Population dynamics of horse mussels Modiolus modulaides (Röding, 1798) in Kendari Bay, Southeast Sulawesi, Indonesia

Horse mussels are bivalves found in Kendari Bay and are frequently consumed by the people in the surrounding coastal communities. The population dynamic of this mussel species in Kendari Bay is not yet fully understood. This study aims to determine the size structure, growth, mortality, and exploitation rate of horse mussels in Kendari Bay. This research was carried out in Kendari Bay on the outskirts of Southeast Sulawesi, Indonesia, from January to December 2019. Horse mussel samples of all different sizes were randomly collected from different points of the area of the mussel habitat. The collected samples were counted in total, and their shell length was measured using a caliper with an accuracy of 0.05 mm. The size, growth, mortality, and exploitation rate data were analyzed using the Bhattacharya method, inverse von Bertalanffy, Pauly empirical, and length-converted catch curve accommodated in the FiSAT II. The results showed that the horse mussels comprised two dominant size groups, with one dominating most of the months. The asymptotic length (L?) of the mussels was 9.7 cm, with a growth coefficient (K) of 1.1 yr-1. Moreover, the growth performance index of the mussels was (Ø)'=2.01 yr-1, and the maximum age (Tmax) was 2.73 years. The generated inverse von Bertalanffy equation for the horse mussels was Lt = 9.7-(9.7-0.025)e-1.1t. The natural mortality (M), fishing mortality (F), and total mortality (Z) of the horse mussels were 2.73 yr-1, 1.17 yr-1, and 3.90 yr-1, respectively. The horse mussels in Kendari Bay were well within the underexploited category, with an exploitation rate of 0.30

Identifikasi Keanekaragaman Bivalvia Hasil Tangkapan Nelayan di Desa Pematang Cengal, Tanjung Pura, Sumatera Utara

Desa Pematang Cengal mempunyai sebagian besar wilayah pesisir dengan keanekaragaman bivalvia yang dimanfaatkan sebagai makanan. Akan tetapi belum ada catatan tentang keanekaragaman bivalvia di Desa Pematang Cengal. Penelitian ini dilakukan pada Mei-Juni 2023 yang bertujuan untuk menganalisis keanekaragaman bivalvia dari hasil tangkapan nelayan di Desa Pematang Cengal, Tanjung Pura, Sumatera Utara. Metode pengambilan sampel dilakukan secara observasi dan survei langsung pada 3 stasiun berbeda, yaitu stasiun I Alur Kapal, stasiun II Pangkalan Garip, dan stasiun III Paluh Nipah. Data juga diperoleh melalui wawancara dengan nelayan terkait spesies bivalvia yang ditemukan serta alat tangkap yang digunakan. Hasil penelitian menunjukkan bahwa terdapat 10 spesies bivalvia dari 5 famili yang ditemuka pada ketiga stasiun. Spesies yang ditemukan yaitu, Atrina pectinata, Anadara antiquata, Meretrix meretrix, Modiolus modulaides, Perna viridis, Anadara granosa, Barbatia foliate, Tellina timotensis, Pinctada albina, dan Pitar tumens. Spesies yang dominan adalah Meretrix meretrix dari famili Veneridae. Indeks keanekaragaman (H') di tiga stasiun tersebut berkisar antara 0-1.19. Indeks keanekaragaman tertinggi terdapat pada stasiun I sebesar 1.19, kedua terdapat pada stasiun III sebesar 0,97, dan indeks keanekaragaman terendah terdapat pada stasiun II sebesar 0

Development of a model for predicting mussel weight: a comparison of traditional and artificial intelligent methods

