Dr. Peter Larson
 
Associate Professor of Biology 
Department of Biology 
St. Anselm College 
100 St. Anselm Drive 
Manchester, NH 03102 
E-mail: plarson(at)anselm.edu 
Phone: 603-641-7156
EDUCATION

B.S. Biology, University of Richmond, 1997 
Ph.D. Biological Sciences, Ohio University, 2003		 2008-2009 COURSES
 
Human Anatomy and Physiology (BI 331)
Comparative Vertebrate Anatomy (BI 315)
Developmental Biology (BI 324)
Independent Research (BI 321-322)
 

RESEARCH INTERESTS

My research currently focuses on evolutionary, developmental and ecological morphology, centering mainly on the ontogeny, form, and function of the musculoskeletal system in anuran (frogs, toads) tadpoles.  A major emphasis of my research program is the incorporation of developmental data in studies of evolutionary and functional morphology.  Central questions in my research are: 1) How do growth and development contribute to morphological and functional variation within and among species?; 2) What factors influence the development and anatomical shape of the larval anuran chondrocranium? 3) What can we learn about frog phylogeny by looking at tadpole morphology, and 4) What are the consequences of morphological variation and evolutionary novelty to tadpole biomechanics, behavior, and ecology?  Current research areas include:
 
1.  The evolution and diversity of cranial anatomy in tadpoles.  I am interested in the evolution of chondrocranial morphology in larval anurans at both intra- and interspecific levels.  Colleagues and I have worked on describing chondrocranial morphology in a variety of groups of frogs (e.g., Leptodactylus, Larson and de Sá, 1998; Melanophryniscus, Larson et al., 2003; Rana, Larson, 2008).  In addition to descriptive comparative anatomy, I have used geometric morphometric techniques to investigate patterns of morphological variation in Rana with the goal of understanding the development and evolution of the chondrocranium in the genus (see right; Larson, 2005). 

 
2.  Patterns of morphological development in larval anurans.  I have investigated the relationship between body size and skeletal morphology in a variety of species (Rana, Bufo) using both linear and geometric morphometric techniques.  Results (Larson, 2002) have indicated that in wood frog tadpoles (see right), functionally important regions of the skull associated with muscles involved in feeding exhibit contrasting patterns of development as compared to the remainder of the skull.  I have compared this data with ontogenetic trajectories for other species of Rana (Larson, 2005) to understand how allometric growth patterns might contribute to morphological and functional differences among species.

 
3.  Ecomorphology and the biomechanics of tadpole feeding.  I am interested in the adaptive significance of variation in larval anuran morphology and am currently surveying and quantifying morphology broadly among larval anuran ecotypes.  Integration of morphological data with functional and experimental studies provides a link between larval morphological variation, feeding function, and tadpole ecology.  For example, I completed an experimental project with Steve Reilly (Ohio University), using kinematic and electromyographic analyses to describe jaw movements and in vivo muscle function during feeding and gill irrigation in bullfrog tadpoles (Larson and Reilly, 2003).  This study provided the first data on muscle function during feeding in tadpoles and provides necessary baseline data for future experimental studies of feeding performance.

Click image to see a video of tadpole feeding.
 

PUBLICATIONS
(click on links for PDF files of publications)

Larson PM. 2008. The chondrocrania of North American Rana larvae (Anura: Ranidae): A morphological comparison. Acta Zoologica (Stockholm) 89:279–288

Herrell A, McBrayer LD, Larson PM. 2007. Functional basis for intersexual differences in bite force in the lizard Anolis carolinensis. Biological Journal of the Linnean Society 91:111–119.

Larson PM. 2005. Ontogeny, phylogeny, and morphology in anuran larvae: A morphometric analysis of cranial development and evolution in Rana larvae (Anura: Ranidae). Journal of Morphology 264:34-52.

Janssen RB, Pitocchelli FJ, Larson PM. 2005. MacGillivray’s Warblers in Minnesota and problems of identification. The Loon: the Journal of the Minnesota Ornithologists’ Union 77(2): 62–74.

Larson PM. 2004. Chondrocranial morphology and ontogenetic allometry in larval Bufo americanus (Anura, Bufonidae).  Zoomorphology 123:95-106.

Larson PM, de Sá RO, Arrieta D. 2003. Chondrocranial, hyobranchial and internal oral morphology in larvae of the basal bufonid genus Melanophryniscus (Amphibia: Anura). Acta Zoologica 84:145–154.

Larson PM, Reilly SM. 2003. Functional morphology of feeding and gill irrigation in the anuran tadpole: Electromyography and muscle function in larval Rana catesbeiana. Journal of Morphology 255:202–214.

Larson PM. 2002. Chondrocranial development in larval Rana sylvatica (Anura: Ranidae): A morphometric analysis of cranial allometry and ontogenetic shape change. Journal of Morphology 252:131–144.

Radice G, Boggiano MK, DeSantis M, Larson P, Oppong J, Smetanick M, Stevens T, Tripp J, Weber R, Kerckhove M, de Sá R. 1999. Three-dimensional reconstructions of tadpole chondrocrania from histological sections. Virginia Journal of Science 50(3):227–235.  

Larson PM, de Sá RO. 1998. Chondrocranial morphology of Leptodactylus larvae (Leptodactylidae: Leptodactylinae): Its utility in phylogenetic reconstruction. Journal of Morphology 238:287–305.

Last Webpage Update: 3/09/2009