Common mudpuppy | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Urodela |
Family: | Proteidae |
Genus: | Necturus |
Species: | N. maculosus |
Binomial name | |
Necturus maculosus (Rafinesque, 1818) | |
Range of N. maculosus | |
Synonyms | |
Sirena maculosa Rafinesque, 1818 |
The common mudpuppy (Necturus maculosus) is a species of salamander in the family Proteidae. [3] It lives an entirely aquatic lifestyle in parts of North America in lakes, rivers, and ponds. It goes through paedomorphosis and retains its external gills. [4] Because skin and lung respiration alone is not sufficient for gas exchange, the common mudpuppy must rely on external gills as its primary means of gas exchange. [5] It is usually a rusty brown color [6] and can grow to an average total length (including tail) of 13 in (330 mm). [7] It is a nocturnal creature, and is active during the day only if the water in which it lives is murky. [3] Its diet consists of almost anything it can get into its mouth, including insects, mollusks, and earthworms (as well as other annelids). [6] Once a female common mudpuppy reaches sexual maturity at six years of age, she can lay an average of 60 eggs. [6] In the wild, the average lifespan of a common mudpuppy is 11 years. [8]
The common mudpuppy can be a rusty brown color with gray and black and usually has blackish-blue spots, but some albino adults have been reported in Arkansas. [6] In clear, light water, their skin gets darker, likewise in darker water, their skin gets lighter in color. [5] At sexual maturity, mudpuppies can be 20 cm (8 in) long and continue to grow to an average length of 33 cm (13 in), though specimens up to 43.5 cm (17.1 in) have been reported. [7] Their external gills resemble ostrich plumes and their size depends on the oxygen levels present in the water. In stagnant water, mudpuppies have larger gills, whereas in running streams where oxygen is more prevalent, they have smaller gills. [4] The distal portions of the gills are very filamentous and contain many capillaries. [7] Mudpuppies also have small, flattened limbs which can be used for slowly walking on the bottoms of streams or ponds, or they can be flattened against the body during short swimming spurts. [7] They have mucous glands which provide a slimy protective coating [4]
Mudpuppies are one of many species of salamanders that fail to undergo metamorphosis. Most hypotheses surrounding the origin of Necturus's lack of metamorphosis concern the effectiveness of the thyroid gland. The thyroid gland in some salamanders, like the axolotl, produce normal thyroid hormones (THs), but cells in the organism express thyroid hormone receptors (TR) that are mutated, and do not bond correctly with thyroid hormones, leading to some salamanders in a state of perpetual juvenile-hood. [9] In contrast to axolotls, in mudpuppies, these THs are normally expressed. However, it is believed that instead of having TH-insensitive tissues that block the effects of THs, some mudpuppy tissues, such as the external gills, have lost the ability to be regulated by TH over time. [10] This selective insensitivity to THs suggests a normal level of activity in the hypothalamo-pituitary-thyroid axis in developing mudpuppies, unlike other salamander species.
The common mudpuppy also does not have a parathyroid gland. [11] The majority of salamanders with parathyroid glands rely on them to help with hypercalcemic regulation; hypercalcemic regulation in mudpuppies is primarily done by the pituitary gland instead. [11] In common mudpuppies, the purpose of the absence of a parathyroid gland is poorly understood. One reason for the absence might be the lack of variability in the climate of mudpuppies, as the parathyroid glands of salamanders vary greatly depending on seasonal changes, or whether the organism hibernates. [12]
Necturus maculosus specimens live in streams, lakes, and ponds in the eastern part of North America. [4] They appear in the southern section of Canada, as far south as Georgia, and from the Midwest United States to North Carolina. Behaviorally, they hide under cover such as rocks and logs during the day and become more active at night. [7] However, in muddy waters, the mudpuppy may become active during the day. [3] Mudpuppies can even live under the ice when lakes freeze. [3] There is an introduced population in Maine. [13]
Mudpuppies use rows of teeth to eat their prey. [5] Salamanders have three different sets of teeth: dentary, premaxillary, and vomerine teeth, which are named due to their location in the mouth. [14] All the teeth, despite their different locations, are very similar. They are small and conical, meaning mudpuppies are homodonts due to their similar shape. [15] [16] The common mudpuppy never leaves its aquatic environment and therefore does not undergo morphogenesis; however, many salamanders do and develop differentiated teeth. [17] Aquatic salamander teeth are used to hinder escape of the prey from the salamander; they do not have a crushing function. [17] This aids the salamander when feeding. When the salamander performs the "suck and gape" feeding style, the prey is pulled into the mouth, and the teeth function to hold the prey inside the mouth and prevent the prey from escaping. [14] At both sides of their mouths their lips interlock, which allows them to use suction feeding. [7] They are carnivorous creatures and will eat almost anything they can get into their mouths. Typically they prey upon animals such as insects and their larvae, [18] mollusks, annelids, crayfish, [19] small fish, amphibians, earthworms, and spiders. The jaw of a mudpuppy also plays a significant role in its diet. The mudpuppy jaw is considered metaautostyly, like most amphibians, meaning the jaw is more stable and that the salamander has a dentary. [15] This affects their diet by limiting the flexibility of the jaw to take in larger prey. The mudpuppy has few predators which may include fish, crayfish, turtles, and water snakes. Fishermen also frequently catch and discard them. [6]
Mudpuppies take six years to reach sexual maturity. [7] Mating typically takes place in autumn, though eggs are not laid till much later. [4] When males are ready to breed, their cloacae become swollen. Males deposit their spermatophores in the substratum of the environment. The female will then pick them up with her cloaca and store them in a small specialized gland, a spermatheca, until the eggs are fertilized. [6] Females store the sperm until ovulation and internal fertilization take place, usually just prior to deposition in the spring. [7] Before the eggs are deposited, male mudpuppies leave the nest. [6] Once ready, the female deposits the eggs in a safe location, usually on the underside of a rock or log. [7] They can lay from 20 to 200 eggs, [4] usually an average of 60. [6] The eggs are not pigmented and are about 5–6 mm (0.20–0.24 in) mm in diameter. The female stays with her eggs during the incubation period (around 40 days). Hatchlings are about 2.5 cm (0.98 in) long and grow to 3.6 cm (1.4 in) before the yolk is completely consumed. [7]
Three subspecies are recognized as being valid, including the nominotypical subspecies.