The relationship between length and weight is non-linear. Predictive modelling using linear regression methods subjects these variables to transformation which results in models of poor predictive value. Hence, a comparative study on developing a predictive model using traditional (length-weight relationship, LWR; multiple linear regression, MLR) and artificial intelligent (artificial neural networks, ANN) methods was conducted. Specimens (n = 320) of the horse mussel Modiolus modulaides were randomly collected from October 2018 to March 2019 at the coastal area of Dumangas, Iloilo, Philippines. Shell length, shell width and shell height were used as predictor variables for total weight. A multi-layer perceptron architecture model was used and the values were determined by the ANNs model using the actual data. In addition, LWR and MLR models were generated from the same data after log-transformation. The results indicated superiority of the ANN model to predict mussel weight to traditional LWR and MLR models. The ANNs model had the highest correlation coefficient and lowest errors among the predictive models. The ANNs model generated from this study can be a good alternative to existing models and may be useful in sustainable fisheries management

Pertumbuhan, Mortalitas Dan Tingkat Pemanfaatan Kerang Pokea (Batissa Violacea Var. Celebensis Von Martens, 1897) Di Sungai Laeya Konawe Selatan Provinsi Sulawesi Tenggara

Kerang pokea merupakan salah satu sumberdaya potensial dan mempunyai peranan penting baik secara ekologis maupun ekonomis. Salah satu wilayah yang cocok untuk kehidupan kerang ini adalah Sungai Laeya. Penelitian ini bertujuan untuk mengetahui pertumbuhan, mortalitas dan tingkat pemanfaatan kerang pokea di Sungai Laeya Konawe Selatan yang dimulai pada bulan September 2016 – Februari 2017. Metode penelitian yang digunakan adalah luas sapuan (swept area method) dengan memakai alat tangkap tangge. Data pertumbuhan, mortalitas dan tingkat eksploitasi masing-masing menggunakan metode Bhattacharya, model inverse von Bertalanffy, hasil tangkapan yang dikonversi dari data lebar cangkang dan empiris Pauly yang terakomodasi dalam program FiSAT II versi 3.0. Total sampel kerang pokea selama penelitian sebesar 849 individu. Hasil analisis pertumbuhan menunjukan nilai lebar asimtotik (L∞), konstanta pertumbuhan (K), nilai dugaan t0 pada pertumbuhan kerang pokea masing-masing 7,41, 0,56, dan -0,38. Hasil analisis pendugaan tingkat mortalitas menunjukkan nilai mortalitas alami (M) 1,84, mortalitas penangkapan (F) 1,19, dan mortalitas total (Z) 3,03. Tingkat eksploitasi (E) yaitu 0,39 yang menunjukkan tingkat eksploitasi kerang pokea di perairan Sungai Laeya masih tergolong rendah (under fishing)

LAJU EKSPLOITASI KERANG REMIS (Corbicula sp.) DI PERAIRAN SUNGAI KONAWEHA KECAMATAN UNAAHA KABUPATEN KONAWE SULAWESI TENGGARA

