CT Scanning of museum specimens: a case study of diversity from the inside out
Amy McCune Ecology and Evolutionary Biology Cornell University and Cornell University Museum of Vertebrates Evolutionary morphology and phylogenetics have long focused on: Computed Tomography (CT) is being used increasingly for evolutionary morphology!
A charciform fish, CU81425 Hoplias, collected ~1940s
but the extent and size of datasets present challenges to museum curators unlike any dissection ever did! Today talk about a case study of anatomy using CT
Are gas bladders modified lungs? What is a gas bladder?
buoyancy, hearing
sb b
Zebrafish (Danio) Chitala chitala
Functions: buoyancy, respiration, hearing, sound production Orthodoxy: gas bladder is a modified lung (but some controversy)
relatively little modification
1. duct and lungs rotate dorsally 2. paired lung reduced to single
(from Romer 1974 The Vertebrate Body of Osteichthyes after B.Dean 1895. Living and Fossil Fishes) One source of controversy is the phylogentic distribution of the pulmonary artery supply
PA PA PA PA PA PA ? PA Is the bowfin pulmonary artery (PA) convergent or homologous? 3-D study of the arterial supply in rayfinned fishes & lungfish Injected barium into dorsal aorta of euthanized fish Imaged with micro-CT (spatial res 50-100 microns) Analyzed with Microview and Osirix.
Mark Sarah Longo Riccio Using micro-CT to show what some AOs actually look like…
AO =air-filled organ, a collective term for lungs & gas bladders Sturgeon (A. transmontanous)
pd Gar (L. platyrhynchus) lungs of bichir (Polypterus ornatipinnis)
dorsal view lungs gut lateral view
ventral view African lungfish (Protopterus dolloi )
lung
• Duct connects ventrally gut • Lung largely dorsal
• Very long (98% coelom)
• Vesicular internally Micro-CTs of injected fish
gar lungfish
sturgeon Polypterus Pulmonary arteries branch off the 4th efferent branchial artery
anterior anterior anterior
PA lateral view lateral view African lungfish bowfin dorsal view amphibian Polypterus Polyodon Acipenser Polypterus Polyodon Acipenser
I I I I II I I Polypterus Polyodon Acipenser II Polypterus II Polyodon Acipenser III II III II II III III IV e IV s IV s IV e lp ’ rp III IV lp rp III IV’ IV co IV s IV co IV s vlp c d c d vlp d c c d c c d da’ Comparativei study of arteriald vasculatureda’ i c’ c’ African lungfish bichir bowfin Lepisosteus Amia Protopterus PoLleyppitesorsutes us PoPoAmiallyyopdteornus AcipenserPoProlytoopdteonrus Acipenser
I I II I I Lepisosteus Amia Protopterus II I I II PoLelyppisteorsutesus PoPoAmiallyyopdteornus II AcipenserPoProlytoodpotenrus IIII Acipenser I III III IIIII II II I I IIIIII III II IV IIIV s I IV IV e II lp rp II s IV rp IV e III III III lp rp III lp IV’ lp s III rp III IV’ IV IV d IV IVIVco IVs sd s rp vlp IV co IV s lp c sc vlp rpc d lpd c d c c d d c c c d d d dad’ i d da’ i c’ da’ da’ c’
Lepisosteus Amia Protopterus PolyptePorulsypterus PolyPoodlyoondon AcipenserAcipenser Lepisosteus Amia Protopterus I I I I I I Lepisosteus Amia Protopterus II PolypPoterlyupsterus II II PolPoyoldyoodnon AcipenserAcipenser I I Lepisosteus Amia Protopterus II III III II II I IIII III II IIIIII II IV III IV IV e II I rp IV s s III IVIV e II II lp rp lp lp ’ III lp rp rp III III IVIV’ IV IIIIV s III d IVIVcoco IVIV s s IV rp IV s d s lp c vlp vlp c dd s rp c d d cc d c c c lp c dd c d ’ d d dada’ da’ i i c’c’ da’
LepisoLsetepuissosteus AmiaAmia paddlefish PrProototopteruusssturgeon gar I I LepisLoespteisuossteus AmiaAmia PrProotopteterruuss IIII From Longo, Riccio, and McCune 2013 I IIIIII I I II II I IVIV II II lplp rp rp III III III III IV IV IVIV ss dd rprp s s lp lp c c d d cc d d da’ da’ Sturgeon and paddlefish have small arteries which branch off the 4th branchial efferent arteries
Are these vestigial pulmonary arteries?
Longo, Riccio & McCune 2013 Bowfin PAs are homologous not convergent PAs are synapomorphy of Osteichthyes
gar Ray
Bonyvertebrates -
bowfin finned sturgeon
paddlefish Fleshy Polypterus pa
tetrapods - lungfish finned coelacanth shark
Ancestral states with R, using Max. Parsimony Reconstruction in APE package (Paradis 2004). One project generated:
~12 jars
and
100.43 GB of CT data (49,966 items)
of associated data Acknowledgements
Collaborators: Sara Longo (undergraduate thesis, Mark Riccio)
For help obtaining specimens: Jan Hoover and Steven George, U.S. Army Engineer Research and Development Center, Waterways Experiment Station • Carl Rathjee, NY State D.E.C. Constantia Fish Hatchery • Glenn Northcutt, Scripps Institute of Oceanography • Charles Dardia, John Friel, Cornell Museum of Vertebrates. Amia: dorsal AO is long (~70% coelom), bilobed, and vesicular internally.
Endoscopy ! Swim bladder morphology is also diverse:
Chitala chitala Soft tissue has been used some, but not extensively
Adult Bowfin gas bladder