On two rare Asteroidea species found in the Adriatic
Abstract
Important data on two rare Asteroidea species have been made available from the material gathered during the M. V. HVAR Expedition in the Adriatic in 1948 and 1949. These data have enabled us to come to the following conclusions:
1) The species Odontaster mediterraneus occurs in the southern and cential Adriatic, its highest concentration being found in the Jabuka Pit at depths ranging approximately from 61 to 256 metres. The largest number of specimens occurred at depths ranging between 180 and 250 metres. The HVAR Expedition covered depths up to 450 metres, but only six samples were taken beyond 300 metres. It cannot be excluded, then, that the non-occurrence of numerous specimens at greater depths happened only by chance since the bottom there suits the species.
2) The species Odontaster mediterraneus found in the Adriatic largely occurred on muddy bottom. This is in agreement with the data referring to some localities in the Mediterranean.
3) The species Sclerasterias neglecta is distributed over the whole of the Adriatic area. Found at depths ranging between 67 and 256 metres, the largest number of specimens was hauled at depths ranging from 100 to 150 metres where the species has its maximum occurrence.
4) The species Sclerasterias neglecta found in the Adriatic has its habitat on sandy, sandy-muddy or muddy bottom; the number of occurring individuals was usually greater on sandy bottom. The non-occurrence of the species at depths beyond 250 metres could perhaps be explained by rare patches of sandy bottom found at such depths.
5) Nowhere in the Mediterranean region has the species Sclerasterias neglecta so far been found at so many localities and in such quantities as in the Adriatic.
