Mudpuppy Dissection (Salamander) PDF

MUDPUPPY (SALAMANDER) DISSECTION: PART 1 Necturus maculosus BIO 415L Presented by Dr. Polekoff MUDPUPPY STRUCTURES Skeletal structures (fig 5.4): External structures (fig 5.9): Transversus abdominis m. (fig 5.11)...

MUDPUPPY (SALAMANDER) DISSECTION: PART 1 Necturus maculosus BIO 415L Presented by Dr. Polekoff MUDPUPPY STRUCTURES Skeletal structures (fig 5.4): External structures (fig 5.9): Transversus abdominis m. (fig 5.11) Rectus abdominis m. (fig 5.11) Premaxilla Mouth Dorsalis trunci m. (fig 5.11) Frontal bone Naris Dorsalis trunci m. (fig 5.12) Cervical vertebrae Eye Middorsal septum (fig 5.12) Humerus Labia Adductor mandibulae externus m. (fig Radius Gular fold 5.13) Ulna Pectoral limbs Dorsalis scapulae m. (fig 5.13) Carpals External gills Latissimus dorsi m. (fig 5.13, 5.18) Phalanges Cloaca Triceps (fig 5.13, 5.14) Trunk vertebrae Pelvic limbs Humeroantebrachialis m. (5.13, 5.14) Ribs Tail fin Forelimb extensors mm. (5.13, 5.14) Sacral vertebra Coracobrachialis m. (fig 5.14) Caudal vertebrae Musculature after removing the skin: Pectorialis m. (fig 5.14. 5.18) Femur Linea alba (fig 5.14) Tibia Myoseptum (fig 5.10) External oblique m. (fig 5.22) Fibula Dorsalis trunci (fig 5.10) Rectus abdominis m. (fig 5.22) Tarsals Rectus abdominis (fig 5.10) Cloacal gland (fig 5.22) Phalanges Epaxial muscles (fig 5.10) Cloaca (fig 5.22) Horizontal skeletogenous septum (fig 5.10) Hypaxial muscles (fig 5.10) Myomere (fig 5.10) External oblique m. (fig 5.11) Internal oblique m. (fig 5.11) Tetrapoda  Sarcopterygii  Tetrapoda Phylogeny within Tetrapoda Lissamphibia Gymnophiona (Caecilians) Caudata (Salamanders) Batrachia Anura (Frogs and Toads) Salamanders  Member of the Caudata  Include salamanders and newts  Salamanders are the second largest group of amphibians  HABITAT: Salamanders range from being fully aquatic to fully terrestrial.  MOVEMENT:  Use their limbs in combination with the side- to-side body undulations characteristic of fish and thus may resemble the earliest land vertebrates in locomotion.  Mudpuppy Background  Aquatic species  Paedomorphic and retain their external gills (Fabre, 2020)  Live exclusively in water  Terrestrial individuals  May be biphasic living in water and land, shedding their gills during metamorphosis Metamorphosis as a driver of morphological diversity in Salamanders Copyright: Anne-Claire Fabre Mudpuppy (Necturus maculosus)  RESPIRATION: External gills.  Lungs are mostly used for buoyancy, inflating and deflating  Very sensitive and absorbent skin.  METAMORPHOSIS: Do NOT go through full metamorphosis like most amphibians do  REGENERATION: mudpuppy has the ability to regenerate portions of its tail and entire limbs.  PROTECTION:  Mucous glands which produce a slimy protective coating, and  Granular glands that dispense poison SKELETAL SYSTEM  PREMAXILLA (paired): Most anterior structure  Followed by the paired frontals and parietals.  FRONTAL BONE  QUADRATE and MECKEL’S CARTILAGE: Form the jaw  CERVICAL VERTEBRAE:  Single cervical vertebra, the ATLAS  Articulates with the occipital condyles of the skull. SKELETAL SYSTEM Chinese Giant Salamander  PREMAXILLA (paired): Most Occipital condyles anterior structure Foramen magnum  Followed by the paired frontals and parietals. Parietal  FRONTAL BONE  QUADRATE and MECKEL’S Frontal CARTILAGE: Form the jaw  CERVICAL VERTEBRAE: Quadrate  Single cervical vertebra, the ATLAS Premaxilla  Articulates with the occipital Dentary condyles of the skull. https://sketchfab.com/3d-models/spotted-salamander-skull-anatomy-d1f2a430dd8c45ce8708d3debcbe0ba8  ATLAS (C1) The cervical vertebra Atlas (C1) is the topmost vertebra in humans among other vertebrates It is the first vertebrate to articulate with the base of the skull. In higher order vertebrates such as humans, it is unique in its anatomy, as it lacks a body and instead has a circular shape to allow for rotation of the head. SKELETAL SYSTEM: FOREARMS HUMERUS: provides brachium support RADIUS and ULNA: antebrachium the radius is the anteromedial bone, and the ulna is the posterolateral bone. CARPALS and PHALANGES: The manus includes six cartilaginous carpals, followed distally by four digits VERTEBRAE  TRUNK VERTEBRAE and RIBS: atlas (C1) articulates with the first of the long series of trunk vertebrae.  Transverse processes: extend from the centrum  articulate with small, Y-shaped ribs.  Neural canal passes dorsal to the centrum. The neural arch forms the roof of the canal and bears a neural process (aka spinal process). VERTEBRAE (cont’d)  SACRAL VERTEBRA (single): articulates with the pelvic girdle  CAUDAL VERTEBRAE: bear a hemal arch, follow the sacral vertebra.  