Feeding ecology of two sympatric species of Acetes (Decapoda: Sergestidae) in Panguil Bay, the Philippines

2016 ◽  
Vol 67 (10) ◽  
pp. 1420
Author(s):  
Ephrime B. Metillo ◽  
Emily E. Cadelinia ◽  
Ken-ichi Hayashizaki ◽  
Takashi Tsunoda ◽  
Shuhei Nishida
Keyword(s):  
Feeding Habits ◽  
Isotope Analysis ◽  
Prey Type ◽  
Sympatric Species ◽  
The Philippines ◽  
Food Sources ◽  
Gut Contents ◽  
Night Time ◽  
Trophic Pathways ◽  
Gut Fullness

Sergestid shrimps of the genus Acetes are important in global shrimp fisheries and nearshore food-webs. The feeding habits of the sympatric species Acetes erythraeus and A. intermedius from Panguil Bay, Philippines were studied using gut contents and stable isotopes analyses. Both species are omnivorous suspension feeders of plankton, macrophyte detritus, and amorphous particulate organic materials. However, the diet of adults and juveniles differed by prey type. Gut fullness differed over 24h with a night-time peak in A. erythraeus and morning and midnight peaks in A. intermedius. Over 1 year gut fullness peaked during July to September for both species, with a minor peak during January for A. intermedius. Stable isotope analysis revealed similar δ15N values, but both species showed ontogenetic and interspecific separation of δ13C. A. erythraeus seemed to assimilate highly depleted carbon food sources by mangrove-based detrital and plankton trophic pathways, whereas A. intermedius relied on plankton and macroalgal and seagrass detrital pathways. These trophic differences may be mechanisms of partitioning the feeding niche, but allotopy in the two species with A. erythraeus confined to more brackish waters and A. intermedius dwelling in more saline marine waters may indicate that habitat niche segregation underlies these contrasting carbon trophic pathways.

Feeding habits of the burrowing shrimp Alpheus macellarius

2004 ◽  
Vol 84 (6) ◽  
pp. 1199-1202 ◽  
Author(s):  
N.E. Palomar ◽  
M.A. Juinio-Meñez ◽  
I. Karplus
Keyword(s):  
Organic Matter ◽  
Feeding Habits ◽  
Organic Matter Content ◽  
The Philippines ◽  
Matter Content ◽  
Food Sources ◽  
Feeding Mode ◽  
Field Surveys ◽  
Sea Grass ◽  
Deposit Feeding

The diet and feeding behaviour of the burrowing shrimp Alpheusmacellarius (Decapoda: Alpheidae) in sea grass beds in the Philippines were evaluated in the present study through field and laboratory activities. Sediment organic matter and sea grass appear to be important food sources for the shrimp based on the combined results of field surveys, gut content, stable isotope (δ13C) and sediment C content analyses. There was a significant positive correlation between organic matter content in the sediment and shrimp densities. In terms of behaviour, observations under controlled set-ups detected marked trends in duration and frequency of feeding. Feeding bouts became longer and more recurrent as the days progressed. Periodicity was exhibited with burrowing generally performed in the morning and feeding in the afternoon. A deposit-feeding mode was predominant in tank conditions as demonstrated by the shrimp's behaviour and burrow features.

Gut content and stable isotope analysis of tadpoles in floodplain wetlands

2018 ◽  
Vol 66 (4) ◽  
pp. 261 ◽  
Author(s):  
J. F. Ocock ◽  
K. J. Brandis ◽  
B. J. Wolfenden ◽  
K. M. Jenkins ◽  
S. Wassens
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Management Strategies ◽  
Isotope Analysis ◽  
Food Sources ◽  
Gut Contents ◽  
Floodplain Wetlands ◽  
Gut Content ◽  
Larval Amphibians ◽  
Aquatic Food

