between gravel. Females tend to deposit eggs in smaller streams, while few spawn in lakes. Spawning starts late in the winter and goes on until midsummer.
Biology
Sonora suckers are often described as a very sedentary species even during rough seasonal changes and major floods. However, due to a high level of predation by the flathead catfish in the Salt River Canyon, Sonora suckers are almost completely absent in the area.
Conservation
Construction of reservoirs has greatly depleted the available habitat for the Sonora sucker. Excessive sand deposition in streams caused by watershed erosion has also affected the sucker's habitat. Two Arizona Game and Fish Departments have taken protective measures by undergoing studies that document the current population dynamics of the fish in two central Arizona rivers. The studies are used to increase awareness of the fish in the area and develop management plans.
