The Vertebrate Animals

Fish, Amphibian and Reptiles Post laboratory discussion

Dennis A. Dolojan

All Vertebrates are Chordates Phylum chordata!

•  Chordates ALL have 4 characteristics sometime during their lives – a notochord

– nerve cord

– gill slits

– a tail

Phylum  Chordata    •  Phylum  Chordata  includes  the  lancelets  and  tunicates  (invertebrate  chordates)  as  well  as  the  vertebrates  

•  All  chordates  have:  

Amphioxus

Characteristics of all Vertebrates

•  Endoskeleton with a backbone for support of a dorsal nerve cord & muscle attachment

•  Distinct skull/cephalization •  Bilateral symmetry •  2 pairs of jointed appendages •  Coelom •  Closed circulatory system & chambered

heart

CartilageBonyAmphibianReptileBirdMammal

Comparative Numbers of Species

Classes of Vertebrates •  Jawless fish

•  Cartilaginous Fishes

•  Bony Fish

•  Amphibians

•  Reptiles

•  Birds

•  Mammals

Major  Groups  of  Vertebrates  

• Fish  –  aquaCc  tetrapods  with  scales,  gills,  &  2  chambered  hearts  

• Agnathans  –  jawless  fishes  –  hagfish  and  lampreys  

• Chondrichthyes  –  carClagenous  fish  -­‐  sharks  &  rays  

• Osteichthyes  –  bony  fish  –  mahi-­‐mahi,  Clapia,  halibut,  puffer  fish,  tetras,  guppies  

• Amphibians  –  semiaquaCc  tetrapods  with  split  lives  &  3-­‐chambered  hearts  

• Anura  –  “tailless  ones”  –  frogs  &  toads  

• Urodela  –  “tailed  ones”  –  salamanders  &  newts  

• Apoda  –  “legless  ones”  -­‐  caecilians  

• Rep-les  –  terrestrial  amniote  tetrapods  with  scales  &  lungs  &  3-­‐ish  to  4  chambered  hearts  

• Squamata  –  lizards  and  snakes  

• Testudines  –  turtles  &  tortoises  

• Crocodilia  –  alligators,  crocodiles,  and  related  species  

 

• Birds  –  terrestrial  amniote  tetrapods  with  feathers  &  lungs  &  4  chambered  hearts  

• RaCtes  –  ostriches,  emus,  kiwis  

• Passeriformes  –  perching  birds  –  jays,  sparrows,  crows,  etc.  

• AquaCc  birds  –  ducks,  swans,  geese  • Raptors  –  eagles,  falcolns,  hawks  • Penguins  

• Mammals  –  terrestrial  amniote  tetrapods  with  lungs,    hair  and  mammary  glands  &  4  chambered  hearts  

• Monotremes  –  echidna  and  platypus  

• Marsupials  –  koala,  kangaroo,  opossom  

• Placentals  –  humans,  bears,  Cgers,  giraffes,  deer,  pigs,  dogs,  cats,  raccoons,  squirrels,  whales,  walruses,  manatees,  etc  

 

Fish  

•  Class  Agnatha  (Jawless  Fish)  – Subclass  Cyclostomata  (hagfish  and  lampreys)  

•  Class  Chondrichthyes  (carClaginous  fish)  –  Subclass  Elasmobranchii  (sharks  and  rays)  

•  Class  Osteichthyes  (Bony  fishes)  –  Subclass  AcCnopterygii  (ray  finned  fishes)  –  Subclass  Sarcopterygii  (flessy  finned  fishes,  

ancestors  of  tetrapods)  

Fish Vocabulary • Gill  –  respiratory  structure  that  uses  countercurrent  exchange  to  extract  oxygen  from  water  

• Operculum  –  gill  covering  in  bony  fish  

• Lateral  line  -­‐  a  row  of  microscopic  organs  sensiCve  to  pressure  changes,  can  detect  low  frequency  vibraCons.  