Larval amphibians (tadpoles) are an important link in aquatic food webs, as they can be highly abundant consumers and prey for a wide variety of predators. Most tadpoles are considered omnivores, predominately grazing on algae, detritus and macrophytes, though recent work has identified greater plasticity and breadth in diet than previously considered. We used gut content and stable isotope analysis (SIA) in a baseline study to determine the important dietary items (ingested material) and food sources (assimilated material) for tadpoles of two abundant generalist frog species in regulated floodplain wetlands of the Murrumbidgee River, south-east Australia. We identified a wide variety of dietary items in the gut contents, including whole microcrustaceans, filamentous algae and macrophytes. The composition of several ingested food items was correlated with their availability in each wetland. However, SIA identified biofilm as the food source most consistently assimilated across several wetlands, though microcrustaceans and algae contributed when abundant. Biofilm is likely the most important basal food item for tadpoles in floodplain wetlands because it is ubiquitous and has a high nutritional quality. Identifying important food sources is a crucial step towards developing management strategies for promoting tadpole recruitment in regulated wetlands.

Feeding behaviour and bioerosion: the ecological role of the rock-boring urchin, Echinometra mathaei (de Blainville, 1825), in Okinawa reef flat

2013 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Noar Muda Satyawan ◽  
Shelly Tutupoho ◽  
Yusli Wardiatno ◽  
Makoto Tsuchiya
Keyword(s):  
Feeding Behaviour ◽  
Reef Flat ◽  
Type A ◽  
Gut Contents ◽  
Biological Processes ◽  
Type B ◽  
Night Time ◽  
Echinometra Mathaei ◽  
Benthic Ecosystems

Erosion rate on corals due to activities of other biota is called bioerosion. The rock-boring urchin, Echinometra mathaei, when it is abundant, plays a significant role in benthic ecosystems, including biological processes like coral erosion. During feeding, E. mathaei erodes calcium carbonate besides grazing on algae living on coral, so it plays an important role in both organic and inorganic carbons in coral reefs. The urchin E. mathaei actively feeds during the night time (nocturnal grazer). Although in Okinawa four types (A-D) of the urchin exist, the research only focused on the types A and B. Type A of E. mathaei produced 0.44951 g feces per day on average while type B produced 0.38030 g feces per day. CaCO3 analysis in feces and gut contents showed bioerosion rate of E. mathaei type A was 0.64492 g/individu/day, and 0.54436 g/individu/day in type B. There were no significant differences in bioerosion impact of E. mathaei type A and B© Laju erosi pada karang yang disebabkan oleh biota, dikenal dengan bioerosi. Bulu babi jenis Echinometra mathaei, ketika melimpah, menjadi sangat berpengaruh terhadap ekosistem bentik termasuk proses biologi seperti erosi karang. Selama aktivitas makan, E. mathaei menggerus kalsium karbonat dalam proporsi yang besar di samping alga yang tumbuh menempel pada karang sehingga memiliki peran penting dalam siklus karbon organik dan anorganik di ekosistem terumbu karang. Bulu babi E. mathaei aktif mencari makan pada malam hari (nocturnal grazer). Meskipun di Okinanawa ada 4 tipe (A-D), pada eksperimen kali ini memfokuskan pada tipe A dan B saja. Tipe A E. mathaei rata-rata memproduksi 0,44951 g feses/hari dan tipe B memproduksi 0,38030 g feses/hari. Berdasarkan analisis CaCO3 yang dilakukan pada feses dan isi lambung, laju bioerosi yang disebabkan oleh E. mathaei tipe A sebesar 0,64492 g/individu/hari sedangkan tipe B sebesar 0,54436 g/individu/hari. Tidak terdapat perbedaan dampak bioerosi yang signifikan antara E. mathaei tipe A dan B©

Feeding ecology of Symbolophorus californiensis larvae (Teleostei: Myctophidae) in the southern transition region of the western North Pacific

2009 ◽  
Vol 90 (6) ◽  
pp. 1249-1256 ◽  
Author(s):  
Chiyuki Sassa
Keyword(s):  
Transition Region ◽  
North Pacific ◽  
Western North Pacific ◽  
Developmental Stages ◽  
Feeding Habits ◽  
Larval Growth ◽  
Trophic Niche ◽  
Size Class ◽  
Gut Contents ◽  
Wide Range

