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There are relatively few studies on parasite fauna of marine fishes in Philippine waters. This study aimed to determine the prevalence of marine ascaridoid infection in Decapterus species in Balayan Bay and Tayabas Bay. A total of 371 fishes belonging to three different species of Decapterus (D. tabl [n = 130], D. macrosoma [n = 121], and D. maruadsi [n = 120]) were collected. Ascaridoid parasite larvae were found in all fish host species, with an overall fish infection rate of 22%. The highest infection rate was observed in D. tabl (27.69%), followed by D. macrosoma (19%), and then D. maruadsi (17.50%). Moreover, a higher prevalence of infection was detected in Tayabas Bay (27.57%) than in Balayan Bay (15.59%). Molecular analyses based on the ITS2 and 18S rRNA gene supported the identification of the larvae into two species: Anisakis typica and Raphidascaris (Ichthyascaris) lophii. This is the first report of the genetic identification of these two helminth parasites in Decapterus fish species in the Philippines. Paucity in the database of Philippine marine fish parasites warrants more research efforts, especially concerning economically important fish species with implications to food safety and food security.

An 18,493 base pair mitogenome of the Philippine Cockatoo (Cacatua haematuropygia) is presented, containing 13 complete protein-coding genes, two rRNAs, 24 tRNAs, two control regions, and two partial duplicate copies of cytb and nd6. The mitogenome contains two complete copies of tRNA-Leu, tRNA-Ser, tRNA-Thr, and tRNA-Pro. Phylogenetic analysis places the Philippine Cockatoo within the subgenus Licmetis, with its closest relatives being the Tanimbar Corella (Cacatua goffiniana) and the Western Corella (Cacatua pastinator) and all three species being sisters to other white cockatoos in the subgenus Cacatua. The gene order and content of the mitogenome are most similar to C. pastinator, containing a partial duplication of cytb, and whole duplications of the control region and several tRNA genes. However, the total duplication of nd6 could not be verified. Analysis of the control regions indicates that these are paralogs of each other; both copies contain preserved features such as the Extended Termination Associated Sequences 1 and 2 (ETAS1, ETAS2) and Conserved Sequence Block 1 (CSB1) associated with d-loop or control region replication in mitogenomes. Gene order for the species cannot be verified since the region corresponding to duplicate copies of tRNA-Glu and nd6 in other cockatoos could not be properly sequenced. [ABSTRACT FROM AUTHOR]

The Chinese pond mussel Sinanodonta woodiana (Lea, 1834) is a large freshwater bivalve species of the family Unionidae and a known invasive alien species. Proper verification of its identity as well as its source population is crucial for the control of its spread. However, its high plastic shell morphology that resembles other non-invasive species of unionids can be an obstacle. The distribution and ecological impact of this invasive unionid is not fully understood and should be further investigated to prevent further spread in the Philippines. In this study, we used the cytochrome oxidase I (cox1) gene to verify the identity of putative S. woodiana samples collected from Bato Creek in Oriental Mindoro and Lake Danao in Leyte, Philippines and elucidate their source populations. Eighteen cytochrome oxidase subunit 1 (cox1) barcodes were generated from samples collected from Lake Danao, Leyte (n=13) and Bato Creek, Oriental Mindoro (n=5). These barcodes were subjected to Basic Local Alignment Search Tool (BLAST) analysis, which showed that the cox1 sequences from the Philippine samples matched with those of S. woodiana (>94%) found in GenBank. The sequences were then aligned with cox1 sequences of S. woodiana and other unionid representatives from GenBank. Phylogenetic and haplotype network analyses also showed three haplotypes (Hap 1, 2, and 4) of S. woodiana samples from Lake Danao and Bato Creek. Hap 1 and 2 are distinct haplotypes observed in Lake Danao samples while Hap 4 is shared between Lake Danao and Bato Creek samples and have clustered with conspecific specimens from Malaysia and Indonesia, suggesting their potential Island Southeast Asian origin. [ABSTRACT FROM AUTHOR]

Eleutherodactylus planirostris (Cope 1862), commonly called the Greenhouse Frog, is an insectivorous, direct-developing frog native to the Caribbean. It has been widely introduced outside of its native range and has been known to reach population densities of about 12,500 frogs per hectare, posing a potential ecological threat in areas of its introduction, especially to local insect populations. Recently, the species has been detected on several islands throughout the Philippines. Samples for this study were obtained from two locations in Quezon City (Luzon Island) and one location in Bacolod City (Negros Island). DNA barcoding using three genes (Cytochrome b, 16S rDNA, and Cytochrome Oxidase subunit 1) was performed with the objective of identifying the source population of Philippine E. planirostris. Our results indicate that E. planirostris samples in the Philippines are identical genetically to populations in Hawai'i and Florida, USA and are closely related to an individual from Matanzas, Cuba. A haplotype network built using the Fitch algorithm also supports the Cuban origin of the Philippine samples. Moreover, the Philippine specimens have nearly identical sequences for all three genes, which may have implications on its success as an introduced species. [ABSTRACT FROM AUTHOR]