• Swim  bladder  –  internal,  air-­‐filled  sac  that  acts  as  an  organ  for  buoyancy  in  bony  fish;  sharks  have  oils  in  their  livers  to  help  them  remain  buoyant    

• Scale  –  small,  platelike  structure  covering  an  organism  (or  parts  of  an  organism);  sharks,  fish,  repCles,  and  birds  all  have  different  types  of  scales  

•  Fin  –  paired  appendage  found  on  fish  used  for  locomoCon  and  steering  

•  ReproducCon  

•  External  ferClizaCon  –  release  of  gametes  to  the  environment  where  ferClizaCon  takes  place;  bony  fish  

•  Internal  ferClizaCon  –  deposiCon  of  sperm  in  the  female  reproducCve  tract  where  ferClizaCon  takes  place;  sharks  

•  Hermaphrodite  –  some  organisms  are  capable  of  producing  both  male  and  female  gametes;  few  are  capable  of  self-­‐ferClizaCon;  most  exchange  sperm;  evoluConary  adaptaCon  for  solitary  and  slow-­‐moving  or  sessile  organisms  

•  Ovoviviparous  =  eggs  are  ferClized  inside  the  parent  and  hatch  inside  the  parent  and  are  born  live  

–  Oviparous  =  eggs  are  laid  in  a  nest  or  in  the  ground  and  hatch  

–  Viviparous  =  internal  ferClizaCon  with  live  born  young  (as  soon  as  the  egg  is  ferClized,  it  becomes  an  embryo  and  develops  as  a  fetus).    

Class Agnatha Hagfish and lampreys

-  Jawless & finless -  Skeleton of cartilage -  Reproduce sexually -  Gills -  2 Chambered Heart -  Oviparous

Hagfish  –  a  detriCvore  

Lamprey  –  an  ectoparasite  

Jawless Fish

Class Chondrichthyes – sharks and rays

-  Endoskeleton made of cartilage -  Paired fins -  Jaws -  2 chambered heart -  Well-developed sense of sight and smell -  Lateral line system (for sensing pressure

changes – vibrations - in water); whole body acts as an “ear”

-  unique scales; teeth may be modified scales

-  Oviparous, ovoviviparous, and a few are viviparous

-  Internal fertilization using claspers to deposit sperm in female reproductive tract

Cartilage Fish

•  Sharks, skates, rays

•  750 species

•  Ventral mouth

•  Spiral valve increases surface area

•  Massive liver (up to half body weight)

•  skin with tooth-like scales

Sharks  have  a  unique  digesCve  structure  called  spiral  valve  that  increases  surface  area  

 

Sharks  &  some  rays  are  carnivores  

Rays  (and  the  largest  sharks)  are  suspension  feeders  

 

Can  detect  electrical  fields  of  living  organisms  with  special  pores  in  their  skin  (not  the  same  as  the  lateral  line  system  which  they  also  have)  

 

Cartilage Fish

Class Osteichthyes

Tuna, perch, bass, clown fish, eels, seahorses, goldfish, catfish, etc…. * One of the most successful groups on Earth – ever!

-  Endoskeleton made of bones -  Swim bladder -  Usually, external fertilization & oviparous (think caviar) -  Lateral line system -  Scales different from those in sharks -  2 chambered heart (all fish!) -  Water balance important; some fish excrete salt through their

gills, others very watery nitrogenous waste using kidneys

Bony Fish

•  20-30,000 species

•  Appeared 400 million years ago

•  Cold blooded, flat scales, swim bladder

•  gills and gill cover

•  Most lay eggs

•  eyes usually on the side of the head

Above:    internal  anatomy  of  a  ray-­‐finned  fish  

 leb  -­‐  photo  of  a  lobe-­‐finned  fish;  right  –  photo  of  a  lungfish  

Three  main  groups  of  Osteichthyes  –  bony  fish  

AquaCc  tetrapods  gave  rise  to  the  first  amphibians,  who  probably  came  on  land  in  search  of  food  (abundant  plant  and  arthropod  species  in  Devonian)  

Bony Fish

Taxonomic hierarchy: Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Actinopterygii (formerly Osteichthyes)

Order: Cypriniformes Family: Cyprinidae Genus: Cyprinus Species: carpio (common carp)

additional standardized endings:

Suborder: - oides Subfamily: - inae Tribe: - ini

Which traits do I use?

