Abstract
Four new species of shallow water pygmy octopus from Tonga are described. Morphologic descriptions and illustrations are given of internal and external anatomy. Octopus gorgonus n. sp. bears enlarged suckers on arms III and IV of males. Normal arms have 105–135 suckers. Preserved specimens are reddish-orange with large, regularly spaced, cream-colored spots on the dorsal mantle, head and arms, and ocelli are absent. Octopus humilis n. sp. bears slightly enlarged suckers on pairs II, III, and IV of the single male specimen. Normal arms which have up to 144 suckers. The dorsal surface is grey-brown. A pair of ocelli is present, without iridescence. Octopus mariles n. sp. has no distinctly enlarged suckers. Sucker counts range from 125–160 on normal arms. Preserved specimens are uniform dark-red to black, and ocelli are absent. Abdopus undulatus n. sp. bears enlarged suckers on arms II and III of males, but diameter is variable. Sucker counts range from 130–178 on normal arms. Preserved specimens are peach to orange-brown, with faint tan smudges spaced evenly on arm crown and webs. No ocelli are present.