Functional Morphology Of Feeding Research Articles

Descriptions of the Immature Stages of Poteriophorus Schoenherr, 1838 (Coleoptera: Curculionidae: Dryophthorinae): Larva, Pupa, and Biology of Poteriophorus uhlemanni (Schultze, 1922) Discovered through Dawu Traditional Ecological Knowledge

Dryophthorinae includes some of the most economically important weevil pests. Feeding damage on host plant occurs primarily during the endophytic larval stages. The immature stages of only approximately 5% of dryophthorine genera are currently known. Traditional Ecological Knowledge of the Dawu People of the island of Lanyu led to the discovery of the immature stages and host plant of the dryophthorine weevil genus Poteriophorus Schoenherr. The larva, pupa, and biology of Poteriophorus uhlemanni (Schultze, 1922) are described for the first time. The newly discovered larva is compared to closely related taxa, including two of the most economically important and commonly encountered genera in Sphenophorina: Metamasius Horn, 1873 and Sphenophorus Schoenherr, 1838. Discovery of the associated larval and pupal stages of P. uhlemanni provides suites of characters for morphologically based phylogenetic studies, insights into the larva's functional morphology of feeding, tunneling, and cocoon-making behavior, and the ability to accurately identify the species at all stages.Knowledge of host preference will inform management strategies for poorly studied endemic species in the area.

New Models and Insights into Primate Evolutionary Morphology

New Models and Insights into Primate Evolutionary Morphology

The ontogeny of feeding behavior and cranial morphology in the leopard shark Triakis semifasciata (Girard 1854): A longitudinal perspective

While much is known about the ecological and functional morphology of feeding in lower vertebrates, studies of elasmobranch feeding over ontogeny are broadly lacking. In this study, the ontogeny of feeding behavior and morphology were investigated in neonatal and young-of-the-year leopard sharks Triakis semifasciata using morphometric measurements of growth and high-speed videography in a longitudinal study. Five food types were used during filming sessions to facilitate differentiation of modulation and variation over ontogeny. Functional aspects of muscle and buccal volume scaling were investigated through dissection. Growth over ontogeny was shown to influence numerous kinematic variables, while intra- and inter-individual variability was the dominant factor affecting feeding behavior. Modulation of feeding behavior based on food size and elusiveness was present for timing variables and predator motion during the strike, but not for food motion or the relative extent of buccal expansion. Allometric growth occurred in all aspects of external cranial morphology measured, resulting in a shallower head profile, anterior displacement of the mouth, and relatively larger jaw musculature over ontogeny. While the degree to which morphology constrains or enhances behavior cannot be directly quantified, variability in behavior greatly exceeds variability in morphology over early ontogeny. Maintenance of a behaviorally and morphologically versatile feeding apparatus throughout ontogeny is proposed to enhance the exploitation of resources and facilitate a diverse diet in T. semifasciata under variable environmental conditions.

Functional morphology of feeding and gill irrigation in the anuran tadpole: electromyography and muscle function in larval Rana catesbeiana.

This study provides the first data on muscle activity patterns during active feeding in a larval anuran. Data regarding muscle function during gill irrigation and hyperexpiration are also provided. Electromyographic and kinematic data were recorded from six mandibular and hyoid muscles in unanesthetized, unrestrained larvae of Rana catesbeiana. Only three (hyoangularis, orbitohyoideus, anterior interhyoideus) of the six muscles examined are active during gill irrigation. Feeding cycles are characterized by the recruitment of three additional muscles: intermandibularis, suspensorioangularis, and levator mandibulae longus superficialis. The latter two contribute, respectively, to wide opening and forceful closing of the mouth during feeding. Hyperexpiration is characterized by a reversal of water flow anteriorly out of the mouth. This hydrodynamic change occurs due to modulation of the timing of firing of the anterior interhyoideus, as well as recruitment of the posterior interhyoideus, which is only active during hyperexpiration. Both regions of the interhyoideus, which are responsible for evacuation of the buccal cavity, are active during the opening phase of hyperexpiration. Kinematically, transitioning from gill irrigation to feeding involves both an overall shortening of the gape cycle and a shift in the relative length of opening phase vs. closing phase. Our results corroborate many of the findings of Gradwell ([1972] Can J Zool 50:501-521) regarding muscle function during gill irrigation and hyperexpiration. Furthermore, we demonstrate that in larval anurans the transition from gill irrigation to feeding involves modulation of gape cycle kinematics, changes in the level of activity of muscles, and recruitment of muscles that are not active during irrigation. In light of new data presented here, a review of muscle function in tadpoles is also provided.

Jaw muscle development as evidence for embryonic repatterning in direct-developing frogs.

The Puerto Rican direct-developing frog Eleutherodactylus coqui (Leptodactylidae) displays a novel mode of jaw muscle development for anuran amphibians. Unlike metamorphosing species, several larval-specific features never form in E. coqui; embryonic muscle primordia initially assume an abbreviated, mid-metamorphic configuration that is soon remodelled to form the adult morphology before hatching. Also lacking are both the distinct population of larval myofibres and the conspicuous, larval-to-adult myofibre turnover that are characteristic of muscle development in metamorphosing species. These modifications are part of a comprehensive alteration in embryonic cranial patterning that has accompanied life history evolution in this highly speciose lineage. Embryonic 'repatterning' in Eleutherodactylus may reflect underlying developmental mechanisms that mediate the integrated evolution of complex structures. Such mechanisms may also facilitate, in organisms with a primitively complex life cycle, the evolutionary dissociation of embryonic, larval, and adult features.

