Bachtiar I, Hadi TA. 2019. Differential impacts of 2016 coral bleaching on coral reef benthic communities at Sekotong Bay, Lombok Barat, Indonesia. Biodiversitas 20: 570-575. Coral bleaching has been a major causal factor of coral mortality worldwide in the last two decades and it is therefore threaten food security. Understanding post-bleaching recovery is therefore very crucial to formulate strategy in promoting natural coral reef recovery. The present study documented coral reef communities both in pre- and post-bleaching event in early 2016. The results show that coral bleaching variably reduced coral and soft-coral covers. Sponge and other fauna cover considerably fluctuated. Since the individual number of soft-coral, sponge and other fauna were small, there is likely no big impact of coral bleaching. Among 12 study sites, 11 sites showed significant reduction of coral cover but one site showed only little fluctuation. Overall mean reduction of coral cover was about 18%. Consequently, algal cover increased by about 24%. The present study revealed differential coral bleaching impact between outer- and inner- reefs. At outer reefs, coral community suffered more severe mass coral mortality than those at inner reefs. This disparity is likely owing to initial coral cover and species composition of the coral communities. In the second year, there is still no visible coral recruitment from larvae. Cascade effects of land-clearing and overfishing due to increasing tourism development is very likely to be additional major stress that pause post-bleaching coral reef recovery at Sekotong Bay, Lombok Island, Indonesia.

Hadi TA, Hafizt M, Hadiyanto, Budiyanto A, Siringoringo RM. 2018. Shallow water sponges along the south coast of Java, Indonesia. Biodiversitas 19: 535-543. Sponges are the most diverse benthic filter feeders, occupying many different types of marine habitat. The south coast of Java is one such marine habitat, very exposed to the open sea. This study investigated the sponge diversity as well as their morphological characters across the south coast of Java. The observations were carried out from 2011 to 2016 in four different locations, including Pamang Peuk, Gunungkidul, Prigi Bay and Bayuwangi. The study found 96 sponge species, from 15 orders, and described them in terms of nine morphological characters. The most common species included Spheciospongia inconstans, Stylissa massa, Callyspongia sp. and Cinachyrella australiensis, while the most common growth forms were massive and encrusting, accounting respectively for 34.4% and 28.1% of the total number of species. There was a significant difference in the number of species found between sub-tidal and intertidal habitats; subtidal sponges were approximately 50% more diverse than intertidal sponges. Apart from the habitat types, the number of sponges varied in relation to the longitude; east Java had more sponge species with more variations in morphology compared to central and west Java. Encrusting and globular growth forms were the most common characteristics of intertidal sponges in west and central Java, while other growth forms comprised the diverse characteristics of the subtidal sponges in the east Java. This baseline information is essential for management of marine biodiversity hotspots in taking decisions for marine life conservation, because the global trajectory of marine habitat degradation is predicted to rise.

A new 3-alkylpiperidine compound (–)-acanthocyclamine A (1) has been obtained from the methanolic extract of Acanthostrongylophora ingens (order Haplosclerida, family Petrosiidae) collected from Wakatobi Marine National Park in South East Sulawesi, Indonesia. The structure of 1 was investigated by extensive 1D- and 2D-NMR experiments. The absolute configuration of 1 was established by X-ray crystallography from anomalous dispersion effects using Cu radiation as C2 (R), C3 (R), C7 (R), and C9 (R). A plausible biosynthetic scheme leading to 1 is presented, and compared with the biosynthetic pathway proposed for the manzamine alkaloids.

There has been emerging evidence that the bacteria associated with marine sponges are the key producers of many complex bioactive compounds. The as-yet uncultured candidate bacterial genus “Candidatus Entotheonella” of the marine sponge Theonella swinhoei from Japan have recently been recognized as the source of numerous pharmacologically relevant polyketides and modified peptides, as previously reported by the Piel group (Wilson et al. 2014). This work reported the presence of “Candidatus Entotheonella sp.” in the highly complex microbiome of an Indonesian marine sponge from Kapoposang Island, South Sulawesi. We further identified the Kapoposang sponge specimen used in this work as Rhabdastrella sp. based on the integrated morphological, histological, and cytochrome oxidase subunit I (COI) gene analyses. To detect the polyketide biosynthetic machinery called type I polyketide synthase (PKS) in this Indonesian Rhabdastrella sp., we amplified and cloned the ketosynthase-encoding DNA regions of approximately 700 bp from the uncultured sponge's microbiome. Further sequencing and analysis of several randomly chosen clones indicated that all of them are mostly likely involved in the biosynthesis of methyl-branched fatty acids. However, employing a PKS-targeting primer designed in this work led to the isolation of four positive clones. BlastX search and subsequent phylogenetic analysis showed that one of the positive clones, designed as RGK32, displayed high homology with ketosynthase domains of many type I PKS systems and may belong to the subclass cis-AT PKS group