Uncategorized – Page 5 – Philippine Journal of Natural Sciences

Distribution of free-living nematodes in a tidal flat of Banate Bay, Iloilo, Philippines

by: Kris Angeli S. Sanchez, Wilfredo L. Campos, and Annabelle G.C. del Norte-Campos, Joey Genevieve
Martinez

Abstract

Meiobenthos samples and related environmental parameters were examined along a transect with six stations extending 4 km from the shoreline in Banate Bay, Iloilo, Philippines in April (dry), July (onset of SW monsoon rain) and October (end of rainy season) in 2014. Free-living nematodes constituted 90% of the total meiofauna and showed a mean density of 51.4 ind. cm-2. A total of 89 nematode genera from 23 families were identified, with Paracomesoma, Viscosia, Daptonema, Paramonohystera, and Cyatholaimus as the top five genera (35.6% of overall frequency). Nematode densities (ln-transformed) showed significant differences (p=0.03) temporally but not spatially. Higher densities were observed during the rainy season than dry season. A stepwise multiple linear regression analysis indicated that nematode density was negatively correlated with bottom salinity, while genus richness was negatively correlated with surface turbidity and bottom salinity. The nematode assemblage was dominated by epigrowth feeders, with a shift to non-selective deposit feeders as sediment organic matter had accumulated in October.

Keywords: OceanBio and Marine Bio Laboratories

April 20, 2021September 30, 2021 ovcre.upvisayas

Morphology and molecular phylogeny of the harmful raphidophyte Chattonella subsalsa isolated from Bolinao, Philippines

Philippine Journal of Natural Sciences

Morphology and molecular phylogeny of the harmful raphidophyte Chattonella subsalsa isolated from Bolinao, Philippines

by: Wai Mun Lum, Garry Benico, Rhodora Azanza, Elsa Furio, Po Teen Lim, Hong Chang Lim, Kazuya Takahashi,
Mitsunori Iwataki

Abstract

Morphology and phylogenetic position of the marine harmful raphidophyte Chattonella isolated from Bolinao, Pangasinan, Philippines in 2013 and 2017 were examined using light microscopy and molecular phylogeny inferred from LSU rDNA and ITS sequences. Cells of Chattonella were variable in shape and typically teardropshaped with a roundish antapical end, 26.0–49.5 μm in length, with an anterior flagellum directing swimming direction and a posterior flagellum trailing backward. Cell surface was covered by numerous small granules and several larger button-like rounded bodies. Discharge of transparent tubular mucocysts was also observed from cells just before collapse. Numerous brownish chloroplasts were located peripherally, each with a pyrenoid. Two Chattonella strains isolated in 2017 had identical LSU rDNA and ITS sequences and branched in the clade of Chattonella subsalsa, and were closely related especially to strains isolated from the Gulf of Mexico and East coast of USA. This is the first report of C. subsalsa based on morphological and phylogenetic information from the Philippines.

Keywords: Chattonella subsalsa, fish kill, harmful algal blooms, LSU rDNA, raphidophyte

April 20, 2021September 30, 2021 ovcre.upvisayas

Age-Growth Parameters of Crescent Grunter, Terapon jarbua (Forsskål 1775) in Mindanao, Philippines

Philippine Journal of Natural Sciences

Age-Growth Parameters of Crescent Grunter, Terapon jarbua (Forsskål 1775) in Mindanao, Philippines

by: Maybelle A. Fortaleza, Reena Cyndi L. Uy, Merlene E. Elumba, Cleto L. Nañola, Jr.

Abstract

Otolith studies provide a breadth of information valuable in investigating the life history of reef fish species. When incorporated with analysis on length-weight relationships, this biological information becomes useful in understanding the population dynamics of economically important reef fishes. This study looked into the lengthweight relationship and age-growth parameters of Terapon jarbua, a euryhaline fish species that is commonly harvested in coastal areas of Mindanao, Philippines. The length-weight relationship for 160 T. jarbua individuals (9– 22.4 cm, standard length) collected from Davao Gulf (n=105) and Iligan Bay (n=55) is given by the equation W = 0.0428 x SL2.8484, with an R2 value of 0.85. Results of Student t-test identified that T. jarbua from these areas exhibit a negative allometric growth pattern, where the fish grows more in length than in weight. High R2 values were obtained from linear regressions between the fish standard length and otolith length (R2 = 0.85), standard length and otolith weight (R2 = 0.83), and standard length and otolith mass (R2 = 0.82), indicating feasibility of otolith measurements in predicting fish size. Based on the pooled age data from all readable otoliths (n = 86) fitted to the von Bertalanffy growth function, this study provides a theoretical maximum length (L∞) of 21.720, curvature parameter (K) of 0.259, theoretical age at length zero (t0) of 0.522, and growth performance (Ф’) of 2.086 for T. jarbua collected from Iligan Bay and Davao Gulf in Mindanao, Philippines. Moreover, the age estimates of T. jarbua reported in the current work presents the first attempt of providing age-growth parameters using sagittal otolith microstructure.