Tools of taxonomy: morphometrics - measurements relative to length meristics - counts

Morphometric/  merisCc  

•  Total  Length  (TL)  •  Standard  length  (SL)  •  Head  Length  (HL)-­‐    •  Body  depth  •  Length  of  the  pectoral  and  of  pelvic  fin  •  Number  of  fin  rays  (spines  and  sob  rays)  

Tools of taxonomy: anatomical traits - shape, presence/absence

•  Scales  – Placoid  scales:  rdermal  denCcles  (similar  to  teeth)  – Ganoid  scales:  flat,  basal-­‐looking  scales  – Cycloid  scales:  oval-­‐shaped  scales  w/  growth  rings  (carps)  

– Ctenoid  scales:  disCnguised  by  spines  that  cover  one  edge  (Cichlids)  

•  Tails  – Crescent-­‐shaped  – Forked  shaped  – Rounded  – Truncated  

•  Caudal  fin  shape  – Homocercal  tail  – Heterocercal  tail  – Non-­‐differenCated  caudal  fin  

•  Mouth  – Terminal  – Up-­‐poinCng  – Sub-­‐terminal  – Specialized    (seahorse)  

Tools of taxonomy: color patterns

white crappie (Pomoxis annularis) black crappie (Pomoxis nigromaculatus)

Pigments:  Melanophores-­‐  Brownish-­‐black  pigment  called  melanin  Erythrophores-­‐Red  pigment  Xanthosphores-­‐  Yellow  Pigment  Iridophores-­‐  contain  crystals  which  refract  and  reflect  light,  given  many  fish  their  metallic  

•  Body  Shapes  – Fusiform  – Laterally  depressed  – Depressed  – Elongated  or  Eel-­‐like  

Tools of taxonomy: physiological differences (e.g., temperature preferences) behavior diet

steelhead trout (Oncorhynchus mykiss) rainbow trout (Oncorhynchus mykiss)

lake trout (Salvelinus namaycush)

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811). D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A 1 + 11‑13 (11‑14); P 18‑19 (17‑20). Scaled on the parietal region, nape, back (all), throat (all or most), abdomen, pectoral fin peduncles, and one quarter of the gill covers. Scales on the middle and anterior nape are cycloid. Head is as wide as or wider than deep; depth is 0.9‑1.2 times the width. Head length 4.2‑4.5 of total body length. Angle of the jaw below the anterior quarter of the eye. Lower jaw not prominent. Snout 1.1‑1.4 times the orbit diameter. Upper lip narrows slightly to the rear. Usually 6, rarely 7, transverse suborbital series of pit organs. Ventral fins reach or almost reach the vent. Pelvic disk is 0.6‑0.8 times the abdomen length. If present, the anterior membrane width is very shallow, with rounded, lateral lobes. Caudal peduncle depth is about two‑thirds its length. Lacks a gas bladder and chemoreceptors.

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811) D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A 1 + 11‑13 (11‑14); P 18‑19 (17‑20). D1 VI (V‑VII); the anterior dorsal fin has 6 spines, ranging from 5‑7

D2 I + 14‑16 (13‑16); the posterior dorsal fin has one spine and 14‑16 soft rays, ranging from 13-16

A 1 + 11‑13 (11‑14); the anal fin has one spine, 11-13 soft rays, ranging from 11‑14

P 18‑19 (17‑20). the pectoral fins have 18-19 soft rays, ranging from 17‑20

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811). D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A 1 + 11‑13 (11‑14); P 18‑19 (17‑20). Scaled on the parietal region, nape, back (all), throat (all or most), abdomen, pectoral fin peduncles, and one quarter of the gill covers. Scales on the middle and anterior nape are cycloid. Head is as wide as or wider than deep; depth is 0.9‑1.2 times the width. Head length 4.2‑4.5 of total body length. Angle of the jaw below the anterior quarter of the eye. Lower jaw not prominent. Snout 1.1‑1.4 times the orbit diameter. Upper lip narrows slightly to the rear. Usually 6, rarely 7, transverse suborbital series of pit organs. Ventral fins reach or almost reach the vent. Pelvic disk is 0.6‑0.8 times the abdomen length. If present, the anterior membrane width is very shallow, with rounded, lateral lobes. Caudal peduncle depth is about two‑thirds its length. Lacks a gas bladder and chemoreceptors.

Amphibians

•  2000 species, appeared 350 million years ago.

