Laurence M. Hardy

Growth Rates and Mortality of the Louisiana Pine Snake (Pituophis ruthveni)

The genus Pituophis (Serpentes: Colubridae) contains three species of snakes in the United States (Collins, 1997): Pituophis catenifer, Pituophis melanoleucus, and Pituophis ruthveni. The Louisiana pine snake, P. ruthveni, was elevated to specific status by Reichling (1995) and is endemic to western Louisiana and eastern Texas (Conant and Collins, 1991; Reichling, 1995; Thomas et al., 1976). Rodriguez-Robles and De JesusEscobar (2000) agreed with the recognition of specific status for P. ruthveni, but few data have been collected on the natural history of P. ruthveni since its original description (Stull, 1929). The paucity of data on P. ruthveni is because of the snake’s limited distribution (Reichling, 1995; Thomas et al., 1976), low population density (Jennings and Fritts, 1983; Reichling, 1989), and secretive nature (Reichling, 1988). A radiotelemetry study initiated in 1993 (Rudolph and Burgdorf, 1997; Rudolph at al., 1998) confirms the basic conclusions about the ecology of P. ruthveni obtained from collection records. Pituophis ruthveni is primarily associated with pine forests in sandy soils within the historic range of longleaf pine (Pinus palustris). Telemetry data indicate a preference for welldeveloped herbaceous vegetation generally maintained by fire (Rudolph and Burgdorf, 1997). A close association with Baird’s pocket gopher (Geomys breviceps) is evident at all sites (Rudolph and Burgdorf, 1997). As part of a rangewide natural history study on P. ruthveni in Louisiana and Texas, we studied 30 naturally occurring (one juvenile, 16 adult males, and 13 adult females) and eight captive-bred (seven juveniles and one adult male) pine snakes in the field for up to 43 months. The objective of this paper is to characterize the growth of this rare and poorly known species. We also compare growth rates of P. ruthveni with data from other studies of Pituophis. Because of the extreme rarity of P. ruthveni, animals (N 5 38) implanted with transmitters were located in several study areas: Bienville, Sabine, and Vernon Parishes in Louisiana, and in Angelina, Jasper, Newton, and Sabine Counties in Texas. All sites are within his-

The Breeding Migration of the Mole Salamander, Ambystoma talpoideum, in Louisiana

A local population of Ambystoma talpoideum in Caddo Parish, Louisiana, was studied by mark and recapture methods to determine the duration of the breeding activity of the population, individual variations in activity periods, and sexual dimorphism in activity periods. During two breeding seasons 323 individuals (157 males, 166 females) were marked and 206 recaptures (103 males, 103 females, including multiple recaptures) were recorded. The total activity periods included 99 and 108 days (December-March). Males arrived at the breeding pond earlier than the females, remained in the pond longer, but left at approximately the same time as the females. The breeding season of the population was a composite of numerous overlapping individual breeding periods. Some individuals displayed a tenacity to emigrate in the direction of their immigration. Immigration was initiated by a combination of rain and temperatures above freezing; emigration was initiated by a combination of rain and temperatures warmer than those of the preceding immigra- tion.

A systematic revision of the genus Pseudoficimia (Serpentes: Colubridae)

The extent and nature of geographic variation in all available specimens of the snake genus Pseudoficimia (distributed in western Mexico) was studied. The genus and single species (P. frontalis) are monotypic; geographic variation exists as geographic dines (north-south). Differences between adjacent populations are not always associated with any particular area. These snakes are uncommon in collections and probably relatively uncommmon in nature; very little is known of their natural history. The hemipenis, tongue, scutellation, size, and selected features of the skeleton and reproductive systems are described. * * *

A Systematic Revision of the Colubrid Snake Genus Gyalopion

The snakes of the genus Gyalopion are distributed from the southern United States to Zacatecas and Nayarit. In addition to the standard morphological characters usually utilized in snake systematics, I examined measurements of head plates, dorsocaudal scale reduction, subcaudal scale fusions, place of origin of the hemipenial retractor muscle, and many new characters of the hemipenis, skeleton, and scutellation. The genus Gyalopion has the rostral in contact with the prefrontals and the retractor muscle originates near the terminus of the tail. Gyalopion quadrangularis has internasals and an entire anal plate and is distributed in the lowlands of western Mexico and Arizona from southern Arizona southward into Nayarit. Gyalopion canum has internasals and a divided anal plate and is distributed from southern Arizona and New Mexico, southward through southern Texas and the Mexican plateau to Durango and San Luis Potosi. Gyalopion atavus is removed from the genus Gyalopion, and synonymized with Conopsis nasus. Females of Gyalopion canum have hemipenes. Hemipenial muscles without hemipenes are

Comparative Morphology and Evolutionary Relationships of the Colubrid Snake Genera Pseudoficimia, Ficimia, and Gyalopion

Characteristics of external anatomy, osteology, hemipenis, and tongue are compared between the genera Pseudoficimia, Gyalopion, and Ficimia. The phylogenetic relationships between these genera and an important specimen, possibly intermediate between Ficimia and Gyalopion, are discussed. The possible relationships of Conopsis and Toluca to the above genera are considered. Speculations of the evolution of the species of each genus are presented.

The Karyotype of Plestiodon anthracinus (Baird, 1850) (Sauria: Scincidae): A Step Toward Solving an Enigma

Abstract The cosmopolitan lizard genus Eumeces was first revised in 1936 and consisted of 15 species-groups comprising a total of 50 species. Nine species in North America were later recognized as belonging to the genus Plestiodon and all contained the diploid chromosome number of 26. Modern cladistic techniques indicated that Plestiodon anthracinus (Coal Skink) was near the ancestral form for the fasciatus group. We employed the hypotonic citrate method to study chromosomes of 5 Coal Skink specimens from Louisiana and Arkansas and found them to have a diploid number of 24 (12 macrochromosomes, 12 distinctly smaller chromosomes, all biarmed) and a fundamental number of 48. The diploid number of 24 is probably derived by some chromosome rearrangements in the evolution of Plestiodon and of the Plestiodon anthracinus group.

GENUS SYRRHOPHUS (ANURA: LEPTODACTYLIDAE) IN LOUISIANA

Abstract The genus Syrrhophus is recorded for the first time from Louisiana due to the discovery of a population of Syrrhophus cystignathoides in Shreveport. The frogs have been documented during 4 years. Calling males and a female with large yolked eggs indicated that this species was reproducing and surviving.