Keywords: age, growth, length-weight relationship, otolith, Terapon jarbua

April 20, 2021September 30, 2021 ovcre.upvisayas

First report of Biecheleriopsis adriatica in Bolinao, Northwestern Philippines and its wide distribution in Southeast Asia and adjacent waters

Philippine Journal of Natural Sciences

First report of Biecheleriopsis adriatica in Bolinao, Northwestern Philippines and its wide distribution in Southeast Asia and adjacent waters

by: Garry A. Benico, Kazuya Takahashi, Wai Mun Lum, Aletta T. Yñiguez, Rhodora V. Azanza, Sandric Chee Yew Leong, Po Teen Lim, Mitsunori Iwataki

Abstract

Morphology and phylogeny of the marine woloszynskioid dinoflagellate Biecheleriopsis adriatica, collected from Philippines, Singapore, Palau and Japan, were examined by using light and scanning electron microscopy (SEM), and molecular phylogeny based on rDNA sequences. Cells of these cultures were ovoid to spherical, measured 11.5–17.3 μm in length, with a displaced cingulum, a sigmoid sulcus and an eyespot. Cells have an elongate apical vesicle (EAV) mostly 3.1–3.8 μm in length with globular knobs up to 32, and straight lower cingular margin in the dorsal side. These morphological characters were identical to those of B. adriatica previously reported from the Adriatic Sea, China, Japan and Korea. Molecular phylogeny based on sequences of ITS and LSU rDNA revealed that the culture isolated from Bolinao, Philippines positioned in a clade with B. adriatica. Cultures isolated from Japan, Palau and Singapore had the identical morphological characters under light microscopy, and cultures investigated were positioned in B. adriatica clade in the phylogenetic tree of ITS and LSU rDNA. B. adriatica co-occurred with a bloom of Takayama sp. associated with mass mortality of farmed milkfish in May 2016 in Bolinao, Philippines. Based on existing data, this species is unlikely the culprit responsible for the massive fish kill event but the results suggest the need for further study to clarify its role in the overall dynamics of algal blooms in Bolinao. The results also show the wide distribution of B. adriatica in Southeast Asia and adjacent waters.

Keywords: Biecheleriopsis adriatica, dinoflagellate, distribution, harmful algal blooms, Southeast Asia, Suessiaceae

April 20, 2021September 30, 2021 ovcre.upvisayas

Physicochemical properties of starches from seed and rhizome of Enhalus acoroides

Philippine Journal of Natural Sciences

Physicochemical properties of starches from seed and rhizome of Enhalus acoroides

by: Nurul Nur Farahin Syed, Muta Harah Zakaria, Japar Sidik Bujang, Shiamala Devi Ramaiya, and K. Hayashizaki

Abstract

Starch, especially from terrestrial plants, is widely used in food and non-food industries. Marine macrophytes such as Enhalus acoroides also provide a considerable amount of starch in their storage parts such as rhizomes and seeds, but these have yet to be explored to fully understand their functionality. This study focused on the morphology, chemical composition and functional properties of starch from Enhalus acoroides collected from Tanjung Adang Laut shoal, Johor, Malaysia.. Starch granules from the seeds were oval, 4.6-28.0 μm in length along the major axis, and possessed a centric Maltese cross, whereas starch granules from the rhizome were rod-shaped, 28.9-53.8 μm long, and with both centric and eccentric Maltese crosses. Seeds yielded 48.9% total starch, much higher than 14.4% in rhizomes. In contrast, resistant starch and amylose accumulated in the rhizomes were 75.3% and 18.8% compared to 1.7% and 10.8% in the seeds, respectively. As for proximate composition, the seeds contained 7.5% protein and 1.4% lipid, both higher than the 3.3% protein and 0.3% lipid in the rhizomes. The phosphorus content of rhizome starch was higher (429.6 mg/kg) than in the seed starch (117.9 mg/kg). X-ray diffractograms showed that the seed starch possessed A-type crystallinity, while rhizome starch was categorized under C-type crystallinity. For starch gelatinization, the seed starch required higher energy (7.7 Jg-1) than the rhizome starch (4.8 Jg-1) while the viscosity value of both seed and rhizome starches were similar. The findings obtained may serve as baseline data and as a guideline on the usage of E. acoroides starches in food and non-food formulations.

