DOCSLIB.ORG

Anesthetic Considerations for Amphibians Mark A

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Anesthetic Considerations for Amphibians Mark A Topics in Medicine and Surgery Anesthetic Considerations for Amphibians Mark A. Mitchell, DVM, MS, PhD Abstract The popularity of amphibians in research, zoological exhibits, and as pets is on the rise. With this increased popularity comes a need for veterinarians to develop methods for managing these animals for various diagnostic and surgical proce- dures. For many of these procedures, the provision of anesthesia is a must. Fortunately, there are a number of different anesthetics available to the veterinary clinician for anesthetizing amphibians, including tricaine methanesulfonate, clove oil, propofol, isoflurane, and ketamine. In addition to the variety of anesthetics at our disposal, there is also a wider range of methods for delivering the anesthetics than are generally available for higher vertebrates, including immersion, topical, and intracoelomic routes of delivery. The purpose of this article is to review the different methods that can be used to successfully manage an amphibian patient through an anesthetic event. Copyright 2009 Elsevier Inc. All rights reserved. Key words: amphibian; anesthesia; anesthetic; anuran; monitoring; urodelan mphibians are commonly used in research will respond to an anesthetic the same way. In cases and are popular exhibit animals in zoological in which there is no reference for a particular spe- Acollections. Although they are not as popular cies, special precautions should be taken to mini- as reptiles in the pet trade, they are being presented mize the likelihood of complications. to veterinarians in clinical practice with increased Regardless of the species, success with anesthesia frequency. Because veterinarians are being asked to can be achieved by following a consistent, well- work with these animals, it is important that we planned protocol. For the author, the most pressing develop standard protocols for managing them in points to consider when establishing a protocol are captivity. the preanesthetic examination, the selection of an Historically, anesthesia has been a specialty in anesthetic that will allow the veterinarian to perform herpetological medicine that has received little at- the desired procedure safely, an anesthetic-monitor- tention. Procedures were often completed with an ing protocol that will help to determine the level of animal being manually restrained or cooled to min- anesthesia, and a postanesthetic plan that considers imize movement. Because these methods would not the recovery and management of the animal af- be acceptable for birds or mammals, they should also not be considered acceptable for reptiles or amphib- ians. Fortunately, in the past 2 decades we have seen From the University of Illinois, College of Veterinary Medicine, an increase in the number of scientific studies eval- Department of Veterinary Clinical Medicine, Urbana, IL USA. uating anesthetics in amphibians. Although many of Address correspondence to: Mark A. Mitchell, DVM, MS, PhD, University of Illinois, College of Veterinary Medicine, Department these articles have been directed toward a specific of Veterinary Clinical Medicine, 1008 W. Hazelwood Dr, Urbana, species, Xenopus laevis, because of its value in re- IL 61802. E-mail: [email protected]. search, the information obtained does have applica- © 2009 Elsevier Inc. All rights reserved. tion across amphibian species.1-4 However, it should 1557-5063/09/1801-$30.00 not be assumed that all 4500ϩ species of amphibians doi:10.1053/j.jepm.2008.11.006 40 Journal of Exotic Pet Medicine, Vol 18, No 1 ( January), 2009: pp 40–49 Anesthetic Considerations for Amphibians 41 ter the completion of the procedure. The purpose require a high degree of restraint for an examina- of this article is to review the methods that can be tion. Urodelans can often be examined while being used to successfully manage anesthesia in captive held in an open hand. If restraint is required, then amphibians. the animal can be gently grasped behind the fore- limbs with an index finger and thumb, with the Preanesthetic Examination examiner’s remaining fingers encircling the rear body (legs and tail). Care should be taken when handling the tail, because tail autonomy can occur. A preanesthetic examination should be performed Because of their natural escape response, anurans on each patient to determine whether an animal is a need to be secured quickly. For most anurans, they suitable candidate for an anesthetic procedure. The can be secured by grasping them in front of their examination should include both a physical evalua- rear legs. For larger specimens, such as the horned tion of the patient and supportive diagnostic tests, frogs (Ceratophrys species), care should be taken to such as bloodwork, to help to characterize the phys- minimize the likelihood of being bitten. The iologic status of the patient. Before performing an amount of restraint required for a caecilian depends examination, however, it is important to consider the different