Bunaken National Park has been surveyed for a fourth time in 14 years, in an attempt to establish the species composition of heterobranch sea slugs in a baseline study for monitoring programs and protection of this special park. These molluscs are potentially good indicators of the health of an ecosystem, as many are species-specific predators on a huge variety of marine benthic and sessile invertebrates from almost every taxonomic group. Additionally, they are known to contain bio-compounds of significance in the pharmaceutical industry. It is therefore of paramount importance not only to document the species composition from a zoogeographic point of view, but to assist in their protection for the future, both in terms of economics and aesthetics. These four surveys have documented more than 200 species, with an approximate 50% of each collection found only on that survey and not re-collected. Many species new to science have also been documented, highlighting the lack of knowledge in this field.

The species diversity of marine heterobranch sea slugs found on field trips around Bunaken Island (North Sulawesi, Indonesia) and adjacent islands of the Bunaken National Marine Park forms the basis of this review. In a survey performed in 2015, 80 species from 23 families were collected, including 17 new species. Only three of these have been investigated previously in studies from Indonesia. Combining species diversity with a former study from 2003 reveals in total 140 species from this locality. The diversity of bioactive compounds known and yet to be discovered from these organisms is summarized and related to the producer if known or suspected (might it be down the food chain, de novo synthesised from the slug or an associated bacterium). Additionally, the collection of microorganisms for the discovery of natural products of pharmacological interest from this hotspot of biodiversity that is presented here contains more than 50 species that have never been investigated before in regard to bioactive secondary metabolites. This highlights the great potential of the sea slugs and the associated microorganisms for the discovery of natural products of pharmacological interest from this hotspot of biodiversity.

Members of the widely distributed and common nudibranch family Phyllidiidae are often easily spotted in the marine environment because of their conspicuous colours and obvious presence on the reef. They are interesting with regard to their defensive chemical compounds that may lead to new drug discoveries. Despite their abundance, the family is also well known for its taxonomic problems and the difficulties in species identification due to very similarly coloured species and lack of morphological characters. In this study, phyllidiid species were analysed using an integrative approach. Molecular analysis of the mitochondrial genes 16S and CO1 was utilised, running phylogenetic analyses, species delimitation tests, and haplotype network analyses. Additionally, for the first time, external morphological characters were analysed, museum material was re-analysed, and chemical profiles were applied for characterising species. The analyses are based on sequences of 598 specimens collected in Indonesia by the team, with the addition of published sequences available on GenBank. This study comprises 11 species ofPhyllidia, seven species ofPhyllidiopsis, and at least 14 species ofPhyllidiella.Moreover, 11 species belonging to these three genera are probably new to science,Phyllidiopsis pipekiis synonymised withP. krempfi, andPhyllidiella albonigrais resurrected. Some of the external colouration previously used for species identification is shown to not be valid, but alternative characters are provided for most species. Chemical analyses led to species characterisation in a few examples, indicating that these species use particular sponge species as food; however, many species show a broad array of compounds and are therefore characterised more by their composition or profile than by distinct or unique compounds.

We describe a new species, Moridilla jobeli sp. nov., belonging to the marine heterobranch group Aeolidioidea. Up to now, it is only recorded from Bunaken National Park, North Sulawesi, Indonesia. A combination of histological, computer tomographic and scanning electron microscopic methods was applied in order to describe and illustrate the anatomy of Moridilla jobeli sp. nov. in detail. Furthermore, we conducted molecular analyses which include available partial COI and 16S rRNA sequences, as well as the nuclear gene Histone 3 (H3) of Facelinidae and Aeolidiidae. NeighborNet analyses, species delimitation tests and phylogenetic reconstruction methods show the distinctiveness of the new species from the type species Moridilla brockii Bergh, 1888 and the two recently described species Moridilla fifo Carmona & Wilson, 2018 and Moridilla hermanita Carmona & Wilson, 2018, as well as the monophyly of the genus. A phylogenetic analysis of the Facelinidae and Aeolidiidae does not result in a resolved tree, therefore relationship of former assumed closely related genera, Noumeaella Risbec, 1937 and Palisa Edmunds, 1964, cannot be discussed in detail.

