THE PAROTOID GLAND OF THE TOAD, BUFO AMERICANUS

1956 ◽  
Vol 34 (3) ◽  
pp. 174-177 ◽  
Author(s):  
David J. McCallion
Keyword(s):  
Histological Study ◽  
Poison Gland ◽  
Glandular Epithelium ◽  
Bufo Americanus ◽  
Large Vesicle ◽  
Poison Glands ◽  
Toad Bufo

A histological study of the poison glands of the toad demonstrated that one of the components of their secretion is adrenalin or adrenalin precursor substances. The poison glands are arranged in aggregates of two or three making up the warts on the skin. Larger aggregates of poison glands on the head are the parotoid glands. Each poison gland is a large vesicle, deep in the corium of the skin, and opening through a pore in the skin by way of a conical duct. The glandular epithelium of the poison gland is a flat acellular layer of cytoplasm containing a large number of flattened nuclei. Forcibly discharged glands disintegrate, are resorbed, and are replaced by new glands regenerated from the Malpighian layer of the epidermis.

Characterization of the spermiation response, luteinizing hormone release and sperm quality in the American toad (Bufo americanus) and the endangered Wyoming toad (Bufo baxteri)

2000 ◽  
Vol 12 (2) ◽  
pp. 51 ◽  
Author(s):  
Amy R. Obringer ◽  
Justine K. O'Brien ◽  
Robin L. Saunders ◽  
Kazutoshi Yamamoto ◽  
Sakae Kikuyama ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Sampling Interval ◽  
Sperm Production ◽  
Bufo Americanus ◽  
American Toad ◽  
Non Invasive ◽  
Lh Release ◽  
Wyoming Toad ◽  
Toad Bufo

Spermiation and LH release in response to several methods of LHRH administration were assessed in the American toad (Bufo americanus), and the most successful method was tested in the endangered Wyoming toad (Bufo baxteri). Specific objectives were to: (1) compare spermiation responses and plasma LH concentration after invasive and non-invasive LHRH treatments; (2) evaluate sperm production in response to different LHRH dosages; (3) characterize the timing of sperm release post LHRH treatment; and (4) assess sperm quality (motility, viability, morphology and acrosomal status). Male American toads were administered 4 g LHRH by one of four routes: (1) intraperitoneal injection (IP); (2) subcutaneous injection (SQ); (3) dorsal dermis absorption (DDA); and (4) ventral dermis absorption (VDA). Aspermic urine only was collected from saline-treated controls and DDA animals. Several VDA animals released spermic urine; however, all LHRH-injected toads released spermatozoa. IP animals produced higher sperm and LH concentrations than SQ animals. The spermiation response in animals treated IP with 1 g LHRH was similar to that in animals treated with 4 g, but lower LHRH dosages tested produced inferior responses. Sperm production in responsive animals increased over time during the 12-h sampling interval. Regardless of treatment, most American toad spermatozoa were motile, viable, and acrosome-intact. Endangered Wyoming toads were treated IP with 4 g LHRH, and spermic urine was collected. Although most spermatozoa were viable and acrosome-intact, a considerable percentage possessed structurally abnormal heads. A single IP injection of LHRH appears to be a reliable and safe method for controlling spermiation in toads and may be useful for assisting endangered amphibian propagation.

The extent of long-term temperature compensation for jumping distance in the frog, Rana pipiens, and the toad, Bufo americanus

1983 ◽  
Vol 61 (6) ◽  
pp. 1284-1287 ◽  
Author(s):  
J. M. Renaud ◽  
E. D. Stevens
Keyword(s):  
Nervous System ◽  
Test Temperature ◽  
Temperature Compensation ◽  
Rana Pipiens ◽  
Acclimation Temperature ◽  
Thermal Compensation ◽  
Muscular System ◽  
Bufo Americanus ◽  
Toad Bufo

The effects of acclimation to either 5 or 25 °C were studied on the longest jumping distances of Rana pipiens and Bufo americanus to estimate their capacity for long-term compensation. Animals were tested randomly at 5, 10, 15, 20, and 25 °C. Both Rana and Bufo jumped further at higher temperatures. For both species, acclimation temperature modified the effect of test temperature. At test temperatures of 20 and 25 °C, frogs acclimated to 25 °C jumped further than those acclimated to 5 °C. There was no evidence for thermal compensation in toads, but half of those acclimated to 25 °C would not jump when tested at 5 °C, whereas only 1 out of 16 cold-acclimated toads did not jump. We suggest that the acclimation effects on the jumping ability of R. pipiens at high temperatures are important in increasing their ability to escape predation and that this effect depends on an effect on the nervous system rather than the muscular system.

Toxicity of Amphibian Breeding Ponds in the Sudbury Region

1993 ◽  
Vol 50 (7) ◽  
pp. 1497-1503 ◽  
Author(s):  
Joseph Freda ◽  
D. Gordon McDonald
Keyword(s):  
Organic Compounds ◽  
Rana Sylvatica ◽  
Low Ph ◽  
Ambystoma Maculatum ◽  
Bufo Americanus ◽  
Spotted Salamander ◽  
Water Ph ◽  
Dissolved Organic Compounds ◽  
High Concentrations ◽  
Toad Bufo

We measured the survival of transplanted embryos and tadpoles of the wood frog (Rana sylvatica), the American toad (Bufo americanus), and the spotted salamander (Ambystoma maculatum) in 16 ponds located approximately 60 km south of Sudbury, Ontario. Mortality of embryos of all species and mortality of B. americanus tadpoles were correlated only with water pH. In two low-pH ponds, high concentrations of dissolved organic compounds might have been a toxic component. Aluminum and pH were correlated with mortality for only R. sylvatica tadpoles. Overall, Al did not appear to be very toxic in both laboratory and field exposures possibly due to complexation by dissolved organic compounds.

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