National Committee on Marine Sciences (NCMS)
Permanent URI for this communityhttps://repository.unesco.gov.ph/handle/123456789/6
Browse
8 results
Search Results
- Microbiome diversity and host immune functions influence survivorship of sponge holobionts under future ocean conditionsPosadas, Niño; Baquiran, Jake Ivan P; Nada, Michael Angelou L; Kelly, Michelle; Conaco, Cecilia (Oxford University Press, 2021-07-03)The sponge-associated microbial community contributes to the overall health and adaptive capacity of the sponge holobiont. This community is regulated by the environment and the immune system of the host. However, little is known about the effect of environmental stress on the regulation of host immune functions and how this may, in turn, affect sponge–microbe interactions. In this study, we compared the bacterial diversity and immune repertoire of the demosponge, Neopetrosia compacta, and the calcareous sponge, Leucetta chagosensis, under varying levels of acidification and warming stress based on climate scenarios predicted for 2100. Neopetrosia compacta harbors a diverse microbial community and possesses a rich repertoire of scavenger receptors while L. chagosensis has a less diverse microbiome and an expanded range of pattern recognition receptors and immune response-related genes. Upon exposure to RCP 8.5 conditions, the microbiome composition and host transcriptome of N. compacta remained stable, which correlated with high survival (75%). In contrast, tissue necrosis and low survival (25%) of L. chagosensis was accompanied by microbial community shifts and downregulation of host immune-related pathways. Meta-analysis of microbiome diversity and immunological repertoire across poriferan classes further highlights the importance of host–microbe interactions in predicting the fate of sponges under future ocean conditions.We thank Francis Kenith Adolfo, Robert Valenzuela, and Ronald De Guzman for field and hatchery assistance and staff of the Bolinao Marine Laboratory for logistical support. This study was funded by the Department of Science and Technology Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (QMSR-MRRD-MEC-295-1449) to CC.
- Fish farm effluents alter reef benthic assemblages and reduce coral settlementQuimpo, Timothy Joseph R.; Ligson, Charlon A.; Manogan, Dana P.; Requilme, Jeremiah Noelle; Albelda, Ritzelle L.; Conaco, Cecilia; Cabaitan, Patrick C. (Elsevier Ltd., 2020)Fish farming in coastal areas is a rapidly growing industry. However, unregulated fish farming practices that release massive amounts of unconsumed feed and fecal material into the water column, can result in a nutrient enriched environment that extends to nearby reef systems. To understand the impact of fish farm effluent on coral settlement, we tested the settlement rate of Pocillopora acuta larvae on artificial substrates conditioned for 12 weeks at three sites with increasing distance (2–10 km) from fish farms in Bolinao, Philippines. Sites far from the fish farms had higher biofilm and crustose coralline algae cover. In contrast, the site closest to the fish farms, where nutrient levels were higher, had greater sediment and turf algae cover. Tiles conditioned at the farther sites promoted higher (6–8%) larval settlement whereas tiles from the nearer site had lower settlement (3%). These findings show that fish farm effluents can indirectly affect coral settlement on adjacent reefs by promoting growth of other biota that may inhibit larval settlement and by reducing the availability of suitable substrate.
- Detection of horizontal gene transfer in the genome of the choanoflagellate Salpingoeca rosettaMatriano, Danielle M.; Alegado, Rosanna A.; Conaco, Cecilia (Springer, 2021-03-16)Horizontal gene transfer (HGT), the movement of heritable materials between distantly related organisms, is crucial in eukaryotic evolution. However, the scale of HGT in choanoflagellates, the closest unicellular relatives of metazoans, and its possible roles in the evolution of animal multicellularity remains unexplored. We identified at least 175 candidate HGTs in the genome of the colonial choanoflagellate Salpingoeca rosetta using sequence-based tests. The majority of these were orthologous to genes in bacterial and microalgal lineages, yet displayed genomic features consistent with the rest of the S. rosetta genome—evidence of ancient acquisition events. Putative functions include enzymes involved in amino acid and carbohydrate metabolism, cell signaling, and the synthesis of extracellular matrix components. Functions of candidate HGTs may have contributed to the ability of choanoflagellates to assimilate novel metabolites, thereby supporting adaptation, survival in diverse ecological niches, and response to external cues that are possibly critical in the evolution of multicellularity in choanoflagellates.We thank Joshua Dizon and Francis Tablizo of the Philippine Genome Center Core Facility for Bioinformatics for assistance with scripts and database construction. We thank Becca Lensing (University of Hawai’i), Cheryl Andam (University of New Hampshire), Deo Onda and Ron Leonard Dy (University of the Philippines) for insightful comments and suggestions on the analysis and interpretation of the data. This work was supported by thesis grants from the Department of Science and Technology Accelerated Science and Technology Human Resource Development Program-National Science Consortium (DOST-ASTHRDP-NSC) and the University of the Philippines Marine Science Institute to DM.