Keywords: Enhalus acoroides, starch, amylose, crystallinity, resistant starch

April 20, 2021September 30, 2021 ovcre.upvisayas

Feeding Behaviour of Tilapia (Oreochromis sp.) Fingerlings to Microbeads

Philippine Journal of Natural Sciences

Feeding Behaviour of Tilapia (Oreochromis sp.) Fingerlings to Microbeads

by: Chua Chiew Peng, Ferdaus Binti Mohamat Yusuff

Abstract

We examined the behavior in response to food- and non-food particles, mortality and gut contents of Oreochromis sp. fingerlings exposed for 96 hours to microbeads extracted from a body scrub, which is a mixture of two types of beads, one positively buoyant, green in color, and larger than the other, which is negatively buoyant and whitish. These were termed green (GB) and white beads (WB), respectively. The exposure was done under four different conditions: Tank A, with microbeads only; Tank B, with microbeads and normal food pellets; Tank C, with normal food pellets followed by microbeads; Control Tank, normal food pellets only. Each tank was placed with four fingerlings, 4.0-5.3 cm in total length, and the experiment was duplicated. The water parameters of all tanks were controlled and monitored at DO > 1 mg/L, pH = 6 – 9, temperature = 29 –31 °C. Behavioral response toward microbeads indicated that fingerlings attempted to consume the microbeads intentionally with the absence of food, or accidentally consumed the microbeads in the presence of food. The number of the GB in the gut was 3–66 in Tank A, followed by Tank B (2–29) and Tank C (2–5). The mortality of these fingerlings due to feeding on the microbeads was not confirmed as fatality was also recorded in the control tank, as well as in the experimental tanks.

Keywords: Microbeads, Oreochromis sp., feeding behavior, microplastics pollution, freshwater species

April 20, 2021September 30, 2021 ovcre.upvisayas

Market surveys of elasmobranch fisheries resources in the Tun Mustapha Park, Sabah, Malaysia

Philippine Journal of Natural Sciences

Market surveys of elasmobranch fisheries resources in the Tun Mustapha Park, Sabah, Malaysia

by: Nadine S. Mopilin and B. Mabel Manjaji-Matsumoto

Abstract

Tun Mustapha Park is a unique, multiple use, marine managed area located in the northern part of Sabah, Malaysian Borneo. Elasmobranchs (sharks and rays) are one of the fisheries resources in this area, as elsewhere in Sabah. They are caught by both commercial and artisanal fishers. In this study, a total of 40 species of elasmobranchs comprising 17 sharks and 23 rays were recorded. A few of them were recorded in high abundance (more than 5 but less than 30 individuals per sighting). These were Oriental Bluespotted Maskray (Neotrygon orientalis), Bluespotted Fantail Ray (Taeniura lymma), Sharpnose Whipray (Maculabatis macrura), Whitespotted Whipray (Maculabatis gerrardi), Milk Shark (Rhizoprionodon acutus) and Spot-tail Shark (Carcharhinus sorrah). There are concerns about the status of the elasmobranch populations, which are generally dwindling globally.

Keywords: biodiversity, abundance, sharks and rays, elasmobranch, fisheries

April 20, 2021September 30, 2021 ovcre.upvisayas

Biochemical and Antioxidant Properties of Seagrasses from Tanjung Adang Laut Shoal, Johor, Malaysia

Philippine Journal of Natural Sciences

Biochemical and Antioxidant Properties of Seagrasses from Tanjung Adang Laut Shoal, Johor, Malaysia

by: Lau Sheng Hann Emmclan, Muta Harah Zakaria, Fatin Mohd Ikhsan Natrah, Japar Sidik Bujang and K. Hayashizaki