Kerang remis merupakan organisme air tawar yang memiliki nilai ekonomis & keberadannya banyak dimanfaatkan oleh masyarakat Sungai Konaweha. Penelitian ini bertujuan untuk mengetahui laju eksploitasi kerang remis (Corbicula sp.). Penelitian ini dilaksanakan tiga bulan yaitu dari bulan Agustus-Oktober 2021. Lokasi penelitian bertempat di Perairan Sungai Konaweha Kecamatan Unaaha Kabupaten Konawe Sulawesi Tenggara. Data dianalisis menggunakan FiSAT II versi 3.0. Hasil penelitian menunjukkan kelompok ukuran berdasarkan frekuensi panjang didominasi ukuran 25-27,7 mm. Parameter pertumbuhan diperoleh panjang asimtotik kerang remis (L) yaitu 40,95 mm. Koefisien laju pertumbuhan (K) 0,82, nilai t0 yaitu -0,12, ’ yaitu 7,23, sedangkan nilai tmaks yaitu 3,66. mortalitas alami (M) kerang remis sebesar 1,51/tahun dan mortalitas penangkapan (F) sebesar 1,40/tahun sehingga mortalitas totalnya bernilai 2,9/tahun, sedangkan tingkat eksploitasi sebesar 0,48/tahun. Hal ini menunjukkan bahwa tingkat eksploitasi di perairan Sungai Konaweha kategori rendah (under exploited).Kerang remis merupakan organisme air tawar yang memiliki nilai ekonomis & keberadannya banyak dimanfaatkan oleh masyarakat Sungai Konaweha. Penelitian ini bertujuan untuk mengetahui laju eksploitasi kerang remis (Corbicula sp.). Penelitian ini dilaksanakan tiga bulan yaitu dari bulan Agustus-Oktober 2021. Lokasi penelitian bertempat di Perairan Sungai Konaweha Kecamatan Unaaha Kabupaten Konawe Sulawesi Tenggara. Data dianalisis menggunakan FiSAT II versi 3.0. Hasil penelitian menunjukkan kelompok ukuran berdasarkan frekuensi panjang didominasi ukuran 25-27,7 mm. Parameter pertumbuhan diperoleh panjang asimtotik kerang remis (L?) yaitu 40,95 mm. Koefisien laju pertumbuhan (K) 0,82, nilai t0 yaitu -0,12, ?’ yaitu 7,23, sedangkan nilai tmaks yaitu 3,66. mortalitas alami (M) kerang remis sebesar 1,51/tahun dan mortalitas penangkapan (F) sebesar 1,40/tahun sehingga mortalitas totalnya bernilai 2,9/tahun, sedangkan tingkat eksploitasi sebesar 0,48/tahun. Hal ini menunjukkan bahwa tingkat eksploitasi di perairan Sungai Konaweha kategori rendah (under exploited)

A review of the zooplankton in Singapore waters

24 pages, 1 figure, 2 tablesThe island of Singapore is located between 1°09'N¿1°29'N and 103°38'E¿104°06'E at the confluence of the Malacca Straits and the South China Sea. To date, both the marine and freshwater zooplanktons of this area are poorly studied, and availability of taxonomic identification is scarce. Moreover, most of the studies were published between the 1950s to the beginning of the 1970s. The available data are mainly qualitative, with only a few studies on zooplankton biology and ecology. Here, the literature on zooplankton communities in Singapore waters is reviewed in order to provide a baseline for future zooplankton surveys, and to better understand the aquatic ecosystems of this area. Also included are recent data obtained from a one-year plankton monitoring in 2012 from two marine stations in Singapore. The temporal variation of the plankton groups was observed in the study to be similar to what was described in some works from the 1970s. The species richness increased in these more recent studies, probably due to changes in the sampling and preservation methods. Because of these changes, comparing between data-sets is challenging; however, similarities in species richness and seasonality between a recent study and previous data-sets were evident. Finally, it is argued that continuous marine plankton monitoring would be an asset for Singapore and the regionThe authors would like to thanks the National Parks of Singapore, the DHI-NTU Research Centre for the financial support of project MadeInPlankton, where the present study is framed. The work was also supported by Elite Forsk grants nb 10-093759 and 10-094773 from the Danish Agency for Science Technology and Innovation to GD, and by project PROTOS (CTM2009-08783) from the Spanish Ministry of Science and Innovation to ACPeer Reviewe

Length weight relationship and size distribution long shells bakalang (Marcia hiantina Lamarck) in the coastal waters of Labakkang, Pangkep Regency

Seagrass ecosystems in the coastal Labakkang Pangkep regency is the habitat of various types of shellfish which is the target of local fishermen catch. One of the many species of shellfish found in this coastal area is the mussel shell (Marcia hiantina L.). This study aims to determine the relationship between the length and weight of the long shell size of mussel shells (Marcia hiantina L.) in the coastal waters catchment of Labakkang. This research was conducted in catching area at three locations in coastal waters of Labakkang based on density of seagrass and population with sampling every month from August 2014 until July 2015 by using descriptive method that is random sampling by measuring the length of shell and weight of each shellfish. The results showed that the constant value (b) of mussel shell (Marcia hiantina L.) in all observation stations ranged from 2,44 to 2,63, meaning growth pattern including negative allometrik means shell length growth faster than body weight with coefficient of determination (R2) ranging from 0,88 to 0,91 means to have a high enough. The distribution of the size of the mussel (Marcia hiantina L.) is found on the smallest C  size station with the range 1,50 – 1,88 cm and the middle value of 1,69 cm and the largest with a range of 5,34 - 5,72 cm and the middle value of 5.53 cm.Keywords: Bakalang shell, Length weight, Coastal waters of Labakkang, Allometric negativ

