Ocoee salamander | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Urodela |
Family: | Plethodontidae |
Subfamily: | Plethodontinae |
Genus: | Desmognathus |
Species: | D. ocoee |
Binomial name | |
Desmognathus ocoee Nicholls, 1949 | |
The ocoee salamander (Desmognathus ocoee) is a species of salamander in the family Plethodontidae. This salamander has a variety of colors and patterns, and got its name from Tennessee state wildflower. Its natural habitats are temperate forests, rivers, intermittent rivers, freshwater springs and wet rocks in mountainous areas of the Southeastern United States. It was first described by Nicholls in 1949. [2] [3] They are territorial and feed on small invertebrates. It is widely distributed in the southeastern United States and is listed as "Least Concern" by the International Union for Conservation of Nature. [1]
The ocoee salamander (Desmognathus ocoee) is a small mountain dusky salamander that exhibits a wide range of colors and patterns. The species got its name from the Tennessee state wildflower and symbol Passiflora incarnata (passionflower), which is termed "ocoee" in the Cherokee tribe. The Ocoee River and the Ocoee salamander were thus named after the Cherokee word for passionflower. [4] Some individuals have distinct red, yellow, or orange patches on their legs and cheeks. Populations in central Tennessee, northwestern Georgia, and northeastern Alabama usually have a dark brown or black color, and faded larval spots. Compared to other Desmognathus species, Desmognathus ocoee have smaller bodies (around 7–11 cm), shorter and narrower heads, longer limbs, and no vomerine teeth in adult males. [4] Juveniles have pairs of alternating pale spots on their middorsal line. As they move on to adulthood, these spots might fuse. [5]
The ocoee salamander is found in two separate populations. The more numerous is in the Blue Ridge Mountains and at lower levels in the gorges of the rivers Hiwassee, Ocoee, Tugaloo and Tallulah. The less numerous population is in the Appalachian Plateau in northeastern Alabama. It is found over a greater range of altitudes than other members of the genus Desmognathus . At lower levels it is an aquatic species but at higher altitudes it is mostly terrestrial. It is found close to fast flowing mountain streams, in seepage areas, on moist forest floors and on wet rocks. In cove valleys in the Appalachian Mountains it prefers hardwood forests with trees that are more than eighty-five years old. [6]
Semi-aquatic salamanders like the ocoee contribute considerably to the terrestrial vertebrate biomass. They depend on water for reproduction, but their short larval period allows them to take advantage of wetted habitats such as small streams and wet rock faces. Despite this, they are the most terrestrial of the stream-breeding Desmognathus salamanders. Under moist conditions, they will leave streambeds and move into the forest. They prefer cove forests of more than 85 years of age, with a significant amount of emergent rocks. These rocks are important for soil moisture retention, and are thus vital for the survival of D. ocoee eggs during brooding. As vertebrate predators, D. ocoee are integral to the dynamics of the food webs around their habitat. They can often be found some distance from a water source, usually in the forest at higher elevations. Population densities on wet rock faces are around six adults per meter square. Overall, the population trends for the ocoee salamanders in the Appalachian Mountains have not changed significantly in the last twenty years. [7]
The ocoee salamander has gone through various classifications in the last century. Originally considered as a single species ( D. ochrophaeus ), populations of Desmognathus salamanders across the Appalachians are now divided into five distinct species D. abditus , D. carolinensis , D. ochrophaeus, D. ocoee, and D. orestes . These five species do not form a phylogenetic clade and are differently related to one another, but complete reproductive isolation is rarely observed in distantly related Desmognathus, and thus some hybridization between geographically-close lineages occurs. The "gray zone" that contains the potential arguments on species delimitation still exists, but genetic analyses provide enough evidence for the delimitation of these five species. [4]
Before the advancement of genetic and molecular techniques, the classification of plethodontids was limited by geographical and morphological differences between individuals and groups. This was not a very accurate method for taxonomy because the color patterns and phenotypic variations among the family of Plethodontids was conserved and the genetic underpinnings of these morphological traits were not well known. In genetic studies in the past few decades, by the use of biochemical markers, it has been shown that this conservatism of morphological traits in many of the salamanders of the family Plethodontidae actually sometimes masks complex patterns of genetic differentiation. These genetic studies ultimately allowed for better-defined species delimitation of Desmognathus ocoee. [8]
The ocoee salamander maintains a small territory when on land, which it defends against other conspecific members. The Ocoee salamanders feed on insects and other small invertebrates. Potential prey species include flies, ants, wasps, beetles, spiders, mites.