The molecular phylogeny of the Philippine tigerperches is first described in this study. Eight species were analyzed: these include one endemic species (Leiopotherapon plumbeus); one introduced species (Bidyanus bidyanus); and six native species (Terapon jarbua, Terapon puta, Terapon theraps, Pelates quadrilineatus, Helotes sexlineatus, and Mesopristes cancellatus). Primers were designed to amplify and sequence the 12S rRNA (12S), cytochrome c oxidase subunit I (COI), and cytochrome b (CytB) genes. The concatenated 12S, COI, and CytB sequences (3529 bp) were used to construct the phylogeny of the tigerperches using Maximum Parsimony (MP), Neighbor Joining (NJ), Maximum Likelihood (ML), and Bayesian Inference (BI) analyses. All four analyses supported the monophyly of tigerperches. Except for the MP tree, all phylogenetic trees showed that Terapon jarbua was the first to have diverged from the rest of the tigerperch species examined. The congeneric T. jarbua, T. puta and T. theraps did not group together, suggesting their non-monophyly. However, SH test on the unconstrained (actual observation) and constrained (the three congeneric species were forced to group together) NJ trees showed no significant difference (p = 0.55). This demonstrated that the monophyly of the genus Terapon remains unclear. Helotes sexlineatus and Pelates quadrilineatus were found to group together based on the three markers, which lends support to assertions in other studies that these taxa are congeneric and should be placed in the same genus Pelates. The immediate sister taxa of B. bidyanus, L. plumbeus, M. cancellatus, and Rhynchopelates oxyrhynchus were not confirmed by the MP, NJ, ML, and BI phylogenetic trees. The inclusion of additional unsampled Philippine species, as well as those from neighboring countries, is recommended to further refine the phylogeny of tigerperches. [ABSTRACT FROM AUTHOR]

Whole mitochondrial genomes (mitogenomes) have been increasingly used as markers for phylogenetic inferences. In the Philippines, a marine snail from the Conidae family has been the only species to date whose mitogenome has been fully sequenced, despite the country's rich malacofaunal diversity particularly in the terrestrial environment. In this study, we sequenced the complete mitogenome of the land snail Ryssota otaheitana (Chronidae), an endemic Philippine pulmonate species. The mitogenome is 13,888 bp in length and encodes the typical 37 genes - including 13 protein-coding, 22 tRNA, and 2 rRNA genes. Short intergenic spacers were found - including a reduced, 42-bp putative control region. Although the gene content is conserved, R. otaheitana showed a novel mitogenome organization involving the translocation of tRNASerine and NADH dehydrogenase subunit 4 gene segment. Combined with available stylommatophoran mitogenomes, different datasets from concatenated sequences of protein-coding and rRNA genes were used for phylogenetic reconstructions. Bayesian Inference (BI) and Maximum Likelihood (ML) trees congruently supported several monophyletic clades within the Stylommatophora such as the Helicoidea, Urocoptoidea, Orthurethra, and Limacoidea sensu lato (syn. 'limacoid clade'). R. otaheitana is grouped with Deroceras reticulatum in the lower Stylommatophora and forms the monophyletic Limacoidea sensu lato. Both sequence-based phylogeny and gene order comparisons have led us to a hypothesis that Limacoidea sensu lato is at the base of the 'non-achatinoid' clade while supporting the division of 'achatinoid and 'non-achatinoid' groups in the Stylommatophora. This study reports the first complete mitogenome from the Chronidae family, which can be used further for the molecular phylogeny of Philippine snails and gastropods at large. [ABSTRACT FROM AUTHOR]

The Philippine Eagle, Pithecophaga jefferyi, is a critically endangered bird of prey that is endemic to the dipterocarp forests of the Philippines. In this study, data from next-generation sequencing (NGS) were used for the development of microsatellites for the Philippine Eagle. A total of 49,965 microsatellite loci were predicted and 20,960 primer pairs were designed. Forty (40) of these pairs were synthesized and were tested on 20 captive individuals. Twenty (20) of these markers showed high amplification success rates and exhibited polymorphism. A maximum of 24 alleles was detected across the 20 markers with an average of 13.9 alleles, which is remarkably higher than other microsatellite studies in eagles. The resulting values for observed heterozygosity (Ho) ranged from 0 to 1.00 with an average of 0.290, while expected heterozygosities ranged from 0.791 to 0.968 with an average of 0.910. [ABSTRACT FROM AUTHOR]

