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Least Chub Reproduction: Effects of Density, Sex Ratio, and Spawning Substrate Transfer Frequency
Author(s) -
Billman Eric J.,
Wagner Eric J.,
Arndt Ronney E.
Publication year - 2007
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/a05-100.1
Subject(s) - broodstock , biology , reproduction , fishery , substrate (aquarium) , fish <actinopterygii> , zoology , aquaculture , sex ratio , threatened species , ecology , population , demography , sociology , habitat
Abstract The least chub Iotichthys phlegethontis , a small cyprinid endemic to Bonneville Basin, Utah, is at risk of becoming a threatened species in Utah. Captive propagation has become necessary to preserve genetically distinct populations and to produce specimens for reintroduction. We conducted two spawning studies to develop intensive aquaculture techniques for the least chub. In the two studies, 162 adults (78 females) produced a total of 12,492 fry. Adult broodstock density (0.03–0.20 fish/L), male : Female sex ratio (1:1, 1:2, and 2:1), and spawning substrate transfer frequency (one versus two times per week) did not significantly affect production. In the second study, female mortality was significantly different between treatments, as more female mortalities occurred in tanks with one spawning substrate transfer per week than in tanks with two such transfers. Single females paired with single males produced multiple clutches at 2‐ to 3‐week intervals. The relationship between fry production and female body size (g) appeared to be positive and linear between 1.0 and 2.2 g but was unclear for larger fish.