Studies suggest that larval D. ocoee prefer to feed at low elevation rock faces and high elevation woodland habitats over high elevation rock faces. This is likely due to the cooler environment associated with elevated altitudes, which reduces the salamander's general activity levels. [9]
The ocoee salamander was used as a study subject to measure the impact of stress on feeding behavior. Stress was induced either by 1) repeated handling, or 2) CORT glucocorticoid hormone administered via a dermal patch. Both stressful conditions led to reduced feeding in females, and reduced activity and body weight in both sexes compared to a control group. [10]
It is preyed upon by birds, snakes, and even another species of salamander. The ocoee salamander has developed many different anti-predator defenses to use in different situations. When approached by a predator it may remain immobile, but is more likely to flee when it encounters the Spring salamander (Gyrinophilusporphyriticus). The salamanders are also prone to autotomizing the tail to avoid an attack. When attacked by a snake, ocoee salamanders writhe about and try to bite the snake on the head. [6]
Pheromonal communication is very common in salamanders, newts, and even in some frogs and toads. Pheromones are chemosensory stimuli that are used to signal information between individuals of the same species. In vertebrates, there are two types of pheromones. Releasing pheromones are usually peptides and proteins that influence behaviors (such as male-female or male-male interactions) through neural systems that detect and process pheromones. Priming pheromones modify the endocrine system or the psychological mood of the individual. Usually, these different types of pheromones exist as a mixture, so they have complex behavioral and psychological effects. Pheromones from other individuals are detected by the chemosensory receptors on the vomeronasal organ and main olfactory epithelium. [11] Chemosensory cues such as pheromones play an important role in mating because they bring males and females together in both aquatic and terrestrial environments. These cues can signal a variety of information to others in the surrounding area, including the species, sex, and the reproductive condition of the individual. Once suitable partners have been attracted, these cues can also help determine mate quality. [11]
Sexually active adults use a variety of tools to court each other before copulation occurs. As is common in the plethodontids, a female is exposed to tactile, chemical, and visual stimuli presented by the male. The females will also signal attraction through chemical cues, reduced tendencies to flee from courting males, and a willingness to engage in tail-straddle walk, which is the phase in courtship where insemination occurs. This course of behaviors from both individuals will lead to successful copulation. [12]
Ocoee salamanders do internal fertilization. When a female is ready for mating, the male uses a spermatophore to transfer his sperm to a female. A spermatophore is a gelatinous capsule containing spermatozoa, and it is accepted into the female's reproductive organ, the cloaca, where it is stored until fertilization. The male typically leads the female to the spermatophore for her to pick it up. [11]
Ocoee salamanders do internal fertilization and thus postcopulatory sexual selection plays an important role in their reproduction. In adult Desmognathus ocoee, the mating period lasts from early fall to late spring. Females tend to engage in multiple matings throughout these 9 months, and store sperm in their bodies for extensive periods. This means that a clutch of female eggs can be fertilized by stored sperm from multiple competing males. Usually it is around two to three males. Sperm competition within males is thus an important aspect of sexual selection. Sperm from the males are stored in spermatheca, an organ in the female's reproductive tract, until June and July, during which ovulation, fertilization, and oviposition all occur rapidly. Until the fertilization event, sperm require hospitable conditions to survive in, and are stored in the spermatheca, where they remain viable. [13]
Females that experience courtship that ends with successful insemination do not become inseminated when they encounter sexually active males for about four nights after the first insemination. This is caused by a temporary inhibition of female sexual responsiveness, which happens during the initial insemination. Upon the female taking in the spermatophore into her reproductive tract, the sperm mass remains externally visible in the female's cloaca for around 38 hours. This extended stay of the sperm mass likely results in tactical and chemical stimulation, which inhibits the female's sexual responsiveness and her willingness to perform behavioral patterns necessary for successful courtship and sperm transfer. Ultimately, this seems to be a mechanism developed in males to compete with other males for egg fertilization. [12]
Oviposition occurs from June to September on land, after which the female tends her clutch of 9–32 eggs for 6–8 weeks. Clutch sizes can vary from female to female, and is closely related to the body size of the female. During oviposition, females tend to deposit their eggs in cavities under rocks, moss, decaying logs, leaf litter, springs, and behind vegetation or in other crevices. It is important to pick a spot with just enough moisture to avoid the desiccation and loss of eggs. [13]
After oviposition, maternal care for the clutch lasts for about 3 months, and ends after the eggs hatch into larvae. Maternal care during brooding includes defense against predators, removal of dead eggs, reduction of egg desiccation and fungal infections, and helping the hatchlings with cracking open their shells. If left unguarded, the eggs are in danger of being eaten by surrounding salamanders. Males do not provide resources to either the female or the offspring. [13]
Oophagy seems to be a normal behavior in brooding females, but is usually suppressed. In the case of limited foraging availability, disturbed or starved females may choose to eat their own eggs. This may also be done if the egg is dead—the female will eat the dead egg in order to remove it from the clutch before it infects other eggs around it. Fungal infections from dead eggs (if not removed in time) will usually lead to the embryos in viable eggs being smothered and killed. [14]
Larvae are smaller than in other subspecies, reaching around 8–10 mm at hatching. Upon hatching, D. ocoee larvae have short and silvery external gills, and they often have distinctive larval spots that other species do not have. The tails of the larvae are keeled and they narrow to a knife edge along the dorsal surface. Once out of the egg, the larvae quickly disperse to a nearby water source. During their development, they are found in shallow waters or in thin films of water, they feed on small aquatic invertebrates. In captivity, they can also eat worms. Usually, the larvae metamorphose into their adult form in the following few weeks, the time depending on the availability of food, other resources in the environment, and the temperature. [15]
The ocoee salamander is one of the most common salamanders in the southern Appalachian Mountains. It is believed to have a large and stable population and much of its range lies in state parks or other protected areas. It faces few threats and is listed as being of "Least Concern" in the IUCN Red List of Threatened Species. [1]
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten extant salamander families are grouped together under the order Urodela from the group Caudata. Salamander diversity is highest in eastern North America, especially in the Appalachian Mountains; most species are found in the Holarctic realm, with some species present in the Neotropical realm.
