Judul: Identification of Sponge Species Based on Morphology and Genetics in Raja Ampat, West Papua
Abstrak: Invertebrata laut termasuk kelompok hewan tidak bertulang belakang yang berperan dalam menjaga kestabilan ekosistem laut. Banyak spesies invertebrata laut yang belum teridentifikasi, salah satunya biota spons. Keberadaan spons tidak banyak diapresiasi, dipelajari dan diteliti dengan baik dibandingkan dengan biota laut lainnya. Beberapa penelitian terkait spons paling banyak dilakukan di wilayah Jawa dan Sulawesi. Penelitian terkait genetik dan tipe spikula tidak banyak dilakukan di Perairan Indonesia. Kesulitan identifikasi morfologi dan taksonomi menjadi salah satu faktor minimnya informasi terkait data spons. Tujuan penelitian ini yaitu mengetahui jenis-jenis spons yang ada di perairan Raja Ampat berdasarkan tipe spikula dan genetik. Identifikasi spesies berdasarkan genetik dilakukan dengan BLAST (Basic Local Alignment Search Tool) pada Genbank di NCBI (National Centre For Biotechnology Information) menggunakan data sekuen yang diperoleh dari sampel setelah melalui tahapan ekstraksi, PCR, elektroforesis, dan sekuensing. Rekonstruksi pohon filogeni dibuat menggunakan model Kimura 2-parameter dengan metode Neighbour Joining dan Maximum Parsimony. Identifikasi bentuk spikula spons dilakukan dengan pengamatan preparat menggunakan mikroskop majemuk. Berdasarkan analisis laboratorium dari 22 sampel ditemukan 5 sampel terdeteksi sebagai spesies spons Halichondria sp., Stylissa carteri, Xestospongia deweerdtae, dan Theonella sp. Rekonstruksi pohon filogeni menghasilkan empat clade besar. Bentuk tipe spikula yang teramati terdiri dari spikula monoaxon dan tetraxon., Marine invertebrates are a group of invertebrate animals that play a role in maintaining the stability of marine ecosystems. Many marine invertebrate species have not been identified, one of which is the sponge. The existence of sponges is not much appreciated, studied and well researched compared to other marine biota. Most research related to sponges has been carried out in Java and Sulawesi. Research related to genetics and spicule types is not much carried out in Indonesian. The difficulty of identifying morphology and taxonomy is one of the reasons for the lack of information related to sponge data. The purpose of this study was to determine the types of sponges in Raja Ampat based on the type of spicules and genetics. Genetic identification of species was carried out using BLAST (Basic Local Alignment Search Tool) on Genbank at NCBI (National Center For Biotechnology Information) using sequence data obtained from samples after going through the stages of extraction, PCR, electrophoresis and sequencing. Phylogenetic tree reconstruction was made using the Kimura-2 parameter model with the Neighbor Joining and Maximum Parsimony methods. Identification of the shape of sponge spicules was carried out by observing the preparations using a compound microscope. Based on laboratory analysis of 22 samples, it was found that 5 samples were detected as Halichondria sp., Stylissa carteri, Xestospongia deweerdtae, and Theonella sp. Phylogenetic tree reconstruction resulted in four large clades. The types of spicules observed consisted of monoaxon and tetraxon spicules.
Keyword: DNA barcoding, genetic, spicule, sponge

Judul: Sponge Biodiversity Study Using DNA Metabarcoding in Dampier Strait, Raja Ampat Island, West Papua
Abstrak: Kepulauan Raja Ampat memiliki kawasan konservasi, salah satunya adalah Selat Dampier. Spons merupakan invertebrata laut dari filum Porifera dengan rongga dan struktur tubuhnya sederhana, serta memiliki kemampuan filter feeder. Tujuan dari penelitian ini adalah mengidentifikasi spons menggunakan DNA Metabarcoding di Selat Dampier. Metode DNA Metabarcoding adalah pendekatan molekuler yang berasal dari satu gabungan sampel melalui proses ekstraksi seluruh DNA dari sampel tertentu sehingga didapatkan taksonomi spesies. Metode yang dilakukan adalah pengambilan sampel, ekstraksi DNA, amplifikasi DNA, sekuensing DNA, identifikasi spesies, analisis sekuens, serta rekonstruksi pohon filogenetik. Terdapat 13 spesies spons yang berhasil diidentifikasi berdasarkan similarity dan query cover. Komposisi genus tertinggi adalah Callyspongia dan Pseudoceratina. Spons memiliki kandungan bioaktif yang digunakan sebagai antibakteri, antimikrobial, antikanker, antiparasit, serta antibiotik. Rekonstruksi pohon filogenetik untuk melihat tingkat kekerabatan spesies spons dengan model Kimura 2-parameter, serta pendekatan Neighbor Joining dan Maximum Likelihood, The Raja Ampat Islands have conservation areas, one of which is the Dampier Strait. Sponges are marine invertebrates from the phylum Porifera with simple body cavities and structures, and have filter feeder capabilities. The aim of this study is to identify sponsors using DNA Metabarcoding in the Dampier Strait. The DNA Metabarcoding method is a molecular approach that originates from a combined sample through the process of extracting all of the DNA from a particular sample in order to obtain a species taxonomy. The methods used were sampling, DNA extraction, DNA amplification, DNA sequencing, species identification, sequence analysis, and phylogenetic tree reconstruction. There are 13 species of sponges that have been identified based on similarity and query cover. The highest genus composition being Callyspongia and Pseudoceratina. Sponges contain bioactive compounds that are used as antibacterial, antimicrobial, anticancer, antiparasitic, and antibiotics. Reconstruction of phylogenetic trees to see the degree of kinship of sponge species with Kimura 2-parameter model, as well as the Neighbor Joining and Maximum Likelihood approaches.
Keyword: Dampier strait, DNA Metabarcoding, Phylogenetics, Sponge

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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