ABSTRACTS OF PRESENTATIONS
<br />-? Tr
<br />DAVIS, D.L.; SHIOZAWA, D.B.r; EVANS, R.P. DLD - University of Kansas Medical Center, Kan as City, KS; DKS and RPE- Department of Zoology,
<br />Brigham Young University, Provo, UT
<br />An appraisal of the usefulness of Polymerase Chain Reaction
<br />amplified mitochondrial DNA to separate some western catostomids
<br />Una valoriz.aci6n de los usos de la Reacci6n en Cadena de Polimeros
<br />amplificada de ADN mitocondrial extraido de algunos Catostomidos del Oeste
<br />KEYWORDS: suckers; mitochondrial DNA; phylogenetics
<br />CLAVES: matalotes; ADN mitocondrial; filogeneticas
<br />ABSTRACT
<br />Six species of western catostomids, Xyrauchen texanus, Chasmistes liorus, Catostomus ardens, Catostomus
<br />latipimtis, Catostomus (Pantosteus) platyrhynchus, and Catostomus (Pantosteus) discobolus, were examined using
<br />restriction digests of PCR amplified fragments of the mitochondrial DNA genome. An eastern catostomid species,
<br />Erimyzon. sucetta, was used as an outgroup. We were able to separate the species based upon restriction fragment
<br />patterns, with the exception of the June Sucker, Chasmistes liorus, which was similar to several Utah Sticker
<br />populations examined. The failure to definitively separate the June Sucker may be due to introgression with Utah
<br />Sticker, C. ardens, also resident in Utah Lake, Utah where the June Sucker is endemic. Additional sampling bias
<br />may have been induced by the small sample size (n=5) of June Sucker used in this study. Other phylogenetic
<br />relationships appear to be reasonable given the limited number of populations examined.
<br />RESUMEN
<br />Seis especies de catostomidos del Oeste, Xyrauchen texanus, Chasmistes liorus, Catostomus ardens, Catostomus
<br />latipinnis, Catostomus (Pantosteus) platyrhynchus, y Catostomus (Pantosteus) eliscobolars, fueron examinadas
<br />utilizando una restricci6n digestiva de fragmentos de RCP amplificados de ADN del genoma mitocondrial. Una
<br />especie de catostomido del Este Erimyzon sucetta fue utilizado como grupo extemo. Nosotros fuimos capaces (le
<br />separar las especies basados en los patrones de fragmentac16n de ]a restricci6n, con la excepcion del matalote de
<br />junio Chasmistes liorus, el cual fue similar a varias poblaciones examinadas del matalote de Utah. Inhabilidad de
<br />separar definitivamente al matalote de junio, puede ser debido al entrecruzamiento con el matalote de Utah
<br />Chasmistes ardens, tambien residence del lago Utah, donde el matalote de junio es endemico. Sesgos adicionales
<br />del muestreo pueden ser inducidos por pequefios tamaiios de muestras (n=5) del matalote de junio utilizados en este
<br />estudio. Otras semejanzas filogenetieas parecen ser razonables dado el numero limitado de poblaciones examinadas.
<br />HENDRICKSON, D. A. ; BROTHERS, E.B. DAH - Texas Memorial Mwetun, 2400 Trinity, University of Texas, Austin, TX 78705; ERB - EFS Consultants,
<br />3 S-et West, Ithaca, NY 14850
<br />Utility of otoliths of Grand Canyon humpback chub Gila cypha for
<br />age detenninations and as indicators of ecological history of individuals
<br />Utilidad de los otolitos del charal ,jorobado del Gran Cafi6n Gila cypha en determinaciones de edad asi
<br />como indicadores de la historia ecol6gica de los individuos
<br />KEYWORDS: humpback chub; Grand Canyon; Little Colorado River; otoliths; ageing; growth rates; movements; life history reconstruction;
<br />Arizona
<br />CLAVES: Charal jorobado; Gran Can6n; Pequefio Rio Colorado; Otolitos; determinaci6n de edad; tasas de crecimiento; movintientos; historic
<br />e vida; Arizona
<br />ABSTRACT
<br />Otoliths of teleosts are crystalline structures of the inner ear, the micro-structure and chemistry of which have
<br />been found in other species to contain detailed growth and temperature histories of individuals. We have verified
<br />the daily periodicity of increment formation in hatchery populations of the surrogate bonytail chub Gila elegans,
<br />and have used daily increments in one of the three otoliths (lapillus) to age young of the year humpback chubs taken
<br />in 1990 and 1991 from both the mainstream Colorado River and the Little Colorado River (LCR). Spawning in the
<br />LCR appears to correlate with decreasing discharge in that river in spring or early slimmer. Growth is rapid in the
<br />LCR, whereas, all fish taken from the mainstream Colorado (a cold, near-constant temperature river comprised
<br />almost entirely of hypolimnetic releases from Glen Canyon dam) are much smaller than individuals of equal age
<br />captured in the LCR. Growth in the mainstream is extremely slow, but otoliths indicate that y-o-y occasionally
<br />encounter warmer, diurnally cycling, temperature regimes, perhaps tributary mouths or backwaters, where they
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