Between December 1978 and March 1979 studies on the ichthyofauna distribution in the regions of the Scotia Sea and Antarctic Peninsula were carried out on board of the r/v "Profesor Siedlecki" during the Fourth Polish Marine Antarctic Expedition. Fisheries were carried out using bottom and pelagic trawls. The presence of about 60 species of 15 families, including among others 17 species of Nototheniidae, 9 species of Chaenichthyidae and 7 species of Bathydraconidae was recorded. Iti the waters of the west regions of the Antarctic such species as Trematomus centronotus and Austrolycichtys botriocephalus were found.

In the bottom fauna of the Van Keulen fiord 53 taxa of invertebrates (51 species) were recorded. Four different bottom types were sampled and the distribution of invertebrates in these bottom types is discussed. The most important components in the benthos of the fiord were Polvchaeta. Crustacea. Bivalvia and Gastropoda (79.2%). From the zoogeographical point of view the Van Keulen fiord should be included into the transient zone, situated at the border of the boreal and arctic zones.

The list of 29 gastropod species and 33 species of bivalves occurring in Hornsund Fiord as well as their zoogeographic status are presented. The occurrence and role of Mollusca in particular parts of the fiord are discussed.

In the material of nearly 2000 individuals of Asteroidea collected in Admiralty Bay, the largest bay of the South Shetlands, 36 species were determined, enriching the list of hitherto known asteroid species of this basin by 17 taxa. One of them, Peribolaster macleani, is recorded for the first time in Western Antarctic. The most frequent and abundant asteroids of Admiralty Bay were Odonlaster validus, Psilaster charcoti, Bathybiaster loripes obesus and Diplasterias brucei. The bathymetric and geographic distribution of all species are discussed.

In a study on the click beetles (Coleoptera: Elateridae) of selected plant communities of the Lasy Janowskie Reserve, 21 species of these beetles were recorded – 10 each in riparian forests and a sub-Atlantic mesic coniferous forest, 11 in a continental mixed coniferous forest, and 6 in wet grassland communities. The numbers of species in the communities was similar to numbers recorded in other, comparable areas of Poland, with the exception of the wet grasslands. Forest species that can also occur outside of forests – Athous subfuscus and Dalopius marginatus – were dominant. The biodiversity of the click beetle fauna in the communities was at an average level. An ecological and zoogeographical analysis was carried out as well.