Conacher, MJ, Lanzing, WJR & Larkum, AWD 1979, 'Ecology of Botany Bay. II. Aspects of the Feeding Ecology of the Fanbellied Leatherjacket, Monacanthus chinensis (Pisces : Monacanthidae), in Pisidonia australis Seagrass Beds in Quibray Bay, Botany Bay, New South Wales', Marine and Freshwater Research, vol. 30, no. 3, pp. 387-387.
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The fanbellied leatherjacket, M. chinensis, was found to ingest fresh seagrass as a major part of its diet. Other important food items were gammarid amphipods, carid shrimps and several species of epiphytic algae. All food items were of seagrass bed origin. Microscopic examination of gut contents suggested that seagrass and algae did not appear to be digested by the fish, but 14C-labelling of the plants showed that significant amounts of the labile carbon compounds were removed and assimilated during digestion. The fanbellied leatherjacket was found to feed in the seagrass beds during the day, probably relying on eyesight for detecting food. Variations in tide height did not seem to affect their feeding pattern. The amounts of seagrass, algae, amphipods and shrimps removed by M. chinensis in Quibray Bay were calculated and compared with the availability of each of these foods. Grazing by M. chinensis had little effect on seagrass and algae production rates and standing crops, but probably had a significant influence on carid shrimp and amphipod populations.
Larkum, AWD & Wyn Jones, RG 1979, 'Carbon dioxide fixation by chloroplasts isolated in glycinebetaine', Planta, vol. 145, no. 4, pp. 393-394.
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Spinach chloroplasts capable of high rates of CO2 fixation have been isolated in glycinebetaine as an alternative osmoticum to sorbitol and found to be very stable. Proline was a less satisfactory alternatine. The possible significance of the use of glycinebetaine is discussed as this solute may be the physiological cytoplasmic osmoticum in members of the Chenopodiaceae. © 1979 Springer-Verlag.
West, RJ & Larkum, AWD 1979, 'Leaf productivity of the seagrass, Posidonia australis, in eastern Australian waters', Aquatic Botany, vol. 7, no. C, pp. 57-65.
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Leaf blade production rates of Posidonia australis Hook. f. have been found to range from 0.7 to 5.5 g dry wt. m-2 day-1, depending on site and season. Leaf-blade production (m-2) was significantly higher in Jervis Bay (New South Wales) compared to Botany Bay (New South Wales) and summer and winter values from a Spencer Gulf (South Australia) site were higher than those of Jervis Bay. In Botany Bay, the average turnover rate of Posidonia leaves is about 0.8-1.1% of leaf biomass per day (i.e. three to four crops of leaves produced per year). Biomass, shoot density and some leaf characteristics are also presented for each site. The contribution of seagrass communities to total primary production in the waters of Botany Bay is estimated to be of major importance, and the continued reduction in this contribution, due to urban development, is a matter of concern. © 1979.
