Morphology and Taxonomy of Isopoda Anthuroidea (Crustacea) from Sulawesi with description of six new species

This is a first inventory of Isopoda Anthuroidea from near-shore marine sites in Sulawesi. The material was collected from reefs, sea-grass beds and mangroves of the Minahasa Peninsula in North Sulawesi. Specimens were washed out from benthos samples collected in shallow water. The new species Hyssura reptans sp. nov., Kupellonura indonesica sp. nov., Kupellonura macaroni sp. nov., Pendanthura bangkaensis sp. nov., Expanathura marcoi sp. nov., and Colanthura gerungi sp. nov. are described. We discovered that in Colanthura the mandible is fused to the cephalothorax, a unique feature among isopods. Expanathura collaris (Kensley, 1979) is described from Bangka Island and several differences between other Indo-Pacific populations are discussed.

TOXICITY OF SEA GRASS EXTRACT (Eucheuma cottonii AND Gracillaria sp) TO LARVA Artemia salina

Seaweed is a source of foreign exchange, namely as a main export product and a source of income for coastal communities. Previous research on species Eucheuma cottonii and Gracillaria sp contain bioactive compounds that can be used in medicine, for example as anti-cancer. The purpose of this study was to determine the LC50 value and safe concentration of Artemia salina larvae. The research was conducted at the Chemical Oceanography Laboratory of the Department of Marine Sciences, Faculty of Fisheries and Marine, Riau University in July 2020. The method used in this research is the experimental method. The results of the research on the toxicity of the n-hexane extract of seaweed E. cottonii and Gracillaria sp had bioactivity compounds against A. salina shrimp larvae, indicated by a small LC50 value (<1000 ppm), namely 62.62 ppm for E. cottonii and 83.55. ppm for Gracillaria sp, so it is included in the toxic category. According to research by experts, if the extract or compound tested is less than 1000 ppm, it is considered that there is biological activity. For a safe concentration for the survival of A. salina, 6.262 ppm for E. cottonii and 8.355 ppm for Gracillaria sp.

Lipid metabolism of sea urchin Paracentrotus lividus in two contrasting natural habitats

Sea urchins Paracentrotus lividus were harvested monthly from April 2015 to March 2016 from two sites in Sardinia (Italy). The two sites, a Posidonia oceanica meadow and a rocky bottom habitat, were naturally characterized by different food sources and availability, being mainly populated by the sea grass Posidonia oceanica and the brown algae Halopteris scoparia, respectively. Total lipids showed a minimum during winter in mature gonads, and a maximum in the summer (recovery stage). Fatty acid (FA) profiles of gut contents and gonads differed from those of the most available food sources. Levels of C18:3 (n-3) (ALA) discriminated samples from the two sites. Despite the very low amounts of C20:5 (n-3) (EPA) and C20:4 (n-6) (ARA) in P. oceanica, the main FA in gonads and gut contents were EPA and ARA in both sites. Increase in green algae intake prior to gametogenesis, especially C. cylindracea, likely affected EPA and ARA levels in gonads. The results show that P. lividus is able to concentrate lipids in gut contents and also to selectively store EPA, ARA and their precursors ALA and 18:2 (n-6) (LA). Moreover, bioconversion of ALA to EPA and of LA to ARA in P. lividus is suggested.

Korelasi Nitrat Fosfat Sedimen terhadap Ekosistem Lamun di Pulau Sintok dan Bengkoang, Karimunjawa, Jawa Tengah

ABSTRAK: Taman Nasional Karimunjawa merupakan daerah yang memiliki ekosistem laut yang masih lengkap dan asri. Ekosistem Lamun merupakan salah satu ekosistem laut yang memiliki banyak peranan bagi kehidupan di laut. Penelitian ini bertujuan untuk mengetahui hubungan kandungan nutrien nitrat dan fosfat pada substrat sedimen terhadap kondisi ekosistem lamun di Pulau Sintok dan Pulau Bengkoang Lamun merupakan organisme yang hidupnya sangat dipengaruhi oleh faktor-faktor lingkungan. Kandungan nutrien substrat merupakan salah satu faktor lingkungan yang mampu mempengaruhi kehidupan lamun. Nitrat dan fosfat merupakan nutrien esensial yang sangat penting untuk menunjang pertumbuhan dan perkembangan lamun. Penelitian ini bertujuan untuk mengetahui hubungan antara kandungan nutrien sedimen terhadap kerapatan lamun di Pulau Sintok dan Pulau Bengkoang, Karimunjawa. Perbedaan jumlah nitrat dan fosfat di lingkungan diduga dapat mempengaruhi kondisi lamun di Pulau Sintok dan Bengkoang. Metode pengamatan kondisi ekosistem lamun menggunakan metode seagrasswatch. Metode analisis statistika yang digunakan adalah analisis pearson-correlation. Analisis hubungan kandungan nitrat dan fosfat terhadap kerapatan lamun di Pulau Sintok didapatkan nilai korelasi pada nitrat sebesar -0,425 dan fosfat sebesar -0,422. Analisis hubungan di Pulau Bengkoang didapatkan nilai korelasi pada nitrat sebesar -0,933 dan fosfat sebesar 0,849. Dari penellitian ini dapat diambil kesimpulan bahwa nutrien nitrat dan fosfat sedimen di Pulau Sintok memiliki arah hubungan negatif dengan kekuatan hubungan yang cukup terhadap kerapatan lamun. Kandungan nitrat sedimen di Pulau Bengkoang memiliki hubungan sangat kuat negatif, sedangkan kandungan fosfat sedimen memiliki hubungan sangat kuat positif terhadap kerapatan lamun. ABSTRACT: Karimunjawa National Park is an area that has a complete and beautiful marine ecosystem. Seagrass Ecosystem is one of the marine ecosystems that has many roles for life at sea. The aim of this study was to understand correlation of the nutrient (Nitrate Phosphate) in the sediment to sea-grass ecosystem at Sintok and Bengkoang Islands. Sea-grass is an organism whose life is strongly influenced by environmental factors. The nutrient content of the substrate is one of the environmental factors that can affect the life of seagrass. Nitrate and phosphate are essential nutrients that are very important to support the growth and development of seagrass. This study aims to determine the correlation between sediment nutrient content on the density of seagrass in Sintok Island and Bengkoang Island, Karimunjawa. The difference in the amount of nitrate and phosphate in the environment is thought to affect the condition of seagrass in Sintok and Bengkoang Islands. The method of observing seagrass ecosystem condition uses seagrasswatch method. The statistical analysis method used is the Pearson-correlation analysis. Analysis of the correlation of nitrate and phosphate content to the density of seagrass on Sintok Island obtained a correlation value of nitrate of -0.425 and phosphate of -0.422. Analysis of the correlation on Bengkoang Island obtained a correlation value of nitrate of -0.933 and phosphate of 0.849. This study can be concluded that the nutrient nitrate and phosphate sediment on Sintok Island has a negative correlation with an adequate strength of correlation to seagrass density. The sediment nitrate content in Bengkoang Island has a very strong negative correlaation, while the sediment phosphate content has a very strong positive correlation to the density of seagrass.

Natural Products from Marine Fungi

Marine fungi have been studied since the first record of the species Sphaeria posidoniae (Halotthia posidoniae) on the rhizome of the sea grass Posidonia oceanica by Durieu and Montagne in 1846 [...]