The ammotheid pycnogonid Ammothea hilgendorfi was first recorded outside its native range of the Pacific Ocean in 1978 in southern England and in the Lagoon of Venice in 1979 to 1981. Both occurrences are attributed to anthropogenic dispersion by shipping. Subsequently, it has spread further in the UK to Dorset and, most recently, to Essex. The world distribution of this species and the history of its occurrence outside the Pacific are reviewed, and hypotheses for its recent spread in the UK, via recreational boating, are presented.

Specimens of 22 species of pycnogonids belonging to twelve genera and seven families were collected during a cruise near Livingston Island, South Shetland Islands. Twenty two of the 94 stations yielded pycnogonids: the new species Ammothea hesperidensis is described fully, illustrated, and compared with similar species. The family Nymphonidae provided both the greatest diversity of species (seven) and number of specimens (35). The most abundant species were Achelia hoekii and Nymphon australe.

Recently collected material from west of the Antarctic Peninsula has proven to be consistent with Nymphon gerlachei Giltay, 1935, previously known only from the holotype. The information now available on its intraspecific morphological variability has allowed the distinctions between this species and N. charcoti to be established.

Fifty-nine species of pycnogonids belonging to sixteen genera and eight families were collected during a cruise near Livingston Island and surrounding waters, from depths between 0 and 1019 m. The new species Ammothea bentartica is described fully, illustrated and compared with similar species. The family Nymphonidae had both the greatest number of species (20) and number of specimens (67% of 1201). The most abundant species were Nymphon charcoti and N. australe. Nymphon paucidens and Pallenopsis buphtalmus were collected for a second time. The collections increased the geographical distribution of five species and the depth range of seven species. This collection appears typical of the West Antarctic zone.