Abstract. Triandiza T, Zamani NP, Madduppa H, Hernawan UE. 2019. Distribution and abundance of the giant clams (Cardiidae: Bivalvia) on Kei Islands, Maluku, Indonesia. Biodiversitas 20: 884-892. Giant clams, ecologically important bivalves in coral reefs, are under anthropogenic pressures in most parts of their range, necessitating the study of population status for conservation management. Here, we assessed species composition, distribution, size density, and habitat condition of giant clams in Kei Islands. A total of 9 reefs around the islands (Dar 1, Dar 2, Pulau Kur, Pulau Tanimbar Kei, Pulau Adranan, Pulau Dullah Laut, Difur, Labetawi, dan Ohoidertoom), were surveyed using quadrat-transect line in September-December 2017. We found five species of giant clams, i.e., Tridacna crocea, T. maxima, T. squamosa, T. noae, and Hippopus hippopus. Of these species, we report a new record for T. noae which was previously not known to be present in the region. The overall density was recorded at 0.0428 individual/m2. Juveniles clams were fewer than the adults clam, this may indicate that the survival rate of recruit is low. Most individuals were found living on dead coral algae substrate (75 %). Based on the findings, this study suggests that giant clam population in Kei Islands are imperiled, indicated by low population density and local extinction for species T. gigas and T. derasa. It is recommended to establish a protected area and restocking of giant clams by through implementing sasi laut (traditional law) with a minimum period of 5 years.

Inventory of mollusk species and its potential on sea grass bed in Kei Kecil islands, Southeast Moluccas have been conducted by using quadrate-transect line method. The study was carried out in February-August 2007. There were 103 species of mollusk observed, 80 species belong to gastropods and 23 belong to bivalves. From the total species, 72 of them were reported as the potential species and the others still unknown. Most of potential group was used as food resources (55 species) and other species were potential as decoration, souvenir, ornament, and accessories (31 species). Some species were potential for building material, knife tool, barter tool and bioactive compounds. The top shells (Trochus niloticus), the giant clams (Tridacna spp. and Hippopus hippopus) and the abalone (Haliotis spp.) were the major trading commodities for shellfish fisheries.

Abstract. Kusnadi A, Kurnianto D, Madduppa H, Zamani NP, Ibrahim PS, HernawanU E, Utami RT, Triandiza T. 2022. Genetic diversity and population structure of the boring giant clam (Tridacna crocea) in Kei Islands, Maluku, Indonesia. Biodiversitas 23: 1273-1282. Giant clams (Tridacninae) are ecologically important species in the coral reef ecosystems. They provide valuable functionsto traditional fisheries in Kei Islands, Maluku. However, their population isunder great pressure due to anthropogenic threats, such as overfishing and habitat degradation. To provide important data for devising effective conservation management strategies for giant clams, we investigated genetic diversity and population structure of the boring giant clams Tridacna croceain Kei Islands based on partial mitochondrial COI gene sequence. Tissue samples were collected from six sites: Kur, Dullah Laut, Tanimbar Kei, Dar, Labetawi, and Difur. We sequenced 477 base pairs of COI gene and identified 42 haplotypes and 52 polymorphic sites. Analysis of genetic diversity showed Dullah Laut and Dar had the highest genetic diversity. Population structure and genetic distance analysis showed unstructured populations with high genetic closeness among sites. This finding was also confirmed by the mixture pattern of the haplotype network. Further analysis using Bayesian models on gene flow revealed high genetic exchange among sites and that Dullah Population predominantly served as a source site for the other sites. This indicated a high probability of successful larval dispersal among sites. Based on these findings, we predict that the boring giant clams likely form a single population in Kei Islands. Our study warrants conservation priority for Dullah population as the main source of gene flow.

The phenomenon of marine cryptic species is frequently found in altered ecosystem such as dead corals habitat. Dead corals as habitat can be used by marine fauna like crustacean from family of porcellanidae. This study was aimed to identify and clarify the species of porcelain crab from Tundai sland, Banten province by applying the morphological analysis and DNA barcoding technique. The result of morphological analysis showed that decapod samples were crabs of the genus Pisidia, family of Porcellanidae with specific morphological characteristics were the ratio of carapace size is longer than tbroad, have long antennae which can be moved, serrated anterior rostrum, chelae rather flattish and unequal size of arms. While based on molecular barcode analysis by using COI, samples were identified as Anomura sp. with 94% of similarities. The difference of the result was suspected due to the lack of suitable genetic data on genbank.

Penelitian kandungan logam berat Pb, Cd, Cu, Zn, Ni dan Senyawa Polisiklik Aromatik Hidrokarbon (PAH) dalam sedimen telah dilakukan di perairan Teluk Jakarta pada bulan Mei 2016. Tujuan penelitian ini adalah untuk mengetahui tingkat pencemaran logam berat Pb, Cd, Cu, Zn, Ni dan PAH dalam kaitnnya dengan perlindungan biota laut. Lokasi penelitian berada di Perairan Ancol/Marunda, Muara Gembong dan Pulau Pari. Contoh sedimen di analisis dengan menggunakan Spektofotometer Penyerapan Atom (AAS) dan Gas Chromatografi. Hasilnya menunjukkan berdasarkan nilai faktor kontaminasi (CF), indek geoakumulasi (I_geo) dan indek beban pencemaran (PLI), sedimen di Perairan Teluk Jakarta ini termasuk kategori terkontaminasi rendah dan kategori tidak tercemar oleh logam berat Pb, Cd, Cu, Zn dan Ni, sedang kandungan total PAH juga masih rendah dibandingkan dengan baku mutu sedimen.