What is a sea slug?
Q: What is a sea slug?
A: A sea slug is an informal name for a group of gastropods which look similar, but are not monophyletic. They are polyphyletic and their similar shape and life styles is an example of convergent evolution.
Q: What clades does the group include?
A: The group includes Heterobranchia Nudibranchs, Sacoglossa, Opisthobranchs, Sea Angels or Cliones, Sea Hares, Cephalaspidea, Onchidiidae and Sea Butterflies.
Q: What do Sacoglossa go in for?
A: Sacoglossa go in for kleptoplasty ('stealing' plastids). They eat algae and keep the chloroplasts for their own use.
Q: What family do Sea Hares belong to?
A: Sea Hares belong to two families of the Opisthobranchia.
Q: What sub-order do Cephalaspidea belong to?
A: Cephalaspidea belong to a sub-order of Opisthobranch gastropod molluscs.
Q: To what clade do Sea Butterflies belong?
A: Sea Butterflies belong to the clade Thecosomata.
Q: How did their similar growth pattern evolve?
A: It would seem that their similar growth pattern with the loss of torsion, bilateral symmetry, reduction of the Gastropod shell, and somewhat similar life styles evolved a number of times in the Gastropods.
