Agnathans - Hagfish & Lampreys Outline
PP SLIDE 1: Phylogeny showing that Hagfish and Lampreys represent two distinct
lineages rendering the “Agnatha” polyphyletic (more than one origin).
http://www.mun.ca/biology/scarr/Agnatha_phylogeny.gif
PP SLIDE 2: Hagfish image: http://people.whitman.edu/~yancey/hagfish.jpg
PP SLIDE 3: Hagfish information: 20 species in 4 genera: Myxine, Neomyxine,
Paramyxine, & Eptatretus; Myxine & Neomyxine species have a pair of gill openings
Paramyxine & Eptatretus have minute gill openings; ~ 50 cm total length; pink to purple;
skin lacking scales; Taste buds in epidermis; innervated by CN V & spinal nerves;
Marine; global distribution; deep cold temperate waters; Scavengers; use olfaction to
locate prey
PP SLIDE 4: Image showing location of slime gland openings: http://universereview.ca/I10-27-hagfish.jpg; image of a slime gland dissected out of the body:
http://nikonsmallworld.com/images/gallery1979/fourbythree/20th1979large.jpg
PP SLIDE 5: Harry covered with hagfish slime: http://www.uoregon.edu/~joet/PicturesPages/Image2.html
PP SLIDE 6: Hagfish in knot: http://grad.bio.uci.edu/ecoevo/aclark/hagfishpic.jpg
PP SLIDE 7: Hagfish collage - focus on the middle section to see the mouthparts:
http://www.jyi.org/volumes/volume5/issue7/images/lee_1.jpg
PP SLIDE 8: Pencil drawing of hagfish mouth::
http://oceanlink.island.net/oinfo/hagfish/hagfish.html
PP SLIDE 9: Hagfish information 2: Attack dead/dying prey; consume polychaetes; Low
metabolic rate; feed infrequently; Grasp item with jaws and tear it with body knot;
burrow towards the guts of dead fish; Hagfish guts produce mucoid sacs that surround
food; products of digestion are released slowly from bag and waste passes out
prepackaged
PP SLIDE 10: Hagfish information 3: # gill slits varies among genera (1-15); no
branchial arches; Notochord & caudal fin rays are only skeletal elements (cartilage);
Large blood sinuses & low blood pressure; 3 accessory hearts & one heart near gills;
aneural heart; 3 chambered; Hemoglobin in RBCs
PP SLIDE 11: Hagfish eggs: http://www.bio.umass.edu/biology/kunkel/fish/albatrossiv/al0509/AL050962.JPG
PP SLIDE 12: Hagfish information 4: Eggs undergo direct development; bypass larval
stage - eggs hatch into small hagfish; Hagfish are always caught at the bottom of the
ocean; deep sea scavengers; colonial with individuals in mud tubes; “Eel-skin leather” is
hagfish; depleted pops in Asia, Pacific US; Can occur in high densities (Gulf of Maine 500,000/sq. km); Many aspects of biology are unknown; Fossil species, Myxinikela
siroka, from Illinois
PP SLIDE 13: Lamprey on fish:
http://kentsimmons.uwinnipeg.ca/16cm05/1116/chordate.htm; Petromyzontoidea =
Hyperoartia; 40 species in 10 genera
PP SLIDE 14: Image of lamprey mouth:
http://kentsimmons.uwinnipeg.ca/16cm05/1116/chordate.htm
PP SLIDE 15: Lamprey information: Distributed in northern and southern latitudes; most
genera are northern (8 out of 10); Lampreys have arcualia that are cartilaginous;
http://images.google.com/imgres?imgurl=http://tolweb.org/tree/ToLimages/vertebrata1.gi
f&imgrefurl=http://tolweb.org/Vertebrata&h=232&w=218&sz=10&hl=en&start=16&tbn
id=L3vnou9O5sd_M:&tbnh=109&tbnw=102&prev=/images%3Fq%3Dlamprey%2Barcu
alia%26gbv%3D2%26svnum%3D10%26hl%3Den%26sa%3DG
PP SLIDE 16: Image of two lampreys on fish:
http://www.nwrc.usgs.gov/world/images/lamprey.jpg
PP SLIDE 17: Image of lamprey mouth:
http://www.alamedacreek.org/About_Alameda_Creek/River%20lamprey%20oral%20dis
k.jpg
PP SLIDE 18: Diagram of lamprey showing external features:
http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Lamprey_illustration_side.p
ng/800px-Lamprey_illustration_side.png
PP SLIDE 19: Diagram of craniates: http://www.tolweb.org/tree/ToLimages/craniata.gif;
hagfish top; lamprey middle, shark bottom; blue = cartilage; green = notochord; yellow =
fibrous sheath around brain
PP SLIDE 20: Lamprey information 2: Brain with poorly developed cerebellum but
large optic lobes; Spinal cord flattened; larger than that in hagfish; Eyes large, no
intrinsic muscles associated with lens; External eye muscles present; superior oblique
unique; Pineal large, well developed; posterior to nostril opening; Cartilaginous skeleton;
Two semicircular canals, blind endolymphatic duct; Heart with vagus nerve innervation;
Gills & kidneys are involved in regulation salts & water
PP SLIDE 21: Lamprey attached to fish showing gill openings:
http://www.wordinfo.info/words/images/fish-sucker.gif
PP SLIDE 22: Lamprey information 3: Distribution is northern/southern temperate
regions of the world; Most lampreys are anadromous; adults in great lakes or oceans;
breed in rivers & streams; die post-mating; 25 cm total length to ~ 1 m total length; Little
known regarding lamprey ecology; Temperature-triggered migration upstream to cobbles;
Males & females nest in rocks; mating may take 2 days; females lay 1000s of eggs; postmating death
PP SLIDE 23: Ammocoetes larva (two views):
http://www.biology.ualberta.ca/courses.hp/zoo.225/ammoecoeteswm.jpeg
http://www.glerl.noaa.gov/res/region/reg_images/lamprey.jpg
Ammocoetes larvae: 6-10 mm long; 7-10 days after hatching; larvae leave nest
PP SLIDE 24: Ammocoetes larva diagram:
http://cas.bellarmine.edu/tietjen/Laboratories/Bio%20Pix%204%20U/Image3.gif
PP SLIDE 25: Sea Lamprey:
http://kentsimmons.uwinnipeg.ca/16cm05/1116/chordate.htm