82
R. 11. MILLAR
in South America (Van Name, 1945). Margalino and de Stefan0 (1960)
found that the flesh of Microcosmus sulcutus is almost as digestible as
whole egg, and the protein content higher.
Such is their abundance in some localities that ascidinns have been
considered as a possible source of cellulose, vanadium, protein and other
chemicals (Elroi and Komarovsky, 1961 ; Hebant-Joder, 1965), and
although the investigations have been confined to warm waters they
might encourage a similar approach applied to some of the dense and
fast-growing populations encountered in certain temperate areas.
The part played by ascidians in the diet of commercial fish, and their
occasional use as bait, have been mentioned elsewhere (p. 48).
C . Uptake of harntful substances
Since the advent of nuclear weapons and nuclear power stations the
presence of radionuclides in the sea and their uptake by marine organisms have received considerable attention. So far as ascidians are
concerned the practical importance of the uptake of radioactive
materials is the possibility that they will be concentrated in the tissues
and passed on to man, either when ascidians are eaten or indirectly
through the consumption of commercial fish which themselves feed on
the ascidians. According to Bryan (1963) Ciona intestinalis shows a low
concentration factor for 13'Cs in all tissues, and Strohal et al. (1969)
found factors of 70 and 90 for Phallusia mammillata and Microcosmus
sulcatus. go,, is of particular importance as an artificial radionuclide, but factors of only 1 and 4 were obtained by Strohal et al. for
P . mammillata and M . sulcatus. These workers found Zn to be eoncentrated by a factor of 940 in both species, although Ciona intestinalis
has a factor of 6 600 (Vinogradov, 1953). Co and Fe are also of interest
as pollutants, and 1Microcosmus sulcutus has factors of 1 350 and 40 000
respectively, the corresponding factors for Phallusia mammillata being
400 and 18 000 (Strohal et al., 1969), and for Ciona intestinalis, 400 and
200 respectively. It is evident that there may be some danger, in certain
areas of the sea subject to radioactive pollution, of radionuclides passing
up the food chain to man.
IX. REFERENCES
Florida. J . Waah. A d . Sci. 41 (9), 302-307.
carpa taylori Huntsman. Univ. Calif. Piibb 2001. 61 ( l ) , 1-47.
curpa taylori. J . Morph. 97, 569-594.
Abbott, D. P. (1951). Boatricliobranchue digonaa, a new molgulid ascidian from
Abbott, D. P. (1953). Asexual rcproduction in the colonial mcidian M e t u ? m -
Abbott, D. P. (1955). Larval structuro and activity in tho aacidinn Melandro-
R. 11. MILLAR
in South America (Van Name, 1945). Margalino and de Stefan0 (1960)
found that the flesh of Microcosmus sulcutus is almost as digestible as
whole egg, and the protein content higher.
Such is their abundance in some localities that ascidinns have been
considered as a possible source of cellulose, vanadium, protein and other
chemicals (Elroi and Komarovsky, 1961 ; Hebant-Joder, 1965), and
although the investigations have been confined to warm waters they
might encourage a similar approach applied to some of the dense and
fast-growing populations encountered in certain temperate areas.
The part played by ascidians in the diet of commercial fish, and their
occasional use as bait, have been mentioned elsewhere (p. 48).
C . Uptake of harntful substances
Since the advent of nuclear weapons and nuclear power stations the
presence of radionuclides in the sea and their uptake by marine organisms have received considerable attention. So far as ascidians are
concerned the practical importance of the uptake of radioactive
materials is the possibility that they will be concentrated in the tissues
and passed on to man, either when ascidians are eaten or indirectly
through the consumption of commercial fish which themselves feed on
the ascidians. According to Bryan (1963) Ciona intestinalis shows a low
concentration factor for 13'Cs in all tissues, and Strohal et al. (1969)
found factors of 70 and 90 for Phallusia mammillata and Microcosmus
sulcatus. go,, is of particular importance as an artificial radionuclide, but factors of only 1 and 4 were obtained by Strohal et al. for
P . mammillata and M . sulcatus. These workers found Zn to be eoncentrated by a factor of 940 in both species, although Ciona intestinalis
has a factor of 6 600 (Vinogradov, 1953). Co and Fe are also of interest
as pollutants, and 1Microcosmus sulcutus has factors of 1 350 and 40 000
respectively, the corresponding factors for Phallusia mammillata being
400 and 18 000 (Strohal et al., 1969), and for Ciona intestinalis, 400 and
200 respectively. It is evident that there may be some danger, in certain
areas of the sea subject to radioactive pollution, of radionuclides passing
up the food chain to man.
IX. REFERENCES
Florida. J . Waah. A d . Sci. 41 (9), 302-307.
carpa taylori Huntsman. Univ. Calif. Piibb 2001. 61 ( l ) , 1-47.
curpa taylori. J . Morph. 97, 569-594.
Abbott, D. P. (1951). Boatricliobranchue digonaa, a new molgulid ascidian from
Abbott, D. P. (1953). Asexual rcproduction in the colonial mcidian M e t u ? m -
Abbott, D. P. (1955). Larval structuro and activity in tho aacidinn Melandro-