The sponge Chelonaplysilla violacea, collected from New Zealand coastal waters, contains as major constituents the diterpenoids aplyviolene (la), norrisolide (2), dendrillolide A (3) aplyroseol-7 (4), spongian-16one (5), chelonaplysin C (6), and a series of new compounds cheloviolene A-F and cheloviolin.Structures were assigned to cheloviolene A (7), [3aR-[3=,4a(l R* ,3aR* ,8aS*) ,5/3,6aa]]-5-hydroxy-4(1,4,4trirnethyl-8methylenedecahydroazulen-1-yl) tetrahydrofuro[2,3-b] furan-2(3 H)-one, cheloviolene B (8), [3aR-[3aa,4a(lR* ,3aR* ,8aS*),5a,6aa]]-5-hydroxy-4-(1,4,4-trimethyl-8-methylenedecahydroazulent

Caldocellum saccharolyticum is an extremely thermophilic anaerobic bacterium capable of growth on cellulose and hemicellulose as sole carbon sources. Cellulase and hemicellulase genes have been found clustered together on its genome. The gene for one of the cellulases (celA) was isolated on a lambda genomic library clone, sequenced and found to comprise a large open-reading frame of 5253 base pairs that could be translated into a peptide of 1751 amino acids. To date, it is the largest cellulase gene sequenced. The translated product is a multidomain structure composed of two catalytic domains and two cellulose-binding domains linked by proline-threonine-rich regions (PT linkers). The N-terminal domain of celA encodes for an endoglucanase activity on carboxymethylcellulose, consistent with its high homology to the sequences of several other endo-1, 4-beta-D-glucanases. The carboxyterminal domain shows sequence homology with a cellulase from Clostridium thermocellum (CelS), which is known to act synergistically with a second component to hydrolyze crystalline cellulose. In the absence of a Caldocellum homologue for this second protein, we can detect no activity from this domain.

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ABSTRACT. Factors affecting the recruitment of a colonial ascidian, Pseudodistoma novaezelandiae (Brewin), were investigated in a rocky subtidal habitat at Leigh, New Zealand. The presence of coralline algal turf enhanced recruitment both in natural conditions, when standardized against adult abundance, and also in an experiment in which algal turf was removed. Removal of the large gastropod Cookia sulcata (Gmelin) and the echinoid Evechinus chloroticus (Val.) had no effect on recruitment.Recruits were aggregated on 2 spatial scales, tens of metres and -1 m; the degree of aggregation changed over the recruitment season, and varied according to the presence or absence of algal turf. Recruits occurred only in the vicinity of the highly localized populations of adult ascidians, separated by 100 m or more. Within these populahons, however, on a scale of tens of metres, numbers of recruits were not correlated with adult abundance.