Table of Contents

by Ianne Keziah O. Agripo, Davin Edric V. Adao and Windell L. Rivera

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14001

Abstract (Primary Research Paper)

Date Posted (Final Published Version) : July 29, 2020

Abstract

Trichomonad isolation from amphibians is new in the Philippines as trichomonad studies in the country are few, limited only to mammals, reptiles and birds. Moreover, there are very few studies on amphibian-associated trichomonad ultrastructure and morphology. Trichomitus batrachorum (Ts. batrachorum) was isolated from Rhinella marina fecal samples and identified using SEM and TEM for ultrastructural study and 18S rRNA gene sequencing. A 37.5% prevalence of Ts. batrachorum from R. marina was observed based on in vitro culture and molecular analysis. Characteristics of this coprozoic trichomonad that provided distinctive features for classification included body size and shape, three anterior flagella and a recurrent flagellum, lamelliform undulating membrane, type A costa periodicity, V-shaped parabasal body, well-developed pelta, shape and location of organelles such as the nucleus, blepharoplast, axostyle, comb-like organelle, hydrogenosomes and the observation of a pseudocyst stage. DNA sequence analysis corroborated these results, and generated phylogenetic trees with high bootstrap support further proved the identity of the isolate. The few identified trichomonads in the Philippines exhibit the capability for adaptation to new hosts and it is possible they have zoonotic potential. These findings contribute to the existing trichomonad data sets in the country. This is the first ultrastructural study of Ts. batrachorum species isolated from a toad.

KEYWORDS: 18S rRNA gene, electron microscopy, Rhinella marina, Trichomitus batrachorum, ultrastructure

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by Raphael Paolo A. Casipit, Carl Anton D. Canlas, Mary Elizabeth C. Legarda, Justinne R. Yap, Sarah Grace S. Zamudio, and Cecilia I. Banag-Moran

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14002
Abstract (Primary Research Paper)
Date Posted (Final Published Version) : July 14, 2020

Abstract

This study aims to assess the intraspecific genetic diversity of Ixora macrophylla, a widespread species of Philippine Ixora recorded from several islands of the Philippines, and I. auriculata, an endemic species that has yet to be included in molecular studies of the Philippine Ixora. The number of haplotypes, haplotype diversity, and nucleotide diversity of 19 trnL-F and 17 ITS sequences of I. macrophylla, as well as 4 trnL-F and 4 ITS sequences of I. auriculata were obtained using DNAsp 5.10.1 software, and pairwise distances were calculated using the nucleotide Kimura 2-parameter using MEGA 6.06. Two haplotypes of trnL-F and nine haplotypes of ITS were identified in six populations of I. macrophylla. One of the two haplotypes of trnL-F was unique to the Mindoro population. One of the nine haplotypes of ITS was common among seven individuals from four populations. Intraspecific pairwise distances ranged from 0 to 0.1% for trnL-F and 0 to 0.9% for ITS. Mantel test showed weak correlations between the genetic and geographic distances for both trnL-F (r = -0.0380) and ITS (r = 0.0980) sequences. For the genetic diversity of I. auriculata, two haplotypes of trnL-F and four haplotypes of ITS were identified, with intraspecific pairwise distances ranging from 0 to 0.1% in trnL-F and 0.3 to 3.5% in ITS. The results for genetic diversity may be used to better understand the population genetics of the Philippine Ixora and provide insights for conservation..

KEYWORDS: haplotype, nucleotide diversity, pairwise distances, phylogenetic analyses, population genetics

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by Ronald Garcia and Rolf Müller
Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14003
Abstract (Primary Research Paper)
Date Posted (Final Published Version) :July 14, 2020

Abstract

Cellulose-degrading myxobacteria are common soil microorganisms with unique morphologies and are united forming the distinct Sorangium and Byssovorax clades in the Polyangiaceae family, order Myxococcales. Cells of these fascinating bacteria can glide, form fruiting bodies and degrade agar and cellulose. However, phenotypic studies based on the swarm, fruiting bodies and cellulose degradation pattern have shown many dissimilarities among strains suggesting more potential to identify new species in Sorangium clade. Currently, nine validly described species are recognized capable of decomposing cellulose in myxobacteria, of which eight species belong to the genus Sorangium and one species to Byssovorax. With the increasing number of species recently validated in Sorangium, likely there will also be more species of Byssovorax that can be found in the environment. BLAST search analysis of Byssovorax 16S rRNA gene sequences in NCBI public database (GenBank) revealed 97-98.8 % similarity with sequences derived from clones of uncultured bacteria. In Sorangium, six 16S rRNA gene sequences derived from clones of uncultured bacteria were identified occupying novel branches and exhibiting 96.9% – 98.6% similarities with type strains. Molecular phylogenetic analysis confirmed the affiliations of these clones within Sorangium and Byssovorax clades, indicating potentially new species within these genera. Surprisingly, one sequence derived from a clone (DEN_SIP_103) may potentially represent a novel genus only if this strain can be successfully cultured in the future.