Nota bene : A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than Necturus .
Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes. All extant (living) amphibians belong to the monophyletic subclass Lissamphibia, with three living orders: Anura, Urodela (salamanders), and Gymnophiona (caecilians). Evolved to be mostly semiaquatic, amphibians have adapted to inhabit a wide variety of habitats, with most species living in freshwater, wetland or terrestrial ecosystems. Their life cycle typically starts out as aquatic larvae with gills known as tadpoles, but some species have developed behavioural adaptations to bypass this.
The endocrine system is a messenger system in an organism comprising feedback loops of hormones that are released by internal glands directly into the circulatory system and that target and regulate distant organs. In vertebrates, the hypothalamus is the neural control center for all endocrine systems.
The hellbender, also known as the hellbender salamander, is a species of aquatic giant salamander endemic to the eastern and central United States. It is the largest salamander in North America. A member of the family Cryptobranchidae, the hellbender is the only extant member of the genus Cryptobranchus. Other closely related salamanders in the same family are in the genus Andrias, which contains the Japanese and Chinese giant salamanders. The hellbender, is much larger than any other salamander in its geographic range, and employs an unusual adaption for respiration through cutaneous gas exchange via capillaries found in its lateral skin folds. It fills a particular niche – both as a predator and prey – in its ecosystem, which either it or its ancestors have occupied for around 65 million years. The species is listed as Vulnerable on the IUCN Red List of Threatened Species due to the impacts of disease and widespread habitat loss and degradation throughout much of its range.
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. Urodela is a scientific Latin term based on the Ancient Greek οὐρά δήλη: ourà dēlē "conspicuous tail". Caudata is the Latin for "tailed ones", from cauda: "tail".
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans, it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the isthmus (pl.: isthmi). The thyroid gland is a butterfly-shaped gland located in the neck below the Adam's apple. Microscopically, the functional unit of the thyroid gland is the spherical thyroid follicle, lined with follicular cells (thyrocytes), and occasional parafollicular cells that surround a lumen containing colloid. The thyroid gland secretes three hormones: the two thyroid hormones – triiodothyronine (T3) and thyroxine (T4) – and a peptide hormone, calcitonin. The thyroid hormones influence the metabolic rate and protein synthesis and growth and development in children. Calcitonin plays a role in calcium homeostasis. Secretion of the two thyroid hormones is regulated by thyroid-stimulating hormone (TSH), which is secreted from the anterior pituitary gland. TSH is regulated by thyrotropin-releasing hormone (TRH), which is produced by the hypothalamus.
Amphiuma is a genus of aquatic salamanders from the United States, the only extant genus within the family Amphiumidae. They are colloquially known as amphiumas. They are also known to fishermen as "conger eels" or "Congo snakes", which are zoologically incorrect designations or misnomers, since amphiumas are actually salamanders, and not fish, nor reptiles and are not from Congo. Amphiuma exhibits one of the largest complements of DNA in the living world, around 25 times more than a human.
The axolotl is a paedomorphic salamander closely related to the tiger salamander. It is unusual among amphibians in that it reaches adulthood without undergoing metamorphosis. Instead of taking to the land, adults remain aquatic and gilled. The species was originally found in several lakes underlying what is now Mexico City, such as Lake Xochimilco and Lake Chalco. These lakes were drained by Spanish settlers after the conquest of the Aztec Empire, leading to the destruction of much of the axolotl's natural habitat.
Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibian ancestors during the Carboniferous period and further diverged into two groups, namely the sauropsids and synapsids, an event that marks the appearance of Amniota, according to the definition established under the PhyloCode. This basal divergence within Amniota has been dated by molecular studies at 310–329 Ma or 312–330 Ma, but the presence of Hylonomus at Joggins implies a minimal age of about 317 Ma. A fossilized birth-death process study of early amniotes suggested an age of 322–340 Ma. Amniotes are distinguished from the other living tetrapod clade — the non-amniote lissamphibians — by the development of three extraembryonic membranes, thicker and keratinized skin, and costal respiration. Additional unique features are the presence of adrenocortical and chromaffin tissues as a discrete pair of glands near their kidneys, which are more complex, the presence of an astragalus for better extremity range of motion, the diminished role of skin breathing, and the complete loss of metamorphosis, gills, and lateral lines.
Ambystomatidae is a family of salamanders belonging to the Suborder Salamandroidea in the class Amphibia. It contains two genera, Ambystoma and Dicamptodon. Ambystoma contains 32 species and are distributed widely across North America, while Dicamptodon contains four species restricted to the Pacific Northwest. These salamanders are mostly terrestrial and eat invertebrates, although some species are known to eat smaller salamanders. They can be found throughout the US and some areas of Canada in damp forests or plains. This family contains some of the largest terrestrial salamanders in the world, the tiger salamander and the coastal giant salamander. Some species are toxic and can secrete poison from their bodies as protection against predators or infraspecific competition. Neoteny has been observed in several species in Ambystomatidae, and some of them like the axolotl live all of their lives under water in their larval stage.
The family Proteidae is a group of aquatic salamanders found today in the Balkan Peninsula and North America. The range of the genus Necturus runs from southern central Canada, through the midwestern United States, east to North Carolina and south to Georgia and Mississippi. The range of the olm, the only extant member of the genus Proteus, is limited to the Western Balkans. The fossil record of the family extends into the end of the Late Cretaceous, with Paranecturus being known from the Maastrichtian of North America.
The olm or proteus is an aquatic salamander which is the only species in the genus Proteus of the family Proteidae and the only exclusively cave-dwelling chordate species found in Europe; the family's other extant genus is Necturus. In contrast to most amphibians, it is entirely aquatic, eating, sleeping, and breeding underwater. Living in caves found in the Dinaric Alps, it is endemic to the waters that flow underground through the extensive limestone bedrock of the karst of Central and Southeastern Europe in the basin of the Soča River near Trieste, Italy, southwestern Croatia, and Bosnia and Herzegovina. Introduced populations are found near Vicenza, Italy, and Kranj, Slovenia. It was first mentioned in 1689 by the local naturalist Valvasor in his Glory of the Duchy of Carniola, who reported that, after heavy rains, the olms were washed up from the underground waters and were believed by local people to be a cave dragon's offspring.
"Labyrinthodontia" is an informal grouping of extinct predatory amphibians which were major components of ecosystems in the late Paleozoic and early Mesozoic eras. Traditionally considered a subclass of the class Amphibia, modern classification systems recognize that labyrinthodonts are not a formal natural group (clade) exclusive of other tetrapods. Instead, they consistute an evolutionary grade, ancestral to living tetrapods such as lissamphibians and amniotes. "Labyrinthodont"-grade vertebrates evolved from lobe-finned fishes in the Devonian, though a formal boundary between fish and amphibian is difficult to define at this point in time.
Necturus is a genus of aquatic salamanders in the family Proteidae. Species of the genus are native to the eastern United States and Canada. They are commonly known as waterdogs and mudpuppies. The common mudpuppy (N. maculosus) is probably the best-known species – as an amphibian with gill slits, it is often dissected in comparative anatomy classes. The common mudpuppy has the largest distribution of any fully aquatic salamander in North America.
Gerrothorax is an extinct genus of temnospondyl amphibian from the Triassic period of Greenland, Germany, Poland, Sweden, and possibly Thailand. It is known from a single species, G. pulcherrimus, although several other species such as G. pustuloglomeratus have been named in the past.
The mouth is the body orifice through which many animals ingest food and vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity, is also the first part of the alimentary canal, which leads to the pharynx and the gullet. In tetrapod vertebrates, the mouth is bounded on the outside by the lips and cheeks — thus the oral cavity is also known as the buccal cavity — and contains the tongue on the inside. Except for some groups like birds and lissamphibians, vertebrates usually have teeth in their mouths, although some fish species have pharyngeal teeth instead of oral teeth.
Branchial arches, or gill arches, are a series of paired bony "loops" that support the gills in fish. As gills are the primitive feature of vertebrates, all vertebrate embryos develop pharyngeal arches, though the eventual fate of these arches varies between taxa. In jawed fish, the first arch pair develops into the jaw. The second gill arches develop into the hyomandibular complex, which supports the back of the jaw and the front of the gill series. The remaining posterior arches support the gills. In amphibians and reptiles, many pharyngeal arch elements are lost, including the gill arches, resulting in only the oral jaws and a hyoid apparatus remaining. In mammals and birds, the hyoid is simplified further.
The Red River mudpuppy, also called Louisiana waterdog or Red River waterdog, is a subspecies of aquatic salamander in the family Proteidae.
Media related to Necturus maculosus at Wikimedia Commons