Although their phylogeny is disputed, the order <i>Acarina</i> may be divided into ticks (<i>Parasitiformes</i>) and mites (<i>Acariformes</i>).

Vinegarroons (whip scorpions, <i>Thelyphonida</i>) have six legs for walking while using their modified their first two legs as antennae-like sensory organs.

Although resembling spiders, windspiders (<i>Solifugae</i>) are moderate to large arachnids and closely related to scorpiones. Most windspiders are carnivorous feeding on small arthropods.

Scorpions (<i>Scorpiones</i>) are predatory arthropod animals with their bodies divided into the cephalothorax (prosoma) and the abdomen (opisthosoma).

Due to their pincers (pedipalps) pseudoscorpions (false scorpions, book scorpions; <i>Pseudoscorpionida</i>) resemble true predatory scorpions (<i>Scorpiones</i>) which are no arachnids.

Harvestmen (<i>Opiliones</i>) are invertebrate animals in the subphylum <i>Chelicerata</i> but do not belong to the spiders (<i>Araneae</i>).

In contrast to other bryozoan species, Phylactolaemata (<i>Phylactolaemata</i>) are freshwater invertebrate animals. Colonies are common and abundant in shallow lakes, ponds, rivers, and streams.

Ctenostomata (<i>Ctenostomata</i>) are an extinct order of Bryozoans. The marine, invertebrate animals built colonies by budding new animals from a slender, creeping stolon.

Cheilostomata (<i>Cheilostomata</i>) contain the most important living bryozoan species. They are colonial marine, invertebrate animals composed of calcium carbonate.

Gymnolaemata (<i>Gymnolaemata</i>) are marine sea mats growing on surfaces of rocks or other animal species like fish. Stenolaemata include most living bryozoan species.

Cyclostomes (<i>Cyclostomatida</i>) are an ancient order of exclusively marine sea mats appearing predominately in temperate and arctic environments.

Stenolaemata (<i>Stenolaemata</i>) are marine sea mats characterized by tubular zooids with calcified walls. Most forms contain a lophophore but no operculum.

Most crustaceans (<i>Crustacea</i>) are aquatic arthropods, living in marine and fresh-water environments whereas terrestrial crabs are adapted to life on land.

Sea spiders (<i>Pycnogonida</i>) are marine chelicerate arthropods most common in shallow waters. They use four to six pairs of comparably long legs for walking.

Merostomata (<i>Merostomata</i>) are marine chelicerate arthropods that have compound eyes.

Profile of George Maine who is a biologist in Pathumthani province, Thailand.

Spiders (<i>Araneae</i>) are air-breathing chelicerate arthropods with eight legs that inhabit every ecological niche on land.

Whip spiders (<i>Amblypygi</i>) have flat bodies with a solid carapace and a segmented abdomen and live in humid environments of tropical and subtropical regions.