7601 - Laserfiche WebLink

Home Browse Search

mountain-sucker (Figs. 17 and 18) co-occurring with trouts, and Cahita sucker/mata/ote eahita (Fig. 43) rarely taken at elevations lower than 900 m. In contrast, the Opata sucker/mata/ote Opata (Fig. 44) lives generally below 900 m in warm, shallow, sand- bottom desert streams of the Rio Sonora immediately west of the Rio Yaqui basin. Nothing is known of the food or spawning habits of any of the last four species. As with the suckers, the ecologies of Mexican chubs are remarkably little known despite their widespread distributions and abundance. The Rio Yaqui supports four kinds, roundtail chub/ehara/ito a/eta redonda, Yaqui chub/ehara/ito Yaqui, Desert chub/ehara/ito de/ desierto, and an undescribed species, the first of which is shared with the Figure 43. Cahita sucker/matalote cahita, 16.0 cm in total length, from the Rio Papigochic, Chihuahua. Little is known of this species of stream-dwelling sucker, which was not described until the 1980s. It is considered threatened. Figure 44. Opata sucker/matalote Opata, 15.0 cm in total length, from "Miller's Canyon," headwaters of the Rio Sonora, Sonora. It remains locally common, but the Rio Sonora is rapidly being developed for water supply and the fish is considered of special concern. Colorado system. Gila chub/ehara/ito de/ Gila is found only in the lower Colorado basin, and another species, the Sonoran chub/ehara/ito sonorense, is restricted to the small Rio Concepcion basin, a small drainage sandwiched with the Rio Sonora between the Yaqui and Colorado systems. Roundtail chubs (Fig. 45) are highly variable in size, with some populations achieving only 15 cm as adults and others ranging to almost 65 cm. The species inhabits pools and eddies below riffles, and often occupies quiet waters beneath cut banks or near boulders adjacent to swifter currents. Roundtail are variable in food habits, sometimes feeding on algae and other times becoming piscivorous or even eating terrestrial animals such as lizards that fall into the water. They breed in spring and early summer in 22