University of Richmond UR Scholarship Repository Master's Theses Student Research 1999 Chondrocranial and oral morphology of Leptodactylid larvae William Hagood Turner Follow this and additional works at: https://scholarship.richmond.edu/masters-theses Part of the Biology Commons Recommended Citation Turner, William Hagood, "Chondrocranial and oral morphology of Leptodactylid larvae" (1999). Master's Theses. 1349. https://scholarship.richmond.edu/masters-theses/1349 This Thesis is brought to you for free and open access by the Student Research at UR Scholarship Repository. It has been accepted for inclusion in Master's Theses by an authorized administrator of UR Scholarship Repository. For more information, please contact [email protected]. Chondrocranial and Oral Morphology of Leptodactylid Larvae by William H. Turner Jr. I certifythat I have read this thesis and find that, in scope and quality, it satisfies the requirements for the degree of Master of Science. Dr. Gary Radice T Other Faculty Members: Tl and Oral Morphology of CHONDROCRANIALLeptodactylid Larvae William H. TurnerJr. Masters of Science in Biology University of Richmond, 1999 Thesis Director: Rafael 0. de Sa Abstract. Leptodactylidae is a diverse assemblage of anurans that varies in their life history, ecology, and morphology. Little is known about the chondrocranial anatomy of this family. Current knowledge of the evolutionary relationships of the family does not include chondrocranial data. The present paper focuses on understanding the larval chondrocranial morphology and internal oral anatomy of Leptodactylidae. Chondrocranial morphology and internal oral anatomy correlate with ecology and life history. A phylogenetic analysis of the family was executed based on 28 chondrocranial charactersusing as the outgroup. The phylogenetic Hyla lanciformis analysis resulted in two clades within Leptodactylidae: the Leptodactylinae-Odontophzynus clade and the Telmatobiinae­ Hylodinae-Ceratophryinae clade. Analyses of chondrocranial and internal oralmorphology can provide useful phylogenetic information for members of Leptodactylidae. ITT Chondrocranial and Oral Morphology of Leptodactylid Larvae By William H. Turner Jr. B.S., Universityof Richmond, 1997 ,l­ A Thesis Submitted to the Graduate Faculty of the University of Richmond in Candidacy for the degree of MASTER OF SCIENCE in Biology April, 1999 Richmond, Virginia N Acknowledgements I would not have been able to complete this degree were it not for the support, tutelage, and emotional backing of several people. I am indebted to Dr. Rafael 0. de Sa for taking me into his lab, assisting me financially (NSF#BIR-9510228), guiding me mentally, and putting his foot down when he saw me straying fromthe academic path. I am grateful to the Graduate School of Arts and Sciences for providing me with research and travel grants, and academic scholarships. I am also grateful to Dr. John Hayden and Dr. Gary Radice who taught me scanning electron microscope procedures. I would like to thank the Biology department faculty, staff, and students, especially Chris Swart, who offeredme many smiles and much encouragement None of this could have been possible without my mom, my brothers, my dogs, and the rest of my family and friends. I dedicate this work in memory of my father, William H. Turner Sr.; thanks for everything. V page Table of Contents List of Figures i. List of Appendices Introduction 1.ii. Background on Chondrocranial Studies 11. Background on Internal Oral Anatomy Studies. 15. Materials and Methods. 17. Results Chondrocranium of 22. Adenomera marmorata. Chondrocranium of 31. Edalorhina perezi . Chondrocranium of 40. Limnomedusa macroglossa Chondrocranium of and Physalaemus gracilis, P. henselii, P. pustulosus. Chondrocranium of and Pleurodema brachyops, P. brachyops2, 49. P. tucumana 59. Oral Morphology of 68. Limnomedusa macroglossa Oral Morphology of 7 4. Physalaemus gracilis Oral Morphology of 80. Physalaemus henselii. LarvalCharacters for phylogenetic analysis . 86. VT page Discussion Chondrocranial Morphology and skeletogenesis. 94. InternalOral Anatomy. 104. Phylogenetic Analysis 105. Literature cited . 117. Appendix . 139. Vita . 142. VTT List of Figures: Page Figure 1. Chondrocranium of at stage 36 . 26. Figure 2. Chondrocranium of Adenomera marmorataat stage 36 . 28. Figure 3. Chondrocranium of Adenomera marmorataat stage 36 . 34. Figure 4. Chondrocranium of Edalorhina perezi at stage 36 . 