Species identification and population genetics in Scylla using morphological and molecular characters

The mud crab, Scylla spp., is an important marine natural resource and comprises a major national industry where the Philippines is 2nd only to China in production. Despite the country’s competitive position, research on the organism and industry practices would benefit from improved species identification in adults and early developmental stages, as well as in the determination of the population structure of the preferred species Scylla serrata. Differentiation of the four existing species, Scylla serrata, S. tranquebarica, S. olivacea and S. paramamosain, is problematic, with morphological markers primarily based on a dichotomous key derived from a wide geographical region with limited sampling intensity. It does not account for local variations in the morphology of a genus known for their plasticity with difficulties aggravated by individuals with ambiguous morphology. In this study, existing molecular methods for species identification, specifically the internal transcribed spaces region I (ITS-1) and the 16S rDNA markers, were used on 1,185 adult mud crabs from wild populations in 7 sites across the Philippines made possible the identification of an updated hierarchy of morphological markers for species identification with 97.8% accuracy. This study was also able to identify 27 morphologically ambiguous mud crabs with atypical ITS-1 markers indicating rare genetic reasons for morphological aberrations. For immature mud crabs, there is no existing diagnostic key for species identification. The overlapping ranges of the Scylla species in the Philippines makes any batch of captured crablets a heterozygous mix preventing the focused allotment of limited space and resources to the rearing of preferred species. Image analysis, using SHAPE, and multivariate analysis, using Principal Component analysis (PCA) and Discriminant analysis (DCA), on 177 wild immature mud crabs from Cagayan detected of subtle morphological similarities on their frontal lobe spines that correspond to differences in species as confirmed by genetic barcoding using ITS-1 and 16S rDNA. Accuracy of the static species diagnostic marker at the instar and juveniles stages were proven when 85.7% of 100 wild immature mud crabs from Bataan and 50 cultured immature mud crabs from Zambales were correctly identified to species using the image comparison program Resemble.js and genetic barcoding. The high demand for stock for the preferred species S. serrata all over the country requires management efforts to be guided by a clear knowledge of genetic structure in existing populations. In this study, the previously observed genetic panmixia in the populations along the Pacific coast of the Philippines was tested using 27 morphometric, 2 mitochondrial and 10 microsatellite markers on 356 S. serrata from Cagayan, Bicol, Quezon, Pangasinan, Bataan, Panay and Iligan. An East- West structure was seen with populations from the Inner Philippine Seas show greater morphological similarity with the populations from the West Philippine Sea that may be You attributed to climate. Molecular markers indicate a distinct West population diverging from the East populations, with Panay exhibiting admixture

Environmental reviews and case studies: Art, environment, and sustainability: Case studies on the Philippine art practice

Art is a powerful tool for conveying ideas. It transcends various modes of communication, allowing it to trigger mental, emotional, and physical responses from its target audience. Its effectiveness as a tool for environmental advocacy, however, is limited by the sustainability of the practice and the materials used. Contemporary art practices in the Philippines have found ways to support the campaign for environmental sustainability by using repurposed materials that result in a decreased carbon footprint in the art production process, while conveying environmental themes. This evaluative article presents two case studies tackling the new-found indigenous art practice of the Talaandig tribe in the province of Bukidnon, Philippines, and the contemporary art practice of select assemblage artists from Metro Manila using found objects. This article illustrates how Filipino artists in both the indigenous and contemporary art scenes are supporting the global campaign of environmental conservation in message and action. © 2016 National Association of Environmental Professionals

Traditional environmental practices of the Eva Aetas: The value of indigenous knowledge in rehabilitation

The Eva Aetas are custodians of a degraded upland environment in Sitio Pita Bayan-bayanan, a small community in the town of Orion, Bataan, the Philippines. Having lived there for seven decades, they have watched their ancestral land decay from a lush forest to barren grassland. Acknowledging the fact that they have played an active role in its degradation, the Eva Aetas have transformed their environmental practices to adapt to their situation. From crop choice to harvesting methods and ethnomedicine, they provide various means to maximize the minimal outputs of grasslands and possibly allow its eventual rehabilitation. The use of development communication and the application of relevant local policies provide the means as to how their current situation could be remedied. © National Association of Environmental Professionals 2015

