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

48
to the base of paraphyses. Antheridia in tight
clusters on branched paraphyses.
Habitat in the sublittoral fringe and the upper
sublittoral zone to a depth of ca 1.5 m; frequently
forms a distinct band below Durvillaea ru!tarctica
and above Lessonia varigata J.Ag. From exposed
to semisheltered locations.
Hold~e: CHR 248262 (9); paratype CHR 248263 (0).
Type locality: Intertidal rodcy platfonn between Hanson
Point and Point Webb at the NW end of Waitangi Bay
Chatham I. (43"56'4"S, 173033'52"W).
SEccimens examined: Fresh from Chatham Islands: Waitangi,
wangamoe Inlet, Owenga Beach, Southeast Rangatira
Island, pitt Island near Glory Bay. Antipodes
Island: CHR 191678, Hut Cove, E. Godley coil.
Differences from other sp,ecies:
(i) From D. potatorum:
Lmninae without any stipitate lateral blades.
(iil From D. antarctica: (Figs 3.5; 3.6; 3.8; 3.9)
Laminae of fully grown specimens devoid of any honeycomb tissue
and with differentiated margins.
Medulla solid, comprised of a
uniformly compact mass of hyphae running predominantly longitudinally
and horizontally in plane of flattening, vacuole-like spaces absent,
.-
no central zone of" loosely interweaving, much branched hyphae.
Shallo\v crater-like depressions (up to 25 rum across and 1-3 mm deep)
common on lamina surface, especially near margins:
this feature was
never observed on D. antarctica laminae. Stipes expanding directly
into leathery palm of lamina;
rarely if ever branched distally into
bough-like branches. Conceptacle wall srIlOOth"" Oogonia borne
predominantly parietally or at very base of paraphyses.
in the sublittoral fringe and upper sublittoral.
Growing
(iii) ~rom D. willana;
Lamina and stipes devoid of ahy s"tipitate lateral blades,
Stipes shorter than 0.5 m and less than 60 ITm\ thick at their base.
Differences are summarised in Table 3,,1.