Pola Pertumbuhan dan Identifikasi Genetik Turbo setosus Gmelin, 1791 [Turbinidae, Gastropoda]

Morphological dan genetic identification is an essential part of biology and ecological study. Environmental degradation, physical and chemical facto in water, and utilization of gastropod by society will give impact in distribution pattern, population size, morphology and genetic characteristic of the snail. This research aims to analyze the growth pattern and molecular aspect of Turbo setosus. The variable that examined is total weight and length, and cytochrome oxidase subunit one gene sequence. The growth factor of T. setosus is negative allometric, which means weight growth is slower than the length growth. The total length of cytochrome oxidase subunit 1 of these samples were 650 base pairs. Based on the DNA barcoding analysis, the sequence is 96.92% identic with the sequence of T. setosus in GenBank. The phylogenetic tree was reconstructed with neighbour-joining methods and 1000 replication bootstrap, show the clade grouping based on the similarity and genetic distance of the species. The sequence data is vital for species identification fast and accurately.    Identifikasi morfologi dan genetik menjadi bagian penting dari setiap studi biologi maupun ekologi, degradasi lingkungan, faktor fisik-kimia lingkungan dan pemanfaatan gastropoda secara terus menerus akan mempengaruhi penyebaran, penurunan populasi, karakteristik morfologi dan juga karakter molekuler spesies. Penelitian ini bertujuan untuk menganalisis pola pertumbuhan dan karakter molekuler Turbo setosus. Variabel yang diukur adalah berat total dan panjang total serta identifikasi molekuler dengan menggunakan gen sitokrom oksidase I. Pola pertumbuhan T. setosus adalah allometrik negatif yang berarti pertambahan berat lebih lambat dari pertambahan panjang. Hasil identifikasi dengan DNA barcoding diperoleh spesies T. setosus dengan panjang sekuen DNA 650 bp. Rekonstruksi filogenetik dengan metode Neighbor-Joining boostrap 1000x memperlihatkan pengelompokan sekuen berdasarkan kimiripan dan jarak genetik antar spesies. penting dalam identifikasi spesies secara cepat, tepat dan akurat

Macro Flora & Fauna of the Gulf of Mannar a checklist

The Gulf of Mannar (GoM) located along the south eastern tip of India falls in the Indo-Pacific realm and is one of the richest regions in the world from a marine biodiversity perspective. The region has a distinctive socio-economic and cultural profile shaped by its geography. It has an ancient maritime history and was famous for the production of pearls, an important item in trade with the Roman Empire as early as the first century AD. Rameshwaram along the GoM with its links to the legend Ramayana is an important pilgrim centre. The region has been and continues to be famous for its production of Indian sacred chanks. It has unique ecosystems mainly consisting of coral reefs, sea grass beds, salt marshes and mangroves which constitute important habitats for many species of commercially important finfishes and shellfishes. The GoM was established as a Biosphere Reserve (the first marine biosphere reserve in south and south east Asia) by 1989 by the Indian Government and the state of Tamil Nadu. A biosphere reserve is an area that is indented to secure the fundamental diversity of life in a region while continuing to advocate in economic growth. The overall objective of this Marine Biosphere Reserve is to conserve the Gulf of Mannar's globally significant assemblage of coastal and marine biodiversity and to integrate biodiversity conservation into coastal zone management plans. Thus, the GoM in addition to being a national priority also assumes global significance