275 research outputs found
Comparisons in Morphology, Reproductive Status, and Feeding Ecology of Plethodon Cinereus at High and Low Elevations in West Virginia
To develop effects of elevation on morphological features, reproductive status, and feeding ecology of Plethodon cinereus in West Virginia, overall comparisons between high (\u3e4000 ft) and low (\u3c1260 ft) elevation populations were made. Adult P. cinereus from high elevations were smaller in SVL (female: p=0.003, male: p\u3c0.001), but stored larger amounts of fat (female: p=0.041, male: p=0.006) in their tails than fromlow elevations. Larger amounts of tail fat could be an adaptation to harsh environments at high elevations. It was determined that in West Virginia, where as females at low elevations oviposit annually, females at high elevations oviposit biennially. Stomach content analysis revealed that salamanders at high elevations were confronted by food shortage. Because of less prey availability and longer winters at high elevations, salamanders at high elevations attained the smaller body size than at low elevations and could not obtain sufficient energy in 1 year to yolk a clutch
Paternal Care Behaviors of Japanese Giant Salamander Andrias japonicus in Natural Populations
Abstract
Parental care among salamanders is typically provided by females. A rare case of parental care by male salamanders appears to occur in Cryptobranchidae. Yet, paternal behaviors have rarely been reported from natural populations of any Cryptobranchid salamanders, and their adaptive significance is poorly understood. The present study aimed to examine paternal care behaviors in a fully aquatic Japanese giant salamander (Andrias japonicus) in situ. At the beginning of the summer breeding season, large males, called den-masters, occupy burrows along stream banks for breeding and nesting. We videotaped post-breeding behaviors of two den-masters that stayed with the eggs, one in a natural and the other in an artificial nest in natural streams. We identified three behaviors, tail fanning, agitating and egg eating, to be parental care. Tail fanning provides oxygenated water for the eggs. We found that the den-master in the artificial nest, where dissolved oxygen level was lower, displayed tail fanning more frequently. Agitating the eggs with its head and body likely prevents yolk adhesions. The den-masters selectively ate whiter eggs that appeared to be dead or infected with water mold. This behavior, which we termed hygienic filial cannibalism, likely prevents water mold from spreading over healthy eggs. Digital video images relating to this article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo140906aj01a, http://www.momo-p.com/showdetail-e.php?movieid=momo140906aj02a, http://www.momo-p.com/showdetail-e.php?movieid=momo140906aj03a and http://www.momo-p.com/showdetail-e.php?movieid=momo140906aj04a.</jats:p
The Effects of Road Salt (NaCl), Predation, and Competition on the Growth and Community Interactions of Spotted Salamanders (Ambystoma maculatum) and Wood Frogs (Lithobates sylvaticus)
Road deicing salts are frequently used in northern regions of the world during the winter and early spring months. As a result, a significant portion of road runoff into surrounding aquatic habitats contains road deicing salts. Previous studies found road salt contaminations in vernal pools that pond-breeding amphibians commonly use, including spotted salamanders (Ambystoma maculatum) and wood frogs (Lithobates sylvaticus). Studies have examined the impact of road salt on both amphibian species, but to our knowledge no previous studies have examined how road salt impacts the interspecific competition between both amphibians. We hypothesized that road salt would negatively impact growth and survivorship of both amphibian species. During the spring and summer of 2017, we conducted an outdoor mesocosm experiment in which we created eight experimental conditions with three main factors:presence/absence of NaCl (1000 mg/L Cl ), presence/absence of interspecific competition between the two amphibian species (A. maculatum and L. sylvaticus ), and presence/absence of predatory dragonfly larvae (Family Libellulidae). Our experiment revealed that salt delayed hatching and increased deformity in spotted salamander hatchlings. Additionally, salt reduced salamander survivorship by 62% and frog survivorship by 30%. Wood frog tadpoles and road salt interacted to diminish salamander survivorship a further 80% beyond salt alone, likely through an increase in interspecific competition. Road salt increased the larval period of salamanders and decreased the proportion metamorphosed by the end of the experiment. Dragonfly larvae reduced salamander survivorship by 35%, whereas they increased wood frog tadpole development rates. Dragonfly larvae and salt interacted to alter tadpole denticle size, with salt negating the impact of dragonfly larvae. Thus, we found that salt interfered with aquatic predatory chemical cues. Overall, the results of this study suggest that management strategies should be implemented in order to reduce the impact of road salts on freshwater aquatic ecosystems
The Role of Olfactory Cues in the Sequential Radiation of a Gall-boring Beetle, Mordellistena convicta
1. Herbivorous insects often have close associations with specific host plants, and their preferences for mating and ovipositing on a specific host-plant species can reproductively isolate populations, facilitating ecological speciation. Volatile emissions from host plants can play a major role in assisting herbivores to locate their natal host plants and thus facilitate assortative mating and host-specific oviposition.
2. The present study investigated the role of host-plant volatiles in host fidelity and oviposition preference of the gall-boring, inquiline beetle, Mordellistena convicta LeConte (Coleoptera: Mordellidae), using Y-tube olfactometers. Previous studies suggest that the gall-boring beetle is undergoing sequential host-associated divergence by utilising the resources that are created by the diverging populations of the gall fly, Eurosta solidaginis Fitch (Diptera: Tephritidae), which induces galls on the stems of goldenrods including Solidago altissima L. (Asteraceae) and Solidago gigantea Ait.
3. Our results show that M. convicta adults are attracted to galls on their natal host plant, avoid the alternate host galls, and do not respond to volatile emissions from their host-plant stems.
4. These findings suggest that the gall-boring beetles can orient to the volatile chemicals from host galls, and that beetles can use them to identify suitable sites for mating and/or oviposition. Host-associated mating and oviposition likely play a role in the sequential radiation of the gall-boring beetle
Sodium-metal-promoted reductive 1,2-syn-diboration of alkynes with reduction-resistant trimethoxyborane
Reductive 1, 2-diboration of alkynes has been accomplished by means of sodium dispersion in the presence of trimethoxyborane as a reduction-resistant boron electrophile. Two boron moieties can be introduced onto alkynes with excellent syn selectivity to afford the corresponding (Z)-1, 2-diborylalkenes. Bis(borate) species generated in situ can be involved in one-pot Suzuki-Miyaura arylation, formal arylboration of alkynes thus being executed
A case of type 1 facioscapulohumeral muscular dystrophy (FSHD) with restrictive ventilatory defect and congestive heart failure
[Background] Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscle disease characterized by asymmetric involvement of muscles in the face, upper extremity, trunk, and lower extremity regions, with variable severity. It was recently reported that restrictive respiratory involvement is more frequent and severe than previously recognized, while cardiac dysfunction other than arrhythmia is still considered extremely rare in FSHD. [Case report] A 59-year-old man presenting with marked muscle atrophy in the trunk and asymmetrical muscle atrophy in the legs was hospitalized because of dyspnea and edema in the face and limbs. Shortness of breath with body movement started from approximately 40 years of age. Muscle biopsy revealed myopathic change with mild to moderate variation in fiber size. The diagnosis of FSHD was made by D4Z4 contraction to three repeats on genetic testing. A pulmonary function test revealed a decline of forced vital capacity (FVC) and a preserved FEV1/FVC indicating restrictive ventilatory defect (RVD). Ultrasonic echocardiogram (UCG) showed diffuse left ventricular hypokinesis, ventricular septum thickening, pericardial effusion, and decreased ejection fraction (LVEF 30%). [Conclusion] Although restrictive ventilatory defect and congestive heart failure are uncommon in FSHD, respiratory and cardiac evaluation may be necessary in patients with FSHD
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