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ACANTHOCHITONIDAE |
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Acanthochitona kimberi (Torr, 1912) Description: Animal ovate, narrowly elongate, girdle moderately broad. Median valves with jugal area indistinct, eroded smooth or weakly pustoluse; lateral and pleural areas not differentiated, with large pustules aligned or irregularly spaced. Girdle with large tufts of very fine spicules that clump together when wet, one beside each median valve and 4 in front of anterior valve; rest of girdle naked. Colour variable: pink, green, pale yellow, or fawn. Size: Up to 16 mm in length. Distribution: Endemic to Australia: NSW, southwards and around southern Australia to south-western WA, including Tas. Habitat: Under stones around the low tide mark. Comparison: In this species the girdle is naked, apart from the large conspicuous tuffs of very fine spicules. Synonymy: Acanthochiton maxillaris Ashby, 1919 is based on a very small, pink individual from SA. Remarks: This species is variable in colour and in the strength of the pustules on the valves. The tufts of girdle spicules are quite large, and clump together when wet, as in Fig. 1. When dry they can spread out, as in Fig. 2. In the original description the girdle was described as "leathery, covered with spinelets". Apart from the tufts of fine spicules, I have not been able to recognise any such spinelets in the specimens available. Fig. 1: Composite drawing by Michael Shea of Australian Museum specimens. Fig. 2: Sydney Harbour (C.367484). This is a dried specimen, collected between 1925 and 1932, so the colour is probably faded. |
Copyright Des Beechey 2019