The Catophragmidae are divided into the subfamilies Catophragminae, in the northern hemisphere, and Catomerinae n. subfam., in the southern hemisphere. The former includes Catophragmus and Catolasmus n. gen., and the latter, Catomerus. All of the genera are considered monotypic, but our preliminary studies suggest there may be two species of Catomerus in Australian and Tasmanian waters and two, if not three, species of Catophragmus in the Caribbean and Western-Atlantic regions. A computer-based phylogenetic analysis of relationships among basal balanomorphs and certain other barnacles that exhibit apparently more plesiomorphic grades of organization results in a fully resolved branching tree with the chionelasmatids occupying the most basal position among the balanomorphs. Waikalasma is placed in Waikalasmatidae, n. fam., and assigned to the Superorder Chionelasmatoidea

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Filtration and ingestion rates of spat of Japanese pearl oyster, Pinctada fucata martensii (average hinge length: 2.61mm), fed the same concentration of micro-algae (Pavlova lutheri: 3.6×10⁴cells/ml) at different water temperatures (20, 26, 32°C) for 14 days were determined. Growth rates of spat hinge length (20°C, 81μm/day; 26°C, 166μm/day; 32°C, 198μm/day) and whole weight (20°C, 123μg/day; 26°C, 288μg/day; 32°C, 424μg/day) increased with water temperature. Filtration rates of pearl oyster spat also increased with water temperature (20°C, 0.98ml/h/spat; 26°C, 2.22ml/h/spat; 32°C, 6.02ml/h/spat on day 4), as did ingestion rates (20°C, 4.75×10⁴cells/h/spat; 26°C, 8.56×10⁴cells/h/spat; 32°C, 17.4×10⁴cells/h/spat on day 4). However, there was little difference in filtration and ingestion rates at 26°C and 32°C on days 7 and 14, respectively. Growth rate of the spat increased with ingestion rate. In sum, filtration and ingestion rates of the spat were affected by water temperature, and then the growth rate of the spat was affected by filtration and ingestion rates. There was a positive correlation between spat size and filtration rate and also between spat size and ingestion rate. The maximum ingestion rate of the spat was estimated to be 20×10⁴cells/h/spat, and the maximum growth rate of spat hinge length was estimated to be 200μm/day.

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The filtration and ingestion rates of spat of the Japanese pearl oyster Pinctada fucata martensii fed various concentrations of micro-algae Pavlova lutheri for 14 days, were determined. On day 4, filtration rates decreased with increasing algal concentration (average spat hinge length: 2.96mm). Ingestion rates increased with increasing algal concentration but reached a plateau at algal concentrations of 3.6×10⁴cells/ml/day or greater. The daily algal feeding rate and whole weight of the spat were determined on day 14 (spat hinge length range: 5.0-5.5mm), when daily consumption of algae, in terms of dry weight of algal cells was estimated about 3-5% of spat whole weight per day. There was a positive correlation between ingestion rate and the product of algal concentration and filtration rate (r=0.857, p<0.05).

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The relationship between attaching organisms and corrosion of different metals was studied using six metal test plates exposed in 3 meters depth in Suruga Bay off Nishiura-Kisyo, Numazu, Shizuoka, in coastal Japan. The extent of corrosion of mild steel depended on the attachment of barnacles and, in addition, there was virtually no attachment to rust surfaces. There was hardly any difference between the corrosion rates of zinc and 90Zn-10Al alloy and the corroded surfaces were smoother than those of mild steel. Furthermore, although Botrylloides and diatoms readily became attached, barnacles did not; the few barnacles that did settle on these plates readily detached along with the zinc hydroxides that are the corrosion products. There was no great difference in the corrosion rates of pure copper and 90Cu-10Ni alloy, although pitting was observed on the pure copper plate. Slime, including diatoms, was observed on both metals, but there was no attachment of macroorganisms. Meanwhile, in the case of stainless steel, surfaces without any attached organisms showed virtually no corrosion, but crevice corrosion was observed here and there at barnacles attachment sites.

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