Subphylum Chelicerata lab notes

BIOL 3270
Zoology


PHYLUM ARTHROPODA
Subphylum CHELICERATA
Some characteristics of this subphylum include, 1) first pair of appendages modified to form chelicerae, 2) body
divided into cephalothorax and abdomen, and 3) lack of antennae.




Subphylum Chelicerata


Class Merostomata (horseshoe crabs, sea scorpions)

Order Xiphosura
IDENTIFY
 Chelicera (clawed, first pair of appendages)
 Mouth, carapace (cephalothorax)
 Compound eye (also have ocelli)
 Gill flaps
 Telson (to flip over)
 Genital operculum
 Pedipalp (look exactly like the other waling legs)
 Walking legs (appendaged
 Body divisions: prosoma (head and thorax), opisthosoma (abdomen)




Class Arachnida
Prosoma
 Fused head and thorax
 Bears chelicera and pedipalps
 Genetic studies suggest that the head of millipedes, centipedes, insects, and crustaceans evolved with the
prosoma.

Opisthosoma
 abdominal segments
 Book lungs
 Spinnerets