animal Type
Maximum Size

51 cm

(20 inches)


2,200-4,000 m

(7,200–13,100 feet)




Sea anemones, hydroids, jellies, and other invertebrates




Eight long and lanky legs make it easy to move along the deep seafloor.

Like spiders on land, sea spiders—also known as pycnogonids—come in a range of sizes and appearances. They’re widespread and occur across a variety of ocean environments. The deep sea is home to the giant sea spider (Colossendeis sp.), which can grow larger than a dinner plate. This spindly spider lumbers along the seafloor on jointed, stilt-like legs.

Instead of spinning a delicate web of silk to trap prey, a giant sea spider uses an elongate, tube-like proboscis to slurp up its prey. While studying the unique communities that form around decomposing whale carcasses on the deep seafloor, MBARI researchers observed a giant sea spider crouched over and clinging to the fleshy tentacle of a pom-pom anemone (Liponema brevicorne). Upon closer inspection, the sea spider was actually sucking out the juices inside the tentacle. Another sea spider was even observed clipping a couple of tentacles and taking its dinner to go!



Video Clips


Lundsten, L., K.L. Schlining, K. Frasier, S.B. Johnson, L. Kuhnz, J. Harvey, G. Clague, and R.C. Vrijenhoek. 2010. Time-series analysis of six whale-fall communities in Monterey Canyon, California, USA. Deep-Sea Research Part I, 57: 1573–1584.