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vol. 36, no. 1
<br />A years studied. CA = number
<br />Fall
<br />CA TD
<br />2 121
<br />28 372
<br />48 442
<br />38 1,322
<br />13 701
<br />1 61
<br />1 126
<br />2.4 18.7 449.3
<br />1.6 19.4 446.1
<br />final activity pattern reported,
<br />\qal
<br />March 1991
<br />ennedy (1978) reported that
<br />:ns in their pond was annual
<br />recorded oviposition in field
<br />February and early March.
<br />illected suggests that north-
<br />sirens are winter breeders. A
<br />ed on 25 January 1978 laid
<br />m. Sirens having bite marks
<br />ie months of December, Jan-
<br />;odley (1983) linked the pres-
<br />to possible courtship activity
<br />he observed bite marks only
<br />.s I observed these marks on
<br />tales.
<br />female sirens with large-yol-
<br />22 mm in diameter. Two of
<br />captured in January, and the
<br />ght in February. Another fe-
<br />pril contained pigmented ova
<br />:r, and a specimen caught in
<br />nature ova only.
<br />ided me with juvenile sirens
<br />•ess Lake near Benton, Bossier
<br />Older juveniles (52 mm and
<br />;th) were collected on 20 June
<br />individuals (X total length =
<br />e collected on 6 May 1985 U.
<br />im.). Godley (1983) reported
<br />ed individuals of S. intermedia
<br />-an total lengths of 11.5 and
<br />ary 1976. These observations
<br />the size of the specimens col-
<br />ins, allowing for 3 months of
<br />0 76 0-
<br />Notes
<br />growth, and provide further support for a winter
<br />breeding season in northwestern Louisiana. Dun-
<br />dee and Rossman (1989) reported that the prob-
<br />able time of hatching of sirens in Louisiana is
<br />midwinter. Courtship activity preceding a winter
<br />breeding season may explain the higher fall cap-
<br />tures reported here.
<br />I thank L. M. Hardy for assistance and en-
<br />couragement throughout the study. S. P. Lynch
<br />provided assistance with the statistical analyses,
<br />and A. C. Raymond prepared Fig. 1.
<br />LITERATURE CITED
<br />DUNDEE, H. A., AND D. A. ROSSMAN. 1989. The
<br />amphibians and reptiles of Louisiana. Louisiana
<br />State Univ. Press, Baton Rouge, 300 pp.
<br />GEHLBACH, F. R., AND S. E. KENNEDY. 1978. Pop-
<br />ulation ecology of a highly productive aquatic sal-
<br />amander (Siren intermedia). Southwestern Nat., 23:
<br />423-430.
<br />GODLEY, J. S. 1983. Observations on the courtship,
<br />nests and young of Siren intermedia in southern
<br />Florida. Amer. Midland Nat., 110:215-219.
<br />HARDY, L. M., AND L. R. RAYMOND. 1980. The
<br />breeding migration of the mole salamander, Ambys-
<br />toma talpoideum, in Louisiana. J. Herpetol., 14:
<br />327-335.
<br />HARLAN, R. 1827. Genera of North American Rep-
<br />tilia, and a synopsis of the species. J. Acad. Nat.
<br />Sci., Philadelphia, 5:317-372.
<br />SAS INSTITUTE INC. 1985. SAS user's guide: basics,
<br />version 5 ed. SAS Institute Inc., Cary, North Car-
<br />olina, 1,290 pp.
<br />STATUS OF COLORADO SQUAWFISH AND RAZORBACK SUCKER IN THE
<br />SAN JUAN RIVER, COLORADO, NEW MEXICO, AND UTAH
<br />STEVEN P. PLATANIA, KEVIN R. BESTGEN, MILES A. MORETTI,
<br />DAVID L. PROPST, AND JAMES E. BROOKS
<br />Department of Biology, Museum of Southwestern Biology, University of New Mexico,
<br />Albuquerque, NM 87131 (SPP, KRB)
<br />Utah Division of Wildlife Resources, 455 West Railroad Avenue,
<br />Price, UT 84501 (MAM)
<br />Endangered Species Program, New Nexico Department of Game and Fish,
<br />Villagra Building, Santa Fe, NM 87503 (DLP)
<br />United States Fish and Wildlife Service, Office of Fishery Assistance,
<br />Dexter, NM 88230 (JEB)
<br />Present address of KRB: Department of Fishery and Wildlife Biology and Larval Fish Laboratory,
<br />Colorado State University, Fort Collins, CO 80523
<br />Colorado squawfish (Ptychocheilus lucius) and
<br />razorback sucker (Xyrauchen texanus) were for-
<br />merly widespread and abundant in large streams
<br />and rivers throughout the Colorado River Basin
<br />(Miller, 1961; Minckley, 1973; Holden and Wick,
<br />1982). Self-sustaining populations of Colorado
<br />squawfish are extant in the Upper Colorado Riv-
<br />er Basin (Holden and Wick, 1982) and are fed-
<br />erally listed as endangered (United States De-
<br />partment of Interior, 1974). Razorback sucker,
<br />proposed for federal listing as an endangered spe-
<br />cies (United States Department of Interior, 1990),
<br />occurs sporadically in the Upper Colorado River
<br />Basin (Tyus, 1987; Lanigan and Tyus, 1989) and
<br />in some mainstream Colorado River reservoirs in
<br />the Lower Colorado River Basin (Minckley,
<br />1983).
<br />Based on unverified records reported by Jordan
<br />(1891), Colorado squawfish and razorback suck-
<br />er were thought to be historic residents of the San
<br />Juan River drainage in Colorado, New Mexico,
<br />and Utah. The limited number of Colorado
<br />squawfish and razorback sucker taken in the San
<br />Juan River after the closure of Navajo Reservoir
<br />(Minckley and Carothers, 1979) led investigators
<br />to report these species as rare or extirpated in the
<br />San Juan River drainage (Tyus et al., 1982;
<br />Holden and Wick, 1982). A primary goal of our
<br />study was to determine the status of Colorado
<br />squawfish and razorback sucker in the San Juan
<br />River.
<br />From May 1987 to October 1989, comple-
<br />mentary studies of the fishes in the San Juan
<br />River were conducted in Colorado, New Mexico,
<br />147
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