lecture quiz 1 Flashcards
What is the definition of “natural history”
Latin: “naturalis historia” - a process of studying natural events
- main topic = WHOLE organism
- will focus on anatomy, physiology, ecology, evolution and molecular phylogeny
What is a vertebrate’s classification?
domain eukarya
kingdom animalia
phyla chordata
subphyla vertebrata
what % of the population are chordates?
1% of all animals
Characteristics of a chordate?
- Deuterostomes
- notochord
- dorsal hollow nerve cord/tube
- one way digestive system at some stage
- post anal tail
- bilateral symmetry
- pharyngeal slits at some stage
- endostyle
- metamerism
What is a deuterostome?
deutero = 2nd stome = mouth
(second opening of digestive tube becomes the mouth)
ex: echinoderms… hemichordates
What is a notochord?
- connective tissue rod
- becomes intervertebral discs
What does the pharyngeal slit become in adults?
thymus and parathyroids
What is the endostyle?
cilia/mucous for trapping food
What is a metamerism?
repeating units
What makes up subphylum cephalochordata?
Lancelets, amphioxus
Know the phylogenetic trees for deuterostomes and chordates
(draw tree)
Describe the characteristics of amphioxus and lancelets
amphi - pointed on both ends
as adults:
- notochord
- endostyle
- post anal tail
- hollow dorsal nerve
burrow in sand
filter feeders
tropics, subtropics
What makes up the subphylum tunicata (urochordata)?
- tunicates, sea squirts
tunicates secrete mucous…
Describe the characteristics of tunicates / sea squirts as ADULTS
as adults:
- few chordate characteristics
- openings : no one way digestive
Describe the characteristics of tunicates/sea squirts in the LARVAL stage
larval :
- notochord
- hollow dorsal nerve cord
- post anal tail
- endostyle
- one way digestive system
Describe vertebrate characteristics
- vertebrae: surrounding nerve cord
- endoskeleton
- paired eyes
- adaptive immune system
- sexual reproduction (a few parthinogenic exceptions)
- endostyle absent in adults: becomes thyroid
- cranial neural crest cells
- hepatic portal system
Describe Charaka’s classification of vertebrates
Jarayuja: invertebrates
Anadaja - Vertebrates
Describe Artistotle’s classification of vertebrates
- Enaima:
Have blood, mammals, birds, reptiles, fish, amphibians - Anaima:
no blood
invertebrates
Describe Pliny the Elder’s classification of vertebrates
- based on location
- aquatilia
- terrestria
- volatrilia
Describe Carolus Linnaeus’ classification of vertebrates
- hierarchical structure of classification
- EXTERNAL ANATOMY
- Levels:
kingdom
phylum
order
genus
species - plantae and animalia… fungi came later
Describe the current classification scheme of vertebrates
- based on molecular data, morphology and fossils
- Agnatha (no jaw)
- Gnathostomata (“Jaw mouth”)
Which classes make up superclass Agnatha
- no jaw
- Class Myxini (greek for slime) - Slime Hags
- Class cephalaspidomorphi - lampreys
which classes make up superclass Gnathostomata
- Jaw mouth
- Classes:
chondrichthyes- cartilaginous
actinopterygii- ray finned
sarcopterygii- fleshy finned
amphibia-
reptilia
mammalia
Aves
Describe the characteristics of AGNATHA
- jawless
- no scales
- simple fins, not paired
- cartilage, not true bone
- notochord as adults
- external fertilization
Describe class Myxini
- hagfish/slime hags
- blind
- bottom dwellers
- produces slime (avoid predators, slime glands, intermediate filaments)
- atypical circulation
open circulatory system… multiple hearts (3-6) - knotting behavior
Use to get leverage… tie into know, knot shortens, uses body
Describe class cephalaspidomorphi
- Lampreys
- head shield shape
- up to 1m in length
- vertebrae : cartilage
- jawless
- parasites
- wrasping tongue
Describe superclass Gnathostomata
- jawed fish
- hinged jaw
- paired appendages
What are the paired appendages within superclass gnathostomata ?
- fins in fish
- pectoral fins : steering
- pelvic fins : steering
- dorsal + anal fins: stability
- unpaired caudal fin : propulsion
Describe Class chondrichthyes?
- cartilaginous fishes
- cartilaginous skeleton: flexible, light, no blood cells
- internal fertilization
- ventral + subterminal mouth
How are blood cells produced in cartilaginous fishes?
- blood cells produced in leydig organ and epigonal organ (around the gonads)
Describe Subclass Elasmobranchii?
- sharks, rays, skates
- Size range: dwarf lantern (20 cm) to whale shark (15m)
- heterocercal caudal fin: propulsion and lift
- no operculum
- placoid scales: modified teeth, point to tail… pulp cavity, enamel, dentine…
- large liver
- teeth
What is the purpose of the shape and direction of the placoid scales?
- to reduce the resistance of water…
- turbulence can help the shark travel faster
Why do subclass elasmobranchii have large livers?
- to fill with squaline:
lipid
nonpolar
low density
buoyancy
Describe class elasmobranchii teeth
- placoid scales
- new rows of teeth every week, constantly replacing
- serrates
Describe subclass holocephali
- ratfish (“chimeras”
- long tails
- operculum
- no placoid scales
- poisonous spine
Describe class actinopterygii
- ray-finned fishes
- actino: ray, Pteryx: wing/fin
- true bone
- operculum
- skeletal rays in fins
- terminal mouth
- external fertilization
- swim bladder (gas bladder)
(buoyancy control, 7% of fish volume)
What are the three fin shapes?
- diphycercal (lung fish)
single pointed tail, bone reaches the tip - heterocercal (sharks)
different points, bone reaches tip of top fin - homocercal
equal size points, skeletal rays
Difference in fertilization between rays and skates?
- rays: viviporous… live birth
- skates: Oviviporous… egg
