Flannelmouth Sucker Research Articles

Spawning ecology of flannelmouth sucker, Catostomus lattipinnis (Catostomidae), in two small tributaries of the lower Colorado River

We report the first published accounts of spawning behavior and spawning site selection of the flannelmouth sucker in two small tributaries of the lower Colorado River in the Grand Canyon, Arizona. Spawning was observed on 20 March 1992 and from 28 March to 10 April 1993 in the Paria River, and from 16 to 19 March 1993 in Bright Angel Creek. Flannelmouth suckers exhibited promiscuous spawning behavior–individual females were typically paired with two or more males for a given event and sometimes changed partners between events. Multiple egg deposits by different females sometimes occurred at one spawning site. Flannelmouth sucker selected substrates from 16 to 32 mm diameter in both streams. Spawning occurred at depths of 10 to 25 cm in the Paria River and 19 to 41 cm in Bright Angel Creek. Mean column water velocities at spawning locations ranged from 0.15 to 1.0 m sec-1 in the Paria River and from 0.23 to 0.89 m sec-1 in Bright Angel Creek. Water temperatures recorded during spawning ranged from 9 to 18° C in the Paria River and 13 to 15° C in Bright Angel Creek. Spawning flannelmouth sucker ascended 9.8 km upstream in the Paria River and 1.25 km in Bright Angel Creek. Spawning females (410–580 mm) were significantly larger than spawning males (385–530 mm) in the Paria River. The mean size of spawning fish in the Paria River was significantly smaller than the entire stock, averaged throughout the study period (380–620 mm). However, fish spawning in 1992–1993 averaged 53 mm larger than fish spawning in the same reach of the Paria River in 1981, indicating a shift in the size structure of this stock.

Hazard Evaluation of Inorganics, Singly and in Mixtures, to Flannelmouth SuckerCatostomus latipinnisin the San Juan River, New Mexico

Larval flannelmouth sucker (Catostomus latipinnis) were exposed to arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc singly, and to five mixtures of five to nine inorganics. The exposures were conducted in reconstituted water representative of the San Juan River near Shiprock, New Mexico. The mixtures simulated environmental ratios reported for sites along the San Juan River (San Juan River backwater, Fruitland marsh, Hogback East Drain, Mancos River, and McElmo Creek). The rank order of the individual inorganics, from most to least toxic, was: copper > zinc > vanadium > selenite > selenate > arsenate > uranium > boron > molybdenum. All five mixtures exhibited additive toxicity to flannelmouth sucker. In a limited number of tests, 44-day-old and 13-day-old larvae exhibited no difference in sensitivity to three mixtures. Copper was the major toxic component in four mixtures (San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek), whereas zinc was the major toxic component in the Fruitland marsh mixture, which did not contain copper. The Hogback East Drain was the most toxic mixture tested. Comparison of 96-h LC50values with reported environmental water concentrations from the San Juan River revealed low hazard ratios for arsenic, boron, molybdenum, selenate, selenite, uranium, and vanadium, moderate hazard ratios for zinc and the Fruitland marsh mixture, and high hazard ratios for copper at three sites and four environmental mixtures representing a San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek. The high hazard ratios suggest that inorganic contaminants could adversely affect larval flannelmouth sucker in the San Juan River at four sites receiving elevated inorganics.

Spatial and temporal variation of fish communities in secondary channels of the San Juan River, New Mexico and Utah

Spatial and temporal variation of fish communities in four secondary channels of the San Juan River between Shiprock, NM and Bluff, UT were investigated from July 1993 through November 1994. Fish abundance and habitat availability data were collected to determine if physical attributes of sites influenced spatial and temporal variation in their fish communities. Stability of habitat was shown to positively influence the stability of the fish community. Analysis of variance revealed greater spatial than temporal variation in the abundance of red shiner, Cyprinella lutrensis, fathead minnow, Pimephales promelas, and flannelmouth sucker Catostomus latipinnis, while speckled dace, Rhinichthys osculus showed greater temporal variation. Ordination, using detrended correspondence analysis, revealed variation in fish communities by site, date, and sample year. Spatial variation was greatest during low-flow periods when the greatest differences in habitat among the four sites occurred. Spring runoff had the greatest temporal effect on the fish communities in secondary channels and appeared to ‘reset’ the communities by displacing those species that were less resistant to increased current velocities. This annual event may help maintain native fish species adapted to these conditions in the San Juan River while moderating the abundance of nonnative fish species.

