Post-metamorphic growth and the reproductive cycle of the eastern narrowmouth toad (Gastrophryne carolinensis) were studied from 204 individuals collected during the AprilAugust 1989 activity season ina two-county area of northeastern Arkansas near the northwestern edge of the species' geographic range. Late summer metamorphs require a fullgrowing season before they can reproduce as they approach their second year of life. The oldest individuals may be at least five years old. By late April, gonadal cycles of adults had commenced; the males were producing sperm, and some of the females were gravid. Fertility ofboth sexes increased during the season and peaked inJune. Males remained fertile through August, but only two gravid females were found after June indicating that adults were physiologically capable of breeding for a period longer than weather conditions were acceptable for oviposition. Neither clutch size nor ovum diameter increased with female body size. Disparity of body size and clutch characteristics throughout the brief breeding season could be explained by deposition of partial clutches. The growth, maturity, and gonadal cycle of this species at the northern edge of its range are similar to findings in southern populations, and climate, not changes inbreeding physiology, constrain breeding at this northern site. collected on 31 separate dates by one of us (RLC) during April-August 1989 from a two-county area (Craighead and Greene) innortheast Arkansas. Individuals were killed ina 20% solution of chloretone and fixed in 10% formalin within 24 hr of capture. Specimens were eventually transferred to 70% ethanol and are currently deposited in the herpetology collection at Arkansas State University (ASUMZ). Introduction The eastern narrowmouth toad, Gastrophryne carolinensis, is a small, semi-fossorial, microhylid species that attains a maximum body length of 38 mm (Conant and Collins, 1998). This species ranges throughout the southeastern and southcentral United States (from Maryland westward to central Missouri and southward to central Texas). Anderson (1954) provided the most thorough study of the ecology of G. carolinensis from populations in Louisiana. Recently, Meshaka and Woolfenden (1999) explained geographic variation incalling and reproductive seasons of G. carolinensis to fit within a framework of climatic constraints. Nelson (1972) summarized the literature on this species; however, quantitative life history information on this species is still rare. In the present study, we report onpopulation structure and reproduction from samples collected during one season from sites near the northwestern edge of its geographic range and relate our finding with those of more southerly locations. Body size of preserved specimens was measured in snout-vent length (SVL) with calipers to the nearest 0.1 mm. Routine histological techniques were used to prepare the testes of 87 males for light microscopy following standard methods (Humason, 1979). Testes were dehydrated in a graded series of ethanol, cleared with xylene, infiltrated and embedded inparaffin, sectioned into serial ribbons (8 (imin thickness), affixed to microscope slides using Haupt's adhesive, stained with Harris hematoxylin followed by eosin counterstaining (H & E), and mounted with coverslips. Maturation of sperm was categorized using the two phase system for G. carolinensis of Anderson (1954). Phase I(Ph-1) =recrudescence (i.e., increased mitotic activity) within the primary spermatogonial cysts following the breeding season. Ph-2 =a proliferation of clusters of secondary spermatocytes and spermatids which dominate the germinal epithelium. Materials and Methods Post-metamorphic individuals of G. carolinensis were After being blotted dry, the ovaries were massed (to the Journal of the Arkansas Academy of Science, Vol. 53, 1999

Female reproductive characteristics of 17 genera of Arkansas snakes (27 species and subspecies) were examined. Most of the snakes (n= 495) were collected over a 10-year span (1984-1993). Methods used to estimate clutch and/or litter size were as follows: 1) counts of previtellogenic ovarian follicles,2) counts ofvitellogenic ovarian follicles,3) counts of oviductal eggs or embryos, 4) counts of corpora luteal scars, and 5) counts of neonates from egg clutches or litters. Inseveral species, Method 1 tended to overestimate clutch size as determined by Mediod 2 by as much as 100% (e.g., inDiadophis punctatus, Elaphe obsoleta, and Lampropeltis getula), whereas these methods produced similar counts in Virginia striatula and Thamnophis proximus. The largest clutch size as estimated byMethod 1was 79 ova in a 744 mmin snout-vent length (SVL) individual of Thamnophis sirtalis; the smallest clutch size as recorded by this method was in Carphophis vermis (2 ova; 182 mm inSVL).Method 2 reduces the total egg count by one third over Method 1inmost species, and this count was very similar to the estimates obtained byMethod 3, the most reliable way to estimate clutch or litter size (without actually having counts from egg clutches or litters). The presence of atretic ovarian follicles accounts for discrepancies found between clutch size estimates using Methods 1and 2 as compared to Method 3. Comparisons of clutch sizes inArkansas specimens to those recorded for snake species inneighboring states revealed similar sizes in 13 species; counts were larger in 8 species from Arkansas and smaller inonly one species.

Seasonal reproductive phenomena in 13 species of salamanders and 1 6 species of anurans from Arkansas were investigated. Most specimens were collected during a span of 6 years (1985-1 990). Clutch characteristics, including mensural and meristic data, were determined from gravid females. Insome species, the size of egg masses was also documented. Among the plethodontid salamanders, average clutch size (in parentheses) was greatest in Eurycea lucifuga (77.7) and smallest inPlethodon serratus (7.0). One of 2 ambystomatid salamanders (Ambystoma texanum) averaged 545.4 eggs per clutch; the other species (Ambystoma tigrinum) averaged 130.5. Siren intermedia nettingi(one of3 large salamanders examined) had the greatest mean clutch size (851.3). Among anurans, Rana catesbeiana had the largest clutch size and mass (43,073 eggs and 55.9 g), whereas clutches of Acris crepitans blanchardi averaged the smallest (264.1 eggs and 0.1 382 g). Multiple clutch production may be the rule in some amphibians (e.g., Desmognathus brimleyorum, A. c. blanchardi, Pseudacris triseriata feriarum, and P. streckeri streckeri); however, partial clutch deposition remains a possibility in these species. By knowing the synchrony between male and female reproductive cycles, a clarification of the onset, timing, and duration of reproductive phenophases (e.g., courtship, breeding, egg laying, etc.) was documented in many species.