Lamprey&Hagfish Flashcards
Hagfish: Class, Order, Family
C: Myxini
O: Myxiniformes
F: Myxinidae
Lampreys: Class, Order, Family
C: Cephalaspidomorpha
O: Petromyzontidifores
F: Petromyzontidae
Which species is more primitive? Hagfish or Lampreys?
hagfish
What primitive characteristics do hagfish and lamprey share?
no paired fisns, no jaws, and rudimentary cartilaginous skeletons
what do hagfish lack that all other craniates have?
vertebral column
how many paired gill openings do hagfish and lamprey have?
H: 1-14
L: 7
Name the gill structure for a hagfish and lamprey
H: branchial pouches
L: branchial baskets
what kind of skeletal system do these fish share?
a simple cartilaginous skeleton
Gnathostome
spp w vertical biting device (jaws)
8 characteristics of hagfish
1) 4 pairs of tentacles
2) esophagocutaneous duct
3) 1-14 gill openings
4) slime glands
5) dorsal, anal and caudal fins w/o fin rays
6) marine
7) osmotic non-regulators
8) low fercundity
what part of the ocean do hagfish live?
benthic zone
13 characteristics of lampreys
1) internal cartilaginous skeleton
2) single dorsal nasal opening
3) pineal eye
4) 2 semi-circular canals
5) solid cartilaginous braincase
6) cartilaginous branchial basket
7) vertibrae and fin rays
8) osmotic regulators
9) fw or anadromous
10) high fecundity
11) ammocete larval stage
12) semelparous
13) some are parasitic-predators as adults, other are strictly breeders as adult
what is a lamprey’s larval form called?
ammocoete
Buccal funnel
sucking disk (lamprey)
oral fimbria
buccal papillae
myomers
segmented body muscle segments
cloacal aperture
the opening of the shallow pit on the underside of the body
what featue of the hagfish’s nostril is extremely rare in fishes?
connection of the nares to the pharynx
motile element of the feeding apparatus for hagfish
dental plate
myosepta
connective material between myomeres
expaxial
dorsal
hypaxial
ventral