36. Figure 5. Chondrocranium of Edalorhina perezi at stage 34 44. Figure 6. Chondrocranium of Limnomedusa macroglqssa at stage 34 46. Figure 7. Chondrocrania of Limnomedusa macroglossaat stage 40, at stage 39, andPhysalaemus P. gracilisat stage 38 P. henselii 54. Figure 8. Chondrocrania of pustulosus at stage 40, at stage 39, andPhysalaemus gracilisat stage 38 P. henselii 56. Figure 9. Chondrocranium of P. pustulosus at stage 35, Pleurodemaat stage 37, andbrachyops at stage 35 63. Figure 10. ChondrocraniumP. brachyops2 of P. tucumanaat stage 35, Plateurodema stage 37, andbrachyops at stage 35 65. Figure 11. ScanningP. brachyops2 electron mi croscope photographP. tucumana of buccal floorof at stage 37 . 71. Figure 12. ScanningLimnomedusa electron microscope macroglossa photograph of buccal roof of at stage 3 7 . 73. Limnomedusa macroglossa Figure 13. Scanning electron microscope photograph of buccal floorof Physalaem us gracilis at stage 37 . 77 . Figure 14. Scanning electron microscope photograph of buccal roof of Physalaemus gra.cilis at stage 37 . 79. Figure 15. Scanning electron microscope photograph of buccal floor of Physalaemus henselii at stage 31 . 83 .J Figure 16. Scanning electron microscope photograph of buccal roof of Physalaemus henselii at stage 31 . 85 Figure 17. Phylogenetic trees 109. Figure 18. Consensus trees . 113. LIST OF TABLES: Table 1. Data matrixof phylogenetic characters . 93. Table 2. Ossificationsequence for the specimens of Physalaemus gracilis and P. pustulosus used in this work. 101. LIST OF APPENDICES: Appendix 1. Stages, measurements, and status of specimens used in this work. 139. ii The word amphibianINTRODUCTION comes from the Greek amphi, meaning "on both sides," and hi.us� meaning "life" or "mode of life." Anurans most accurately definethe word amphibian because considering their larvaland adult forms, they live a dual lifestyle,aquatic and terrestrial. These two stages of their life cycle are connected by an intricate metamorphic event that morphologically, ecologically, behaviorally, and physiologically transformsthe tadpole into the adult frog (Orton, 1953). Any shift in the timing or rate of the metamorphic events would be an example of heterochrony, and heterochronic mechanisms have been shown to be driving forces in amphibian evolution (Gould, 1977; Wassersug, 1980; Trueb and Alberch, 1985; Davies, 1989; Richardson, 1995; Haas, 1996b; Wakahara, 1996). An increase in the ways anurans have diversified results from heterochronic mechanisms acting on the larval stage of the life cycle and selective pressures acting on both the larva and the adult. The diversity of anurans is not reflected in their overall simple body plan (Sokol, 1975). Anuranshave achieved high levels of specialization yet the anatomical differences across frogs are subtle. This constancy of form presents a challenge to studies of anuran evolution and systematics. Consequently, a variety of data sets must be used to decipher anuran evolution (Duellman and Trueb, 1994; Kluge, 1989; Brooks and Mcclennan, 1991). In fact, anuran research has expanded into� di':ersefield of study incorporating a variety of data sets. Osteological studies have been useful in diagnosing species and determining anuran relationships (Cope, 1865, 1889; Noble, 1922, 1931; Parker, 1927; Lynch, 1970, 1971; Trueb, 1973 ). More recently, many studies have included additional characters such as: karyotype (Barrio and Rinaldi de Chieri, 1970; Bogart, 1970; Veloso et al., 1973; Duellman and Veloso, 1977; King, 1990; Green and Sessions, 1991), behavior (Wells, 1977; Greer and Wells, 1980; Martins, 1989; Cardoso and Heyer, 1995), diet (Premo and Atmowidjojo, 1987; Toft, 1995; Kovacs and Torok, 1997; Howard et al., 1997), call analysis (Barrio, 1964; Duellman, 1973; Duellman and Veloso, 1977; Ryan and Rand, 1995), development (Wassersug and Hoff, 1982; Trueb and Hanken, 1992) and molecular data (Hillis and Davis, 1987; Maxson and ?. Heyer, 1988; de Sa and Hillis, 1990; Hillis et al., 1993; Hay et al., 1995; Ruvinsky and Maxson, 1996). Anuran research has also focused on larval characters. Research on the structure of the head in anuran larvaeand studies of their internal oral anatomy date back to the early 19th century (Martin St. Ange, 1831; Schulze, 1870, 1892). Tlfese iµitial studies are characterized by inconsistent terminology and varied thoroughness of their descriptions. De Beer (1937) summarized what was known about the development of the vertebrate skull through detailed descriptions and illustrationsof four anuran taxa. The use of larval charactersin systematics began in the 1950s when a comparative study of tadpoles at similar stages of development was undertaken (Orton 1953, 1957). Orton (1957) grouped tadpoles into four major categories based on external morphology. Subsequently, Orton's data were combined with other larval characters such as larval musculature and chondrocranial data (Starrett, 1973; Sokol, 1975, 1977). Larval chondrocranial descriptions exist for less than 5% of known species (Haas, 1996a). Few chondrocranial