Judul: Diversity of Biometric, Genetik and Population Biology of White-spotted rabbitfish (Siganus canaliculatus Park, 1798) in the Inner Ambon Bay Waters
Abstrak: The waters of Inner Ambon Bay (IAB) are influenced by tidal currents that distribute food, physical dan chemical environmental parameters, waste, sediment, and larvae of fish. One of the fish resources associated with seagrass habitats in TAD waters is White-sptotted rabbitfish (Siganus canaliculatus). Seagrass habitat is widely distributed in IAB which form single and mixed vegetation seagrass beds, with different vegetation densities and their presence is influenced by environmental parameters, substrate type/sediment and anthropogenic activity. The differences in the physical characteristics of the seagrass habitat in IAB are thought to affect the character biometric, genetic, and population biological of S. canaliculatus in IAB. This study aims to compare 1) biometric character, 2) genetic character, 3) spatial distribution, 4) variation of growth and reproduction in different seagrass habitats, and 5) to analyze population dynamics of S. canaliculatus in IAB waters. Research in IAB waters was conducted in August 2018 - July 2019, the sampling stations namely Station 1. (Tanjung Tiram) and 2 (Halong) represent mixed vegetation seagrass habitat, Station 3 (Poka) and 4 (Nania) represents a single vegetation seagrass habitat. Fish samples were collected once a month using beach seine, along with the measurement of enivonmental parameters, including depth, turbidity, temperature, salinity, pH, dissolved oxygen, phosphate, nitrate, and chlorophyll-a. The density and diversity of seagrass vegetation were estimated based on a systematic sampling method. Observations of biometric characters, gonad maturity levels, and fecundity were carried out at the Oceanographic Biology Laboratory, Center for Deep Sea Research - LIPI Ambon. Genetic testing was carried out at the Molecular Biology Laboratory of the Department of Aquatic Resources Management, Faculty of Fisheries and Marine Sciences, IPB University. The collected fish samples were classified into 3 stages, namely: juvenile, pre-adult, and adult. A total of 50 fish samples were measured 21 characters truss morphometric, and 14 fish samples were genetically tested using the mitochondrial cytochrome oxidase I (COI) molecular marker amplified by the Polymerase Chain Reaction (PCR) technique using universal primers for aquatic biota. All good quality PCR products are shipped to 1st Base in Malaysia. Fish samples were also measured for length, weighed, and dissected for determination of the gonad maturity levels morphologically and fecundity observations. Biometric analysis using Minitab ver. 16 for Principal component analysis (PCA) and similarity dendrogram, while discriminant canonical analysis using SPSS ver. 16. Sequencing data were corrected and aligned using MEGA (Molecular Evolutionary Genetics Analysis) software version 7.0. DNA Sequence Polymorphism (DnaSP ver 5) was used to analyze genetic diversity including haplotype diversity (Hd) and nucleotide diversity (π). Phylogeny tree construction based on the Neighbor-Joining method and genetic distance using MEGA ver. 7. Genetic differentiation intra and inter population using Analysis of Molecular Variance (AMOVA) and Fixation Index (Fst) using Arlequin software. Analysis of growth patterns, condition factors, sex ratios, size of gonad maturity, and fecundity using Excel 2010 software. processed using Past ver.3.14 software. Analysis of fish population dynamics using ELEFAN (Electronic Frequency Analysis) I FiSAT model (FAO-ICLARM Stock Assessment Tools) includes growth, mortality, and recruitment. The results showed that the biometric character of White-spotted Rabbitfish (S. canaliculatus) in IAB
Keyword: Siganus canaliculatus, biometric and genetic characteristics, spatial distribution, growth, reproduction, population dynamics