- Variation in epibiont communities among restocked giant clam species (Cardiidae: Tridacninae) and across different habitat typesde Guzman, Ian Joseph A.; Cabaitan, Patrick C.; Hoeksema, Bert W.; Sayco, Sherry Lyn G.; Conaco, Cecilia (Springer, 2023-07-07)Giant clam shells provide a solid substrate for various species of epibionts. Yet, it is not well known how epibiont communities vary among populations of different giant clam species and in giant clams restocked in different habitat types. Here, we examined differences in the epibiont communities of three species of giant clams with different shell morphology (Tridacna gigas, Tridacna derasa, and Hippopus hippopus), and characterized the epibiont communities on T. gigas from three different habitat types (sandy reef flat, seagrass bed, and coral reef). Tridacna gigas had higher species richness, abundance, and cover of epibionts compared to the other two species. Tridacna gigas in coral reef habitat also displayed higher species richness and cover of sessile epibionts, while the same species in the sandy reef flat had higher species richness and abundance of mobile epibionts. Epibiont communities were more variable across habitat types than among different giant clam species restocked in a similar area. Differences in abundance of Trochus sp., Pyramidella sp., and crustose coralline algae contributed to the variability in epibiont communities among the giant clam species and across habitats. A few taxa were observed only on specific giant clam species and sites. For instance, Diadema sp. and Echinometra sp. were found only on T. gigas, and Diadema sp. was present only in the sandy reef flat. Both the complexity of the giant clam shells and habitat type contribute to differences in associated epibiont communities. This further emphasizes the ecological importance of giant clams as habitats for other invertebrates.The authors acknowledge Jun Castrence and the staff of Bolinao Marine Laboratory for assistance with field work. We also acknowledge the assistance of Edwin Dumalagan with coral and algae identification, Timothy Quimpo for his assistance and advice on statistical analysis, and Elizabeth Gomez for her assistance in generating the map of study sites. Lastly, we would like to thank members of the Coral Reef Ecology Laboratory (CoRE) for their helpful comments and suggestions on the study. This study was supported by a grant from the Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development of the Department of Science and Technology to PCC and CC (QMSR-MRRD-MEC-314-1542) and a Department of Science and Technology ASTHRDP Scholarship and University of the Philippines Marine Science Institute Thesis Writing Grant 2020 to ID. We thank the reviewers for the suggestions that helped improve our paper.
- Ontogenetic variability in the diel activity pattern of the marine gastropod Cassis cornuta(Mollusca: Cassidae)Calle, Lala Grace; Cabaitan, Patrick C; Sayco, Sherry Lyn G; Tan, Shau Hwai; Conaco, Cecilia (Oxford University Press, 2024-01-25)Examining activity patterns is essential in understanding gastropod feeding and movement ecology. However, the diel activity patterns of large-bodied gastropods, such as Cassis cornuta, remain poorly studied. Here, we conducted outdoor hatchery-based experiments to examine the diel activity patterns of C. cornuta adults and juveniles under natural sunlight and photoperiod. Activities of C. cornuta, such as crawling, hunting, feeding, burrowing and resting on the substratum, were examined every hour for 3 days. Although most individuals were inactive for a greater part of the observation period, active behaviours were recorded for some individuals during both daytime and nighttime, suggesting that C. cornuta is cathemeral, as supported by a nonsignificant result from a Rayleigh's test of uniformity. A higher proportion of adult and juvenile C. cornuta were inactive, either burrowed or resting on the substratum, during the 24-h period. Peak activity time for juveniles started at 20:00, with up to 50% of individuals active, while peak activity time for adults started at 21:00, with up to 20% of active individuals. Adults spent more time resting aboveground, whereas juveniles spent more time burrowed under the sand when not feeding. Juveniles hunted more frequently and spent more time feeding compared to adults. Additionally, juveniles crawled faster and were more successful in capturing sea urchins than adults. The information on variability in the diel activity patterns and movement rates between adult and juvenile C. cornuta would allow further demographic studies, and provide insights into possible conservation strategies for this species.