techniques that can be used to safely on the species and general demeanor of the animal. restrain the animal for the examination. Some caecilians can be examined similar to snakes, Amphibians, like fish, require some special con- whereas others need to be chemically immobilized sideration when planning for a procedure that re- because they cannot be secured for an examination. quires restraint. The integument of both of these The hands-on examination of an amphibian groups of animals is an important component to should be done in a thorough but rapid manner. their innate immune system, and damage to the skin The oral cavity should be opened atraumatically. during an examination could compromise the pa- Processed radiograph film or a rubber spatula can be tient. To minimize the likelihood of causing prob- used to gently pry open the mouth of an amphibian. lems, an amphibian should be handled with care. The mucous membranes should be moist and pale Latex or vinyl examination gloves are strongly rec- pink in color. Increased tackiness may be an indica- ommended when handling an amphibian. The tor of dehydration. The integument of the amphib- smooth texture of the gloves will minimize the po- ian should be moist and free of defects. Animals that tential for injury to the amphibian’s integument. appear dry should be kept moistened with distilled The gloves should be premoistened with distilled or or dechlorinated water. Body condition can be used dechlorinated water. Wearing gloves also has a ben- to determine the general health status of the am- efit to the individual restraining the amphibian. phibian. The muscling over the limbs of anurans and Many amphibians can secrete toxins that can be urodelans and the tail of urodelans can be evaluated absorbed through the skin of the handler.5 The to assess body condition. In many amphibians, tran- integument of an amphibian can also be covered sillumination can be done to evaluate the coelomic with a variety of opportunistic pathogens (e.g., cavity/viscera. Positioning a pen light or transillumi- Pseudomonas species, Aeromonas species). The exami- nator on the lateral body wall will enable the exam- nation gloves can serve as a protective barrier against iner to see various organ systems. For most species, both potential toxins and pathogens. respirations can be measured by counting gular The physical examination of an amphibian movements or rib excursions. A Doppler ultrasound should include both a hands-off and hands-on review can be used to measure the heart rate. The probe of the patient. The hands-off examination will en- can be placed on the ventral aspect of the pectoral able the clinician to evaluate the breathing pattern, girdle to obtain the heart rate. general demeanor, and locomotion of the patient. Preanesthetic bloodwork can be used to assess the Animals that are dyspneic or depressed should be physiologic status of an amphibian patient. Unfortu- handled carefully. Amphibians should have a natural nately, many of the animals we work with in captivity escape response when approached. Anesthetic pro- present challenges for collecting samples or obtain- cedures should be delayed in animals displaying ab- ing sufficient volumes of samples for screening. normal behaviors. Blood samples can be collected from the ventral tail For the hands-on examination, the animal may be vein of larger urodelans, the ventral abdominal vein manually restrained. For small or fractious amphib- of anurans and urodelans, the femoral vein of an- ians, chemical restraint may be necessary to com- urans and urodelans, and the sublingual vessels of plete a hands-on examination without injuring the anurans. Cardiocentesis can be done, but can result patient or handler. Amphibians do not generally in cardiac arrest in some species. If only a small 42 Mitchell volume of blood can be collected, then a packed-cell PropofolT (PropoFlo; Abbott Animal Health, Abbott volume or blood smear can be done at a minimum. Park, IL USA), have also been used. This type of data can be used to determine the The water used to make anesthetic water for an general health of the patient and provide insight amphibian should be of high quality. The author into potential complications. For example, if a pa- always prefers to use water from the animal’s enclo- tient is anemic, then recovery from the anesthetic sure for the base of the anesthetic solution. To de- event might be expected to be prolonged and the termine the value of the water, it is important to clinician can plan for it. Plasma chemistries can pro- evaluate the ammonia and nitrite levels, hardness, vide insight into the hydration status of the amphib- alkalinity, and chlorine/chloramine levels. If the wa- ian and general organ function. In the past, there ter is deemed to be of good quality (e.g., no ammo- were often limitations with processing small sample nia, no nitrite, neutral pH, good buffering capacity volumes; however, there is now equipment that can and hardness, and no chlorine or chloramines), it provide complete biochemistry analysis on samples should be used as the base for the anesthetic.