Fossil horses: systematics, paleobiology, and evolution of the family equidae

Preface 1. Introduction: why study fossil horses? 2. A renaissance in paleontology 3. Orthogenesis and scientific thought: old notions die hard 4. Collections, museums, and exceptional discoveries 5. Systematics and phylogeny: Ungulata, Perissodactyla, and Equidae 6. Isotopes, magnetic reversals, fossils, and geological time 7. Ancient geography, changing climates, dispersal, and vicariance 8. Evolutionary processes: Variation, speciation, and extinction 9. Rates of morphological and taxonomic evolution 10. Trends, laws, direction, and progress in evolution 11. What's the use? functional morphology of feeding and locomotion 12. Population dynamics, behavioral ecology, and 'paleoethology' 13. Fifty-eight million years of community evolution 14. Epilogue: summary and perspective Appendix References Subject index Taxonomic index.

Functional Morphology of Feeding and Grooming in Crustacea

Functional Morphology of Feeding and Grooming in Crustacea

Metamorphosis of cranial design in tiger salamanders (Ambystoma tigrinum): A morphometric analysis of ontogenetic change.

While ontogenetic analyses of skull development have contributed to our understanding of phylogenetic patterns in vertebrates, there are few studies of taxa that undergo a relatively discrete and rapid change in morphology during development (metamorphosis). Morphological changes occurring in the head at metamorphosis in tiger salamanders (Ambystoma tigrinum) were quantified by a morphometric analysis of cranial osteology and myology to document patterns of change during metamorphosis. We employed a cross-sectional analysis using a sample of larvae just prior to metamorphosis and a sample of transformed individuals just after metamorphosis, as well as larvae undergoing metamorphosis. There were no differences in external size of the head among the larval and transformed samples. The hyobranchial apparatus showed many dramatic changes at metamorphosis, including shortening of ceratobranchial 1 and the basibranchial. The subarcualis rectus muscle increased greatly in length at metamorphosis, as did hypobranchial length and internasal distance. A truss analysis of dorsal skull shape showed that at metamorphosis the snout becomes wider, the maxillary and squamosal triangles rotate posteromedially, and the neurocranium shortens (while maintaining its width), resulting in an overall decrease in skull length at metamorphosis. These morphometric differences are interpreted in light of recent data on the functional morphology of feeding in salamanders. Morphological reorganization of the hyobranchial apparatus and shape changes in the skull are related to the acquisition of a novel terrestrial feeding mode (tongue projection) at metamorphosis. Metamorphic changes (both internal and external) that can be used to judge metamorphic condition are discussed.

Felgenhauer, B. E., L. Watling, and A. B. Thistle, eds. 1989. Functional morphology of feeding and grooming in Crustacea.Crustacean issues 6: i-x, 1-225. A. A. Balkema Publishers, Rotterdam, The Netherlands.

Felgenhauer, B. E., L. Watling, and A. B. Thistle, eds. 1989. Functional morphology of feeding and grooming in Crustacea.Crustacean issues 6: i-x, 1-225. A. A. Balkema Publishers, Rotterdam, The Netherlands.

Ultrastructure and Functional Morphology of Feeding and Associated Appendages in the Tropical Fresh-Water Shrimp Atya innocous (Herbst) with Notes on Its Ecology

Ultrastructure and Functional Morphology of Feeding and Associated Appendages in the Tropical Fresh-Water Shrimp Atya innocous (Herbst) with Notes on Its Ecology

The functional morphology of feeding in three species of maldanid polychaetes

The functional morphology of deposit feeding relative to proboscideal morphology of the maldanid polychaetes Axiothella rubrocincta (Johnson, 1901), Clymenella californica Blake & Kudenov, 1974, and Praxillella affinis pacifica (Berkeley, 1929) from central California is presented. The proboscides of these species are externally and internally similar. They consist of a cuticulatized buccal mass, a bucco-pharyngeal junction and ciliated pharynx. A functional unit of the feeding process is the palpode because its secretions enable the proboscis to be effectively everted. These worms exploit die physical properties of the substratum by changing its dilatancy (and thixotropy) while feeding. The rapidly emerging buccal mass increases the dilatancy of the sediment and provides a penetration anchor. The buccal mass partially deflates and loosens the substratum just prior to the forceful extrusion of the bucco-pharyngeal junction. Sediment about the latter region becomes dilatant. The proboscis then shortens and widens, causing the substratum about the pharynx to become thixotropic while it becomes dilatant about the region of the proboscis proximal to the pharynx. The worms push their proboscides into the loosened sediment while pharyngeal ciliary currents and the undulating bucco-pharyngeal margin draw food into the pharynx. Pharyngeal cilia and the buccal mass function in particle selection. The maldanids and arenicolids examined to date share similar and basic proboscideal morphologies and activities. It is suggested that the feeding mechanism described for the maldanids, A. rubrocincta, C. californica and P. affinis pacifica, will be found in some members of both families.