Exam 1 Questions Flashcards
Explain the importance of amphibian skin morphology. List important functions.
Amphibian skin morphology is important as it helps amphibians live in both aquatic and terrestrial environments. The skin is highly glandular which provides protection through the poisons produced. In general, the skin helps with defense, communication, camouflage, and gas exchange
Why are amphibians considered bioindicators? What implications does this definition have on conservation of amphibian species and wider ecosystems?
Amphibians are considered bioindicators as the status of the environment and any pollutants in it can affect the health and populations of amphibians, such that they are sensitive to habitat destruction and pollution. This definition shows that conservation of these species are important as they help us regulate and conserve ecosystems. As pollutants and habitat destruction increase, amphibian larval survival and development decrease
Describe the important relationship between the diverse behavioral vocalizations of anurans and their well-developed hearing physiology: listing different calls and their purpose?
Vocalizations are used for various social interactions such as territoriality, reproduction, and predator avoidance. Long distance vocalizations are used for reproduction/advertisement calls and distress calls. Close-range calls are used for courtship, encounter, and reciprocation calls. The call itself has several components that make it unique, such as the dominant frequency (pitch), the duration, and the pulse rate.
What differentiates amphibians from their fish ancestors and other tetrapod vertebrates?
Amphibians are different from fish ancestors and other tetrapod vertebrates due to their offspring development, as well as they are cold-blooded
How do amphibians’ role in their environment impact different ecosystem services?
a. Cultural
b. Provision
c. Regulatory
d. Supporting
a. Cultural: mythology, literature, art
b. Provisional: food, drugs
c. Regulatory: predation of mosquitos
d. Supporting: structural to ecosystem (aquatic turbidity)
What are carotenoids, and how do they reflect the nutritional status of amphibians?
Carotenoids are pigments that are found within xanthophores in a dermal chromatophore unit. They are important for coloration but also play important roles in antioxidant and immune defenses. They are only acquired via the diet
Describe the process by which coloration or pigmentation is used as cues for mating.
Once individuals have met their basic physiological needs (antioxidant and immune responses), organisms can devote excess carotenoids to investing in coloration in order to enhance their display and appearance for mating. For this reason, healthier organisms will have more carotenoids and will be able to devote more resources to their coloration after meeting their initial basic needs.
Give an example of how genetic isolation due to geographical barriers can impact populations of amphibians.
When geographical barriers are present, organisms on either side of the barrier cannot mate with one another, which often leads in speciation because of the genetic isolation. The population of A. callidryas is currently geographically isolated because of the central mountain ranges in Costa Rica, resulting in two different “morphs” or populations that look distinct from one another.
Assessing nutritional status of organisms can be difficult in free-living species. Provide examples of what analyses can be used to determine and estimate the health of amphibians.
When nutritional status is difficult to assess because a species is free-living, it can be measured by estimating body condition (measuring and comparing size and weight) and measuring metabolite concentrations within the blood.
Describe Batrachochytrium dendrobatidis (Bd) and how it impacts amphibians.
Bd is a dangerous fungal pathogen that impacts amphibians by resulting in a deadly skin disease called chytridiomycosis. This pathogen led to many deaths and several declines in amphibian populations in the 1980s and 1990s, and the pathogen is still prevalent in many populations.
Briefly explain how amphibian coloration can change in response to changes in environment.
Amphibians are very sensitive to changes in environmental conditions. Climate change, UV radiation, chemical contaminants, diseases, and many other factors can lead to a change in coloration and even a decline in amphibian populations because of the importance of color for mating success. Many differences in markers were observed in the study between the two A. callidryas populations that were attributed to differences in environment by the researchers.
How many amphibian orders exist? Name them, and give the common name for an organism from each
Three orders exist: Anura (frogs), Caudata (salamanders), and Gymnophiona (caecilians).
Explain the difference between infection prevalence and infection load
Infection prevalence is the number or percentage of organisms in a population that are infected with a pathogen or microbe, while infection load is the relative amount of pathogen present in an organism (often controls the severity of the infection.)
Describe what foraging-reproduction habitat index (FRHI) is and name the three categories of life history traits that make up the classification.
This is a method of classification the researchers used in order to group organisms based on life history traits that reflected their foraging and reproduction habits. The organisms were classified according to their development, foraging habitat, and reproductive habitat.
As suggested in the paper, how are mountainous habitats in higher elevations able to facilitate a greater level of diversity among amphibians?
