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<br />The systematic status of this varied form and of <br />the flannelmouth are under study and our findings <br />will appear elsewhere. <br /> <br />Reproductive data were recorded for the blue- <br />head sucker at a number of tributaries. Spawn- <br />ing was observed a number of times. The longest <br />periods of observations were made at Shinumo, <br />Kanab and Havasu creeks. Numerous ripe specimens <br />were collected at the mouth of the Paria River but <br />the water was always turbid which prevented direct <br />observations. <br /> <br />Several ripe male bluehead suckers were collec- <br />ted from Crystal Creek on April 2B, 1975. These <br />ripe individuals were taken from the mixing zone <br />of the creek and the Colorado River where the <br />water temperature at time of capture was 150-170C. <br />Upstream in the creek the temperature was 220C <br />and the Colorado River was 11oC. A slight pink <br />colored band appeared on the sides of the ripe <br />males after they were in preservative for several <br />hours. Crystal Creek was revisited on June 6, <br />1975. One small group (one female and four males) <br />was observed spawning in a small plunge pool area <br />about a mile upstream from the mouth. Four adults <br />(spent) were found dead along the stream between <br />the mouth and the spawning site at the plunge pool. <br />Three were preserved and one was discarded because <br />it was rotten. The water temperature at the site <br />of spawning was 220C. <br /> <br />Many groups of spawning bluehead sucker were <br />observed in Kanab Creek on May 1, 1975. Spawning <br />was observed in a section of stream several hun- <br />dred meters above the mouth of the creek. Spawn- <br />ing occurred in the deep plunge pools and in deep <br />raceways. Usually several males were associated <br />with each female. The pink lateral band was not <br />pronounced on any of the spawning individuals. <br />The water temperature at the site of spawning was <br />160C. The Colorado River was 10.50C. <br /> <br />No adults were seen or collected during a visit <br />to Kanab Creek on June 9, 1975. Only small young <br />and juvenile bluehead suckers were taken. Also, <br />on June 6, 1976 only small young and juvenile <br />specimens were collected. <br /> <br />Ripe males of the bluehead sucker were collec- <br />ted from the Paria River on May 2, 1976. A light <br />pinkish band was developed on the sides. The <br />Paria ranged in temperature from 220C to 240C in <br />the area where the ripe suckers were taken. Sev- <br />eral ripe males and one "running" ripe female were <br />collected from the Pari a River on May 4, 1976. <br />The female was robust which indicated that spawn- <br />ing had just begun. The water temperature was <br />140C at site of collection. <br /> <br />On May 2, 1975 several ripe male bluehead suck- <br />ers were obtained from the mixing zone at the <br />mouth of Havasu Creek. A moderately developed <br />pink band was present on one specimen. The tem- <br />perature at the mixing zone was 120C. After col- <br />lecting at the mouth the senior author climbed <br />up on an overhanging ledge to make observations. <br />Shortly after getting to the observation place a <br />group of four bluehead suckers was observed going <br />through spawning movements in the deep part of the <br />lower creek pool which was "crystal" clear. Soon <br />after a pair was sighted which moved over a mixed <br />gravel and sand area at the tail end of the deep <br />pool where it was about a half meter deep. The <br />pair spawned four times within 10 minutes. The <br />vibration or quivering of bodies during spawning <br />was clearly visible. <br /> <br />Spawning of the bluehead sucker was observed on <br />May 24, 1973 in Havasu Creek. Spawning was ob- <br />served for nearly half an hour before we decided <br />to collect a series of specimens. The spawning <br /> <br />activity occurred in a pool about a hundred meters <br />up from the mouth of the creek. The spawning <br />groups were composed of one female and two to <br />five males. Most of the spawning occurred over <br />gravel and rubble, around bases of large boulders <br />where the depth was about one meter. The ripe <br />males had an orange-pink stripe above a black lat- <br />eral band. Beneath the dark lateral band the <br />lower side and belly were white. Silver flecks <br />were visible on the dorsal and lateral aspects of <br />the peduncle. These flecks seemed to flash as the <br />fish twisted and turned. <br /> <br />A single ripe male was taken from the Colorado <br />River at the mouth of Royal Arch Creek on May 23, <br />1973. This male had a broad light pink lateral <br />band. An adult female was taken at the same time <br />but was not ripe. The temperature in the river <br />was 10oC. Later in the day several ripe male blue- <br />head suckers were collected from the Colorado <br />River at the mouth of Deer Creek. The water was <br />a little over a meter in depth where the collec- <br />tion was obtained and was 10.50C at the time of <br />collection. We presume that our presence in each <br />of the areas scared the fish out of the warmer, <br />clear tributary water into the turbid river where <br />we caught them. <br /> <br />Shinumo Creek flowing from the north rim is one <br />of the colder tributaries in the Grand Canyon area. <br />The temperature was 90C on April 29, 1975 while <br />the Colorado River at the mouth of the Shinumo <br />Creek was 11.50C. Nine adult bluehead suckers <br />were collected from the creek but none was in nup- <br />tial condition. On June 7, 1975 and June 4, 1976 <br />many spawning groups were observed. Actually <br />hundreds of individuals were observed in the few <br />meters between the river and the falls. The water <br />temperature in Shinumo Creek was 170C on June 7, <br />1975 and 230C on June 4, 1976. There were various <br />color patterns however most individuals displayed <br />a pink stripe above a dark lateral band. We found <br />no evidence of spawning of the bluehead sucker <br />later than the middle of June, however, sporadic <br />spawning may take place throughout the summer in <br />the Paria River area where there is a compara- <br />tively large mixing zone of Paria and Colorado <br />river waters. <br /> <br />As stated above spawning of blue head suckers <br />was observed in Kanab Creek on May 1, 1975. The <br />seven young collected on June 9, 1975 from Kanab <br />Creek ranged in standard length from 16.0 to 19.7 <br />mm with an average standard length of 17.9 mm. <br /> <br />The speckled dace, Rhinichthys osculus, is the <br />only species of the four native fishes that occurs <br />naturally outside of the Colorado River system. <br />It is widespread over the Great Basin area and <br />there are numerous subpopulations recognized. <br />The speckled dace was found in the main stream <br />of the Colorado River in the Grand Canyon area <br />(River Mile 0 down to River Mile 246) as well as <br />in most of the tributaries. A variety of color <br />patterns was found in the main river and the vari- <br />ous tributaries. Although most specimens can be <br />placed into either the "bandedu~or "unicolored" <br />categories (Minckley 1973:130) some have inter- <br />mediate patterns. Figure 2, lower, represents a <br />unicolored specimen which was taken from the <br />Colorado River at mouth of Royal Arch Creek, <br />River Mile 116.5. <br /> <br />The speckled dace was taken from a number of <br />very small tributaries from which neither the <br />flannelmouth sucker, Catostomus latipinnis, nor <br />the bluehead sucker, pantosteus discobolus, was <br />taken. These small tributaries are Hermit Creek <br />(River Mile 95), Boucher Creek (River Mile 96.5), <br />Blacktail Canyon Creek (Mile 120), Stone Creek <br />(Mile 132) and Travertine Creek (Mile 229). <br />Blacktail Canyon Creek and Stone Creek enter the <br /> <br />602 <br />