•  Cold-blooded, moist skin, lungs, no claws •  Lay jellylike eggs

•  Life cycle includes a larval stage •  90% are frogs and toads

Amphibian  Vocabulary  

Ectotherm  –  organism  that  must  gain  (or  lose)  heat  from  the  environment  to  maintain  body  temperature;  metabolism  is  NOT  sufficient  to  heat  the  body;  most  invertebrates,  fish,  amphibians,  &  repCles  

Endotherm  –  organism  that  maintains  a  stable  body  temperature  through  metabolism;  few  repCles,  most  birds  and  mammals,  insects  

Metamorphosis  –  change  from  a  sexually  immature  stage  to  a  sexually  mature  stage  in  the  life  cycle;  involves  change  in  body  structure  and  niche;  ex)  tadpoles  are  herbivorous,  aquaCc  larvae  with  gills  and  no  limbs  that  change  into  carnivorous,  terrestrial  adult  frogs  with  lungs  and  4  limbs  

Tetrapod  –  vertebrate  with  4  limbs  located  in  pectoral  and  pelvic  girdles  

Lungs  –  internal  respiratory  organs  that  exchange  gases  across  a  membrane  surface,  usually  in  conjuncCon  with  the  circulatory  system  

Cloaca  –  common  opening  to  the  outside  of  the  body  through  which  fecal  material,  nitrogenous  waste  and  gametes  pass;  common  to  amphibians,  repCles,  and  birds  

 

Class Amphibia Frogs, toads, salamanders, and newts

-  Ectotherms -  Need H2O for breeding -  Metamorphosis (tadpole à frog) -  Gas exchange through moist skin & mouth; primitive

balloon-like lungs -  External fertilization -  Oviparous -  3-chambered heart -  Many have chromatophores in the skin for coloration,

as well as poison glands for defense -  Nitrogenous waste varies – aquatic habitat – dilute

urine; terrestrial, concentrated urine

Amphibians

   

3  major  groups  of  amphibians:  

Apoda  –  caecilians;  legless  

Anura  –  frogs  &  toads;  tailless  

Urodela  –  salamanders  &  newts  

FROGS  AND  TOADS    

•  Frog  skin  smooth  &  moist  for  cutaneous  respira-on  •  Toads  is  rough  &  warty  with  poison  glands  

CharacterisCcs  of  Frogs  &  Toads      

•  Both  terrestrial  &  freshwater  species    •  Tadpole  with  tail,  gills,  &  two-­‐chambered  heart    •  Adults  without  a  tail,  four  limbs,  &  lungs    •  Long  hind  limbs  for  jumping    •  Long,  forked  tongue  hinged  at  front  of  mouth  

Amphibians  –    Frogs  &  Toads  ID  Traits    

Amphibians  –    Hind  Feet  

•  a.  True  frogs  –  webbed  toes    •  b.  Tree  frogs  –  toe  pads  &  webbing    •  c.  Toads  –  tubercles  &  no  webbing    •  d.  Spadefoot  Toads  –  thorny  projecCons(spade)  and  reduced  webbing    

Salamander    ID  features    

Salamanders  and  Newts    

 •  Have  elongated  bodies  with  a  tail  &  4  limbs    •  Smooth,  most  skin  for  cutaneous  respira-on  •   Less  able  to  stay  on  dry  land  than  frog  and  toads  •  Nocturnal  when  live  in  drier  areas  •  Newts  are  aqua-c  species      

Order Differences •  Limbs •  Tails •  Vision •  Fertilization

Size-Largest

-Chinese Giant Salamander-up to 180 cm -Goliath Frog-up to 32 cm

http://www.guardian.co.uk/environment/gallery/2008 www.sandiegozoo.org

Size-Smallest

Smallest- Thorius sp. - 15 mm. Eleutherodactylus sp.- 10 mm

http://www.science.psu.edu/alert/FROG.htm http://www.state.tn.us/twra/tamp/salamanders.htm

Reptiles

•  6500 species, appeared 300 million years ago.

•  Cold-blooded, hard shelled eggs, internal fertilization

•  Body covered with scales.

