DFC PRocEEDn ics - AI-PF{ABETTCAL usTlrw oFABsrrACTs

Authors: con etiquetas’ De l99o hasta i994, estimaci6nes de la poblaci6n de adultos han variado entre 4oo, ooo andl’4oo’0oo’ Supervivencia de adultos se extiende “r, tr” i7 a lo0%. La poblaci, 5n actual de adultos contienepeces nacidos en los primeros anqs del 1980. l^os datos del estudio estan actualmente en analisis y se esperaterminar el modelo de viabilidad de 1996.

Year: 1995 (xxvii)

Abstract

The habitat and ctrrrent conservation status of the partially armored threespine sticklebaclq a fluvialsubspecies with distribution from the Bering skait (Ataska) to Arroyo El Rosario, baja California (Mexico),was monitored during a period of eight years (1987-1995) at the historical localities of distribution innorthwestern Baia California. From a total of I I known localities, the species was found only the aroyosfin Ll ljescanso and El Rosario where it was “y.* rare. The progressive alteration of the aquatic and ,ipiecosysterns along the goastal region of northwestern Baia Califomia by anthropogenic irnpact has reducedthe distribution and abundance of this subspecies. Its currenr conservation status in Baja California isconsidered as threatened.. RESL?Vr’N El habitat y estatus actual de conservaci6n del pez espinoso parcialmente armado, una subespecie{iuvial con distribuci5n desde el Bering Skait (Alaska) hasta el Arroyo El Rosario, Baja Califomia (M6,6co),fueron monitoreados durante “l p.tloao de ocho arios (i987:1995) en las locatidades hist6ricas de $stribuci6n del noroeste =d:-B”i“ California. De once localidades hist6ricas, solo dos de ellas (bocanas delos arroyos El Descanso y El Rosario) registraron actualmente la ocurrencia de esta subespecie en cantidad.esmuy baias’ l’a alteraci6n progresiva de los ecosistemas acu6ticos y riberefros por actividades anlropog€nicasa lo largo de la regi6n noroccidental de Baia Califomia, ha reducido la distrlbucion y abundancia de estasubesPede’ Su estatlrs actual de conservaci6n en Baia California es consider“do.omo amenazado. sanv;r-in, o. I-‘; DrMto, ct A.; Querrno,I. M.; vnrJrr.nroEK, R. c. <o,r’rcRCV-coafarh.cih!&Appricdca:ue Ruqgo udiv l{o &uwrdr’ Nl; cAD - uri!6ity of Ddrc, car.g” of v“ri s-ordio.c.@ Leb, Lffi, DE; JMe - Dcpartmnt of Btdogr, Univoity of sorhCedirr Cdunbil SC) M:l:dT sYstematics of the I-eptorhaphis Group of Poeciliopsrs (pisces: poeciliid,ae) “rdrelationships with endangered populationl of Arizona KEYWORDS: restocking molecular systematics; Arizona; Sonora; M6xico; topminnows ; poeciliopsis ABSTRACT’ We investigated evolutionary relationships among populations of the Leptorhaphis species group oftopminrrows genus: Puciliopsis from western Mexico anJso,rth..n Aizona. BLed on morphol”fr.“i Lageographical criteria, this group indudes three allopatric species: Puciliopsis oecidentalis; e. uaai; and p.infou’ Because these doseiy releted species have the .“p.aty to hybridize in the laboratory, populationsflom adiacent river q/sterns may have the capacity to intelgrade in nature. To assess the genetic boundariesdelimiting the three putative species, and, lo determine the partitioning of genetic diversity within andamong populations of each species, we exarnined allozyme and mitochlnarid DNA sequence (D_loop)variation’ The genetic relationships among the threl species correspond.ed with their geographicaldistributions’ Relative to outgroup taxa the mJst southerly jistributed spices, p. infaw (states of Nayarit, BO