Most lack ribs but bear transverse processes. PECTORAL SKELETON HUMERUS: supports the brachium RADIUS and ULNA: In the antebrachium the radius is the anteromedial bone, and the ulna is the posterolateral bone. CARPALS and PHALANGES: The manus includes six cartilaginous carpals, followed distally by four digits PELVIC SKELETON FEMUR: single bone of the thigh. TIBIA and FIBULA: Tibia and fibula lie anteriorly and posteriorly, respectively, in the crus. TARSALS and PHALANGES: six cartilaginous tarsals and distally by four ossified digits. Proximal bone of each digit is a metatarsal Distal elements are phalanges. PELVIC SKELETON FEMUR: single bone of the thigh. TIBIA and FIBULA: Tibia and fibula lie anteriorly and posteriorly, respectively, in the crus. TARSALS and PHALANGES: six cartilaginous tarsals and distally by four ossified digits. Proximal bone of each digit is a metatarsal Distal elements are phalanges.  MOUTH  EXTERNAL GILLS: larval stage,  NARIS presence of three pairs of EXTERNAL filamentous external gills, located   EYE LABIA just posterior to the flattened head. ANATOMY Two pairs of pharyngeal slits  GULAR FOLD: prominent transverse  PELVIC LIMBS Gular fold of a gular fold. A gular fold is a feature of Florida Brown the body of lizards and many other  TAIL FIN Anole reptiles found on the ventral throat  PECTORAL LIMBS  MYOMERE and MYOSEPTUM: MUSCULAR  Myomeres separated by myosepta as in fishes  Note that the myomeres are relatively simple rather than SYSTEM assuming the complexly folded pattern observed in fishes.  DORSALIS TRUNCI (epaxial): longitudinal muscle extending anteroposteriorly from the trunk into the tail  HORIZONTAL SKELETOGENOUS SEPTUM MUSCULAR  Divides the epaxial muscles (dorsal) and hypaxial muscles (ventral) SYSTEM  Epaxial musculature:  Relatively reduced  Diminished importance in locomotion  Hypaxial musculature: subdivided MUSCULAR into several portions.  Three sheet-like flank layers SYSTEM that cover the pleuroperitoneal cavity laterally. 1. External oblique (most superficial of these layers) fibers extend posteroventrally 2. Internal oblique (middle layer) and extend posterodorsally 3. Transverse abdominis (deeper layer)  TRANSVERSUS ABDOMINIS MUSCULAR SYSTEM M. (FIG 5.11): deepest layer is the transversus abdominis.  RECTUS ABDOMINIS (hypaxial): ventral subdivision of the hypaxial musculature. Clearly visible in external view. Extends anteroposteriorly just lateral to the linea alba MUSCULAR SYSTEM  LINEA ALBA (FIG 5.14): saggital division of the ventral musculature  Translates to “white line” from Latin MUSCULAR SYSTEM (Dorsal View)  MIDDORSAL SEPTUM: musculature is subdivided into left and right portions by a middorsal septum (Figure 5.12)  Linea alba = ventral division  ADDUCTOR MANDIBULAE EXTERNUS M: muscles that close the jaw. Lateral and dorsal surfaces of the head largely posterior to the eyes  DORSALIS SCAPULAE M. (FIG 5.13): arises from the MUSCULAR suprascapular cartilage and passes ventrally, its fibers converging to insert on the humerus. SYSTEM  LATISSIMUS DORSI M. (FIG 5.13, 5.18): arises from the fascia covering the dorsalis trunci. MUSCULAR  Its converging fibers extend mainly anteroventrally to insert on SYSTEM the humerus, and it functions to retract the forelimb. Compare with human lat. dorsi  TRICEPS (FIG 5.13, 5.14): MUSCULAR dorsal surface of the brachium, and consists of SYSTEM two easily recognizable parts. 1. Humeral head, arising from the humerus, is dorsolateral (Figures 5.17 and 5.19) 2. Coracoid head, arising from the coracoid, is more medial  HUMEROANTEBRACHIALIS M. (5.13, 5.14): anterior to the coracobrachialis, extends between the humerus and proximal end of MUSCULAR the radius and flexes the antebrachium. SYSTEM  CORACOBRACHIALIS M. (FIG 5.14): adducts the forelimb  PECTORIALIS M. (FIG 5.14. 5.18): humeral adductors. MUSCULAR SYSTEM  CLOACA: cloaca, marking the posterior end of the trunk, lies ventrally between the pelvic limbs.  Males: the cloacal aperture is surrounded by small projections or papillae.  CLOACAL GLAND: provides swollen appearance to the cloaca.  Swelling in males increase during breeding season References Fabre, A.C. (2020, May 22). Metamorphosis as a driver of morphological diversity in Salamanders. Nature Portfolio Ecology & Evolution Community. https://ecoevocommunity.nature.com/posts/metamorphosis-as-a- driver-of-morphological- diversity-in-salamanders Iuliis, G. D., & Pulerà, D. (2019). The Dissection of Vertebrates (3rd Edition). Elsevier S & T. https://bookshelf.vitalsource.co m/books/9780124105003