Selenium concentrations in the razorback sucker (Xyrauchen texanus): Substitution of non-lethal muscle plugs for muscle tissue in contaminant assessment

A single muscle plug was collected from each of 25 live razorback suckers inhabiting the Colorado River basin and analyzed for selenium by instrumental neutron activation. Eight fish from Ashley Creek and three from Razorback Bar exhibited selenium concentrations exceeding 8 μg/g, a level associated with reproductive failure in fish. Concentrations of selenium in eggs and milt were significantly correlated with selenium concentrations in muscle plugs and together indicate a possible explanation for the decline of this species in the Colorado River basin. Muscle plugs (<50mg) and muscle tissue (20 g) were collected from dorsal, anterior, and posterior areas of common carp, flannelmouth sucker, and an archived razorback sucker and analyzed for selenium. Concentrations of selenium in muscle plugs were significantly correlated with selenium concentrations in muscle tissue from the same location and fish (r=0.97). Coefficients of variation for selenium concentrations in each fish were <6.5% for muscle tissue, but ranged from 1.5 to 32.4% for muscle plugs. Increased variation in muscle plugs was attributed to lower selenium concentrations found in the anterior muscle plugs of flannelmouth suckers. Mean selenium concentrations in muscle plugs and tissue from dorsal and posterior areas and muscle tissue from the anterior area were not significantly different. The non-lethal collection of a muscle plug from dorsal and posterior areas of the razorback sucker and other fish species may provide an accurate assessment of selenium concentrations that exist in adjacent muscle tissue.

Impact of Mainstream Impoundment on the Distribution and Movements of the Resident Flannelmouth Sucker (Catostomidae: Catostomus latipinnis) Population in the White River, Colorado

Impact of Mainstream Impoundment on the Distribution and Movements of the Resident Flannelmouth Sucker (Catostomidae: Catostomus latipinnis) Population in the White River, Colorado

Description and Identification of Razorback, Flannelmouth, White, Utah, Bluehead, and Mountain Sucker Larvae and Early Juveniles

Description and Identification of Razorback, Flannelmouth, White, Utah, Bluehead, and Mountain Sucker Larvae and Early Juveniles

Behavioral Interactions between Young Colorado Squawfish and Six Fish Species

We evaluated patterns of space use, activity, and agonistic interactions between young Ptychocheilus lucius, an endangered cyprinid, and similar-size individuals of native and non-native fishes (i.e., Catostomus latipinnis, Notropis lutrensis, Richardsonius balteatus, Pimephales promelas, Lepomis cyanellus, and Ameiurus melas), which co-occur in shoreline riverine habitats. Vertical distribution of P. lucius was most similar to that of L. cyanellus and R. balteatus. We detected no overt shifts in vertical space use by P. lucius due to the presence of non-native fishes. Lepomis cyanellus, N. lutrensis, and Pimephales promelas initiated more interspecific aggression than Ptychocheilus lucius. Agonistic behavior in P. lucius and C. latipinnis was mostly intraspecific. Richardsonius balteatus and P. lucius were the most active and widely ranging species, but only N. lutrensis, Pimephales promelas, and C. latipinnis significantly increased their activity during feedings. Predation by Ptychocheilus lucius on live fish was slower than that of L. cyanellus, N. lutrensis, and R. balteatus. Overt physical damage was infrequent, however, the aggressive nature of the non-natives, in concert with similar activity schedules, space use patterns, and shared habitat use, suggests that L. cyanellus, N. lutrensis, and Pimephales promelas may adversely affect growth and survival of age-0 Ptychocheilus lucius. THE native fish fauna of the Colorado River

Food Partitioning among Fishes of the Virgin River

Food partitioning of one introduced and six native fishes was investigated from two different sites in the Virgin River. Replicate benthic samples from riffle areas indicated that chironomid and simuliid larvae composed the major food base available to fishes. Relativized electivity values suggest that chironomid larvae were nearly always selected over simuliid larvae by all species. Stomach analysis revealed seasonal interand intra-specific differences in diets. Desert and flannelmouth suckers fed on a mixture of sediment, detritus, filamentous algae and invertebrates. Roundtail chubs consumed largely Spirogyra, Cladophora and diatoms. Woundfin and spinedace were omnivorous, consuming an array of benthic and drift animals and plant matter. Speckled dace and red shiners were insectivorous, consuming large numbers of small dipterans. Food overlap among native fishes was uncommon, occurring in a biologically meaningful way on only four (7%) of the 55 possible occasions. Biologically meaningful food overlap (>0.60) between the exotic red shiner and native fishes occurred on four (25%) of the 16 possible occasions.

