Figure 8

Developmental sequence of the cystocarp of Galaxaura pacifica Tanaka from Small Port, KNP, southern Taiwan. (A) Young carpogonial branch replaces one of the dichotomous vegetative cortical (co) branches showing a trichogyne (t), a carpogonium (c), a hypogynous cell (h), and a basal cell (b); (B) Young carpogonial branch protruding between the dichotomous vegetative cortical (co) branches showing a trichogyne (t), a carpogonium (c), a hypogynous cell (h) bearing the sterile branch (arrow), and a basal cell (b); (C) Two mature carpogonial branches borne on the vegetative cortical (co) branch showing trichogyne (t), carpogonium (c), hypogynous cell bearing several sterile branches (arrowheads), and basal cell bearing several involucral filaments (arrows); (D) Mature carpogonial branch showing a trichogyne (t), a carpogonium (c), a hypogynous cell (h) bearing several sterile branches (arrowheads) with darkly stained nuclei, and a basal cell (b) bearing several involucral filaments (arrows); (E) Cross section of young cystocarp showing developing gonimoblast filaments (gf), a distinct fusion cell (fc), a hypogynous cell (h), and a basal cell (b) bearing numerous involucral filaments (arrows) surrounding the base of cystocarp; (F) Cross section of immature cystocarp showing the fusion cell (fc) incorporated with the inner three gonimoblast cells and gonimoblast initial (gi), a hypogynous cell (h) bearing several modified sterile branches (arrowheads), and a basal cell (b) producing several involucral filaments (arrows) surrounding the base of the cystocarp; (G) Further development of immature cystocarp showing the gonimoblast filaments producing terminal carposporangia (cp), the distinct fusion cell (fc) incorporated with 7-10 inner gonimoblast cells and gonimoblast initial (gi), a hypogynous cell (h) bearing several modified sterile branches (arrowheads), and a basal cell bearing numerous involucral filaments surrounding the base of the cystocarp; (H) Cross section of mature cystocarp showing gonimoblast filaments (gf) producing terminal carposporangia (cp), the distinct fusion cell (fc), a hypogynous cell (h) with its derived sterile branch (arrowhead), and a basal cell (b) producing numerous involucral filaments (arrows) surrounding the base of the cystocarp.