KEYWORDS: myxobacteria, metagenomics, 16S rRNA gene, Sorangium, Byssovorax, cellulose-degradation

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by Anthony T. Buaya and Marco Thines

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14004

Abstract (Review Paper)

Date Posted (Final Published Version) :July 15, 2020

Abstract

Holocarpic oomycetes are ubiquitous especially in marine and freshwater environments. These organisms are mostly obligate biotrophic parasites and members of the deep-branching, early-diverging clades of the Oomycota, comprising of several genera that had their phylogenetic position only recently investigated (Miracula, Olpidiopsis, Eurychasma, Haptoglossa, Anisolpidium, Diatomophthora, Pontisma, Haliphthoros) as well as some unresolved genera (Ducellieria, Petersenia, Sirolpidium, Eurychasmidium, Pseudosphaerita, Rozellopsis). Despite their widespread occurrence and importance for understanding the evolution of the oomycetes, knowledge on the biology and ecology of these bizarre organisms is still fragmentary for temperate regions and almost absent for the tropics. Here, an overview on the current state of knowledge on early-diverging oomycetes is presented, with emphasis on the general biology, systematics and ecology.

KEYWORDS: early-diverging clades, Oomycetes, Oomycota, phylogeny, systematics

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by Jaycee Augusto G. Paguirigan, Bjorn Adrian P. David, Rjan Nichole Marie S. Elsisura, Alissa Jane R. Gamboa, Reyzen Francis P. Gardaya, Josh Patrick N. Ilagan, Julianne Paula L. Mendiola, Patricia B. Pineda, River N. Samelin, and Ma. Victoria Pangilinan

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14005

Abstract (Short Communication)

Date Posted (Final Published Version) :August 25, 2020

Abstract

The Philippines is known for its environmental diversity due to its ideal climatic conditions. Scientists have studied various species of flora and fauna in the country, including macrofungi. However, not all regions have been studied and explored for macrofungi such as Mount Isarog in Camarines Sur. To add to Philippine macrofungal diversity, this study accounted for naturally occurring macrofungi collected in April 2018 at Consocep Mountain Resort in Tigaon and Mount Isarog National Park in Goa, Camarines Sur. The samples collected were identified based on their morpho-anatomical characteristics, as well as their substrate with the aid of published taxonomic keys. A total of 36 taxa were identified from the two sites and classified under eight orders, 17 families, and 26 genera. Order Polyporales had the most number of specimens. The number of species provided evidence for the high diversity of macrofungal species in the area with most of them attached to bark substrates.

KEYWORDS: Ascomycetes, Basidiomycetes, mycology, Philippines, taxonomy

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by Justine Grace A. Perez, Arlice Kristel A. Mappala, Cendrix Kyle L. Icaro, Ana Marinella T. Estrada, Kim Hazel V. Arafiles, and Gina R. Dedeles

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14006

Abstract (Primary Research Paper)

Date Posted (Final Published Version) :July 20, 2020

Abstract

Thraustochytrids are marine protists that can be abundantly found on fallen mangrove leaves. These organisms are drawing attention from scientists and commercial manufacturers alike primarily because they are able to produce omega-3 polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in copious amounts within their cells. Scientists from Brazil, Malaysia, Taiwan, and Thailand have capitalized on their country’s thraustochytrids; yet, in the Philippines only a limited number of researches have been conducted on these organisms. Thus, the significance of this research is to further investigate, supplement additional information, and add to the number of existing studies on the thraustochytrids from Philippine mangroves. This research isolated, purified, and characterized thraustochytrids present in yellow, yellow brown, and brown leaves from two (2) mangrove species—Avicennia and Rhizophora spp. in Pagbilao Mangrove Forest. The thraustochytrids from each leaf sample of the two mangrove species were isolated and purified on GYPSA (Glucose Yeast Peptone Sea Salt Agar) media. Morphological characterization was done through microscopy for partial identification. The isolates present on fallen mangrove leaves from Pagbilao, Quezon were preliminarily identified as morphologically indicative to either be Aurantiochytrium, Hondaea, or Monorhizochytrium.