Load more

Recommended publications
  • Pedal Luring in the Leaf-Frog Phyllomedusa Burmeisteri (Anura, Hylidae, Phyllomedusinae)
    Phyllomedusa 1(2):93-95, 2002 © 2002 Melopsittacus Publicações Científicas ISSN 1519-1397 Pedal luring in the leaf-frog Phyllomedusa burmeisteri (Anura, Hylidae, Phyllomedusinae) Jaime Bertoluci Departamento de Zoologia, Universidade Federal de Minas Gerais. Caixa Postal 486, Belo Horizonte, MG, Brazil, 31270-901. E-mail: [email protected]. Keywords - Phyllomedusa burmeisteri, Phyllomedusinae, Hylidae, Anura, pedal luring, prey capture, feeding behavior. Luring behavior as a strategy of prey cap- the frog was maintained in a 60 × 30 × 37-cm ture has evolved independently in several glass terrarium containing soil and a bromeliad. squamate lineages, including pygopodid lizards On the fourth day of acclimation at 2300 h and (Murray et al. 1991), and boid (Murphy et al. under dim light, pedal luring was observed in 1978, Radcliffe et al. 1980), viperid (Greene response to offering the frog an individual adult and Campbell 1972, Heatwole and Dawson cricket (Orthoptera); the same observations were 1976, Henderson 1970, Sazima 1991), elapid made the next night. During the next three days, (Carpenter et al. 1978), and colubrid snakes the frog fed on domestic cockroaches (Sazima and Puorto 1993). Bavetz (1994) (Blattaria), but pedal luring was not observed in reported pedal luring related to predation in these circumstances. Larval mealworms ambystomatid salamanders. In anurans, this (Tenebrio sp.) also were offered to the frog, but feeding behavior has been described only for the always were refused. terrestrial leptodactylid frogs Ceratophrys Phyllomedusa burmeisteri is a sit-and-wait calcarata (Murphy 1976) and C. ornata predator that typically perches with its hands (Radcliffe et al. 1986). Pedal luring apparently and feet firmly grasping the substrate while does not occur in the terrestrial leptodactylids searching for prey.
    [Show full text]
  • Ceratophrys Cranwelli) with Implications for Extinct Giant Frogs Scientific Reports, 2017; 7(1):11963-1-11963-10
    PUBLISHED VERSION A. Kristopher Lappin, Sean C. Wilcox, David J. Moriarty, Stephanie A.R. Stoeppler, Susan E. Evans, Marc E.H. Jones Bite force in the horned frog (Ceratophrys cranwelli) with implications for extinct giant frogs Scientific Reports, 2017; 7(1):11963-1-11963-10 © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Originally published at: http://doi.org/10.1038/s41598-017-11968-6 PERMISSIONS http://creativecommons.org/licenses/by/4.0/ 19th of April 2018 http://hdl.handle.net/2440/110874 www.nature.com/scientificreports OPEN Bite force in the horned frog (Ceratophrys cranwelli) with implications for extinct giant frogs Received: 27 March 2017 A. Kristopher Lappin1, Sean C. Wilcox1,2, David J. Moriarty1, Stephanie A. R. Stoeppler1, Accepted: 1 September 2017 Susan E.
