Exoskeletal Structures Flashcards
derived from dermis and are therefore mesoderm in origin
scales of sihes
the dermal embedded, flat, bony base of the scale
basal plate or root
shiny curved dermal outgrowth directed caudad and erupts from the epidermis
spine
Consist of dentine that is covered with a hard layer of virodentine (both are mesodermal origin)
spine
spine consists of what
dentine
what covers dentine
virodentine
cavity found at the center of the basal plate and spine
pulp cavity
scales found in cartilaginous fishes
placoid scales
a fish of a large group that comprises all ray-finned fishes apart from the primitive bichirs, sturgeons, paddlefishes, freshwater garfishes, and bowfins.
teleost fishes
lobe-finned fish
sacopterygii
ray-finned fish
actinopterygii
label the different scales
grade yourself accordingly
roughly circular, fluted, thin, and flexible scale
cycloid
scale that is made up of concentric ridges
cycloid scales
Expected free half is smooth and cleft
cycloid scales
Embedded portion of the scale constitutes the other half if fluted
cycloid scales
also thin with ridges, but the basal embedded portion is scalloped
ctenoid scale
Free edge hears numerous comb-like or tooth-like
projections called ctenidia or
teeth
ctenoid scale
tooth-like projections in ctenoid scale
ctenidia
Both ____ and _____ scaleconsist of a thin layer of cellular lamellar bone
cycloid
ctenoid
scale is rhomboidal in shaped and covered by a hard, shiny, translucent material
ganoid scale
ganoid scale is covered by a hard, shiny, translucent material called what
ganoin
ganoid scale is what in origin
mesodermal
Edges are darkly stained due to the presence of ganoin
ganoid scale
athickenedbonyplate on a turtle’s shell or on the back of acrocodile
scite
– mark the boundaries of the large, thin horny, epidermal scutes of the surface of the carapace
grooves
label the scutes in the dorsal side of the carapace
grade yourself accordingly
median row of five scutes
central scutes
circular row of 25 scutes consisting of nuchal scute
costal scute
an anterior smaller, median unpaired scutes
nuchal scute
two median posterior scute
supracaudal scute
can be removed from the carapace but its boundaries are not the same as that of underlying plates
scutes
scute is what in origin ____
epidermal
since scutes are epidermal in origin, where is it originate in embryonic origin
ectodermal
label the ventral side of the carapace
grade yourself accordingly
continuation or extension of marginal scutes covering the margin of the underside of the carapace
inframarginal scute
made up of heavy bony plates, which are dermal and mesodermal in origin (which side of carapace)
ventral side
plates are fused to the vertebrae or ribs and are bounded by what
jagged sutures
made up of bony dermal plates covered by horny epidermal scutes bounded by sutures (what side of plastron)
dorsal