Animal Biology Vocabulary

Keylosterates

• A pretty big group with something like 114,000 species.
• Includes sea spiders or pycnogonids.
  • Solely aquatic, living in marine environments.
  • Use long legs to swim, resembling swimming sea spiders.
  • An example of convergent evolution.
  • Small in intertidal zones but can be very large in the deep sea due to deep sea giganticism.
  • Their central body is small, with legs being quite large relative to their body size.
  • Their internal organs are located in their legs, with one leg filled with reproductive organs, another with nervous tissue, and others with gonads.

Horseshoe Crabs

• There are only three populations on Earth, one of which is located in Chesapeake Bay.
• Not related to other crabs, lobsters, or crabs that a person would eat.
• Mate by spawning by releasing huge amounts of gametes out kind of at the same time.
  • This happens on the high tide closest to the full moon of the spring equinox.
  • Synchronize their movement, with females marching up to the shore.
  • Females release pheromones, attracting males who grab onto her carapace (shell).
  • Multiple males may grab onto each other, forming a line hanging off the female.
  • The female comes out of the water and digs a hole, lays eggs, and the males release sperm to fertilize the eggs.
  • Clutch of eggs has a mixed paternity.
• Shorebirds eat the eggs during this event.

Medical Industry

• Horseshoe crab blood contains a coagulation factor that forms rosettes around gram-negative bacteria.
• Used as a final check in quality control to see if saline is contaminated with bacteria before administering it.
• To obtain blood, horseshoe crabs are taken, drained, and thrown back, with a high mortality rate.
• The practice is harmful to the horseshoe crab population.
• A synthetic version of the protein exists, but it is more expensive than bleeding the horseshoe crabs.

Arachnids

• A terrestrial group descended from a terrestrial ancestor.
• Examples include spiders, ticks, mites, and daddy long legs (harvestman).
• Have four pairs of walking legs (eight legs).

Mandibulates

• A larger group of arthropods, with two groups which include myriapodes and crustacea.
• Contain antenna.

Myriapodes

• Poda means leg, myriapoda which means countless.
• Includes centipedes and millipedes.
  • The very first animals to live on dry land, possibly as early as 400,000,000 years ago.
• Centipedes are carnivores and venomous, using poison to hunt.
• Millipedes are vegetarians and toxic, concentrating poisonous compounds in their bodies for defense.
• Millipedes have two leg pairs per body segment, while centipedes have one leg pair per body segment.
• The group only contains 13,000 described species.

Pancrustacea

• Hexapods evolved from within the crustaceans.
• Crustaceans are primarily aquatic animals, while hexapods are terrestrial.
• Crustaceans have appendages coming out of the end of their body, while insects do not.

Crustaceans

• Have a range of body plans.
• Some are sessile as adults, like barnacles.
• Includes crabs, lobsters, crayfish, copepods, etc..
• Are the dominant marine arthropods.
• Sowbugs (roly polys) are a terrestrial crustacean.

Hexapods

• Include small groups like springtails and silverfish.
  • Video of springtails was assigned to watch.
• The largest and most important group is the insects, also called pterygoats.
  • Pterygoat means the ancient flyer, because insects were the first animals to evolve wings and fly.
• Insects have six legs coming out of their thorax.
• The insect ancestor had two pairs of wings, with some insects today having secondarily lost wings.
• Insects exhibit diversity with large, heavy insects like the Goliath beetle, long insects like giant stick insects, and small insects like the fairy fly wasp.
• Sophisticated insect behaviors include sexual selection in tree hoppers and eusociality in bees and termites.

Deuterostomes

• Timeline - origin with Paleozoic era
• Key features include through gut, gill slits, and segmentation.

Extant groups

• Ambulacrarians (Echinoderms: starfish, sea urchins, brittle stars, feather duster, sea cucumber etc.)
• Chordates

Chordates

• Features include a dorsal hollow nerve cord, a post anal tail, and a notochord.
• Notochord - a supportive rod that is the precursor to an internal skeleton.
• Vertebrates replaced notochord with vertebrae, but we still have a remnant of the notochord (discs in backbone).
• Compared to other animals, chordates as a group are relatively small. Only 68,000 chordates.
• 60,000 of those are vertebrates.

Expansion of Genetic Material

• Vertebrates have two rounds of whole genome duplication (WGD \times 2).
  • This expansion gives a lot more space for new functions and new body parts to evolve.
  • There is yet another whole genome duplication that occurred in the bony fishes.

Vertebrates

• Vertebrates have vertebrae, brain encased in skull, and a powerful closed circulatory system.
• These traits allow a higher metabolic rate than other animals.