    [Show full text]
  • Micro-CT Imaging of Anuran Prey in Ceratophrys Ornata (Anura: Ceratophryidae)
    SALAMANDRA 51(2) 209–211 30 June 2015 ISSNCorrespondence 0036–3375 Correspondence To have a frog in the throat: micro-CT imaging of anuran prey in Ceratophrys ornata (Anura: Ceratophryidae) Thomas Kleinteich Christian-Albrechts-Universität zu Kiel, Funktionelle Morphologie und Biomechanik, Am Botanischen Garten 9, 24118 Kiel, Germany e-mail: [email protected] Manuscript received: 21 May 2014 Accepted: 11 July 2014 by Alexander Kupfer Frogs of the genus Ceratophrys are sit-and-wait preda- solution as a contrast agent, following the protocol suggest- tors that feed on a variety of different prey types, includ- ed by Metscher (2009) but with a staining time of three ing spiders, insects, crabs, annelids, but also vertebrates weeks. The specimen was scanned in distilled water. like snakes, lizards, rodents, and other frogs (Duellman & In the resulting micro-CT dataset, I identified a second Lizana 1994). Among amphibian pet keepers, Ceratophrys frog inside the digestive tract of the Ceratophrys ornata spp. are often referred to as pac-man frogs on account of specimen (Figs 1A–C). By using the 3D analysis and visual- their ability to consume vast amounts of prey as well as isation software package Amira 5.4.3, I virtually separated relatively large prey items. Chávez et al. (2011) reported the prey frog from the C. ornata to visualise the prey speci- on an individual of C. cornuta preying upon Leptodactylus men separately for estimating volume measurements. The dydimus (Anura: Leptodactylidae) that was approximate- volume of the C. ornata was 52.26 cm3. From this volume, ly two thirds of its own snout–vent length.
    [Show full text]
  • In Search of the Horned Frog (Ceratophrys Ornata) in Argentina: Complementing Field Surveys with Citizen Science
    Herpetological Conservation and Biology 12(3):664–672. Submitted: 26 May 2017; Accepted: 8 November 2017; Published 16 December 2017. IN SEARCH OF THE HORNED FROG (CERATOPHRYS ORNATA) IN ARGENTINA: COMPLEMENTING FIELD SURVEYS WITH CITIZEN SCIENCE CAMILA DEUTSCH1,4, DAVID BILENCA2,3, AND GABRIELA AGOSTINI1,2 1Conservación de Anfibios en Agroecosistemas, La Plata (1900), Argentina 2Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires Instituto de Ecología, Genética y Evolución de Buenos Aires, Grupo de Estudios sobre Biodiversidad en Agroecosistemas, Buenos Aires, Argentina 3Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina 4Corresponding author, e-mail: [email protected] Abstract.—The Horned Frog (Ceratophrys ornata) is a threatened amphibian that occurs in the temperate grasslands of Argentina, Brazil, and Uruguay. Several populations from Argentina have apparently declined and the species has not been recorded in Uruguay and Brazil for the last 35 y. In Argentina, published occurrence data based on field surveys are scarce, representing only a few localities in the Pampean Region. Considering thatC. ornata is an iconic and distinctive species, we conducted a citizen science program to obtain occurrence data as a complement to field surveys. From 2008 to 2017, we used auditory and visual methods to survey adult C. ornata at 78 localities in the Pampean Region during both spring and summer. From 2015 to 2017, we conducted the citizen science program using online surveys and direct interviews to gather records obtained in the last 10 y. The citizen science program yielded 147 records, representing a nine-fold increase from the 15 records obtained during field surveys.
