Monday, February 27, 2012

Scribe Post 2/27/12

Today in Class...
-Turned in the isopod lab
-Starfish dissecting lab- UP 63-66
-Watched a video about invertebrates
Starfish Lab
Starfish are a part of the Echinodermata Phylum
-echin means prickly
-derma means skin
Starfish feel prickly and squishy
Parts of Starfish- what we looked for
Dorsal View
Central disc- center of starfish
Rays- "arms" usually five
Madreoporic plate- small yellow or red structure on central disc
Spines- hard, covers everything, part of exoskeleton
Aye spot- tip of each arm
Anus- opening in center of central disk
Ventral View
Mouth- center of central disk, surrounded with spines
Ambulacral groove- groove along center of rays
Tube feet- at tips of ambulacral groove, help with movement
After snipping of the tip of one ray, there is a gland called the pyloric cecum - part of digestive system
There are 5 in a starfish
Starfish have separate sexes,
testes are gray, ovaries are orange- but it is hard to tell in preserved starfish
There are 5 paris of gonads in a starfish
They have 2 stomachs
The mouth is on the ventral side- above stomach
The anus is on the dorsal side-under stomach
Water vascular system- Madreoporic plate and anything connected to it
Tube feet- suction cups, help starfish move and hold prey
Ampullae- connected to a tube foot, pink and bulblike
5 Radial Canals- inside ambbulacral groove, long hollow tube that is connected to all other radial canals through ring canal
1 circular canal
Human Ciculatory system is like the Starfish's Vascular sytem because they both have "canals"(blood vessels) that transport things
Invertebrates can live without vertebrates, but vertebrates can't live without invertebrates.
Most animals are invertebrates.
Not the same video but its a good review about invertebrates:
Finish UP 63-66
Up 75-76
Nature due this Friday
Next Scribe:


  1. The labeled picture of the starfish and the video were both nice touches!! Helped get the point of the experiment across.

  2. Thank you Melissa for this nice post. The phito was very helpful and important information was given. Thanks, good job!

  3. Great job Melissa! Your post helped really look over my lab and correct some of my answers. The starfish diagram really helped.