. Advances in marine biology: volume 17. Coral fisheries. 202 L. HILLIS-COLINVATJX. Fig. 63. Cloning of incrassata. The two large thalli have lived in the aquarium for approximately 14 weeks. The tallest of the five young thalli, produced by "riinners" in the sand, is 23 days old. The others are less than 10 days old. Scale bar is 1 cm. A. Sexual processes in Halimeda Feldmann (1951) provided the first modern description of the contents of the small globules or gametangia borne externally on a segment. His material was the large-segmented Mediterranean tuna, and he noted that mature
. Advances in marine biology: volume 17. Coral fisheries. 202 L. HILLIS-COLINVATJX. Fig. 63. Cloning of incrassata. The two large thalli have lived in the aquarium for approximately 14 weeks. The tallest of the five young thalli, produced by "riinners" in the sand, is 23 days old. The others are less than 10 days old. Scale bar is 1 cm. A. Sexual processes in Halimeda Feldmann (1951) provided the first modern description of the contents of the small globules or gametangia borne externally on a segment. His material was the large-segmented Mediterranean tuna, and he noted that mature gametangia were of two different colours, brown and green, which occurred on different thalli. The gametes released by the two were different also. Those from the brown game- tangia were slightly larger (macrogametes), and usually contamed three small chloroplasts and a posterior eyespot. Those from the green gametangia (microgametes) possessed the same number of chloroplasts but lacked an eyespot. He noted, too, that when the gametangia were first formed almost all the contents of the coenocytic filaments of the segment, especially the chloroplasts and amyloplasts, moved into the gametangia. The filaments of the segment, therefore, were essentially empty, and the thallus, as a result, appeared white. These observations show that the sexual process involves: (i) growth of gametangia on stalks or gametophores (Fig 64); (ii) the transfer of the free organic matter of the thallus, includhig reserves, to the gametangia (holocarpy), a process that turns the parent thallus white; (iii) release of gametes of different sizes; (iv) fusion of gametes; (v) death of parent thallus; (vi) development of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Hillis-Colinvaux, Liewellya. London : Academic Press ; Toro
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