Hagfish, Lamprey, Sharks, Rays, etc Flashcards
Class Myxini - controversial relationship
- partial cranium
- no jaws (agnathan)
- round buccal cavity, rasping teeth, & tongue
- four hearts
- slime glands & pores
- one semicircular canals
Class Myxini - distribution
- world wide
- cold marine
- 43 species
Class Myxini - characteristics
- single gonad
- tests & ovaries present in immature but only one develops at maturity
- iteroparous
- direct development
- few, large eggs
- scavenger feeders
Class Petromyzontida
- lampreys
- parasitic & nonparasitic species
- Ammocoete larvae
Petromyzontida morphological features
- round buccal cavity with rasping teeth
- largest diploid vertebrate chromosome number
- pharyngeal gill openings
- better developed eyes
- semelparous
- indirect development
Petromyzontida diversity & distribution
- worldwide, Northern latitudes
- non parasitic freshwater
- parasitic freshwater & anadromous
Ohio Lamprey species
- sea
- silver
- ohio
- northern brook
- mountain brook
- least brook
- american brook
Class Chondrichthyes morphological features
- cartilaginous skeleton
- jaws
- true teeth
- placoid scales
- heterocercal tail
- ceratotrichial fins
- 5-7 external gill slits
- claspers in males
Chondrichthyes life history attributes
- slow growth & maturity
- internal fertilization
- few large eggs
- viviparity ancestral
- ovoviviparity
- oviparity
- carnivorous
viviparity ancestral
- Lecithotropy
- Matrotrophy
Lecithotrophy
yolk sac
Matrotrophy
- uterine secretions
- oophagy
- embryophagy
Hexanchiforms
- sixgill sharks
- sevengill sharks
- frill shark
Pristiophoriformes
saw sharks
Squatiniforms
angel sharks
Squaliformes
- spiny dogfish
- cookiecutter shark
the more well known sharks belong to which order?
Galeomorphii
Galeomorphii shark orders
- Heterodontiforms
- Lamniformes
- Orectolobiformes
- Carenarhiniformes
Heterodontiforms
- horn sharks
- 8 species - all marine
Lamniformes
- 7 families, 15 species
- sand tigers, threshers, mackerels, goblins, basking sharks
Megamind Shark
deep ram-feeding planktivore
Orectolobiformes
- whale sharks
- nurse sharks
- wobbegongs
Carenarhiniformes
- 225 species
- bull, blue, hammerhead, cat, & requiem sharks
Batoidea
- skates & rays
- pectoral fin fused to head
- dorsoventral flattened
- whip like tail
- anal fin reduced or absent
Batoidea ecology & life history
- primarily marine
- skates abundant in deep water
- rays inshore tropical
- mollusk & plankton feeders
- slow growth
- internal fertilization claspers
Batoidea locomotion
rajiform
exceptions to Batoidea locomotion
eagle rays & manta rays flap fins
4 orders of Batoidea
- Torpediniformes
- Rhinopristiformes
- Myliobatiformes
- Rajiformes
Torpediniformes
electric rays
Rhinopristiformes
- shovelnose rays & allies
- sawfishes
- guitarfishes
Myliobatiformes
stingrays & allies
Rajiformes
skates
Torpediniforms description
- torpedo electric rays
- piscivorous
- Atlantic, Mediterranean, Australia, NZ
Rajiforms description
- kite shaped
- oviparous
Myliobatiforms description
- kite shaped
- viviparous
Holocephali
- chimaeras & ratfishes
- pelvic claspers
- bottom dwelling
- mollusk & crustacean eaters
value of sharks
- tourism
- keystone species
- health of coral reefs