Population Differentiation and Introgressive Hybridization of the Flannelmouth Sucker and of Hatchery and Native Stocks of the Razorback Sucker

Introgressive hybridization has important management and evolutionary consequences in regard to the maintenance of the integrity of gene pools and the acquisition of new alleles by means other than mutation. Among North American cypriniform fishes, hybridization often occurs between historically allopatric forms placed into sympatry via human activities and between sympatric forms inhabiting a modified environment. In the Colorado River system, several native catostomids are known to hybridize, including flannelmouth sucker Catostomus latipinnis and razorback sucker Xyrauchen texanus. Allozymic data enabled direct quantification of presumed introgression which was in the range of 0–5% toward flannelmouth sucker and 0–3% toward razorback sucker. Levels of presumably introgressed genes in the stock of razorback sucker from the Dexter Fish Hatchery were as low as or lower than those of the parental stock population from Lake Mohave.

Drift of Larval Fishes in the Upper Colorado River

ABSTRACT Native as well as some non-native fishes in the upper Colorado River were found drifting during their larval and early juvenile stages of development. Five native fishes (flannelmouth sucker, bluehead sucker, roundtail chub, speckled dace, and mottled sculpin) dominated the drift with about 87 percent of the catch. The only 3 non-native species found in the drift (white sucker, fathead minnow, and green sunfish) occurred in very low numbers. Significantly greater numbers of drifting fishes were found along the shoreline than in the midchannel surface zone. Larval fish were first caught in the drift when the water temperature reached 16°C during a rapid warming trend in mid-to-late July. About 65 percent of the drift recorded in the two studies occurred during a two to three week period when water temperatures ranged from 18 to 21°C, during the descending limb of spring runoff. A diel pattern in drift densities was seen at both sites, with highest numbers of larvae caught between 2000 and 0400 hours, and lowest numbers between 1600 and 2000 hours. This diel pattern suggests that many of the larval fishes of the Colorado River are photosensitive, and actively capable of entering and escaping the surface drift currents.

Distribution of Fishes in the White River, Utah

ABSTRACr.-A survey of the White River, Utah, was made during the summer of 1978 and 1979 to determine the abundance and distribution of endemic fishes during and after spring runoff. The fish population was similar to that in other eastern Utah streams. Red shiners (Notropis lutrensis) were most abundant, followed, in order, by roundtail chubs (Gila robusta), flannelmouth suckers (Catostomus latipinnis), speckled dace (Rhinichthys osculus), fathead minnows (Pimephales promelas), carp (Cyprinus carpio), and channel catfish (Ictalurus punctatus). Bluehead suckers (Catostomus discobolus), black bullheads (Ictalurus melas), green sunfish (Lepomis cyanellus), brown trout (Salmo trutta), and Colorado squawfish (Ptychocheilus lucius) individually comprised less than 0.5% of the total number of fish. Native fishes dominated the fish fauna at upstream stations; introduced fishes dominated at downstream stations. A total of 15 adult Colorado squawfish, an endangered fish, was captured or observed.

Distribution of Fishes in the San Rafael River System of the Upper Colorado River Basin

The San Rafael River and lower reaches of four major tributaries, Cottonwood, Huntington, Ferron, and Rock Canyon creeks, were sampled for fish and water quality in March-April, June, and October, 1977. Native species of fish included speckled dace (Rhinichthys osculus), flannelmouth suckers (Cato- stomus latipinnis), bluehead suckers (C. discobolus), and roundtail chubs (Gila robusta). Red shiners (Notropis lutrensis), fathead minnows (Pimephales prom- elas), black bullheads (Ictalurus melas), and channel catfish (I. punctatus) were recorded introduced species. A single young-of-the-year Colorado squawfish (Ptychocheilus lucius) was caught in the lower San Rafael River in October. This is the first documented record of Colorado squawfish in the San Rafael River. Native fish were dominant at seven stations in the tributary streams and middle section of the San Rafael River and introduced fish dominated the fauna near the mouth of the river.

Distribution and Abundance of Mainstream Fishes of the Middle and Upper Colorado River Basins, 1967-1973

Twenty-nine species of fishes were collected in the middle and upper Colorado River basins in 1967-1973. The native suckers, Catostomus latipinnis and C. discobolus, were the dominant species in the study area. Introduced species outnumbered native species 19 to 10. The introduced Ictalurus punctatus and Notropis lutrensis were abundant throughout most of the upper basin. The abundance of introduced species has increased steadily since 1900 as has the introductions of new species. Four endemic species, Ptychocheilus lucius, Gila elegans, Gila cypha, and Xyrauchen texanus, are considered endangered. These rare forms reproduce in the lower Yampa River, Desolation Canyon of middle Green River, and the lower Green River in Canyon-lands National Park. The major reasons for the decline of native fishes are considered to be alterations of habitat by high dams and introductions of exotic species.