Record Details
Biology of the blue and tui chubs in East and Paulina Lakes, Oregon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Biology of the blue and tui chubs in East and Paulina Lakes, Oregon |
| Names |
Bird, Franklin Howard
(creator) Donaldson, John R. (advisor) |
| Date Issued | 1975-01-29 (iso8601) |
| Note | Graduation date: 1975 |
| Abstract | This research was conducted on the life history of the blue chub, Gila (Gila) coerulea (Girard), inhabiting Paulina Lake, Oregon, and the tui chub, Gila (Siphateles) bicolor (Girard), East Lake, Oregon. The results are applied to the fisheries management of these lakes. Both species are endemic to the Klamath River System. Blue chub eggs had an incubation period of 7 to 9 days at 58.1°F to 69.3°F. Blue chub larvae first appeared in shallow water within spawning areas, remained there until August and then dispersed into all shallow areas of the lake. The juveniles remained dependent on the shallow water until maturity as age III fish. Spawning occurred from early July to mid-August in less than one meter of water and never in direct sunlight. Spawning took place directly adjacent to the shoreline in areas of clean gravel or large rock. The body weightfecundity relationship (R2 = 0.935) provides the most useful means of predicting fecundity. The oldest, and largest, blue chub was an age X female (234 mm). Growth rate was greatest in juveniles, decreasing markedly at maturity and gradually diminishing further throughout the remaining life span. The least squares regression of length on weight for 895 blue chub (R2 = 0.96) was, Log body weight 7= -L7129 + 3.1069 (-Log 25.4 + Log body length in mm). The blue chub diet consisted mainly of diptera larvae, cladocerans, gastropods, and amphipods, of which diptera larvae, cladocerans, and amphipods were the most preferred food items of Paulina Lake rainbow trout. Blue chub were vitually free of parasites. The osprey and a large dragonfly nymph were the only observed predators on the blue chub, but other possible predators were the rainbow trout, mink and marten. Tui chub eggs incubated in 7 to 8 days at 5 8.3oF to 71.5°F. Tui chub larvae first appeared within heavily vegetated areas within East Lake, areas which were the most probable spawning sites. They remained there until dispersal in August. Juveniles remained dependent on the vegetation and shallow beach areas until maturing as either age II or age III fish. Spawning most probably occurred in the heavily vegetated areas during mid-June to late July, with deposition of the adhesive eggs on to the vegetation. The ovary weight-fecundity relationship (R2 = 0.87 8) provides the most useful means of predicting fecundity. The oldest tui chub was an age IX fema,le (226 mm), The longest (FL) was an age VIII female (249 mm). Growth rate was greatest in juveniles, decreasing significantly at maturity and gradually diminishing further throughout the remaining life span. The least squares regression of length on weight for 940 tui chub (R2 =0.97) was, Log body weight = -1.0518 + 2.8807 (-Log 25.4 + Log body length in mm). The tui chub diet consisted mainly of amphipods, diptera larvae, gastropods and cladocerans, of which amphipods, diptera larvae and cladocerans were the most preferred food items of East Lake rainbow trout and brook trout. Tui chub were virtually free of parasites. The osprey and a large dragonfly nymph were the only observed predators on the tui chub, but other possible predators were the rainbow trout, :brown trout, brook trout, mink and marten. |
| Genre | Thesis |
| Topic | Freshwater fishes -- Oregon |
| Identifier | http://hdl.handle.net/1957/9101 |
