Computer analysis of cross sections of leaves of Chrysothamnus taxa and their relation to environmental conditions

Thirty-eight accessions of 20 taxa (species and subspecies) of Chrysothamnus from a range of environments were grown in a uniform garden. During mid-June, terminal and lateral leaves were removed, fixed, and processed for light-microscopy studies. Area and perimeter measurements of ink tracings of midleaf vein cross sections were measured using computer-scan techniques. Leaf area and perimeter were compared with vein perimeter and area measurements. Area and perimeter of these Chrysothamnus leaves varied in response to the environment at the collection location. Plants native to hot, dry conditions had small, thick leaves, whereas plants native to cooler, more mesic conditions had relatively large, thin leaves. Similarly, leaves with round veins were adapted to hot, dry environments and leaves with elliptical veins were adapted to cooler, more mesic environments. Both terminal (young) and lateral (older) leaves were sampled. Terminal leaves showed significant (p < .05) correlational responses to environmental parameters, whereas the lateral leaves, while fronding in the predicted morphological directions, did not generally show significant responses. The different responses of terminal and lateral leaves may have been due to canopy position and uniform environmental conditions of the garden. Leaves with large cross sections characteristically had large veins, and leaves with small cross sections characteristically had small veins. Large leaf cross sections were normally flat. Small leaf cross sections were normally round. Decreasing leaf size and increasing leaf thickness were correlated with aridity.     

A new Hypsiglena from Tiburon island, Sonora, Mexico

This third report on the herpetofauna of Chihuahua deals exclusively with amphibians. The first plethodonid salamander is reported, species Ambystoma rosaceum is discussed in greater detail than before, and two subspecies are recognized. Spea is elevated from subgeneric to generic rank, and S. stagnalis Cope is removed from synonymy and is recognized as a subspecies of hammondii . The species listed include the following: 2 salamanders and 19 anurans (1 Scaphiopus , 2 Spea , 9 Bufo , 1 Eleutherodactylus , 2 Hyla , 3 Rana , and 1 Microhyla ). Reference is made to vaious habitats that are associated with elevations arising form lower deserts and extending into the western mountains. The role played by the dry and wet annual cycles is also noted.     

Growth of juvenile American lobsters in semiopen and closed culture systems using formulated diets

Growth of juvenile American lobsters, Homarus americanus , raised in four semiopen culture systems, with daily water exchange rates ranging from 29 percent to 3.3 percent, was compared with growth in a completely closed system. Animals were fed a formulated pelleted ration, water quality factors were measured daily, and changes in concentration of nitrate, orthophosphate, and total organic carbon were monitored. Results of two 90-day trials indicate that growth increased in the system with the lower water exchange rates. Maximum growth occurred in the closed system.     

Buccal floor of reptiles, a summary

A general survey of the information presently available on the osteology and myology of the hyobranchial apparatus. Included in the survey are examples of the hyobranchial skeleton of the major groups of reptiles, including the Chelonia, Crocodilia, Rhynchocephalia, and Squamata. The myology treats the muscles directly associated with the hyoid as well as those associated with the functioning of the apparatus, but not arising or inserted directly on or from the hyoid. The innervation of the hyobranchial apparatus is reviewed and briefly discussed based on the information available in a few major studies. An attempt is made to cite all pertinent literature references, and in Tables 1 and 2 the references to basic areas are indicated. Twenty - nine plates and figures are included, some of which represent original research.     

Terrestrial vertebrate fauna of the Kaiparowits Basin

This report includes data collected during an investigation by Brigham Young University personnel from 1971 to 1976, as well as a literature review. The fauna of the Kaiparowits Basin is represented by 7 species of amphibians (1 salamander, 5 toads, and 1 tree frog), 29 species of reptiles (1 turtle, 16 lizards, and 12 snakes), 183 species of birds (plus 2 hypothetical), and 74 species of mammals. Geographic distribution of the various species within the basin are discussed. Birds are categorized according to their population and seasonal status. Avian habitat relationships are discussed, and extensions of range are reported for 5 species of birds. Three threatened or endangered avian species occur in the basin. Four avian species seem to have declined significantly in numbers in recent years.     

A small carnivore survey technique

Thirty-nine previously unpublished reports of the endangered black-footed ferret from Wyoming are listed with dates, locations, number of animals, sources, and comments.     

Pathology of an unusual lumbar condition in a young black bear ( Ursus americanus ) from the Big Bend region of Trans-Pecos Texas

The skeleton of a young American black bear ( Ursus americanus ) possessing asymmetrical distortions of the 5 caudalmost lumbar neural spines was recovered from west Texas. We attribute this abnormality, presumed to be congenital, to the absence or atrophy of the right multifidus muscle straddling L3 and to the series of compensatory muscle adjustments required to maintain spinal alignment. This finding may have important management implications for black bears in Texas, given the possibility that our specimen originates from a partially isolated population. El esqueleto de un oso negro juvenil ( Ursus americanus ) con distorsiones asim&eacute;tricas de las cinco espinas neurales lumbares inferiores fue descubierto en el oeste de Texas. Atribuimos esta anormalidad, suponiendo que es de origen cong&eacute;nito, a la ausencia o atrofia del m&uacute;sculo multifidus derecho que se extiende a ambos lados de la v&eacute;rtebra L3 y la serie de ajustes musculares compensatorios necesarios para conservar el alineamiento espinal. Este hallazgo podr&iacute;a tener implicaciones importantes para esta especie en Texas, dada la posibilidad de que nuestro esp&eacute;cimen provenga de una poblaci&oacute;n parcialmente aislada.