Chp 33 Part 2 Flashcards
What are chitons?
- Oval shaped marine animals encased in an armor of eight dorsal plates
What are some characteristics of gastropods?
- most are marine, but many are terrestrial and freshwater species
- Move slowly by a rippling motion of the foot or by cilia
- ## Most have a single, spiraled shell that functions in protection from injury, dehydration, and predationMost gastropods are herbivores, but some species use modified radula to feed on prey
What are bivalves?
- aquatic and include many species of clams, oysters, mussels, and scallops
- They have a shell divided into two halves drawn together by adductor muscles
What are cephalopods?
Cephalopods are carnivores with beak-like jaws surrounded by tentacles of their modified foot
What do cephalopods have?
A closed circulatory system, well-developed sense organs, and a complex brain.
What are shelled cephalopods called?
Ammonites
What animal group has the largest number of recent extinctions?
Molluscs
What are the most threatened molluscs groups?
Freshwater bivalves (pearl mussels)
- Terrestrial gastropods (Pacific Island land snail )
What are molluscs threatened by?
- habitat loss
- pollution
- non-native species
What are annelids?
coelomates with bodies composed of a series of fused rings
What are the 3 traditional clades of the phylum Annelida?
- Polychaeta (polychaetes)
-Oligochaeta (oligochaetes)
- Hirundinea (leeches)
What are the more recent 2 major clades of Annelids?
- Errantia
- Sedentaria
What are errantians?
Members of the clade Errantia that are mobile, marine organisms that have paddle-like or ridge-like structures called parapodia on each body segment.
What are sedentarians?
Organisms that are less mobile than errantians.
- Contains leeches and earthworms
What do leeches include?
Predators of invertebrates and parasites that suck blood
- live in fresh water, some are marine or terrestrial
What are earthworms?
Organisms that eat thru soil, extracting nutrients as the soil moves thru the alimentary canal
- asexually reproduce via fragmentation
What is the most species-rich animal group?
Ecdysozoans
What is a cuticle?
A touch coat that covers the ecdysozoans
What is ecdysis?
A process in which the cuticle is shedded or molted
What are the two largest phyla of Ecdysozoans?
- Nematodes
- Arthropods
What are the 3 major lineages of arthropods?
- Chelicerates (sea spiders, horseshoe crabs, scorpions, ticks, mites, and spiders)
- Myriapods (centipedes and millipedes)
-Pancrustaceans (lobsters and other crustaceans, as well as insects and their relatives)
What are chelicerae?
Clawlike feeding appendages found in chelicerates
What were the earliest chelicerates?
- Eurypterids (water scorpions)
What are most modern chelicerates?
Arachnids: spiders, scorpions, ticks, and mites
What are book lungs?
Respiratory organs where gas exchange occurs in spiders
What does the clade Myriapods include?
- millipedes
- centipedes
What makes up pancrustaceans?
- insects
- crustaceans
What consists of crustaceans?
- lobsters
- crabs
- crayfish
- shrimp
What are pill bugs?
Well-known group of terrestrial isopods
What do planktonic crustaceans include?
Many species of copepods
What are barnacles?
A group of mostly sessile crustaceans
What is the hexapoda?
Enormous clade that includes insects and their relatives
(6-legged)
What happens during incomplete metamorphosis?
The young or nymphs resemble adults but are smaller and go through a series of molts until they reach full size
What do insects with complete metamorphosis have?
- Has larval stages known by such names as maggot, grub, or caterpillar
What is in the clade deuterostomes?
- Echinoderms
- Chordates
What is included as echinoderms?
stars
sea urchins
What is included in the chordates?
Vertebrates
What are some shared developmental characteristics of Deuterostomes?
- Radial cleavage
- Formation of the anus from the blastopore
What are the 5 clades of living echinoderms?
- Asteroidea (sea stars and sea daisies)
- Ophiuroidea (brittle stars)
- Echinoidea (sea urchins and sand dollars)
- Crinoidea (sea lilies and feather stars)
- Holothuroidea (sea cucumbers)
What is a one example of great success of insects?
- Flight; insect wings are an extension of the cuticle
