Chelicerates
What are chelicerates named for?
Chelicerae - the pincer or claw-like appendage found on spiders and scorpions
T/F: Crustaceans have antennae
How do insects breathe?
They use trachea that branch throughout their body and connect to the outside world through small pores called spiracles
What is the largest group within phylum arthropoda?
Group insecta
T/F: All chelicerates are arachnids
False! Horseshoe crabs are an example of a chelicerate that is not an arachnid, but still has chelicerae
Why are krill so significant?
They make up a large portion of the ocean's biomass and act as food for many other species such as whale, particularly in the Antarctic when they form swarms
How can you tell what an insect eats based on its anatomy?
Observing their mouthparts, as these are specialized structures depending on the diet of the insect.
e.g. Piercing, sponging, siphoning and chewing mouth parts
What are the names of body segments found in phylum arthropoda?
Head, thorax and abdomen
Head + thorax = cephalothorax
What is the organ for spiders that produces silk?
Spinnerets
What are some examples of body structures that are unique to the crustacean group?
Carapace - exoskeletal plate covering the cephalothorax
Swimmerets - flipper-like appendages
Chelipeds - claws
Which of the following would you expect to have NO wings?
a. Lepidoptera
b. Thysanura
c. Hymenoptera
d. Coleoptera
b. Thysanura
-ptera refers to wings, this can be helpful to remember! (Odonata is an exception to this rule however, which includes damselflies)
What is unique about the way blood flows in arthropods?
They have an open circulatory system - blood flows using gravity and "washes" or "bathes" the tissues
How do chelicerates sense their environment?
Pedipalps - Appendages in front of the walking legs that help chelicerates eat and sense their environment
Chelicerates do NOT have antennae!
How do crustaceans breathe?
They use gills for gas exchange - they must be wet in order to function
Which order of insect would butterflies be classified as?
Lepidoptera
What do arthropods have to support their bodies?
Exoskeletons made up of chitin, which must be molted as they do not grow along with the organism