Sharks as a group have a long history as highly successful predatory fishes
. Although, the number of recent studies on their diet, feeding behavior, f
eeding mechanism, and mechanics have increased, many areas still require ad
ditional investigation. Dietary studies of sharks are generally more abunda
nt than those on feeding activity patterns, and most of the studies are con
fined to relatively few species, many being carcharhiniform sharks. These s
tudies reveal that sharks are generally asynchronous opportunistic feeders
on the most abundant prey item, which are primarily other fishes. Studies o
f natural feeding behavior are few and many observations of feeding behavio
r are based on anecdotal reports. To capture their prey sharks either ram,
suction, bite, filter, or use a combination of these behaviors. Foraging ma
y be solitary or aggregate, and while cooperative foraging has been hypothe
sized it has not been conclusively demonstrated. Studies on the anatomy of
the feeding mechanism are abundant and thorough, and far exceed the number
of functional studies. Many of these studies have investigated the function
al role of morphological features such as the protrusible upper jaw, but on
ly recently have we begun to interpret the mechanics of the feeding apparat
us and how it affects feeding behavior. Teeth are represented in the fossil
record and are readily available in extant sharks. Therefore much is known
about their morphology but again functional studies are primarily theoreti
cal and await experimental analysis. Recent mechanistic approaches to the s
tudy of prey capture have revealed that kinematic and motor patterns are co
nserved in many species and that the ability to modulate feeding behavior v
aries greatly among taxa. In addition, the relationship of jaw suspension t
o feeding behavior is not as clear as was once believed, and contrary to pr
evious interpretations upper jaw protrusibility appears to be related to th
e morphology of the upper jaw-chondrocranial articulation rather than the t
ype of jaw suspension. Finally, we propose a set of specific hypotheses inc
luding: (1) The functional specialization for suction feeding hypothesis th
at morphological and functional specialization for suction feeding has repe
atedly arisen in numerous elasmobranch lineages, (2) The aquatic suction fe
eding functional convergence hypothesis that similar hydrodynamic constrain
ts in bony fishes and sharks result in convergent morphological and functio
nal specializations for suction feeding in both groups, (3) The feeding mod
ulation hypothesis that suction capture events in sharks are more stereotyp
ed and therefore less modulated compared to ram and bite capture events, an
d (4) The independence of jaw suspension and feeding behavior hypothesis wh
ereby the traditional categorization of jaw suspension types in sharks is n
ot a good predictor of jaw mobility and prey capture behavior. Together wit
h a set of questions these hypotheses help to guide future research on the
feeding biology of sharks.