Population structure of Scylla serrata from microsatellite and mtDNA markers

Abstract only.Determination of the population structure and connectivity of natural populations of Scylla serrata are useful tools for decision making related to conservation and management efforts of this species. They provide important considerations as recovery and sustainability of the industry relies on the availability of hardy recruits that can replenish harvested resources from the system. In the case of marine domesticated species, admixture is expected due to commodity trade and exchanges. Current population structure of five wild populations of S. serrata from Pangasinan, Bataan, Cagayan, Quezon, and Panay was determined using five microsatellite markers, cross-amplified from Scylla paramamosain in a total of 259 samples. Mitochondrial 16S rDNA sequences of 25 representative individuals from the same locations were used to provide a comparison with original evolutionary patterns. Quality check of microsatellite data revealed no null alleles in the data set, with all loci and populations exhibiting Hardy-Weinberg Equilibrium. Pairwise FST analysis reveals FST values between 0.001-0.08432 with 9 out of the 16 possible comparisons considered significant. Phylogenetic analysis was performed on the 16S rDNA sequences, supported by bootstrap values. Both sets of data suggest 2 distinct groupings: the east coast populations of Cagayan and Quezon, the west coast populations of Pangasinan and Bataan, with admixture observed in the group from Panay. Additional data from 5 microsatellite markers specifically developed for S. serrata and the D-loop region will be added to the analysis. The results from both mitochondrial and microsatellite markers, revealing an East-West separation of S. serrata populations, suggest that current and evolutionary population patterns are matching. Aquaculture practices appear to have not yet significantly affected the population structure of this domesticated species, as initially speculated

Heavy metal levels in mud crabs (Scylla spp.) from East Bataan Coast

Heavy metal levels (Pb and Cu) on adult mud crabs (Scylla spp.) from the East Bataan Coast were determined. Muscle tissue from each crab was processed through nitric acid digestion and analyzed using atomic absorption spectroscopy. The average concentrations in the samples were 3.37 × 10−3 and 1.01 mg/L—both within WHO acceptable limits. These were contrasted with the levels found in sediments from catch and grow-out sites (17.9, 14.5, 37.8, and 31.3 mg/L) and were found to be significantly lower in concentration. It takes 3–8 months before adult mud crabs can be harvested from grow-out ponds, and the data suggests that the organisms, even when constantly exposed to high levels of Pb and Cu, do not bio-accumulate toxic levels of these heavy metals. Mud crabs constitute a major economic natural resource in the Philippines and in the province of Bataan. Commanding high prices due to the quality of its meat, it is also a preferred culture product due to its impressive size, rapid growth rate, and high flesh content. Mud crab culture in Bataan is primarily driven by grow-out of captured juveniles in pen or pond cultures sourced from nearby bodies of water—making them vulnerable to prolonged exposure to pollutants. The East Bataan Coast shares its waters with the polluted Manila Bay, giving rise to the concern of the quality of seafood acquired from the area. © 2015, Springer-Verlag Berlin Heidelberg

Shaping minds to action: An evaluation of the environmental influences of primary school students in an urbanizing community

Environmental perspectives are shaped by both affective and cognitive domains of education. In the urbanizing municipality of Balanga City, the primary school students of its 19 public schools were reported to have a skewed perspective of the environment, equating the term to only the natural components of their surroundings. This does not prevent the students from being actively concerned about the environment, but their confusion is aggravated by the contrasting habits observed in their households to those taught in school. Education is only a limited means to help develop sustainable practices needed as the global community addresses the challenges brought by climate change so to determine how to further develop the environmental knowledge of primary school students in Balanga City, and the influences enumerated by the children of its public schools were studied. Based on the students’ response, their school and television provide the fundamentals for their understanding of the environment, but the social atmosphere in their homes causes the trivialization of the environmental information they acquire. The ease by which these students are compelled to let go of environment-friendly habits may be caused by the absence of a solid cognitive foundation of environmental science due to the integrated curriculum design for teaching science to elementary students and the lack of sufficient training of the teachers involved. Although reiteration and emphasis of learned environmental principles in school can also come from mass media, the forms the students are exposed to are local and subject to sensationalism. There is a lack of sufficient infrastructure needed to expose the students to global viewpoints and issues about the environment, while those with immediate family members overseas have limited avenues for sharing their external influences. Involving the family in environmental education is the key, together with proper training of faculty and a modification of how environmental science is taught, to create an effective system for the improvement of the environmental perspectives of the children of Balanga City. Though environmental education may rely on the linearity of communication, the meeting point of the social influences of these children should emphasize the values of environmental stewardship for them to ascertain the right perspectives toward the environment. © 2014, Springer Science+Business Media Dordrecht