    [Show full text]
  • Pzg Library News
    1/4 Vernacular Name FROG, ORNATE HORNED (aka: Argentine Horned Frog, Argentine Wide-mouthed Frog, Bell’s Horned Frog, Pacman Frog) GEOGRAPHIC RANGE South America: Argentina, Uruguay, Brazil. HABITAT Burrow in the leafy, muddy vegetation of the tropical forest floor of tropical lowlands. CONSERVATION STATUS • IUCN: Not Yet Assessed (2014). • This species is in significant decline (but at a rate of less than 30% over 10 years) because it is subject to intense persecution: habitat loss (due to agricultural development and housing development) is a major threat, as is water and soil pollution due to agriculture, industry and human settlement. COOL FACTS • The horned frog is named so because it has large fleshy points above its eyes that resemble small horns – e.g., fleshy eyelid “horns”. The "horn" is a triangular prolongation of the edge of the upper eyelid. It is not hard or sharp, as it is only a flap of skin, but perhaps it makes the wide head appear even wider and, therefore, less acceptable to predators. • The horned frogs' most prominent feature is its mouth, which accounts for roughly half of its overall size. These frogs are often called "mouths with legs" because the mouth appears to be the entire front half of the body. Their huge mouths and ravenous appetites have earned them the pet trade nickname “Pac Man frogs”. • One extraordinary characteristic that these amphibians possess is their innate ability to devour organisms larger than their own body size. They feed on frogs, lizards, other reptiles, mice and large insects. • Like all amphibians, horned frogs have porous skin and respond quickly to changes in the environment.
    [Show full text]
  • Frog Eat Frog: Exploring Variables Influencing Anurophagy
    Frog eat frog: exploring variables influencing anurophagy G. John Measey1, Giovanni Vimercati1, F. Andre´ de Villiers1, Mohlamatsane M. Mokhatla1, Sarah J. Davies1, Shelley Edwards1 and Res Altwegg2,3 1 Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa 2 Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences, University of Cape Town, Rondebosch, Cape Town, South Africa 3 African Climate and Development Initiative, University of Cape Town, South Africa ABSTRACT Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data.
    [Show full text]
  • Islet Hormones from the African Bullfrog Pyxicephalus Adspersus (Anura:Ranidae): Structural Characterization and Phylogenetic Implications
    General and Comparative Endocrinology 119, 85–94 (2000) doi:10.1006/gcen.2000.7493, available online at http://www.idealibrary.com on Islet Hormones from the African Bullfrog Pyxicephalus adspersus (Anura:Ranidae): Structural Characterization and Phylogenetic Implications J. Michael Conlon,*,1 Amber M. White,* and James E. Platz† *Regulatory Peptide Center, Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178; and †Department of Biology, Creighton University, Omaha, Nebraska 68178 Accepted March 28, 2000 The African bullfrog Pyxicephalus adspersus is generally amino acid sequence of PP, but not those of the other islet classified along with frogs of the genus Rana in the subfam- hormones, is of value as a molecular marker for inferring ily Raninae of the family Ranidae but precise phylogenetic phylogenetic relationships between early tetrapod species. relationships between species are unclear. Pancreatic © 2000 Academic Press polypeptide (PP), insulin, and glucagon-like peptide (GLP-1) were isolated from an extract of P. adspersus Pancreatic polypeptide (PP) is a 36-amino acid res- pancreas and characterized structurally. A comparison of idue C-terminally ␣-amidated peptide that is synthe- the amino acid sequence of Pyxicephalus PP (APSEPQ- sized primarily in the F cell of the pancreatic islets of 10 20 30 ⅐ HPGG QATPEQLAQY YSDLYQYITF ITRPRF NH2) tetrapods. PP is a member of a family of homologous with those of the known amphibian PP molecules in a max- regulatory peptides that comprises, in addition to PP, imum parsimony analysis generates a single phylogenetic neuropeptide tyrosine (NPY) synthesized in neurons tree in which Pyxicephalus is the sister to the clade compris- of the central and peripheral nervous systems and in ing the members of the genus Rana.
