Mottled spinefoot Siganus fuscescens and white-spotted spinefoot Siganus canaliculatus are two similar species that differ subtly in colouration and morphology. Three major mtDNA clades were identified for these species, but individuals were clustered by amplified fragment length polymorphism (AFLP) according to geography rather than morphology, suggesting that the colour morphs are interbreeding.

Species and sex identification are among the most important parameters for conservation management. However, it is extremely difficult to perform such identification in Formosa landlocked salmon (Oncorhynchus masou formosanus). Both sexual dimorphism in landlocked dwarf form Formosa landlocked salmon and morphological difference among cherry salmon complex are minimal. We developed a simple, rapid and noninvasive method for identifying sex and species of this critically endangered species using a loop-mediated isothermal amplification (LAMP) technique. The LAMP assay showed the advantage of simple detection (evaluated by visual inspection), rapid reaction time (< 1 h), isothermal condition (less equipment required) and high efficiency (only 0.5-5 pg of DNA was required in the reaction mixture). Therefore, the method is more economical and practical than PCR. The LAMP assay can be easily performed in the field and is a valuable tool for detecting sex ratios in wild populations and identifying species in commercial imports. This is the first application of LAMP in identifying species and sex of salmonids as far as we know and clearly shows the potential application of LAMP in molecular ecology and conservation efforts.

No abstract

Betta (Betta sp.) is an anabantidae fish with sexual development that can be directed at the embryonic and larval stages. One way to direct the sex development of these fish is by using hormone therapy using natural ingredients. Coconut water is one of the natural ingredients that can be used because it contains high potassium. This potassium can convert cholesterol in fish body tissue to pregnenolone which will affect the increase in testosterone production. This study aims to determine the best dose and age group in directing the sex of Betta fish experimentally using a randomized block design (RBD) with 4 treatments and 3 replications. The immersion treatment of larvae in the age group of 3 days, 5 days, and 7 days for 15 hours with a dose of 0%, 10%, 20%, and 30% coconut water was carried out in a 3 L jar containing 30 larvae. The results showed that coconut water was able to influence the increase in the percentage of male betta fish (P <0.05) with the highest value at a dose of 30% as much as 86.26 ± 8.34% and the 3 day larvae age group of 72.78 ± 16.03, and have a different effect on other treatments. In addition, the survival calculated after immersion shows a value of 100%, meaning that coconut water does not have a harmful effect on fish. Based on the results of this study, the best treatment for directing the sex of betta fish is a dose of 30% coconut water with the 3 day age group

Perikanan lobster di Provinsi Lampung telah dilakukan sejak tahun 1980-an dengan kegiatan perikanan tangkap yang dilakukan oleh nelayan dan dijual pada pedagang pengumpul lokal. Studi tentang perikanan lobster di Provinsi Lampung masih terbatas, sehingga masih banyak fakta secara biologis dan sosial ekonomi dapat dikembangkan yang tujuannya dapat membantu pembangunan perikanan lobster dimasa mendatang. Penelitian dilakukan dengan survei pada nelayan dan pedagang pengumpul lobster di Kabupaten Pesisir Barat pada Agustus sampai dengan Desember 2016. Hasil survei menunjukkan bahwa kegiatan penangkapan lobster tidak mengalami perkembangan yang pesat tetapi menunjukkan penurunan volume tangkap dengan makin berkurangnya jenis lobster yang berharga tinggi dan ukuran yang semakin kecil. Perlu dikembangkan perikanan lobster tidak hanya perikanan tangkap yang perlu dibatasi kuota penangkapannya tetapi juga perikanan budidaya untuk mengantisipasi peningkatan konsumsi dan perlindungan stok alam dengan pelepasliaran yang berpijak pada bidang biologi perikanan. Peta jalan kegiatan penelitian perikanan tangkap dan budidaya lobster yang dapat dikembangkan pada jangka pendek dan jangka panjang telah disusun agar menjadi rujukan oleh masyarakat luas untuk pembangunan perikanan lobster lebih khusus lagi pada kajian fisiologi reproduksi. Terkait dengan pelarangan penangkapan lobster ukuran kecil dan lobster bertelur, penjualan puerulus dan lobster konsumsi juga dibahas dalam tulisan ini.