Electrophoretic study of cutthroat trout populations in Utah

Thirty - nine Utah streams were sampled for cutthroat trout. Of these, 31 contain cutthroat or cutthroat / rainbow hybrid populations. By using starch gel electrophoresis, these populations were segregated into three groups. One group consisted predominately of fish from the Sevier River (of the Bonneville Basin) and Colorado drainages. A second was primarily populations from the Bear River Drainage (Bonneville Basin) as well as some scattered populations along the Wasatch Front (Bonneville Basin). The third consisted of Wasatch Front populations and populations that have hybridized with rainbow trout. Since different subspecies of cutthroat trout are native to the Colorado and Bonneville drainages, one would expect the populations from within the Bonneville Basin to be more similar to one another and less similar to the Colorado River populations. That this did not occur raises questions concerning the evolutionary relationships of the subspecies and the populations. It is clear that at least a northern (Bear River) and southern (Sevier River) form of the Bonneville cutthroat exists. The Wasatch Front may represent an intermediate zone where these two forms intergrade.         

Stinger utilization and predation in the scorpion Paruroctonus boreus

The utilization of the stinger and the predatory technique of the scorpion, Paruroctonus boreus, was studied under laboratory conditions. During the study, 83 feedings were observed. Age of the scorpions and the percentage of prey stung by them were used to classify the scorpions into groups. The scorpions aged 13–61 days always stung prey. After 62 days the scorpions began to selectively utilize the stinger. Utilization declined until it reached 30 percent in the adult stage. The stinger is apparently necessary for prey capture only in the early life stages.       

Recovery of Gambel oak after fire in central Utah

The height of oak ( Quercus gambelii Nutt.) stems was measured on several fire scars within the Uinta National Forest and vicinity and compared with the height of oak stems on adjacent, nonburned areas. A significant relationship exists between the recovery rate of oak after fire and elevation, with the recovery rate being greatest at low elevations. A trend also exists showing that recovery tends to be greater on south to westerly exposures than on north to easterly exposures.     

Distribution of the Shoshone scuplin ( Cottus greenei: Cottidae) in the Hagerman Valley of south central Idaho

Cottus greenei, a potentially threatened species endemic to Idaho, was collected from 49 localities in 25 springs/streams in south central Idaho. Most localities were along the north bank of the Snake River in waters of the Thousand Springs formation, Gooding County. One population was found in a spring in the main Snake River. Another sculpin, Cottus bairdi, was collected with C. greenei at 23 locations in 16 springs/streams. Confusion concerning the type locality of Cottus greenei is discussed.        

Mate sampling in a natural population of Pecos gambusia, Gambusia nobilis

Normal 0 false false false MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Much research has been conducted on the mating systems of poeciliid fish in aquaria; however, there are fewer studies that examine mate sampling of these fish in the wild. In general, male poeciliids are characterized as being unselective in their mate choices and will attempt to copulate with seemingly all available females. Females are selective, copulate infrequently, and are often pursued by “ardent” males who may force copulations. To avoid male harassment, females in aquaria will often shelter from males among other females in shoals. Here, we examined the mate-sampling behaviors of male and female Pecos gambusia Gambusia nobilis by following individuals swimming in an outflow pool of Diamond Y Spring in southwestern Texas. In most cases, a male approached a solitary female, followed her briefly, and then left for no apparent reason. Approaching a number of females increased the likelihood that the male would follow one, and the longer a male followed a female, the more likely he was to copulate with her. As females were larger and faster than males, they could avoid males by swimming away from them. We found no evidence of the persistent males that harass seemingly unreceptive females as seen under aquarium conditions, nor did we see females join a shoal to stop pursuit by males. However, the activity of one male following a female did appear to attract other males who would compete to follow and attempt copulation. This competition might ensure that only superior males gain reproductive opportunities. Se han investigado extensamente los sistemas de apareamiento de pecílidos en acuario; no obstante, hay relativamente pocos estudios que examinan la elección de pareja de estos peces en su hábitat natural. Los pecílidos machos no suelen ser selectivos en su elección de pareja y parecen intentar copular con todas las hembras que estén a su alcance. Las hembras son selectivas, no copulan frecuentemente y a menudo las persiguen machos excitados que pueden copular con ellas forzadamente. Para evitar el acosamiento de los machos, en acuario las hembras a menudo se refugian de los machos entre otras hembras en bancos. Para este estudio, examinamos el comportamiento de elección de pareja de gambusias de pecos ( Gambusia nobilis ) machos y hembras al observar algunos individuos en un remanso del Diamond Y Spring en el suroeste de Texas. En la mayoría de los casos, el macho se acercaba a una hembra solitaria, la seguía brevemente y luego se alejaba sin motivo aparente. El acercarse a varias hembras aumentaba la probabilidad de que persiguiera a una de ellas, y cuanto más la seguía, más probable era que copulara con ella. Dado que las hembras son más grandes y más rápidas que los machos, podían eludirlos si no correspondían. No observamos machos persistentes que acosaran hembras aparentemente poco receptivas como se ha documentado en acuario, ni tampoco vimos hembras que se unieran a bancos para evitar la persecución de machos. Pero cuando un macho perseguía una hembra, parecía atraer otros, los cuales competían entre sí para seguirla e intentar copular con ella. Esta competencia podría garantizar que solo los machos superiores tengan oportunidades reproductivas.     

