Genus Desmognathus Research Articles

The Status of Desmognathus brimleyorum Stejneger and an analysis of the genus Desmognathus (Amphibia: Urodela) in Florida

This is a systematic study of three externally similar species of plethodontid salamanders (genus Desmognathus) previously considered to occur sympatrically in northern Florida (D. auriculatus, D. brimleyorum, and D. fuscus). Larval morphology, color pattern, relative size, and tail morphology were reinvestigated. The morphology of teeth, jaw profile, premaxillary fontanelle, and prearticular spine were studied in detail for the first time, and color changes due to ontogenetic melanization and to metachrosis were also evaluated. All the above characteristics were found to be taxonomically signifcant. In addition, the microhabitat selection and ecological associates of D. auriculatus and D. fuscus were different, indicating ecological isola-tion of the two species in the area of sympatric contact in northern Florida. Desmognathus brimleyorum Stejneger is a species endemic to the Ouachita Mountains of Arkansas and Oklahoma. The name D. fuscus carri Neill is a synonym of D. auriculatus Holbrook. Populations referred to D. fuscus in this study compared morphologically more closely with D. ochrophaeus from the southern Appalachians than with populations from near the type locality of D. fuscus Rafinesque.

Variation in the Genus Desmognathus (Amphibia:Plethodontidae) in the Western Limits of Its Range

Certain selected morphological and osteological characters were examined on available samples of adults and larvae of the genus Desmognathus from different localities in eastern Texas to determine if character variations exist. Although major variations were not found throughout the different localities, lesser character differences were observed; however, the latter characters were extremely variable, often differing within one locality. Hence, diagnostic values were established only when all characters were considered together. Statistical analysis of differences vs. localities indicated that no distinct geographic pattern existed. Texas specimens were found to be different from specimens referrable to D. brimleyorum and D. fuscus from near their type localities. Based on morphology, color patterns, and habitat preference, adult and larval forms from Texas were considered closely related if not conspecific with specimens referrable to D. auriculatus from Louisiana, Mississippi, and Florida.

Ontogenetic Allometry in the Salamander Genus Desmognathus

The number of species contained in the salamander genus Desmognathus on the basis of adult morphology is conjectural (current estimates range from seven to 10). The species recognized by the author are: Desmognathus aeneus, auriculatus, brimleyorum, fuscus, monticola, ochrophaeus, ocoee, quadramaculatus, welteri, and wrighti. The present study was initiated to determine the value of ontogenetic growth patterns of desmognathine larvae as discriminate characters. The numbers of larval specimens obtainable restricted the scope of the study to 19 populations of six species: Desmognathus fuscus, auriculatus, brim- leyorumn, quadramaculatus, welteri, and ochrophaeus. A linearizing transformation of Huxley's power equation (log Y log b + a log X) was applied to 30 morphometric characters (28 of which are osteological) to determine allometric relationships with individual body size. Observed morphological differences between cranial elements (e.g., premaxilla, palatopterygoids, frontals, parietals and vomers) indicate their use as specifically discriminate characters. The comparative strength of the anterior cranial elements coincides with differences in larval habitat. Relative ontogenetic increase in overall dimensions (e.g., depth, width and length) of the skull and jaw is proportional between species and suggests phylogenetic conservatism within the genus. The relationship of paedomorphosis and increasing terrestriality within the genus is reexamined in light of adaptive proportions of larval charac- teristics.