Abstract

The search for marine phytochemicals as an alternative antioxidant source has gained considerable attention in the past few decades. This study attempts to determine the biochemical composition and antioxidant activity of five seagrass species, i.e., Enhalus acoroides, Halophila spinulosa, Cymodocea serrulata, Halodule uninervis and Syringodium isoetifolium based on their leaf and rhizome. The seagrass methanolic extracts were used to determine the total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power activity (FRAP), 2,2-diphenyl-1-picrylhydrazyl activity (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline- 6-sulphonic acid activity (ABTS). Significantly higher (p<0.05) TFC was obtained in seagrass leaves compared to rhizomes for all species, with H. spinulosa getting the highest record of 68.37 ± 2.92 mg QE/g. A very strong correlation was observed between rhizome’s TPC and FRAP (r=0.99, p<0.05), and DPPH (r=0.97, p<0.05) and ABTS (r=0.99, p<0.05) activities, indicating the antioxidant activities are attributable to phenolic compounds from seagrass extracts. Total phenolic content was highest in E. acoroides rhizomes (76.19 ± 3.37 mg GAE/g) and the rhizome of this species possessed significantly higher (p<0.05) antioxidant activity in terms of FRAP (10.56 ± 0.74 x 10-4 mg Fe2+/g), DPPH (114.99 ± 2.17 μM TE/g) and ABTS (144.34 ± 10.67 μM TE/g) compared to similar parts of other seagrass species. These values were also significantly higher (p<0.05) than synthetic antioxidant butylated hydroxytoluene (FRAP activity 3.70 ± 0.12 x 10-4 mg Fe2+/g and DPPH activity 45.80 ± 0.83 μM TE/g) and commercial ascorbic acid (DPPH activity 94.33 ± 0.42 μM TE/g), suggesting their potentials as alternative natural antioxidant sources. Further studies are required to isolate and identify these compounds that are responsible for the antioxidant activity.

Keywords: seagrass, biochemical, antioxidant activity

April 20, 2021September 30, 2021 ovcre.upvisayas

Zygote culture and zoospore release experiment of a green seaweed Monostroma nitidum Wittrock (Chlorophyta) for possiblemass cultivation in Taiwan

Philippine Journal of Natural Sciences

Zygote culture and zoospore release experiment of a green seaweed Monostroma nitidum Wittrock (Chlorophyta) for possible mass cultivation in Taiwan

by: Hsih-Hsin Chen, Ai-Meng Cheng, Chuan-Wen Chen, Ching-Yi Cheng, Masayoshi Matsuoka, Li-Chin Chou, Hisao Ogawa, and I Chiu Liao

Abstract

Artificial seed production and field culture experiments of Monostroma nitidum Wittrock, a green seaweed grown in Taiwan, was conducted. Mature fronds were collected on February 20, 2017. Gametes were released in the following morning from them and their fusion was observed. Zygotes developed into cyst-like forms called Codiolum-cyst and were cultured under room conditions with temperature range of 23–290C until they grew to 36.3±3.2 μm in August. Dark treatment to induce the maturity was applied to them from September 12 to October 30. On November 1, zygotes kept under dark conditions were taken out to the outdoor tank to release zoospores and to collect them on culture nets, which were then kept for five weeks in the tank. The nets were opened in the sea at Jiang-Mei on December 8, 2017. Young fronds about 5–8 cm in length were observed on January 10, 2018 which grew to over 10 cm in length by February 6, 2018. Through the experiments, the dark treatment proved to be effective in inducing gamete release and to synchronizing zygote maturity of M. nitidum.

Keywords: tropical seaweed, Monostroma nitidum, artificial seed production, culture condition

April 19, 2021May 20, 2022 ovcre.upvisayas

Influence of fish feeds with plant proteins on sediment quality conditions: A microcosm experiment

Philippine Journal of Natural Sciences

Influence of fish feeds with plant proteins on sediment quality conditions: A microcosm experiment

by: Jirah P. Mamigo, Sheila Mae S. Santander-de Leon

Abstract

Plant proteins have been widely utilized for aquaculture however its environmental effects remained understudied. A microcosm experiment was conducted to determine the effects of feed types (feeds with plant protein vs feeds with fishmeal only) and feed levels on sediment quality conditions. Sediments were treated with three feed types composed of different protein sources: a) fishmeal only (FM) b) soybean, copra, and fishmeal (SC); and c) soybean, wheat, and fish meal (SW) at low feed (LF, 0.07 g) and high feed (HF, 0.40 g) levels; and incubated for 20 days. Results revealed that all feed treatments created anoxic (redox potential, -103 to -135 mV) and toxic sulfidic sediment conditions (FM, > 2.5 mg. g-1, and SC and SW > 1.7 mg. g-1). Effects of differences in feed types were apparent on higher pore water Ammonium – N concentrations in plant-added fish feeds SC (414.08 ± 29.32 ppm) and SW (310.45 ± 113.18 ppm) than in FM (249.43 ± 86.95 ppm) at HF level. Protein concentration in sediments was highest in SW feed type. Effects of LF and HF did not show significant differences but both clearly showed poor sediment quality conditions when compared to sediments without feeds. The results suggest that the current use of plant-proteins as an alternative to fishmeal in aquaculture feeds may pose similar deleterious effects to sediment quality.

Keywords: fish feeds, plant protein, fishmeal, sediment quality, total sulfides