Soil properties associated with vegetation patches in a Pinus ponderosa —bunchgrass mosaic

Since Euro-American settlement, fire exclusion and other factors have dramatically altered interior western coniferous forests. Once open and parklike, present-day structure in many southwestern Pinus ponderosa forests consists of dense stands of young, small-diameter trees, with small patches of larger, old trees, and relict open bunchgrass areas. Our objectives were to assess differences in soil properties associated with these different vegetation patches. We examined soil morphological characteristics, pH, organic C concentration, total N concentration, C:N ratio, and phytolith concentration from profiles within 6 transects (18 soil pedons) crossing patches of dense stands of small diameter trees, patches of old-growth trees, and open grassy areas. Results indicate that old-growth plots had significantly lower A horizon pH and thicker O horizons than grass plots. In general, we found vegetation patches had statistically similar C and N concentrations and C:N ratios for A and B horizons; however, C in the A horizon was positively correlated with O horizon accumulation ( r 2 = 0.79). Greater accumulation of organic C in the A horizon of forested areas contrasts with commonly reported results from mesic, mid-continental prairie-forest ecosystems but is typical for many arid, semiarid, and humid savanna ecosystems. Phytolith concentration was similar among old-growth pine, dense younger pine, and open grassy plots; the lack of a spatial pattern in phytolith distribution could indicate that grass cover was more spatially continuous in the past. Additionally, this interpretation is consistent with current theories regarding historical vegetation change in these forests.     

Vascular flora of Kane Lake Cirque, Pioneer Mountains, Idaho

Kane Lake Cirque lies in the western Pioneer Mountains of south central Idaho. An inventory of the high elevation flora of the cirque revealed the presence of 180 vascular taxa representing 95 genera and 30 families. Five alpine taxa are here documented from Idaho for the first time: Carex incurviformis Mack., Draba fladnizensis Wilfen., Potentilla nivea L., Ranunculus gelidus Kar. & Kir., and Ranunculus pygmaeus Wahlenb. Kane Lake Cirque also contains populations of four additional alpine taxa considered to be of conservation concern in Idaho: Erigeron humilis Graham, Parnassia kotzebuei Cham., Saxifraga adscendens L., and Saxifraga cernua L.     

Roost sites used by Sandhill Crane staging along the Platte River, Nebraska

We assessed the influence of water depth, extent of unobstructed view, and human disturbance features on use of roost sites by Sandhill Cranes along the Platte River, Nebraska, during spring migratory stopover. Aerial photos taken near dawn were used to determine areas of flock use and habitat availability in four sample reaches, and measurements were made on the ground at flock roost areas. In general, depths of 1-13 cm were used by sandhill cranes in greater proportion than those available. Exposed sandbars and depths >20 cm were avoided, while depths of 14-19 cm were used in proportion to their availability. Sites 11-50 m from the nearest visual obstruction were used significantly greater than their availability, while sites 0-4 and >50 m from visual obstructions were avoided. Sandhill Cranes avoided sites near paved roads, gravel roads, single dwellings, and bridges when selecting roost sites; however, they did not appear to be disturbed by private roads, groups of residential buildings, gravel pits, railroads, or electrical transmission lines.     

The anatomy and taxonomy of Vanclevea (Asteraceae)

Wood, leaf, and floral anatomy of Vanclevea stylosa is compared with that of several possibly related species in the genera Acamptopappus, Eastwoodia, Grindelia, Haplopappus, and Petradoria. Although V. stylosa was originally described as a Grindelia, it is clearly distinct from that genus. Of the taxa studied, it is most closely allied to Haplopappus salincinus and H. scopulorum. The taxonomy, morphology, and distribution of the monotypic Vanclevea are detailed, and known exsiccatae are listed.     

Early development of the razorback sucker, Xyrauchen texanus (Abbott)

  Fertilized ova of razorback sucker, Xyrauchen texanus, were adhesive for 3 to 4 hours after fertilization. Cleavage was completed at 24 hours, gastrulation occurred at 34 hours, and blood circulation was established at 117 hours. Hatching occurred from 5.2 to 5.5 days after fertilization. Larvae were from 6.8 to 7.3 mm TL at hatching. Yolk was assimilated at 13 days (10 mm TL). All fins were formed and had ossified rays at 64 days (27 mm TL). The unique nuchal keel appeared about 200 days after fertilization.