Abstrak : Variasi bentuk dan pola pewarnaan tubuh ikan kerapu (Famili Serranidae) sangat variatif, sehingga pengenalan spesies secara morfologis sering tidak akurat. Penelitian ini bertujuan untuk mengautentikasi ikan kerapu dengan menggunakan marka gen COI. Contoh ikan kerapu yang diamati berjumlah 29 ekor yang dikumpulkan dari tiga tempat pendaratan ikan di Perairan Peukan Bada, Propinsi Aceh. Secara karakter morfologis, ikan kerapu tersebut teridentifikasi lebih dari 8 spesies. Untuk analisis DNA, sebanyak 30 mg daging sirip dari setiap ikan contoh diambil untuk dilakukan isolasi dan ekstraksi DNA, kemudian visualisasi elektroforesis dan fragmentasi DNA gen COI dengan metode PCR-sekuensing. Setelah diekstraksi, diperoleh 20 sampel DNA yang tervisualisasi dengan baik, yang dari jumlah tersebut terdapat 16 sampel dapat diamplifikasi. Hasilnya menunjukkan terdapat 6 spesies yang terautentikasi. Kelompok pertama adalah Variola albimarginata, Cephalopholis urodeta, dan C. sexmaculata dengan tingkat kemiripan ≥ 97%. Berikutnya C. boenak, Epinephelus merra, dan Scolopsis vosmeri tingkat kemiripannya ≤ 97%. Bila dibandingkan hasil autentikasi DNA, hasil penelitian menunjukkan bahwa 13 sampel atau > 80% tidak teridentifikasi dengan benar secara morfologis. Berdasarkan jarak genetik, pohon filogeni membentuk 2 clade antara Serranidae dan Nemipteridae. Hasil penelitian menunjukkan bahwa penggunaan marka gen COI sangat efektif untuk autentikasi spesies yang dapat dijadikan sebagai instrumen dalam pemanfaatan dan pengelolaan ikan kerapu.Kata kunci : kerapu, variasi morfologi, gen MT-COI, autentikasi.Abstract : The groupers (family Serranidae) show high variability both in body shapes and coloration leads to highly morphological-based misidentification. The research was aimed in autenthication of the grouper species using MT-COI gene. A total of 29 grouper fishes were collected from three fish landing sites of Peukan Bada, Aceh Province. These fishes were morphologically identified from which more than 8 species were obtained. A 30 mg of the fin meat of each sample was taken for DNA extraction, isolation, electrophoresis visualization, and DNA fragmentation of COI gene using PCR-sequenching.  There were 20 DNA samples was clearly visualized of which 16 has been proceeded for amplification. The results showed that V. albimarginata, C. urodeta, and C. sexmaculata showed ≥ 97% similarity, whereas C. boenak, E. merra, dan S. vosmeri with ≤ 97% similarity. Based on phylogenetic tree analysis there was 2 clearly different clades separating family of Serranidae and Nemipteridae. The use of MT-COI gene was effective and accurate tool in species authentication which could be used as an instrument for utilization and management of the grouper species.Keywords : groupers, morphological variation, MT-COI gene, autenthication.

BackgroundThree specimens of Puerulus mesodontus Chan, Ma & Chu, 2013 (Crustacea, Decapoda, Achelata, Palinuridae) were collected from Palabuhanratu Bay, southern Java, Indonesia. There is no previous record on the presence of the species in Indonesia. This finding represents the first record of this species in Java, Indonesia, and confirms that the species is present in the Indian Ocean. The morphological characters of the species are described.New informationThis paper contains a new distribution record of a lobster species from Indonesian waters.