- Fish and benthic communities in an offshore and well-managed coral reef after bleaching disturbance in the PhilippinesQuimpo, Timothy Joseph R.; Requilme, Jeremiah Noelle; Gomez, Elizabeth; Sayco, Sherry Lyn; Dumalagan, Edwin E.; Siringan, Fernando P.; Conaco, Cecilia; Cabaitan, Patrick C. (Springer, 2023-08-29)Climate change is perhaps the greatest threat to coral reefs worldwide. However, there is spatial variation in the extent and severity of this disturbance, with offshore and well-managed reefs presumed to be less vulnerable to anthropogenic disturbance. Here, fish and benthic communities at the offshore and well-managed reefs of Apo Reef Natural Park, Philippines, were examined during a bleaching disturbance in 2016 and reassessed 2 (2018) and 3 years (2019) after using scuba surveys. Results showed that benthic communities varied more strongly with year attributed to changes in the benthic cover of coral. These changes were influenced by site, with some sites experiencing coral loss of 41–48%, while other sites exhibited minimal changes. Site differences in coral loss may be associated with coral cover, with sites that had high coral cover prior to bleaching incurring larger loss of coral cover. Fish communities varied more with sites and was associated with differences in the predominant benthos. The stability of fish communities with year despite coral loss may be attributed to the minimal loss of coral cover at some sites. For sites that experienced high losses of coral cover, the presence of alternative and deeper habitats may have provided shelter and food for more mobile fishes maintaining taxonomic composition within sites. This study shows that bleaching disturbance circumvents effective management, but impacts are variable even at small (≤ 3 km) spatial scales. Benthic community composition and presence of alternative habitats potentially alleviate the negative impacts of bleaching on reef fish diversity and abundance.We are grateful to the laboratory assistants F Castrence, R de Guzman, B Gabuay, R Valenzuela and K Adolfo for their assistance in the fieldwork. We thank the comments and criticisms of two anonymous reviewers that greatly improved the content of this manuscript.
- Microbial community structure and settlement induction capacity of marine biofilms developed under varied reef conditionsPadayhag, Blaire M.; Nada, Michael Angelou L.; Baquiran, Jake Ivan P.; Sison-Mangus, Marilou P.; San Diego-McGlone, Maria Lourdes; Cabaitan, Patrick C.; Conaco, Cecilia (Elsevier, 2023-08)Coral larval settlement relies on biogenic cues such as those elicited by microbial biofilm communities, a crucial element of coral recruitment. Eutrophication can modify these biofilm-associated communities, but studies on how this affects coral larval settlement are limited. In this study, we developed biofilm communities on glass slides at four sites with increasing distance from a mariculture zone. Biofilms farthest from the mariculture area were more effective at inducing the settlement of Acropora tenuis larvae. These biofilms were characterized by a greater proportion of crustose coralline algae (CCA) and gammaproteobacterial taxa compared to biofilms from sites closer to the mariculture zone, which had a greater proportion of cyanobacteria and no CCA. These findings suggest that nutrient enrichment due to mariculture activities alters the composition of biofilm-associated microbiome at nearby reef sites and indirectly causes poor coral larval settlement.
- Gene networks governing the response of a calcareous sponge to future ocean conditions reveal lineage-specific XBP1 regulation of the unfolded protein responsePosadas, Niño; Conaco, Cecilia (John Wiley and Sons, 2024)Marine sponges are predicted to be winners in the future ocean due to their exemplary adaptive capacity. However, while many sponge groups exhibit tolerance to a wide range of environmental insults, calcifying sponges may be more susceptible to thermo-acidic stress. To describe the gene regulatory networks that govern the stress response of the calcareous sponge, Leucetta chagosensis (class Calcarea, order Clathrinida), individuals were subjected to warming and acidification conditions based on the climate models for 2100. Transcriptome analysis and gene co-expression network reconstruction revealed that the unfolded protein response (UPR) was activated under thermo-acidic stress. Among the upregulated genes were two lineage-specific homologs of X-box binding protein 1 (XBP1), a transcription factor that activates the UPR. Alternative dimerization between these XBP1 gene products suggests a clathrinid-specific mechanism to reversibly sequester the transcription factor into an inactive form, enabling the rapid regulation of pathways linked to the UPR in clathrinid calcareous sponges. Our findings support the idea that transcription factor duplication events may refine evolutionarily conserved molecular pathways and contribute to ecological success.