title: Early life history of three pelagic-spawning minnows Macrhybopsis spp. in the lower Missouri River.
abstract: Life-history characteristics of age-0 sturgeon chub Macrhybopsis gelida, shoal chub Macrhybopsis hyostoma and sicklefin chub Macrhybopsis meeki were compared using several methods. All Macrhybopsis species consumed mostly midge pupae, but M. meeki had the most general diet (Levins' index, B = 0.22) compared with M. hyostoma (B = 0.02) and M. gelida (B = 0.09). Morisita's diet overlap index among species pairs ranged from 0.62 to 0.97 and was highest between M. hyostoma and M. gelida. Daily ages estimated from lapilli otoliths for each species ranged from 15 to 43 days for M. gelida, 19 to 44 for M. hyostoma and from 16 to 64 days for M. meeki. Mean growth rates ranged from 0.79 mm day(-1) for M. meeki to 1.39 mm day(-1) for M. gelida. Mortality estimates indicated high daily survivorship rates for M. meeki (0.985), but could not be estimated for the other two species. Hatch date histograms were congruent with the belief that M. hyostoma and M. gelida spawn periodically from June to September. Macrhybopsis meeki, however, appeared to respond to a specific spawning cue as hatch dates were unimodal with a peak in July. These results fill a gap in current knowledge of these imperilled species that can be used to guide management decisions.
authors.affiliation: Department of Natural Resources Ecology and Management, 008 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, U.S.A.
authors.forename: T A
authors.initials: TA
authors.lastname: Starks
authors.affiliation: Habitat and Assessment Monitoring Program, U.S. Army Corps of Engineers, 601 E. 12th St, Kansas City, MO 64106, U.S.A.
authors.forename: M L
authors.initials: ML
authors.lastname: Miller
authors.affiliation: U.S. Geological Survey, Oklahoma Cooperative Fish and Wildlife Research Unit, Department of Natural Resources Ecology and Management, 007 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, U.S.A.
authors.forename: J M
authors.initials: JM
authors.lastname: Long
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000254:growth & development / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D008018:Life Cycle Stages; D008923:Missouri; D010037:Otolithic Membrane / Q000254:growth & development; D012098:Reproduction; D045483:Rivers
keywords: broadcast spawners; daily age; daily growth; diet; hatch date; otolith