A Radio-Telemetry Technique for Monitoring Temperatures from Unrestrained Ungulates

A Radio-Telemetry Technique for Monitoring Temperatures from Unrestrained Ungulates

SIZE-FECUNDITY RELATIONSHIPS AND THEIR EVOLUTIONARY IMPLICATIONS IN FIVE DESMOGNATHINE SALAMANDERS

EvolutionVolume 22, Issue 4 p. 806-816 ArticleFree Access SIZE-FECUNDITY RELATIONSHIPS AND THEIR EVOLUTIONARY IMPLICATIONS IN FIVE DESMOGNATHINE SALAMANDERS Stephen G. Tilley, Stephen G. Tilley Museum of Zoology, University of Michigan, Ann ArborSearch for more papers by this author Stephen G. Tilley, Stephen G. Tilley Museum of Zoology, University of Michigan, Ann ArborSearch for more papers by this author First published: December 1968 https://doi.org/10.1111/j.1558-5646.1968.tb03479.xCitations: 37AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume22, Issue4December 1968Pages 806-816 ReferencesRelatedInformation

Population Structure and Biomass Production by a Stream Salamander

A life-table based on collections from a population of Desmognathus fuscus in Gaston Co., North Carolina, is presented. An estimate based on the weight of captured individuals predicts that salamanders from each clutch will provide 17.5 g of salamander biomass to other community predators and decomposers, or an average of 1.8 g per year. Population density is estimated to be between 0.4 and 1.4 salamanders per square meter of stream bed. The corresponding average annual production would then fall between 0.1 and 0.3 g/m2 of stream bed. INTRODUCTION Measures of the importance of populations of a particular species in a particular community are usually based on abundance and size of the individuals of the species. When these measures are used to define the importance of plant species, the information gained is of considerable value, for the physical structure of the community can be derived from them. The same inforrmation about an animal species, however, does not define a particular structure. A more interesting measure of the importance of an animal species in its community would be an estimate of the annual production of the pop'ulation of that species. The resulting figure can then be compared with the production of the community as a whole or with that of populations of other species. This paper will present an estimate of the biomass production rate of the stream salamander, Desmognathus fuscus. A population of D. fuscus in Gaston Co., North Carolina, was sampled in five spring collections during 1961 and 1962. The data obtained from these collections are presented graphically in Fig. 1. POPULATION STRUCTURE The initial step in the technique of production estimation which will be utilized in this paper is the derivation of a life-table for the population. The life-table gives the rate at which animals in different age classes are dying, or contributing their biomass to the community. When these rates are multiplied by the weights of the animals in these age groups, the desired rates of biomass production are obtained. The life-table derived from the data in Fig. 1 is given in Table 1. The construction of this table follows the directions of Birch (1948), and the example of Organ (1961) for salamanders of the genus Desmognathus. The remainder of this section is a description of the construction of the life-table. 1 Present address: Department of Zoology, University of Washington, Seattle, Washington 98105.

Brachycoelium ambystomae sp. n. (Trematoda: Brachycoeliidae) from Ambystoma opacum

Brachycoelium ambystomae sp. n. is described from the marbled salamander, Ambystoma opacum (Gravenhorst), from Leon County, Florida. This species differs chiefly from the 11 other described members of the genus by its spination, distribution and development of vitellaria, position and size of its ovary and testes, and body length. Specimens of the genus Desmognathus from the same locality were not infected with this trematode. Nine marbled salamanders, Ambystoma opacum (Gravenhorst), collected in Leon County, Florida, in November 1961, harbored trematodes of the genus Brachycoelium. Byrd (1937) reported the possibility that 13 well defined species were included in this genus. Rankin (1938) reduced all 14 described species to synonymy with the type species, Brachycoelium salamandrae (Frolich, 1789). Parker (1941) and Cheng (1958), after careful studies, agreed that specimens which they collected possessed diagnostic characters of some particular species and not of others. Cheng (1958) and Cheng and Chase (1961) reported that there were enough distinct characters, e.g., shape and position of testes and distribution of vitellaria, to recognize 11 species in the genus Brachycoelium. Careful study of the specimens from northwest Florida indicated that on the basis of their extensive spination, development and distribution of vitellaria, size of testes and ovary, and body length, they represent a new species, here designated as Brachycoelium ambystomae.

Studies of the Local Distribution, Life History, and Population Dynamics of the Salamander Genus Desmognathus in Virginia

Studies of the Local Distribution, Life History, and Population Dynamics of the Salamander Genus Desmognathus in Virginia