•  Include crocodilians, lizards and snakes, turtles and the tuatara

Rep-le  Vocabulary  

AmnioCc  egg  –  adaptaCon  to  terrestrial  life  that  results  in  a  water-­‐proof  egg  with  extra-­‐embryonic  membranes  that  aid  in  the  vital  funcCons  of  a  living  organism  

ExCnct  –  all  members  of  a  species  have  died;  ex)  pterosaurs  

Extant  –  members  of  a  species  are  sCll  alive  

Bask  –  behavioral  adaptaCon  of  ectotherms  to  increase  body  heat;  involves  moving  to  locaCons  where  more  radiant  energy  (such  as  from  the  sun  or  warm  rocks)  is  available  for  absorpCon  

   

 

Class Reptilia turtles, snakes & lizards, crocodiles

-  Ectotherms – bask and hide to regulate temperature* -  Scaly, waterproof skin -  Respire through lungs only** -  Internal fertilization -  Oviparous, ovoviviparous, viviparous (depending on species) -  3 or 4 chambered heart -  Nitrogenous waste is a paste rather than a liquid for water

conservation; uric acid -  Extinct reptiles include dinosaurs and pterosaurs, which

dominated the Earth during the Triassic period

Reptiles

AmnioCc  egg  in  repCles  

 -­‐  note  leathery  shell  characterisCc  of  repClian  eggs  

Major  extant  groups  of  rep-les:  

Squamata  –  snakes  &  lizards  

•   both  snakes  and  lizards  shed  their  skin  as  they  grow  

• Loss  of  legs  is  unique  to  snakes  within  the  repCles;  remnants  of  pelvic  girdles  present  in  boas,  as  are  external  claws  on  the  abdomen  

•   many  have  unique  adaptaCons  for  life  as  predators  

• Jacobson’s  organ  –  when  a  snake  flicks  its  tongue  it  is  collecCng  molecules  that  are  then  brought  in  to  Jacobson’s  organ  for  “processing”;  kind  of  a  combined  sense  of  taste  and  smell  

• Pits  –  many  snakes  have  heat  sensory  organs  on  their  head  that  gives  an  IR  picture  of  an  organism,  decreasing  dependency  on  vision  

• Hollow  fangs  –  with  or  without  poison  glands  for  capturing,  holding,  and  killing  prey  

• Muscles  the  length  of  the  body  allow  it  to  move  quickly  and  many  use  those  muscles  for  immobilizing  and  strangling  prey  

Major  extant  groups  of  rep-les:  (cont’d)    

Testudines  –  turtles  and  tortoises    

 *  Some  are  herbivorous,  but  most  are  carnivorous  

• Lay  eggs  on  land  (oviparous)  • Cloaca  is  secondary  respiratory  surface  in  aquaCc  species  **  • Shell  is  part  of  the  body,  connected  to  muscle  and  inCmately  intertwined  with  the  skeleton  

 

Crocodilia  –  alligators  and  crocodiles  (caiman,  and  other  related  species)  • Adapted  for  aquaCc  life  with  upturned  nostrils  and  eyes  on  top  of  head  

•   endothermic*  

• 4-­‐chambered  heart  

• Related  to  feathered  repCles    

Major  extant  groups  of  rep-les:  (cont’d)    

crocodiles  

American  alligator  

gharial  

Snakes  

•  Venomous  snakes-­‐three  fang  types  •  Rear-­‐fanged  snakes  (boomslang)  •  Front-­‐fanged  snakes  (cobra)  •  Hinge-­‐fanged  snakes  (raPlesnake,  water  moccasin,  copperhead)  

•  ORen  camouflaged  for  defense  •  May  have  defense  signals  as  expanding  hood  of  cobra,  raPles  of  raPlesnakes  or  hissing  

•  May  be  oviparous  or  ovoviviparous    

Snakes  –  ID  features    

Lizards    

•  Four  limbs    •  Rely  on  speed,  agility,  &  camouflage  to  catch  prey  •  Feed  on  insects  &  small  worms  •  Some,  such  as  anole  &  chameleon,  can  change  colors  for  

protec-on  •  May  use  ac-ve  displays  such  as  squir-ng  blood,  hissing,  or  

infla-ng  bodies  •  Some  can  show  autotomy  (breaking  off  tail  to  escape  predators)  •  Two  poisonous  U.S.  species  include  Gila  Monster  &  Beaded  Lizard    

Lizards  –  ID  features