What are small arthropods?

Answer 1

On the biological ruler, arthropods tend towards the small end of the spectrum, owing to physical limits imposed by their methods for respiration, gas exchange and circulatory system; a high surface area to volume ratio serves them quite well on these counts.

The smallest arthropods known are a crustacean parasite, Stygotantulus stocki, around a hundred micrometers long (about 4 thousandths of an inch).

Answer 2

If by 'categories' you mean subphylums and classes, then the major ones are:

Phylum Arthropoda

---Subphylum Chelicerata

-Class Arachnida (Spiders, sea spiders, horseshoe crabs, scorpions ticks/mites)

---Subphylum Crustacea (crabs, lobsters, shrimps, barnacles, etc.)

---Subphylum Myriapoda

-Class Chilpoda (centipedes)

-Class Diplopoda (millipedes)

---Subphylum Hexapoda

-Class Insecta (Insects and their wingless, six-legged relatives)

Reminder: The subphylums (with their respected classes) listed above are the four major lineages of the Arthropods

Answer 3

The term "arthropods" means "jointed legs". Think of all the other animal phyla without backbones. Only the arthropods (insects, spiders, crustaceans, millipedes and centipedes) have legs with joints.