Five Chromodoris species from North Sulawesi, Indonesia, were investigated for their sequestration of marine natural products. The cytotoxic 2-thiazolidinone macrolide latrunculin A (LatA) was the major metabolite in all examined Chromodoris species, as well as in one of the associated sponges Cacospongia mycofijiensis (Kakou, Crews & Bakus, 1987), supporting a dietary origin of LatA. Furthermore, LatA was secreted with the mucus trail, suggesting a possible use in short-range chemical communication. MALDI MS-Imaging revealed an accumulation of LatA throughout the mantle tissue, mucus glands, and especially in vacuoles of the mantle dermal formations (MDFs). Cytotoxicity of the isolated LatA was tested in HEK-293 cells, confirming that LatA targets the actin cytoskeleton. In vivo toxicity experiments with the sacoglossan Elysia viridis (Montagu, 1804) showed 100% mortality, but 100% survival of Chromodoris specimens, demonstrating resistance to LatA. A novel actin isoform was detected in all investigated Chromodoris species with two amino acid substitutions at the ‘nucleotide binding’ cleft, the binding site of LatA. These are suggested to cause insensitivity against LatA, thus enabling the storage of the toxin within the body for the slugs’ own defense.

Ultraviolet is one part of a sunbeam that which have beneficial and detrimental effects on humans. Materials that can protect the skin from exposure to ultraviolet (UV) are called sunscreens or Sun Protecting Agents. The value of the Sun Protection Factor or known as SPF is to show how many times a person's skin protection is doubled so that it is safe under the sun without experiencing dermal problems. Mangroves have long been known to have secondary metabolites including alkaloids, phenolics, steroids, and terpenoids. These compounds have pharmacological and ecological effects. in this study, we obtain extracts from Avicennia marina and Aegiceras floridum leaves followed by testing spectrophotometric to determine their anti-UV activity. The result shows that A.marina and A. floridum extracts have anti-UV activity in the area of 230-270 nm with an SPF value ranging from very high to extreme protection.Moreover both extract do not show dermatological problem on human stability test. Keywords: Mangrove, Avicennia marina, Aegiceras floridum, Extract, Anti-UV, SPF value ABSTRAK Sinar ultra violet adalah salah satu bagian dari cahaya matahari yang dapat memberikan efek yang menguntungkan dan merugikan bagi manusia. Bahan yang mampu melindungi kulit dari paparan sinar ultraviolet (UV) disebut tabir surya atau Sun Protecting Agent.Nilai Sun Protectian Factor adalah menunjukkan berapa kali perlindungan kulit seseorang dilipatgandakan sehingga aman dibawah matahari tanpa mengalami eritema. Tumbuhan mangrove mepunyai Metabolit sekunder meliputi senyawa golongan alkaloid, fenolat, steroid, dan terpenoid. Senyawa-senyawa ini memiliki efek toksik, farmakologi, dan ekologi penting.tujuan dari penelitian ini untuk mendapatkan ekstrak dari daun mangrove jenis Avicenia marina dan Aegiceras floridum yang kemudian uji menggunakan metode spektrofotometri untuk mengetahui kelayakan penggunaan sampel sebagai bahan dasar pembuatan tabir surya. Hasil yang didapatkan ekstrak daun mangrove jenis A. marina dan A. floridum memiliki aktivitas Anti-UV pada kisaran panjang gelombang maksimum λ 230-270 nm dan dikategorikan memiliki nilai SPF sangat tinggi dan ekstrim. Selanjutnya kedua ekstrak tidak memperlihatkan adanya masalah dermatologis saat diaplikasikan pada obyek coba manusia saat dilakukan uji stabilitas. Kata kunci : Mangrove, Avicennia marina, Aegiceras floridum,Ekstrak, Anti UV, Nilai SPF