Segmentations of the cartilaginous skeletons of chondrichthyan fishes by the use of state-of-the-art computed tomography

Table 1 Overview of the study specimens

	Southern Shovelnose ray	Skilletskate	Goblin shark	Lemon shark
Scientific name	Aptychotrema vincentiana	Dactylobatus armatus	Mitsukurina owstoni	Negaprion brevirostris
Kingdom	Animalia	Animalia	Animalia	Animalia
Phylum	Chordata	Chordata	Chordata	Chordata
Class	Chondrichthyes	Chondrichthyes	Chondrichthyes subclass: Elasmobranchii	Chondrichthyes subclass: Elasmobranchii
Order	Rajiformes	Rajiformes	Lamniformes	Carcharhiniformes
Family	Rhinobatidae	Rajidae	Mitsukurinidae	Carcharhinidae
Genus	Aptychotrema	Dactylobatus	Mitsukurina	Negaprion
Species authority	Haacke, 1885	Bean and Weed, 1909	Jordan, 1898	Poey, 1868
Distribution	Eastern Indian Ocean: endemic to Australia (20°S - 40°S)	Western Central Atlantic: South Carolina, United States to the Gulf of Mexico and along Central America to Venezuela Also found on middle continental slope off southern Brazil (35°N - 35°S, 30°W - 98°W)	Western Atlantic: Guyana, Suriname and French Guiana Eastern Atlantic: France (Bay of Biscay), Madeira, Portugal, and South Africa Western Indian Ocean: off South Africa. Western Pacific: Japan, Australia (South Australia, New South Wales), New Zealand Eastern Pacific: United States (southern California) (8°N - 55°S, 180°W - 180°E)	Western Atlantic: New Jersey, United States to southern Brazil, including the Gulf of Mexico, the Bahamas, and the Caribbean; also in Gulf of Mexico Northeast Atlantic: Senegal, Côte d'Ivoire and probably wide-ranging off West Africa, but this requires confirmation. Eastern Pacific: southern Baja California, Mexico and the Gulf of California to Ecuador (45°N - 39°S, 114°W - 0°)
Environment	Marine; demersal;	Marine; bathydemersal;	Marine; bathydemersal;	Marine; brackish; reef-associated; oceano-dromous
	Depth range: 0-32 m	Depth range: 300-900 m (usually 300-700 m)	Depth range: 30-1300 m (usually 270-960 m)	Depth range: 0-92 m
Size (cm)	Maximun length: 79.0 cm	Maximun length: 32.0 cm	Maximun length: 617.0 cm	Maximun length: 340.0 cm
	Presented specimen: 72.9 cm	Presented specimen: 23.5 cm	Presented specimen: 119.5 cm	Presented specimen: 95.6 cm
Red list category	Least concern	Data deficient	Least concern	Near Threatened
Threat to humans	Harmless	Harmless	Harmless	Minor Threat

Table 2 Computed tomography protocol

Acquisition parameters	Thorax Hd	DE Thorax
Section collimation	192 mm × 0.6 mm	192 mm × 0.6 mm
Slice thickness (mm)	0.5	0.5
Increment (mm)	0.3	0.5
Rotation time (s)	0.5	0.3
Pitch	0.35	0.65
Tube voltage (kV)	120	80 + 150
Effective tube current–time product (mAs)	37-104	1107/615
DLP (mGy/cm)	2.3-6.23	17.55-27.76
Reconstruction kernel	Bf32/Br54	Qr32/Qr54
	Admire 3	Admire 3