Mobility and attachment type

The terms used to describe mobility traits are listed below

Trait Definition
Sessile, permanent attachment Non-motile; permanently attached at the base (Lincoln et al., 1998) (e.g. cup corals).
Mobile Capable of movement from one location to another.
Sedentary, temporary attachment Temporary or sporadic attachment. Attached to a substratum but capable of movement across (or through) it (i.e. sedentary) (e.g. sea anemones).
Swimmer An organism that moves through the water column via movements of its cilia, flagella, fins, legs or appendages, via undulatory movements of the body or via jet propulsion (e.g. fish, squid).
Swimmer (cilia or flagella) Swimming by beating of cilia or flagella (includes the fused cilia of Ctenophores).
Swimmer (muscular contraction along body) Swimming by muscular contractions along the length of the body, which may be aided by body protrusions or structures (e.g. parapodia, fins).
Swimmer (appendages, paddles) Swimming using one or more pairs of appendages (legs or paddles) e.g. the pleiopods of Isopods, Amphipods or Decapod crustaceans, or the legs of amphibians and vertebrates.
Swimmer (jet propulsion) Swimming by contraction of the body or body cavity to produce a 'jet' of water, e.g. medusae and cephalopods (from Barnes et al., 2006).
Glider An organism that is able to glide through the air (e.g., using some form of membrane or airfoil) but cannot propel itself through the air (e.g., flying fish).
Drifter An organism whose movement is dependent on wind or water currents (e.g. by-the-wind sailors, jellyfish).
Passive drifter Movement dependent on wind or water currents
Bysso-pelagic drifter Use of a length of byssus thread (e.g., micro-molluscs, juvenile molluscs) or mucus (e.g. Nemertesia planulae) to be carried by water flow.
Ballooning or kiting Use of a length of silk to be carried by the wind (e.g. spiders).
Jumper or hopper Organisms able to undertake a rapid jump or hop several times their own body length, using specialized limbs or appendages (e.g. sand hoppers, spring tails, grass hoppers etc).
Creeper An organism that slowly moves or 'creeps' along the surface of the substratum, e.g. snails and slugs. 
Crawler or Walker An organism that moves along or across the substratum via movements of its legs, appendages or muscles (e.g. crabs).
Burrower An organism that moves through the substratum by burrowing (e.g. earthworms, polychaetes).


  1. Barnes R.S.K., Calow P., Olive P.J.W., Golding, D.W, and Spicer, J.I., 2006. The invertebrates: a new synthesis, 3rd edn. Oxford: Blackwell Science Ltd.
  2. Lincoln, R., Boxshall, G. & Clark, P., 1998. A dictionary of ecology, evolution and systematics. Cambridge: Cambridge University of Press.