Plethodontidae, or lungless salamanders, are a family of salamanders. With over 500 species, lungless salamanders are by far the largest family of salamanders in terms of their diversity. Most species are native to the Western Hemisphere, from British Columbia to Brazil. Only two extant genera occur in the Eastern Hemisphere: Speleomantes and Karsenia.
Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction. For internal fertilization to happen there needs to be a method for the male to introduce the sperm into the female's reproductive tract.
The cabbage looper is a medium-sized moth in the family Noctuidae, a family commonly referred to as owlet moths. Its common name comes from its preferred host plants and distinctive crawling behavior. Cruciferous vegetables, such as cabbage, bok choy, and broccoli, are its main host plant; hence, the reference to cabbage in its common name. The larva is called a looper because it arches its back into a loop when it crawls.
The almond moth or tropical warehouse moth is a small, stored-product pest. Almond moths infest flour, bran, oats, and other grains, as well as dried fruits. It belongs to the family of snout moths (Pyralidae), and more specifically to the tribe Phycitini of the huge snout moth subfamily Phycitinae. This species may be confused with the related Indian mealmoth or the Mediterranean flour moth, which are also common pantry pests in the same subfamily.
The European corn borer, also known as the European corn worm or European high-flyer, is a moth of the family Crambidae. It is a pest of grain, particularly maize. The insect is native to Europe, originally infesting varieties of millet, including broom corn. The European corn borer was first reported in North America in 1917 in Massachusetts, but was probably introduced from Europe several years earlier. Since its initial discovery in the Americas, the insect has spread into Canada and westwards across the United States to the Rocky Mountains.
The Cumberland dusky salamander is a species of salamander in the family of lungless salamanders, Plethodontidae. It is endemic to the United States. Its natural habitats are temperate forests and rivers. This species is threatened by habitat loss.
The seepage salamander is a small, terrestrial species of salamander in the family Plethodontidae. It is endemic to the United States. They are found in small areas of Tennessee, North Carolina, Georgia, and Alabama. Its natural habitats are temperate forests, intermittent rivers, and freshwater springs. It gets its name from the seepages around which it lives. It is very similar in its appearance and life history to the pygmy salamander. These two species differ greatly from the other Desmognathus species. They are the smallest salamanders in the genus, measuring only 3–5 cm (1–2 in) in length. They are also the only two terrestrial, direct-developing Desmognathus species. However, the two species are not often seen to coexist, differing in distribution by elevation; although there are exceptions. The seepage salamander is currently listed as Near Threatened, with its numbers declining in most of states in which it is found. It is threatened by habitat loss, with logging having a major effect.
Desmognathus fuscus is a species of amphibian in the family Plethodontidae. The species is commonly called the dusky salamander or northern dusky salamander to distinguish it from populations in the southern United States which form several distinct species, the southern dusky salamanders. The northern dusky salamander is the most widespread representative of its genus in Canada. It can be found in eastern North America from extreme eastern Canada in New Brunswick south to South Carolina. The size of the species' total population is unknown, but is assumed to easily exceed 100,000. The species' habitat differs somewhat geographically; dusky salamanders in the northern part of the range prefer rocky woodland streams, seepages, and springs, while those in the south favor floodplains, sloughs, and muddy places along upland streams. They are most common where water is running or trickling. They hide under various objects, such as leaves or rocks, either in or near water. Alternatively, they may enter burrows for protection. The dusky salamander lays its eggs close to water under moss or rocks, in logs, or in stream-bank cavities. The larval stage which follows is normally aquatic.
The imitator salamander is a species of salamander in the family Plethodontidae. It is endemic to the Appalachian Mountains in the southeastern United States.