The feeding habits of myctophid larvae of Symbolophorus californiensis were examined in the southern transition region of the western North Pacific where the main spawning and nursery grounds of S. californiensis are formed. This species is a key component of the pelagic ecosystems of this region, and their larvae attain one of the largest sizes among myctophids. To analyse gut contents larvae, including most life history stages after yolk-sac absorption (3.7 to 22.2 mm body length (BL)), were collected in the upper 100 m layer in 1997 and 1998. Feeding incidence was higher during the day than at night (53.1–92.3% versus 0–5.6%), and daytime feeding incidence increased gradually with larval growth. Larvae fed mainly on copepods of various developmental stages. Larvae of S. californiensis showed an ontogenetic change in their diet: larvae ≤7.9 mm BL (i.e. preflexion stage) fed mainly on copepod eggs and nauplii, while the larvae ≥8 mm BL consumed mainly calanoid copepodites such as Pseudocalanus and Paracalanus spp. In the largest size-class (16–22.2 mm BL), the furcilia stage of euphausiids was also an important prey item. There was an increase in the average prey size with growth in larvae ≤11.9 mm BL, while the number of prey eaten positively correlated with growth in larvae ≥12 mm BL. The trophic niche breadth also increased with larval growth, which would ensure a wide range of available food resources for the larger size-class larvae.

scholarly journals Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis

2006 ◽  
Vol 86 (6) ◽  
pp. 1443-1447 ◽  
Author(s):  
D. Fourgon ◽  
G. Lepoint ◽  
I. Eeckhaut
Keyword(s):  
Stable Isotopes ◽  
Potential Benefit ◽  
Feeding Habits ◽  
Isotope Analysis ◽  
Tracer Experiment ◽  
Trophic Relationships ◽  
Nitrogen Stable Isotopes ◽  
Carbon And Nitrogen ◽  
C And N ◽  
The One

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiuroids. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate δ13C values between both adult species. The high proportion of 13C in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston from their associated host, O. scolopendrina.

Food sources for the bivalve Corbicula japonica in the foremost fishing lakes estimated from stable isotope analysis

2006 ◽  
Vol 72 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Akihide KASAI ◽  
Haruhiko TOYOHARA ◽  
Akiko NAKATA ◽  
Tsunehiro MIURA ◽  
Nobuyuki AZUMA
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Food Sources ◽  
Corbicula Japonica

scholarly journals Measuring the Street Layout Orientation Entropy of Cities in the Philippines

2019 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Homer Pagkalinawan
Keyword(s):  
Environmental Variables ◽  
The Philippines ◽  
City Development ◽  
Street Network ◽  
Poverty Level ◽  
Night Time ◽  
Quezon City ◽  
Street Layout ◽  
Urban Heat ◽  
The Difference

<p><strong>Abstract.</strong> Selected cities in the Philippines follow, to a certain extent, an organized street layout and orientation based on a designed plan including major cities like Manila and Quezon City. However, others cities developed organically on a less organized manner, expanding haphazardly. Being the spatial backbone of these cities, street patterns controls and limits the flow of people, goods, and activities. Measuring entropy, or the state of orderliness or disorderliness, of a street network can assess the difference between a planned and an unplanned city development. Possibly, it can be correlated to the various socioeconomic variables e.g. population, density, income level, poverty level, etc. or environmental variables e.g. night time light data, urban heat, vegetation cover, etc., that characterizes a city.</p>

scholarly journals Sonar Technology Assisted Vehicle Sensor

2019 ◽  
Vol 8 (4) ◽  
pp. 2505-2510
Keyword(s):  
Mobile Communications ◽  
Text Messaging ◽  
The Philippines ◽  
World Health ◽  
Delayed Response ◽  
State University ◽  
Night Time ◽  
Usability Tests ◽  
Gps System ◽  
Vehicle Sensor

