Lecture 18 Note Guide- Chordata and start Craniata

SUNY ESF DIV OF LIFE 2 LECTURE 18 FLASH CARDS 2026

What makes a protostome different from a deuterostome?

cleavage pattern spiral

*development determinant

mouth origin blastospore becomes the mouth

What makes a deuterostome different from a protostome?

cleavage pattern radial

development indeterminant

mouth origin blastospore becomes the anus

Describe echinoderms habitats

they are found in marine habitats and most of them are benthic.

Describe echinoderms symmetry in terms of different life stages

adults have pentaradial symmetry while larvae are bilaterally symmetrical. (Planktonic)

Describe Robert Paine’s ecological theories in terms of study and location

developed by studying sea stars in the pacific northwest, Robert Paine showed sea stars help control mussels and are considered keystone predators.

Describe echinoderms in terms of anatomy, describe specific examples

echinoderms have endoskeletons made of calcium carbonate and have separate plates or ossicles.

urchins/ sand dollars have interlocking plates forming a test.

describe sea stars adaptations

sea stars can adapt to challenging conditions and use their mutable, collagenous tissue to harden and stick to rocks and it also protects them from high energy waves.

tube feet help with…

locomotion

gas exchange

feeding

attachment

sensory reception

describe a sea stars tube foot

tube feet are fueled by the water vascular system and each tube foot has its own hydrostatic skeleton

describe sea stars respiration

respirations occurs through papullae (skin gills) or projections on the epidermic of the sea star.

describe a sea stars oxygenation

oxygenation occurs via concurrent exchange with the water vascular system.

what is the opening to the water vascular system in a sea star?

madre porite

because sea stars are sessile, in terms of predation they can be described as

vulnerable

give an example of protection sea stars have from predation

mutable collagenous tissue

most sea stars can _______________ an arm

regenerate/grow

there are 5 echinoderm classes! list them

asteroidia

ophiuroidea

echinodea

holothuroidea

crinoidea

ateroida are

sea stars and sea daisies

describe asteroidia (aka sea stars and sea daisies)

more than 1.9k spp

opportunistic predators

common on rocky shorelines

ophiuroidea are

brittle stars and basket stars

describe ophiuroidea (aka brittle stars and basket stars)

about 2.3k spp

lack a papulae

madre porite on oral surface

scavengers/detrivores

echinodea are

sea urchins, sand dollars and ❤ urchins

describe echinodea (aka sea urchins, sand dollars and ❤ urchins)

about 955 spp.

lack arms

have spines and arisdotle’s lantern

holothuroidea are

sea cucumbers

describe holothuroidea (aka sea cucumbers)

about 18k spp.

leathery skin

ossiles reduces

oral-aboral axis elongates

detritivores

crinoidea are

sea lillies (sessile) and feather stars (free -moving adults)

describe crinoidea (aka sea lillies and father stars)

about 700 spp

suspension feeders

abundant in fossil record

describe chordata’s symmetry

bilateral

chordata includes the following groups

cephalochordata

urochordata

craniata (=vertebrata)

all chordates have a few universal traits, what are they?

notochord

dorsal hollow nerve chord

pharyngeal slits

post anal tail

tunicates are

urochordata

summarize tunicates

filter feeders with colonial solitary and social forms

describe tunicates larval stage

larval (free swimming/tadpole) life stage which can sometimes only last a few hours, prior to settling and becoming sessile

what are some unique characteristics of the clade urochordata?

cellulose tunic

siphons (incurrent/excurrent)

chordate features present in larvae but its reduced in adults

monoecious (hermaphrodites)

sexual reproduction by external fertilization

asexual reproduction by budding

colonial with zooids

can be invasive

lancelets are

cephalochordata

lancelets live buried in the sand in what type of environment?

marine

describe lancelets feeding

they are filter feeders by using their pharyngeal slits

what structure do lancelets retain (uniquely) ?

their notocord as adults

some strictly unique characteristics to cephalochordata are

that they are dioecious and are strictly marine

Craniata are

=vertebrata

what unites craniata (=vetrebrata)

cranium (skull)

neural crest cells

endoskeleton v/ vertebral column

complex organs ie. ❤ , kidney, liver)

red blood cells with hemoglobin

neural crest cells are…

pluripotent

pluripotent

means the cell can differentiate into many cell types (ie. teeth bones/cartilage, neurons, sensory cells, skin cells)

why are vertebrates having pluripotent cells helpful?

it allowed vertebrates to build complex, diverse structures from a single embryonic cell population.

what type of clade are fish and why?

paraphyletic, because not all of the descendants are considered to be fishies

what are the 2 super classes of fish you should know, what are they?

Cyclostoma and Osteichthyes

cyclostoma includes (2 common names for the clades)

hagfish and lampreys

what is a unique characteristic of hagfish?

lack true vertebrae (they have a cranium but no vertebral column)

what is a unique characteristic of lamprey

they are parasitic

class chondrichthyes has an endoskeleton that is made of

cartilage

class chondrichthyes includes the superclass

osteichthyes

osteichthyes includes the 2 bony fish classes that are:

actinopterygii (ray finned fishes)

sarcopterygi (lobe finned fishes)

most fishes are ______ with _______ fertilization

dioecious, external

describe fishes circulatory system

fishes have a closed (single-loop) circulatory system, a protective operculum that covers their gills that they exchange O2 and CO2 with water via concurrent gas exchange.

an ancestral adaptation to overcome gravity as a terrestrial challenge for vertebrates is

having an endoskeleton

a derived adaptation to overcome gravity as a terrestrial challenge for vertebrates is

limbs, bones, neck and ribs

a derived adaptation to overcome efficient respiration as a terrestrial challenge for vertebrates is

lungs/air sacs in birds

a derived adaptation to overcome efficient transportation as a terrestrial challenge for vertebrates is

a multichambered ❤

a derived adaptation to overcome protection of gametes as a terrestrial challenge for vertebrates is

internal fertilization, amniotic eggs/placenta

a derived adaptation to overcome desiccation as a terrestrial challenge for vertebrates is

dry skin, scales

the aquatic ancestor for the terrestrial organism: terrestrial vertebrates is

aquatic lobe-fin