KEYWORDS: marine protists, heterotrophs, Thraustochytriacae, Philippines

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by Reuel M. Bennett and Marco Thines

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14007

Abstract (Review Paper)

Date Posted (Final Published Version) : September 7, 2020

Abstract

Estuarine saprotrophic oomycetes are a group of eukaryotic, fungal-like protists of the Kingdom Straminipila. Species classified as estuarine oomycetes are commonly present on mangrove leaf litter and saltmarsh plant debris. They are distributed over several families (i.e. Peronosporaceae, Pythiaceae, Salisapiliaceae, and Salispinaceae). It is estimated that there are more than 100 species of estuarine oomycetes and, surprisingly, some supposedly terrestrial phytopathogenic hemibiotrophic oomycetes, e.g. Phytophthora elongata, Ph. insolita, and Ph. ramorum, are likewise present in the estuarine biome. In the Philippines, this group has been neglected for several decades as compared to the obligate biotrophic and hemibiotrophic members of Peronosporaceae and Albuginaceae. In this account, a general overview on the systematics and phylogeny of estuarine oomycetes is given. Further, the state of knowledge regarding thallus organization, taxonomy, habitat, and status of Philippine oomycetes are presented.

KEYWORDS: estuarine, mangroves, oomycetes, phylogeny, taxonomy

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by Pia S. Corre, Mary Rose Clarence S. Abadilla, Mark Nathaniel L. Arnaldo, Marianne Therese S. Irlanda, Andrea Czarina P. Mariano, Irineo J. Dogma, Jr., and Rey Donne S. Papa

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14008

Abstract (Primary Research Paper)

Date Posted (Final Published Version) : August 12, 2020

Abstract

The chitinous exoskeleton of copepods serves as a scaffold for microepibionts such as protozoa. Although copepods are highly cosmopolitan, their associated epibionts in the tropics are poorly known. This study presents the first account in the Philippines of the ciliate Vorticella on calanoid copepod Arctodiaptomus dorsalis and both Vorticella and the euglenoid Colacium on the cyclopoid copepods Thermocyclops crassus and Mesocyclops microlasius in the Pasig River. Infestation, however, was low at 0.83% (108 out of 13,039) observed copepods from four collection sites in January-May and July-December 2018. Interestingly, Vorticella and Colacium were frequently observed in cyclopoid than on calanoid copepods, predominantly on the urosome, thorax, cephalosome of copepodites and adult stages of copepods. Colacium was also found attached on the antennules, swimming legs, caudal rami and setae. Prevalence of epibionts was site-related; Vorticella being more abundant in waters near Manila Bay (Site 1) where high salinity, conductivity and total dissolved solids were recorded while Colacium was found more near Laguna de Bay (Site 4). Both were abundantly present in September and absent in May, due to increased inflow of seawater from Manila Bay. Nevertheless, overall low infestation resulted in neither significant spatial nor temporal variation of epibiosis in Pasig River, probably due to heavy loadings of wastewater from nearby tributaries, noticeable algal blooms, detachment of epibionts by predations and changes in water chemistry.

KEYWORDS: protozoa, zooplankton, epibiosis

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by Janelle Laura J. Gacad and Jonathan Carlo A. Briones

Philippine Journal of Systematic Biology, Volume 14, Issue 1, 2020, DOI: 10.26757/pjsb2020a14009

Abstract (Short Communication)

Date Posted (Final Published Version) : October 16, 2020

Abstract

Bacterial infections are high-risk factors in fisheries, with reports of high mortality among diseased fish stocks posing a threat to both capture and aquaculture fisheries in inland waters. Diseases-causing bacteria in fishes may lead to decreased yield and economic loss to fishers, whose livelihood primarily depends on landed catch. Lake fisheries are most affected by such disruptive changes because of limitations in water turnover aggravated by wastewater inputs. In this study, we isolated and characterized gut bacteria from landed catch of the gobiid Glossogobius aureus from Lake Sampaloc, a small but commercially important aquaculture area in Luzon. Isolated axenic gut bacteria were identified through Gram stain reaction, microscopy, API biochemical tests, and 16s rRNA gene sequencing. From these, we identified two species with known fish pathogenicity, namely Aeromonas veronii and Plesiomonas shigelloides which are known to thrive in disrupted and nutrient-rich habitats and cause visible damage to fish health. Interestingly, our samples have shown no such visible signs of the disease. It is therefore important for future researches to determine what conservation and management practices in small inland waters like lakes will limit potential environmental stressors that may trigger susceptibility of both capture and farmed fish species to infection. Ultimately, rehabilitation of inland water aquaculture areas such as Lake Sampaloc is essential not only to fish conservation but also to public health and local food security.

KEYWORDS: aquaculture, bacteria, goby, lake fisheries

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