Behaviour and growth of southern leopard frog (Rana sphenocephala) tadpoles: effects of food and predation risk

2001 ◽  
Vol 79 (5) ◽  
pp. 809-814 ◽  
Author(s):  
K J Babbitt
Keyword(s):  
Food Resource ◽  
Leopard Frog ◽  
Rana Sphenocephala ◽  
Food Treatment ◽  
Leopard Frogs ◽  
Resource Level ◽  
Size At Metamorphosis ◽  
Interesting Possibility ◽  
Limited Food ◽  
Level I

I examined the effects of a nonlethal predator, larvae of the odonate Anax junius, and food-resource level on behaviour and growth of larval southern leopard frogs (Rana sphenocephala) to test whether the strength of effects of a nonlethal predator was influenced by background resource level. I crossed two levels of food resources, growth-limiting and non-growth-limiting, with the presence or absence of A. junius. Tadpoles responded to predators by altering spatial distribution and activity. When predators were present, tadpoles on both food treatments had similar low levels of activity, but tadpoles on the nonlimiting food treatment showed a much larger reduction in activity than tadpoles on the growth-limiting treatment. Tadpoles on both food treatments delayed metamorphosis when exposed to predators. Growth and size at metamorphosis were affected significantly by food treatment but not by predator treatment. However, the direction of response to predators differed. Tadpoles on the growth-limiting treatment were larger at metamorphosis and grew faster when exposed to predators; the opposite was true for tadpoles on the non-growth-limited food treatment. This raises the interesting possibility that for some species experiencing low resource availability, predators may induce a behaviourally mediated positive effect on growth.

scholarly journals Calcein staining of calcified structures in pearl oyster Pinctada margaritifera and the effect of food resource level on shell growth

Aquaculture ◽  
2011 ◽  
Vol 313 (1-4) ◽  
pp. 149-155 ◽  
Author(s):  
Clémentine Linard ◽  
Yannick Gueguen ◽  
Jacques Moriceau ◽  
Claude Soyez ◽  
Bélinda Hui ◽  
...  
Keyword(s):  
Shell Growth ◽  
Food Resource ◽  
Pearl Oyster ◽  
Pinctada Margaritifera ◽  
Resource Level ◽  
Effect Of Food

Development and Survivorship of Northern Leopard Frogs (Rana pipiens) and Green Frogs (Rana clamitans) Exposed to Contaminants in the Water and Sediments of the St. Lawrence River near Cornwall, Ontario

2004 ◽  
Vol 39 (3) ◽  
pp. 160-174 ◽  
Author(s):  
Tana V. McDaniel ◽  
Megan L. Harris ◽  
Christine A. Bishop ◽  
John Struger
Keyword(s):  
Rana Pipiens ◽  
Early Stage ◽  
Sediment Quality ◽  
Leopard Frog ◽  
Reference Sites ◽  
Aquatic Life ◽  
Leopard Frogs ◽  
Water And Sediment ◽  
Northern Leopard Frogs ◽  
St Lawrence River

Abstract High levels of contamination in the aquatic environment and wildlife within the Ontario portion of the St. Lawrence River at the Cornwall Area of Concern (AOC) have raised questions about potential impacts on wildlife health. Northern leopard frog embryos were raised in two wetland sites within the AOC and at two reference sites to assess differences in water and sediment quality on survivorship and deformity rates. Chlorinated hydrocarbons (total polychlorinated biphenyls, organochlorine pesticides), polycyclic aromatic hydrocarbons, nutrients and heavy metals were measured in sediment and/or water from the study sites. Levels of some metals such as aluminium, cadmium, chromium and copper, exceeded federal and provincial guidelines for the protection of aquatic life, especially in the two AOC wetlands. Early stage tadpole survivorship was significantly lower and deformity frequency significantly higher at wetlands within the AOC; however, differences were likely not biologically significant. Survivorship and deformity rates of leopard frogs (Rana pipiens) at metamorphosis did not differ significantly among sites. Onset of metamorphosis was accelerated in tadpoles raised in wetlands within the AOC. Tadpoles raised in wetlands within the St. Lawrence River AOC took significantly less time to complete metamorphosis (53–55 days) than did tadpoles raised at reference sites (61–64 days). The phenology of metamorphosis was also more synchronous in tadpoles raised in the AOC, with all tadpoles reaching metamorphosis within a space of 3 to 7 days, as compared to 9 to 12 days at reference wetlands; these differences could not be accounted for by water temperature. Differences in development and survivorship rates between AOC and reference sites may be related to contaminant concentrations in water and sediment. However, no strong evidence for beneficial use impairment in terms of reproductive impairments or elevated deformity rates were seen from caged leopard frogs in the two AOC wetlands.