Cyclostomes

• No jaws present
• Includes hagfish and lampreys, probably most closely resemble the ancestor of all the vertebrates
• Hagfish
  • Appear worm like. Though specialized with pores down its side that allow it to eject a proteinaceous slime.
  • No animals eat hagfish!

Gnathostomes

• Animals do have jaws
• All the rest of the vertebrates have a hinged jaw, which used to be gill slits.
• The jaw increases the efficiency of predation.
• After determining the jaw (or lack thereof) the next determination is bone composition.

The Chondrichthyans

• Internal skeleton made of flexible cartilage.
• Includes sharks, rays, and ratfish (chimeras).
• They don't have a great solution to maintaining their buoyancy in water, which is why they constantly have to keep in motion to maintain their position in the water column, and they have to keep moving to breath for the same reason.

Bony Vertebrates

• Hard calcified bone.
• They don't have this issue and were able to create a solution using structure called a lung/swim bladder to maintain buoyancy and get oxygen.
• • The ancestral version of that thing could do both gas exchange, and it could, like, help an animal hold its position in the water column.
• Two groups
  • Ray finned fishes
  • Lobe finned vertebrates

Ray Finned Fish

• 90% of verebrates are bony vertebrates.
• Spines or rays connect appendage to the rest of the body.
• There was also another whole genome duplication event that occurred in this ractin fish.
• Biggest group with Telos fish
  • Root Telo, telo, telo, television, telescope = to make things appear for far away. They can telescope their jaws so they can eat.
  • A structure called an operculum.
    • Did you learn in lab what the operculum is? Yeah? Sounds familiar. It sounds familiar.
    • Have you already vanished lab work into the into the past? You know, I'll tell you. The operculum is that structure that was over the gill.
    • Oh, it's kinda protecting the gill, but its more than just protecting the gill, it actually pumps.

Lobe Limbed Vertebrates

• Have Single bone attaches limb.
• Three clades
  • Coelacanths - passing mention.
  • Lungfishes.
  • Tetrapods - These alone of the vertebrate animals that have evolved the terrestrial lifestyle

Tetrapods

• Features that allow animals to live in the terrestrial environment?
  • Support the mass of your body, away from the buoyancy of water
  • Move around
  • Breathe air
  • Eat
  • Prevent Drying Out and reproduce.
• All tetrapods have some bone architectures that make us able to support the mass of our body on land and to move our bodies around on land.
  • Have flexible bony neck/we have a neck, fish don't.
  • One bone, two bone lots of little bones - ancestral feature that they retain.

Amphibians

• Like ferns, they’re great, but when it comes time to reproduce, ferns can't live in the desert, they need water to reproduce.
• They have bone support that can live in terrestrial environments, BUT THEY NEED STANDING WATER to reproduce eggs.
• One time frog and toads were really the dominant animals!
• They were predators like the era the erops skull example
• In adult animals, are not fully adapted to terrestrial environment
  • Adult frogs and and other amphibians have wet skins.
    • they actually do gas exchange through their skins

Amniotes

• Private pond in which the offspring can develop
• Private pond inside of a shelled egg
• What the amnion is, is the amniotic sac.
• Protected from drying out when we are developing
• In the body of the adult animal, there is also adaptations that prevent the adult from drying out. So we all have, like, keratinized skin, right, that kind of a going to, like, prevent us from water loss in dry environments
• KIDNEYS! What do kidneys do? Kidneys produce urine! that as a win for an organism that's trying to avoid losing a lot of water.
• Can take advantage of all those dry environments too.
• 2 groups
  • Reptiles
  • Masis - Mammals

Reptiles

• Lizards snakes turtles all around today.
• The archosaurs = Crocodiles and Birds
  • Dinosaurs = Birds Today
• Being able to fly allows access to get different Habitats.
• Biggest group are birds.
• This ability to fly no matter who does it = VERY METABOLICALLY Expensive. ATP HIGH
• They have to have an incredibly high metabolic rate.
• Four chamber heart
• The heart IS much much bigger than like a mammalian four chamber Heart
• BIRD's LUNG.
  • lung is evolved to a totally different way than our lungs

Mammals

• Small group compared to other animals. SMALL
• Largest that has EVER an animal that has ever existed on Earth = BLUE Whales
• Very High metabolic rate.
• Monotremes (Egg laying like ancestral tetrapod, have pouches)
• Marsupials(short gestation, babies have to crawl in pouch -Biogeopgraph.
• (Eupherians) - Placentals (Longer gestation.) Almost ALl are these. Cheetahs, Zebra, Bear, dolphin and giraffe!

Examples

• Rodents50%.
  • Grasshoppers. (meat eaters lol)
  • Bats- 25%. They have the high metabolic rates. but they have specialized metabolism to survive those!