    [Show full text]
  • 5-Minute Guide to Amphibian Disease
    CLINICIAN’S NOTEBOOK 5-minute Guide to Amphibian Disease MADS BERTELSEN ■ GRAHAM CRAWSHAW THE AMPHIBIAN PATIENT IS mammography units. Ultrasonogra- often presented late in the disease phy may help identify coelomic process, and the presenting signs are masses or fluid accumulation and commonly limited to anorexia, weight assist in guiding transcutaneous loss and/or fluid retention. A review aspiration or biopsy. Laparoscopy, of the husbandry and feeding history using a small fiberoptic arthroscope, should be part of any workup. Diag- offers internal visualization. nostic information may be obtained in Careful post mortem examination of a manner similar to that used with diseased specimens followed by other vertebrates, although the small histopathologic examination is crucial size of many patients limits the quan- in diagnosing and treating problems tity and usefulness of diagnostic affecting several animals. Common samples. Mads Bertelsen, DVM clinical manifestations, selected [email protected] Thorough physical examination may differential diagnoses and diagnostic Veterinary Resident reveal fractures, impactions, swellings, options are presented in Table 2. Zoo/Wildlife Medicine and Pathology masses, fluid accumulations or skin Graham Crawshaw, BVetMed, Once a tentative or final diagnosis has and eye abnormalities. Blood can be MRCVS, Dipl ACZM been made, amphibians may be collected from peripheral superficial Toronto Zoo subjected to standard surgical and Scarborough, Ontario veins, but collection is generally more medical treatment. Amphibians have Canada reliable from the heart. Although low metabolic rates but high rates of [email protected] hematologic and biochemical values fluid turnover, placing them between vary and only limited normal values mammals and reptiles in the pharma- are available, analysis of the blood cokinetic spectrum.
    [Show full text]
  • Unrestricted Species
    UNRESTRICTED SPECIES Actinopterygii (Ray-finned Fishes) Atheriniformes (Silversides) Scientific Name Common Name Bedotia geayi Madagascar Rainbowfish Melanotaenia boesemani Boeseman's Rainbowfish Melanotaenia maylandi Maryland's Rainbowfish Melanotaenia splendida Eastern Rainbow Fish Beloniformes (Needlefishes) Scientific Name Common Name Dermogenys pusilla Wrestling Halfbeak Characiformes (Piranhas, Leporins, Piranhas) Scientific Name Common Name Abramites hypselonotus Highbacked Headstander Acestrorhynchus falcatus Red Tail Freshwater Barracuda Acestrorhynchus falcirostris Yellow Tail Freshwater Barracuda Anostomus anostomus Striped Headstander Anostomus spiloclistron False Three Spotted Anostomus Anostomus ternetzi Ternetz's Anostomus Anostomus varius Checkerboard Anostomus Astyanax mexicanus Blind Cave Tetra Boulengerella maculata Spotted Pike Characin Carnegiella strigata Marbled Hatchetfish Chalceus macrolepidotus Pink-Tailed Chalceus Charax condei Small-scaled Glass Tetra Charax gibbosus Glass Headstander Chilodus punctatus Spotted Headstander Distichodus notospilus Red-finned Distichodus Distichodus sexfasciatus Six-banded Distichodus Exodon paradoxus Bucktoothed Tetra Gasteropelecus sternicla Common Hatchetfish Gymnocorymbus ternetzi Black Skirt Tetra Hasemania nana Silver-tipped Tetra Hemigrammus erythrozonus Glowlight Tetra Hemigrammus ocellifer Head and Tail Light Tetra Hemigrammus pulcher Pretty Tetra Hemigrammus rhodostomus Rummy Nose Tetra *Except if listed on: IUCN Red List (Endangered, Critically Endangered, or Extinct
    [Show full text]
  • The Diversity and Evolution of Amphibia: What Are They and Where Did They Come From?