The mountain ranges were able to provide numerous microhabitats for niche differentiation because of the differences in altitude, allowing for increased speciation and ultimately higher diversity.
When looking at a Spectacled Caiman and an American Crocodile, what about their head/snout allows you to distinguish one from the other?
American Crocodiles have a longer and narrower snout, with the 4th tooth on the bottom jaw protruding from the mouth. The spectacled Caiman has a short and stout snout with no exposed teeth.
Differentiate between the Plastron of mud turtles, which makes them different from pond turtles?
Mud turtles have two hinges, allowing them to close their shells completely. Pond turtles only have a single hinge.
What adaptations have reptiles evolved to allow them to survive on land?
a. Rough and scaly skin reduces abrasion to the skin.
b. A more robust and complex circular system compared to amphibians supports a more extensive skeletomuscular system.
c. Eggs are encased in a complex membrane that prevents water loss and does not require water to survive.
What adaptations of some geckos and other lizards have been utilized to get away from predators?
a. Geckos and a few other lizards have developed the ability to drop their tails. When dropped, the tails wiggle around, attracting the predator and allowing the gecko to run away to cover.
b. Addition of suction pads to promote climbing.
c. Crypsis of skin to hide from predators.
How are the fangs between coral snakes and vipers similar? How are they different?
The fangs of a coral snake and vipers are large and hollow. They are different because coral snakes’ fangs do not hinge. Therefore, they are always up. Vipers can hinge their fangs.
Provide examples of direct and indirect services provided by amphibians and reptiles.
Reptiles provided direct services such as a main source of protein, provides materials for trade such as handbags, and even ecotourism. In Costa Rica, turtle watching tourism is very popular. Indirect services provided include disease and pest control, and along with seed dispersal of fleshy fruits and plants. For example, the spiny iguana and black wood turtles of Costa Rica were mentioned to provide a varied of seeds.
What is the difference between ecosystem services and ecosystem functions? Discuss functions provided by reptiles and amphibians.
Ecosystem services are benefits humans gain from functioning ecosystems, and ecosystem functions are the physicochemical and biological processes that occur in the ecosystem to maintain life. Reptiles disperse seeds and participate in nutrient cycling that is vital to plant propagation in some systems, along with being ecologically and economically important food sources for urban and rural communities.
Why is it important to consider the benefits humans societies gain from reptiles and amphibians?
It is important because the decline in reptile and amphibian populations in turn affects the ecosystem services they provide. The development of conservation plans for species could directly and indirectly help protect the ecosystem services provided by the organism.
How do reptiles provide ecosystem services to rural and urban communities?
Reptiles provide a variety of ecosystem services. Some direct services they provide are provisionary services such as a main source of protein, along with medical resources and are used in trade.
Why is it beneficial to humans to have an ecosystem service that is provided by more than one species of reptiles and amphibians?
It is beneficial to humanity to have more than one reptile and amphibian supporting an ecosystem service because that means that service is more resilient to potential threats. If a service is strictly provided by one reptile or amphibian, then the endangerment of that species could lead to the loss of that service as well.
What is color plasticity and what factors influence rapid color change?
Color plasticity is the expression of different coloration in response to an environmental factor. Some reasons for rapid color change could be to avoid predators, response to abiotic challenges, and conspecifics.
What are some of the reasons for the brightening coloration of Anolis aquaticus in response to environmental stressors?
The bright coloration of the anoles in this study could offer camouflage in their environment as they spend a lot of time on moss-speckled riverbanks. Bright colors cause disruptive camouflage in bright surfaces. Furthermore, bright colors might be linked to stress because moss speckled environments tend to be more exposed. Another reason discussed could be to show off success to other taxa.
How do green anoles and water anoles differ in their coloration when exposed to a mild stressor?
The green anoles’ coloration turned from green to brown due to increased light exposure and changed from brown to green in response to total darkness. Furthermore, time was strongly correlated in their color as most anoles were green at night and variable during the day. In contrast, the Anolis aquaticus in this study turned brighter in response to stressors such as increased light exposure every time. The saturation and hue of the water anoles’ were not affected by time.
What is the melanocyte-stimulating hormone (MSH), and what effect does it have on anole coloration.
The MSH hormone produces receptors that regulate skin coloration. These receptors are the alpha-receptor and the beta-receptor. The alpha receptor correlates with bright colors and the beat-receptor dark colors. A hypothesis for why Anolis aquaticus brighten in response to stress is that they lack beta-receptors that acquire the dark coloration.