The blackbelly salamander is a species of salamander in the family Plethodontidae. It is endemic to the United States. Its natural habitats are rivers, intermittent rivers, and freshwater springs. It is threatened by habitat loss.
The pygmy salamander is a species of salamander in the family Plethodontidae. It is endemic to the United States in the southern Appalachians in North Carolina and Tennessee. Desmognathus wrighti is a member of the family Plethodontidae and is commonly known as the pygmy salamander. As the name suggest the pygmy salamander is the smallest of the nineteen species in the genus Desmognathus. D. wrighti undergoes direct development and does not have a free-living larval stage. Only two other taxa in Desmognathus, D. aeneus and D. organi, exhibit direct development along with the pygmy salamander. In the genus Desmognathus, body size, habitat preferences, and patterns used by males during courtship are quite variable. D. wrighti courtship is noted by the male biting and seizing its partner in order to provide them with a chemical stimulus. The pygmy salamander can be found in the southern Appalachians of the United States in western North Carolina and eastern Tennessee. Geographical distribution of the Desmognathus wrighti is fragmented and the highest abundance of the species can be found at high elevations in spruce and fir tree forest.
The northern two-lined salamander is a species of salamander in the family Plethodontidae found in Canada and the United States. Its natural habitats are temperate forests, temperate shrubland, rivers, intermittent rivers, freshwater marshes, freshwater springs, arable land, and urban areas. It is more water-oriented than the related northern redback salamander, and can often be found in and around water such as rain puddles, streams, swamps, and damp stream beds, whereas the northern redback tends to be found in damp ground, but usually not near open water.
The spring salamander is a species of salamander in the family Plethodontidae. It is found in Canada and the United States. The genus, Gyrinophilus, means "tadpole lover" and refers to the long period of time it spends as a gilled larva before maturing. The specific epithet, porphyriticus, is Latin from Greek, meaning the color of porphyry, a purple stone, and this salamander has also been called the purple salamander.
The variable checkerspot or Chalcedon checkerspot is a butterfly in the family Nymphalidae. It is found in western North America, where its range stretches from Alaska in the north to Baja California in the south and extends east through the Rocky Mountains into Colorado, Montana, New Mexico and Wyoming. The butterfly is usually brown or black with extensive white and yellow checkering and some red coloration on the dorsal wing. Adult wingspan is 3.2–5.7 cm (1.3–2.2 in). Adult butterflies feed on nectar from flowers while larvae feed on a variety of plants including snowberry (Symphoricarpos), paintbrush (Castilleja), Buddleja, Diplacus aurantiacus and Scrophularia californica.
Utetheisa ornatrix, also called the ornate bella moth, ornate moth, bella moth or rattlebox moth, is a moth of the subfamily Arctiinae. It is aposematically colored ranging from pink, red, orange and yellow to white coloration with black markings arranged in varying patterns on its wings. It has a wingspan of 33–46 mm. Moths reside in temperate midwestern and eastern North America as well as throughout Mexico and other parts of Central America. Unlike most moths, the bella moth is diurnal. Formerly, the bella moth or beautiful utetheisa of temperate eastern North America was separated as Utetheisa bella. Now it is united with the bella moth in Utetheisa ornatrix.
Carabus insulicola is a species of black-colored beetle from the family Carabidae native to Japan. They are also known as ground beetles, and are oval shaped and elongated. They are black with a green metallic hue and vertical stripes running down their backs. The length of a fully grown beetle ranges from 27 to 31 mm. They have three pairs of legs and two pairs of wings. The outer wings are greatly degenerated, making them unable to fly. However, their relatively long legs allow them to walk and run fast. They have prominent mandibles that allow them to capture and eat prey.
Sexual selection in amphibians involves sexual selection processes in amphibians, including frogs, salamanders and newts. Prolonged breeders, the majority of frog species, have breeding seasons at regular intervals where male-male competition occurs with males arriving at the waters edge first in large number and producing a wide range of vocalizations, with variations in depth of calls the speed of calls and other complex behaviours to attract mates. The fittest males will have the deepest croaks and the best territories, with females making their mate choices at least partly based on the males depth of croaking. This has led to sexual dimorphism, with females being larger than males in 90% of species, males in 10% and males fighting for groups of females.
Cryptic female choice is a form of mate choice which occurs both in pre and post copulatory circumstances when females in certain species use physical or chemical mechanisms to control a male's success of fertilizing their ova or ovum; i.e. by selecting whether sperm are successful in fertilizing their eggs or not. It occurs in internally-fertilizing species and involves differential use of sperm by females when sperm are available in the reproductive tract.
The northern pygmy salamander is a terrestrial species of salamander in the family Plethodontidae and genus Desmognathus. Along with the southern pygmy and the seepage salamander, these are some of the smallest salamander species in North America and can be found in higher elevations in the southern Appalachians.