BIOLOGY OF SEAWEEDS OF ECONOMIC IDIPORTANCE
163
14. Ecklonia
This genus resembles Nereocystis and is found principally in the
Southern Hemisphere. The long stalk terminates in a small air bladder,
this in turn bearing a primary blade from the base of which numerous
sporophylls are produced (Fritsch, 1945).
Other large members of the Laminariales used for a number of
purposes include Lessonia variegata, Eisenia bicyclis, and Pelagophyczcs
porra (Chapman, 1950). The prodigious spore output of the Laminariales is also of significance as food for invertebrate larvae in the general
turnover of organic matter in the sea (Scagel, 1959).
C. Rhodophyceae
1. Porphyra
The several species of Porphyra used as food have been enumerated
(p. 109). The starting point for present-day knowledge of the Porphyra
life history may be seen in Drew’s work (Drew, 1949, 1954a, b), which
first showed the presence of both a shell-boring Conchcelis-phase
and the leafy thallus during the life history. The shell-boring phase was
obtained by Drew when the “ carpospores ’’ of the leafy thallus of
Porphyra purpurea ( = P. umbilicalis f. laciniata) were germinated on
sterilized shell fragments. The use of this substratum (as found in the
vicinity of the leafy Porphyra plant on the shore) followed unsuccessful
attempts to obtain the continued growth of the filaments on glass slides.
Drew’s studies showed that the flaments of the Conchcelis-pham
produced “ fertile cell rows ”, and that the cell contents of these fertile
cell rows rounded-off, forming spore-like bodies ; the intervening walls
of the cell rows then broke down forming a tube which could pass to
the surface of the shell (Drew and Richards, 1953). Small, muchbranched “ plantlets ’’ were obtained under culture conditions, but
these were not observed to form spores. Neither spore release nor
subsequent germination was observed by Drew, who was also unable
to obtain the leafy-thallus from the shell-boring phase. A Conchocelisphase has been shown to be part of the life-history of a number of
Porphyra speoies (e.g. Tseng and Chang, 1955a, b; Kurogi 1963a, b,
for Porphyra tenera; Graves, 1955, for Porphyra capensis; Miura,
1961, for Porphyra tenuipedalis; Joly and Yamaguishi, 1963, for
Porphyra atropurpurea). Demonstration of the full cycle from leafy
thallus to shell-boring phase and back to the leafy plant again has been
reported under culture conditions by Tseng arid Chang (1955b)’
Hollenberg (1958), Kornmann (1960), and Iwasaki (1961). Whilst
Graves (1955) was able to obtain the large plants of Porphyra capensis
163
14. Ecklonia
This genus resembles Nereocystis and is found principally in the
Southern Hemisphere. The long stalk terminates in a small air bladder,
this in turn bearing a primary blade from the base of which numerous
sporophylls are produced (Fritsch, 1945).
Other large members of the Laminariales used for a number of
purposes include Lessonia variegata, Eisenia bicyclis, and Pelagophyczcs
porra (Chapman, 1950). The prodigious spore output of the Laminariales is also of significance as food for invertebrate larvae in the general
turnover of organic matter in the sea (Scagel, 1959).
C. Rhodophyceae
1. Porphyra
The several species of Porphyra used as food have been enumerated
(p. 109). The starting point for present-day knowledge of the Porphyra
life history may be seen in Drew’s work (Drew, 1949, 1954a, b), which
first showed the presence of both a shell-boring Conchcelis-phase
and the leafy thallus during the life history. The shell-boring phase was
obtained by Drew when the “ carpospores ’’ of the leafy thallus of
Porphyra purpurea ( = P. umbilicalis f. laciniata) were germinated on
sterilized shell fragments. The use of this substratum (as found in the
vicinity of the leafy Porphyra plant on the shore) followed unsuccessful
attempts to obtain the continued growth of the filaments on glass slides.
Drew’s studies showed that the flaments of the Conchcelis-pham
produced “ fertile cell rows ”, and that the cell contents of these fertile
cell rows rounded-off, forming spore-like bodies ; the intervening walls
of the cell rows then broke down forming a tube which could pass to
the surface of the shell (Drew and Richards, 1953). Small, muchbranched “ plantlets ’’ were obtained under culture conditions, but
these were not observed to form spores. Neither spore release nor
subsequent germination was observed by Drew, who was also unable
to obtain the leafy-thallus from the shell-boring phase. A Conchocelisphase has been shown to be part of the life-history of a number of
Porphyra speoies (e.g. Tseng and Chang, 1955a, b; Kurogi 1963a, b,
for Porphyra tenera; Graves, 1955, for Porphyra capensis; Miura,
1961, for Porphyra tenuipedalis; Joly and Yamaguishi, 1963, for
Porphyra atropurpurea). Demonstration of the full cycle from leafy
thallus to shell-boring phase and back to the leafy plant again has been
reported under culture conditions by Tseng arid Chang (1955b)’
Hollenberg (1958), Kornmann (1960), and Iwasaki (1961). Whilst
Graves (1955) was able to obtain the large plants of Porphyra capensis