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3 In terms of relative abundance, the humpback chub was the mostcorr@on fish collec~ed during this survey. Four . other species of fish were collected and were, in decreasirig order of abundance, the flannelmouth sucker, speckled dace, carp and channel catfish (Table 1). . Table 1. Relative abundance and number of fish collected from the Little Colorado River in the vicinity of the confluence, during July, 13-15, 1979. Ranking Percent of Collection Number Collected 1. Humpback Chub 2. Flannelmouth Sucker 3. Speckled Dace 4. Carp 5. Channel Catfish 47.4 30.4 11.9 5.9 4.4 100.0 87 56 22 11 8 184 Totals ~ Behavioral Observations ---- During July, adult humpback chubs were seen to forage actively along the substrate, ledges, and in mid-water areas. Unfortunately, the material they were eating was not determined. At this time fish were observed in schools of 15-20 individuals. Another behavioral trait was also suggested to be occurring during July, namely that of possible size segregation by this species. This was reflected by the size of fish taken which, although varying, appeared to represent distinct size classes. In these coll- ections, several size groups were taken, i.e. fish 100 mm, between 100-200 mm, 200-300 mm, and over 300 mm in total length. This observation, although very preliminary, is interesting, and will be further examined in future studies. Tag~in~ ---- During this survey, 67 humpback chubs were tagged and released, bringing the number of this species marked within the Grand Canyon region to 216. To date, no recaptures have been obtained. Where these taggEd fish go is currently ~~known, although movement into the mainstream Colorado River is considered the strongest possibility, followed by movement upstream in the Little Colorado River. However, until recap- tures are obtained, these suggestions remain undocumented. Fctoparasites ---- Achorworm ectoparasites, first. noticed during October 1978, were still present, although in low numbers. In July, they infested 2.3 % of the humpback chubs taken, which contrasts markedly with October, 1978 data, when ,