Selection of Experimental Fishes
THERE IS obviously a considerable morphological
and physiological difference between the primitive
and recent fishes, or one might say there is a phylogenetic basis for selecting an experimental fish. The
bony fishes, class Osteichthyes, may be divided into
the fleshy-finned fishes and the rayed-fin forms. The
first group is for the most part extinct and of no interest here. The rayed-fin forms may be divided into the
three groups: Chondrostei, Holostei, and Teleostei.
The first group is represented in our fauna by the paddle fish ( Polyodon spatula ) and sturgeons ( Acipenser
spp. ) and the second by gar pikes ( Lepisosteus spp.
)
and the bowfin {Amia calva). Both of these groups
are poorly represented in present day fauna, and
forms available are too large for most experimental
work.
The group Teleostei includes the great majority of
our present day fishes, but even within this group