A biological study of Durvillaea antarctica (Chamisso) Hariot and D ...

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IJuroillm:o differs from most fUCillcan genet-a in posscssinq
four ova in each oogonium. Of those related genera with four ova,
none has -the same arrangement as is found in all Du2'v1:17"aea species"
The most impor.tant. older cont:ributors t.o present: underst.anding
of the genus \Ilere Areschoug (1847. 1854) r who studied samples
of preserved plants from the Falkland Islands and Skottsberg (1907,
1921, 1941), who was familiar with growing plants in the Magellanic
region of South Americao More recently, Naylor (1949. 1953).
investigated t:he anatomy oE two species. The present revision
evolved from G_ detailed biological study (l972-6) of species growing
in New Zealand and i:he Chatham Islands. Specimens were examined in
European 1'I.nd American herbaria. and where it \-las not possible to see
type material, photographs were ob"tained. With the assistance of
Dr R.B. Searles of Duke University, North Carolina, photographs and
preserved lamina samples of D. antaY'ctica were obtained from numerous
localities along the Chilean coast" Fresh lamina sample.s of D.
potato-Y'um were sent airmail from Australia-
(a)
(i) Habitat
Ecological t:olerances of all species appear to be similCi.'C
laterally, but differ vertically, One species is confined to the
lO'N'er littoral. rarely if ever growing below MLWS. The other species
grow in the upper sublittoral and the sublittoral fringe. There may
be differences between species with regard to the \i1aximum depth O.t
which they will growo
(ii)
Wor,td distribution
The distribu'cions of three species are localis