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Dinamika populasi merupakan aspek penting sebagai dasar pengelolaan perikanan dan informasi tentang aspek tersebut pada lobster pasir masih minim di perairan Palabuhanratu. Tujuan penelitian ini adalah mengkaji aspek pertumbuhan, pola rekrutmen, mortalitas dan laju eksploitasi lobster pasir (Panulirus homarus) di perairan Palabuhanratu. Penelitian ini dilakukan periode Juni 2015-Mei 2016 dengan metode sensus. Lobster pasir hasil tangkapan jaring insang dasar dengan jumlah total sampel 483 ekor mempunyai panjang karapas antara 28-100 mm. Pola pertumbuhan berdasarkan hasil regresi linear memperlihatkan allometrik negatif. Hasil analisis menggunakan metode ELEFAN I (Electronic Length Frequency Analysis) menunjukan koefisien pertumbuhan lobster pasir jantan (K = 0,29 per tahun), lebih kecil dibandingkan dengan betina (K = 0,40 per tahun). Rekrutmen terindikasi dua puncak dalam setahun: yaitu pada Februari-Mei dan September-Oktober). Laju mortalitaskarena penangkapan (F) mencapai 1,9-2,2 kali laju mortalitas alami (M). Nilai Lc<Lrmemperlihatkan lobster pasir sudah tertangkap sebelum mencapaiukuran rata-rata mengerami telur atau ukuran kematangan reproduktif. Laju eksploitasi lobster pasir mencapai 32-38% di atas laju eksploitasi optimum, sehingga lobster pasir sudah mengalamieksploitasi yang berlebih.Population dynamics is an important aspect as basic of fisheries management and little information of this aspect for spiny lobster fishery in Pelabuhanratu waters. This research aims to evaluate of growth aspects, recruitment pattern, mortality, and exploitation rate of scalloped spiny lobster (Panulirus homarus) in Palabuhanratu waters. This research was conducted in June 2015 until May 2016 using census method. The size of P. homarus captured using bottom gill-net with total sample 483 specimen was between 28-100 mm carapace lengths (CL). Linear regression showed that growth pattern was negative allometric. The growth coefficient of male (K = 0.29 per year) was found smaller than female (K = 0.40 per year) based on ELEFAN I (Electronic Length Frequency Analysis) method. Recruitment seems to be accrued twice peaks a year (February to May and September to October) and the highest was at February to May. Fishing mortality (F) reached 1.9 to 2.2 times of natural mortality (M). The LcÂLr value showed that female has been caught before reached the average size of bearing eggs or reproductive maturity size. The exploitation rate of spiny lobsters reaches 32-38% above optimum level. This study suggests that the spiny lobster fishery in Palabuhanratu in the state of overexploitation.

Measurements of the dimensions of the different gills and the suprabranchial chambers have been made and the data analysed with respect to body weight using logarithmic transformations (Y = aWb). The slope (b) for area of the total gill surface is 0–592 and for the supra‐branchial chamber 0–696, and their combined respiratory surface: 0–623. The slope values for the surface areas of the 1st, 2nd, 3rd and the 4th gill arches were 0–595,0–578,0–614 and 0–572 respectively. The slope for secondary lamellae/mm is –0138 and that for the bilateral surface area of an average‐sized lamella 0–304. These results indicate differences in growth patterns for the dimensions of the different gills. The growth‐related decrease in the number of secondary lamellae/mm and size of an average secondary lamella together with evidence from “drowning” experiments and diffusing capacity calculation, suggest that this fish is better adapted for aquatic respiration than Anabas or Saccobranchus. The slopes for the total respiratory surface area and gill area seem to be comparatively low in this species.

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Widigdo B, Rukisah, Laga A, Hakim AA, Wardiatno Y. 2017. Carapace length-weight and width-weight relationships of Scylla serrata in Bulungan District, North Kalimantan, Indonesia. Biodiversitas 18: 1316-1323. The mud crab, Scylla serrata lives associated with mangrove ecosystems and is widely distributed in the Indo West-Pacific. The present work was aimed to reveal the carapace length/width-weight relationships of Scylla serrata in two mangrove ecosystem area of Bulungan District, North Kalimantan- Indonesia, i.e. Kahayan Delta and Tibi Island. The crabs were collected by using ambau pancang (trap) for two months from November to December 2016. A total of 522 individuals were collected and their carapace length, carapace width, and weight were measured. The sex ratio of total collected samples (male to female) was 1:0.79. Carapace length and width of S. serrata caught in these two study area ranged from 40 to 89 mm for male; 32 to 91 mm for female and 59 to 128 mm for male; 53 to 122 mm for female, respectively. The carapace length-weight relationships of total samples showed logarithmic equations as follow: W = -3.2194 + 2.9725 Log CL for male and Log W = -2.2010 + 2.3750 Log CL for female. While the carapace width-weight relationships are as follow: W = -3.9162 + 3.1012 Log CW for male and Log W = -2.6001 + 2.3968 Log CW for female. The b values of carapace width-weight relationship indicated that the growth pattern of male was positive allometric and female was negative allometric. Size frequency of crab population is also presented.

a b s t r a c tTwo species of slipper lobster, Thenus indicus Leach, 1815, and Scyllarides haanii De Haan, 1841, are reported for the 1 st time from the coastal waters of South of Java, part of the Indian Ocean. A total of two specimens, one specimen of T. indicus from Palabuhanratu Bay and one specimen of S. haanii from Yogyakarta coastal waters, were collected in April and September 2015, respectively. Descriptions and illustrations of the morphological characteristics of the two species and their habitat are presented.