Chondrichthyans
Dan Fitzpatrick & Elizabeth Ezrike
Major Classes
Elasmobranchii
Holocepheli
Examples Of Species
Great White Shark
Manta Ray
Tiger Shark
General Facts
• Live in marine conditions. More specifically, they live in
oceans as well as sand, mud, reefs, and rivers.
• There are slightly under 1,000 species of Chondrichthyes
known to exist, and it is predicted that approximately 1,200
exist.
Interesting Facts & Importance to Humans
• Sharks are the only animals with an entire week dedicated to
them.
• Shark attacks are quite uncommon; only 60 shark attacks per
year are reported, most of which are non-fatal.
• In some Asian markets, shark fins can be sold for $300 per
pound
• Sharks eat abundant species as prey, therefore balancing the
ecosystem
• Sharks, in their hunting, actually use mathematical principles.
(http://www.sciencenews.org/view/generic/id/60106/title/Shark
s_use_math_to_hunt )
External Features
Placoid Scales (don’t grow)
Internal Anatomy
Type of Symmetry
Bilaterally Symmetrical
Type of Skeleton
Mostly cartilage,
calcium impregnated.
Life Cycle
• OVIPAROUS: EXTERNAL FERTILIZATION OF
EGGS
• OVOVIVIPAROUS: EGGS KEPT IN MOTHER
AND HATCHES IN MOTHER
• VIVIPAROUS: PLACENTAL CONNECTION VIA
UMBILICAL CORD
Distinguishing Characteristics
• Spiral valve digestive tract
• No lungs or eardrums
• Use muscles in jaw to push water through gills when
at rest.
• Nostrils are closed, used for olfaction
• One opening for anus and reproductive tract called
the cloaca
• Rays use their pectoral fins as water wings
• Regions in the head have sensory glands
Bibliography
• 2. INTRODUCTION. (n.d.).FAO: FAO Home. Retrieved
February 17, 2011, from
http://www.fao.org/docrep/003/x8692e/x8692e06.htm
• ADW: Chondrichthyes: Pictures . (n.d.). Animal Diversity Web.
Retrieved February 17, 2011, from
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/
Chondrichthyes.html
• Introduction to the Chondrichthyes. (n.d.). UCMP - University
of California Museum of Paleontology. Retrieved February 17,
2011, from http://www.ucmp.berkeley.edu/