    The diversity and evolution of Amphibia: What are they and where did they come from? Lecture goal To familiarize students with characteristics of the Class Amphibia, the diversity of extant amphibians, and the fossil record of amphibians. Reading assignments: Wells: pp. 1-15, 41-58, 65-74, 77-80 Supplemental readings on amphibian taxa: Wells: pp. 16-41, 59-65, 75-77 Lecture roadmap Characteristics of amphibians Extant amphibian orders Characteristics of amphibian orders and diversity Amphibian fossil record and evolution 1 What are amphibians? These foul and loathsome animals are abhorrent because of their cold body, pale color, cartilaginous skeleton, filthy skin, fierce aspect, calculating eye, offensive smell, harsh voice, squalid habitation, and terrible venom; and so their Creator has not exerted his powers to make many of them. Carl von Linne (Linnaeus) Systema Naturae (1758) What are amphibians? Ectothermic tetrapods that have a biphasic life cycle consisting of anamniotic eggs (often aquatic) and a terrestrial adult stage. Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Amphibia (amphibios: “double life”) Subclass: Lissamphibia Orders: •Anura (frogs) •Caudata (salamanders) •Gymnophiona (caecilians) Amphibia characteristics 1) Cutaneous respiration Oxygen and CO2 Transfer Family Plethodontidae Plethodon dorsalis Gills (larvae, few adult salamanders), 2 Lungs (adults) 2) Skin glands Mucous glands Granular glands 2 Amphibia characteristics 3) Modifications of middle and inner ear Middle ear consists of 2 elements
    [Show full text]
  • Pac Man Frog / Ornate Horned Frog Ceratophrys Ornata
    Pac Man Frog / Ornate Horned Frog Ceratophrys ornata LIFE SPAN: about 6-10 years AVERAGE SIZE: 6-7 inches Males are a bit smaller than females. CAGE TEMPS: 81o HUMDITY: 60-70% * If temp falls below 70° at night, may need supplemental infrared or ceramic heat WILD HISTORY: Native to the rainforests of Brazil, Uruguay and Argentina of South America. PHYSICAL CHARACTERISTICS: The frogs get their common name, “Pac Man Frog” from their round, plump shape and large mouths, which make them resemble the video game character. Their large eyes stay open while they are sleeping. Pac mans are available in many patterns and colors, the most common being yellow and green, with mottled spots/patches. These colors and patterns prove to be perfect camouflage for hiding on the rainforest floor, waiting for prey to happen by. Because of their delicate and porous skin, handling your frog is not recommended. NORMAL BEHAVIOR & INTERACTION: Pac mans are relatively inactive and sedentary. They are beautiful and entertaining pets, but they have no desire to be handled. Handling a pac man frog is very stressful for it and may result in illness. Their skin is very sensitive, being a secondary breathing organ. Some pac mans are diurnal; some are crepuscular. NOTE: DO NOT house Pac Man frogs with others of their species or any other species to prevent cannibalism – your pac man will most likely eat any unsuspecting visitor. Each species may also harbor different parasites/protozoans/bacteria (even a healthy reptile harbors a small amount at all times), which may make each other ill.
    [Show full text]
  • A Different Type of Amphibian Mesoderm Morphogenesis in Ceratophrys Ornata
    Development 117, 307-317 (1993) 307 Printed in Great Britain © The Company of Biologists Limited 1993 A different type of amphibian mesoderm morphogenesis in Ceratophrys ornata Susan M. Purcell* and Ray Keller Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA *Present address: Department of Pharmacology, School of Medicine, University of Washington, Seattle, WA 98195, USA SUMMARY Ceratophrys ornata, the Argentinean horned frog, has a Prospective somitic tissue ingresses first from two lat- significantly different pattern of early morphogenesis eral zones, followed by ingression of prospective noto- than does the most studied amphibian, Xenopus laevis. chord from the medial zone and tailbud mesoderm from Time-lapse videomicroscopy, scanning electron the circumblastoporal zone. This is unlike X. laevis, in microscopy, histological sections and lineage tracers which no cells with constricted apices are present on the have shown that, in C. ornata, some prospective noto- dorsal surface of the archenteron, nor do any cells chord, somite and tailbud mesoderm cells leave the sur- ingress into the deep mesodermal layers from the sur- face epithelium of the archenteron by ingression. After face layer. gastrulation, SEM reveals cells with constricted apices and a bottle shape in three zones on the archenteron roof and in a fourth zone around the blastopore. Key words: mesoderm, notochord, ingression, amphibian INTRODUCTION from X. laevis. Since Keller published the fate map of X. laevis in 1975, some have speculated that Vogt’s and Pas- It was long thought that early and fundamental processes teels’ fate maps may be incorrect (Løvtrup, 1975; of development such as gastrulation, were conserved fea- Nieuwkoop and Sutasurya, 1976).
    [Show full text]