The Philippines is the center of radiation of the land snail subfamily Helicostylinae, with around 253 recognized species. Despite their morphological diversity, research on their biology and taxonomy is lacking. We present here the first mitochondrial COI profiles of 32 species of Philippine helicostyline land snails. With the addition of sequences downloaded from GenBank, we tested the utility of the COI for species identification. Relative distributions of intraspecific and interspecific distances overlapped; hence, no barcoding gap was observed. However, 90% of uncorrected interspecific comparisons can distinguish species at 14% genetic distance or lower. Furthermore, the COI barcodes could not discriminate several co-distributed species that have similar conchological features, which should be flagged for taxonomic re-evaluation. [ABSTRACT FROM AUTHOR]

Schistosomiasis japonica is a water-borne trematode infection transmitted by different subspecies of Oncomelania hupensis. As parasites may either co-evolve or locally adapt with their hosts, snail diversity, as revealed by morphometric and genetic studies, may reflect parasite diversity and elucidate snail susceptibility and transmission patterns. This study aimed to compare isolates of O. h. quadrasi based on a 342-bp fragment of the 16S ribosomal RNA gene. O. h. quadrasi isolates were collected from nine provinces known to have S. japonicum in the Philippines, namely Cagayan Valley, Bohol, Negros Occidental, Leyte, Davao, Davao del Sur, Mindoro Oriental, Northern Samar, and Sorsogon. O. h. hupensis and O. h. nosophora isolates were also collected from China and Japan, respectively. The 16S ribosomal RNA gene of each specimen was amplif ied and sequenced. Phylogenetic and network analyses based on the 221 16S rRNA gene sequences revealed that O. h. quadrasi clustered as a distinct clade from the two other subspecies. Of the four identif ied haplotypes for O. h. quadrasi, two haplotypes were from Negros Oriental (Ohq2 and Ohq3), and one haplotype was from Bohol (Ohq4). The isolates from the remaining seven provinces shared a common haplotype (Ohq1). The current study was able to show the relationship among O. hupensis subspecies and demonstrate the limited ability of mitochondrial 16S ribosomal molecular marker in differentiating O. h. quadrasi geographic strains in the Philippines. [ABSTRACT FROM AUTHOR]

This study reports the presence of the Charru mussel Mytella charruana d'Orbignyi, 1846 (Bivalvia: Mytilidae) in Manila South Harbor, Manila Bay, Luzon Island, Philippines. In 2014, mussels previously identified as Mytilus spp. were reported in Manila Bay. The species was detected as part of an ecological dynamics study of previously-recorded marine non-indigenous mollusc species. DNA barcoding results suggest that the previously identified Mytilus are in fact Mytella charruana with an average identity match of 94%. The trends in abundance of Mytella during the 2014-2015 sampling season are described and the potential of this new species to become invasive and competitive with native Perna viridis (Linnaeus, 1758). [ABSTRACT FROM AUTHOR]

In the Philippines, rats and snails abound in agricultural areas as pests and source of food for some of the local people which poses risks of parasite transmission to humans such as Angiostrongylus cantonensis. This study was conducted to determine the extent of A. cantonensis infection among rats and snails collected from rice-farming villages of Muñoz, Nueva Ecija. A total of 209 rats, 781 freshwater snails, and 120 terrestrial snails were collected for the study. Heart and lungs of rats and snail tissues were examined and subjected to artificial digestion for parasite collection. Adult worms from rats were identified using SSU rDNA gene. Seven nematode sequences obtained matched A. cantonensis. Results revealed that 31% of the rats examined were positive with A. cantonensis. Rattus norvegicus and R. tanezumi showed prevalence of 46% and 29%, respectively. Furthermore, only Pomacea canaliculata (2%) and Melanoides maculata (1%) were found to be positive for A. cantonensis among the snails collected. Analysis of host distribution showed overlapping habitats of rats and snails as well as residential and agricultural areas indicating risks to public health. This study presents a possible route of human infection for A. cantonensis through handling and consumption of P. canaliculata and M. maculata or crops contaminated by these snails. [ABSTRACT FROM AUTHOR]

The Philippine Eagle Pithecophaga jefferyi is a diurnal raptor endemic to the Philippines. Its distribution is restricted to remaining forests on the islands of Luzon, Samar, Leyte and Mindanao. The Philippine Eagle is classified as a Critically Endangered species under the IUCN Red List, with a high end estimated population of only 500 breeding pairs in the wild. Population decline has been attributed to continuing deforestation, particularly since the mid-1900s, and hunting. This study aimed to identify the effects of population decline on the genetic structure of the present population of the Philippine Eagle by sequencing 1132bp of the mitochondrial control region from 22 individuals. Control region haplotype diversity (h = 0.8960±0.05590) and nucleotide diversity (π = 0.006194±0.003372) are comparable with other accipitrid species. Maximum likelihood trees and network analysis show that the Luzon and Samar individuals come from different lineages, but both shared a common ancestral population with the Mindanao population. The genetic diversity, multimodal mismatch distribution for the control region and high frequency of lower class modes all indicate a recent bottleneck for the Philippine Eagle population. Possible strategies for conservation are discussed. [ABSTRACT FROM AUTHOR]