Measuring Frog Visual Acuity by a Novel Method

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 65-65
Author(s):  
A-C Aho
Keyword(s):  
Visual Acuity ◽  
Spatial Frequency ◽  
Rana Temporaria ◽  
Leopard Frog ◽  
Retinal Cell ◽  
Common Frog ◽  
Optomotor Response ◽  
Leopard Frogs ◽  
Grating Pattern ◽  
The Common

The sensory capabilities of animals have usually been measured either by lengthy conditioned discrimination procedures, or by using some specific unconditioned reflex. Amphibian visual acuity has previously been measured only by the latter type of method. Birukow's (1937 Zeitschrift für Vergleichende Physiologie25 92 – 142) optomotor response experiments on the common frog ( Rana temporaria) yielded an acuity of 4.3 cycles deg−1, which is surprisingly high in the sense that the retinal cell mosaics would suggest a substantially lower acuity. I have used a new method of measuring acuity based on the frog's prey-catching behaviour, a behaviour that has proved very useful for investigations of amphibian vision. Leopard frogs ( R. pipiens) were presented with a stimulus screen where two patches of identical black/white vertical grating were seen through two small horizontal oval windows (left and right) in a large screen displaying a horizontal grating pattern. The windows were of ‘mealworm’ size (18 mm long and 7 mm high, with the frog positioned 220 mm from the screen). One of the two vertical gratings was drifting in the window. If resolved, the movement triggered prey-catching behaviour in the frog: orienting, jumping towards the target, and even snapping. The spatial frequency of the two vertical gratings was varied, while the horizontal pattern of the screen was kept constant throughout the experiment. Orienting or jumping towards the moving grating was taken as an indication that the frog was able to resolve the spatial frequency in question. This method yielded a visual acuity of 2.8 cycles deg−1, which is in good agreement with the eye optics and the retinal grain of frogs (very similar for the common frog and the leopard frog). The method in itself implies that this is a ‘functional’ acuity value.

scholarly journals CARCINOMA IN THE LEOPARD FROG: ITS PROBABLE CAUSATION BY A VIRUS

1938 ◽  
Vol 68 (4) ◽  
pp. 457-468 ◽  
Author(s):  
Balduin Lucké
Keyword(s):  
Leopard Frog ◽  
Intranuclear Inclusions ◽  
Kidney Tumor ◽  
Cranial Cavity ◽  
Local Growth ◽  
Kidney Tumors ◽  
Epithelial Tumor ◽  
Leopard Frogs ◽  
Organ Specific ◽  
Specific Virus

An epithelial tumor with acidophilic intranuclear inclusions frequently occurs in the kidneys of leopard frogs. This tumor usually has the appearance of an infiltrating and destructive adenocarcinoma, which, when large, not uncommonly metastasizes; less often it is more orderly and adenomatous. When inoculated as living fragments or cell suspensions into the lymph sacs, the cranial cavity, or the abdomen, no significant local growth results and the implanted material is resorbed. However, in approximately 20 per cent of the frogs surviving inoculation for more than 6 months, tumors develop in the kidney, which are like the "spontaneous" neoplasms. The incidence far exceeds that in the controls. Desiccated and glycerinated tumor injected into the abdomen gives the same result as inoculation with living tumor; in somewhat over 20 per cent of animals surviving more than 6 months kidney tumors occur. In alien species of frogs, no such tumors are produced by inoculation either with living or with desiccated tumor. These experiments indicate the probability that the kidney tumor of the leopard frog is caused by an inclusion-forming, organ-specific virus.

Development and characterization of 18 microsatellite loci for the Southern Leopard Frog, Rana sphenocephala

2010 ◽  
Vol 3 (2) ◽  
pp. 267-269 ◽  
Author(s):  
Anna M. McKee ◽  
Stacey L. Lance ◽  
Kenneth L. Jones ◽  
Cris Hagen ◽  
Travis C. Glenn
Keyword(s):  
Microsatellite Loci ◽  
Leopard Frog ◽  
Rana Sphenocephala

Is there a seasonal variation in mucus transport and nutrient absorption in the leopard frog?

1992 ◽  
Vol 70 (4) ◽  
pp. 442-446 ◽  
Author(s):  
Bruce K. Rubin ◽  
Chris I. Cheeseman ◽  
Sita Gourishankar ◽  
Malcolm King
Keyword(s):  
Seasonal Variation ◽  
Seasonal Variability ◽  
Rana Pipiens ◽  
Mucociliary Clearance ◽  
Intestinal Transport ◽  
Leopard Frog ◽  
Intestinal Lumen ◽  
Leopard Frogs ◽  
Different Seasons ◽  
Frog Palate

We postulated that as a hibernating species, frogs might have variable demands for nutrients at different seasons of the year and that this must be reflected in seasonal variations of physiologic processes related to nutrient transport and absorption. We examined the rate of mucus transport on the ciliated palate and the movement of nutrients across the intestinal lumen of leopard frogs, Rana pipiens. Mucus transport on the frog palate was strongly influenced by season, with maximal transport occurring in late June (Julian day 178, p = 0.0001; r = 0.58). This increased transport rate was associated with a summertime increase in mucus recoil (lower tangent δ) and a decrease in mucus hydration (increase in percent solids composition). Intestinal transport of leucine, lysine, and galactose did not appear to exhibit seasonal variability. These data suggest that different mechanisms may operate in determining seasonal variability in physiologic responses.Key words: mucociliary clearance, mucus viscoelasticity, intestinal absorption, Anura, seasonal variation.

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