In the Philippines, more than half of its vehicular accidents are caused by motorcycles, and most of the reasons why these accidents are happening is because of distracted driving, lowered road awareness, delayed response to emergency such as accidents, and over speeding to name a few as confirmed by World Health Organization’s reports. Premised on this idea, the researchers decided to design, develop, and test a device that would provide a solution to this. Thus, the title “Sonar Technology Assisted Vehicle Sensor” was created. The device was completed after three months of research and development in Eastern Samar State University Salcedo Campus. Results of the four-stage test: the Benchmark; Alpha; Beta; and Usability tests indicated that the Sonar Technology Assisted Vehicle Sensor is fully functional and can detect vehicles approaching and can produce corresponding alarms, and can now be implemented. As an additional feature, the device has been imbedded with a Global Positioning System (GPS) Tracker that activates whenever an accident happens to the user/rider. The GPS Tracker would extract the device’s location and the system would automatically send the data to appropriate authorities using its Global System for Mobile Communications (GSM) shield through text messaging. The researchers recommend that the device should be marketed directly to motorcycle companies; its GPS system should be submitted for further testing, while the image processing should be trained in computers with RAM size of 8 GB and should be tested paired with an infrared lamp to maximize its use in night time traveling conditions.

scholarly journals Floating nurseries? Scyphozoan jellyfish, their food and their rich symbiotic fauna in a tropical estuary

2018 ◽  
Author(s):  
José M Riascos ◽  
Willington Aguirre ◽  
Charlotte Hopfe ◽  
Diego Morales ◽  
Ángela Navarrete ◽  
...  
Keyword(s):  
Surface Waters ◽  
The Body ◽  
Food Sources ◽  
Gut Contents ◽  
Estuarine System ◽  
Symbiotic Association ◽  
Bell Diameter ◽  
Associated Fauna ◽  
Size Relationship ◽  
Scyphozoan Jellyfish

The anthropogenic modification of basal trophic pathways is seemingly prompting the increase of jellyfish populations at the expense of planktivorous fishes. However, gross generalizations are often made because the most basic aspects of trophic ecology and the diverse interactions of jellyfish with fishes remain poorly described. Here we inquire on the dynamics of food consumption of the medusoid stage of the scyphozoan jellyfish Stomolophus meleagris and characterize the traits and diversity of its symbiotic community. S. meleagris and their associated fauna were sampled in surface waters between November 2015 and April 2017 in Málaga Bay, an estuarine system at the Colombian Pacific. Stomach contents of medusae were examined and changes in prey composition and abundance over time analysed using a multivariate approach. The associated fauna was identified and the relationship between the size of medusae and the size their symbionts tested using least-square fitting procedures. The presence of S. meleagris medusa in surface waters was seasonal. The gut contents analysis revealed that algae, copepods and fish early life stages were the more abundant items, and PERMANOVA analysis showed that the diet differed within the seasons (P(perm)=0.001) but not between seasons (P(perm)=0.134). The majority of the collected medusae (50.4 %) were associated to individuals of 11 symbiotic species, 95.3% of them fishes, 3.1% crustaceans and 1.6% molluscs. Thereby, this study reports 10 previously unknown associations. The bell diameter of S. meleagris was positively related to the body sizes of their symbionts. However, a stronger fit was observed when the size relationship between S. meleagris and the fish Hemicaranx zelotes was modelled. The ocurrence of S. meleagris was highly seasonal, and the observed patterns of mean body size through the seasons suggested the arrival of adult medusae to the estuary from adjacent waters. The diet of S. meleagris in the study area showed differences with previous reports, chiefly because of the consistent abundance of algae that are seemingly ingested but not digested. The low number of zooplanktonic items in gut contents suggest the contribution of alternative food sources not easily identifiable. The observed changes in the composition of food in the guts probably reflect seasonal changes in the availability of prey items. The regular pattern in the distribution of symbionts among medusae (a single symbiont per host) and the positive host-symbiont size relationship reflects antagonistic intraspecific and interspecific behaviour of the symbiont. This strongly suggest that medusa represent an “economically defendable resource” that potentially increases the survival and recruitment of the symbionts to the adult population. We argue that, if this outcome of the symbiotic association can be proven, scyphozoan jellyfish can be regarded as floating nurseries.

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