Diet-tissue stable isotopic fractionation of tropical sea cucumber, Holothuria scabra
jircas.affrc.go.jp Abstract
To provide a basis for a stable carbon and nitrogen isotope ratio (δ13C / δ15N) analysis to determine the assimilated organic matter in sea cucumber, Holothuria scabra, diet-tissue fractionations were experimentally determined by mono-feeding rearing with diatom. While δ15N fractionation of the whole body wall (2.4‰) was similar to the commonly accepted value (2.6 - 4‰), δ13C fractionation of the body wall (4.2‰) showed considerable discrepancy with the commonly accepted value (0 - 1‰) due to the high content (35% dry wt/wt) of calcareous spicules (CaCO3) in the body wall, which had significantly higher δ13C (-8.6‰) than the organic fractions. Computational elimination of spicules based upon spicule content and spicule δ13C reduced the δ13C fractionation of the body wall to 1.5‰, close to the common value. δ13C fractionation after spicule removal by acid decarbonation and subsequent rinsing (3.2‰) did not agree with the common value, and δ15N fractionation was significantly elevated by decarbonation. δ15N and δ13C fractionations of the intestine (1.5 and 2.2‰, respectively) did not agree with the common values. Since δ13C and δ15N of the feces did not differ significantly from those of the diet, feces may be used to determine ingested organic matter in the wild.
Citation
Watanabe, S., Kodama, M., Sumbing, J. G., & Lebata-Ramos, M. J. H. (2013). Diet-tissue stable isotopic fractionation of tropical sea cucumber, Holothuria scabra.Publisher
Japan International Research Center for Agricultural Sciences (JIRCAS)Subject
Acknowledgment/Sponsorship
This study was funded by the Japan International Research Center for Agricultural Sciences (JIRCAS).
Collections
- Journal Articles [1049]
Related items
Showing items related by title, author, creator and subject.
-
Article
Stable carbon and nitrogen isotope ratios of penaeid juveniles and primary producers in a riverine mangrove in Guimaras, Philippines
-Bulletin of Marine Science , 1996 - University of Miami, Rosenstiel School of Marine and Atmospheric ScienceStable carbon and nitrogen isotope ratios were analyzed for primary producers and juveniles of four penaeid species (Metapenaeus ensis, Penaeus indicus, P. merquiensi and P. monodon) in a riverine mangrove in Guimaras, central Philippines. δ13C values of shrimp (- 15.5 to - 19.6‰) were closer to phytoplankton (-23.8‰) and possibly epiphytic algae (-24.2‰) than to mangrove leaves (-26.9 to -30.0‰) or detritus (-28.0‰). Differences in δ15N values suggested 2-3 trophic shifts between phytoplankton (0.6‰) and shrimp (6.9‰), assuming a 2.4‰ enrichment per trophic level. There were no significant differences in δ13C and δ15N ratios between green and decomposing leaves, and among mangrove species, shrimp species and different size groups of shrimp. -
Article
Clearance rates and ingestion efficiency of the Japanese scallop Patinopecten yessoensis
-Plankton and Benthos Research , 2013 - Plankton Society of JapanIn coastal ecosystems, variations in food quantity may have significant effects on the clearance and ingestion rates of suspension-feeding bivalves. In this study, clearance rates and ingestion efficiencies were determined for Japanese scallop (Patinopecten yessoensis) juveniles (60.6±4.5 mm in shell height) under laboratory conditions. Scallops were kept individually in glass beakers at 15°C and fed with different cell numbers of Pavlova sp. (0.8 to 57.60×106 cells) to provide a wide range of food quantity as particulate organic carbon (POC). Clearance rates (CR) and ingestion efficiencies (IE) were estimated by monitoring POC concentration over a two-day period, and from 2 to 14 days of feeding, respectively. Both CR and IE were significantly influenced by POC concentration. CR ranged from 15.8 to 38.5 mL ind-1 h-1 (or 8.9 to 49.6 mg Ch-1 g dry weight-1) with maximum values at high POC concentrations. IE varied from 40 to 71% and differed significantly between the lowest (2,900 μg C L-1) and highest (8,000 μg C L-1) food rations. The feeding response of juvenile scallops to different POC concentrations was fitted to a power curve equation: IE (%)=0.9272×POC0.5105, r=0.98. Extrapolated field-based estimates of IE ranged from 7.8 to 12.7% in response to seasonal changes in POC concentration (64.5 to 168.6 μg C L-1). It is concluded that particle filtration rates by juvenile scallops are related to food quantity, as suggested by both field and laboratory-derived feeding rates. -
Conference paper
Effects of CO2-induced ocean environmental changes on marine life: implications for aquaculture.
- In BO Acosta, RM Coloso, EGT de Jesus-Ayson & JD Toledo (Eds.), Sustainable aquaculture development for food security in Southeast Asia towards 2020. Proceedings of the Regional Technical Consultation on Sustainable Aquaculture Development in Southeast Asia Towards 2020, 2011 - Aquaculture Department, Southeast Asian Fisheries Development CenterThe world's oceans are becoming warmer and acidic. The atmospheric carbon dioxide concentration has increased from 280 ppm at pre-industrial revolution to above 380 ppm today. The 4th IPCC report predicts that it will range from 540 to nearly 1,000 ppm by the end of the century. The increased CO2 not only warms surface seawater, but also acidifies it (usually termed as ocean acidification) by diffusing across the ocean surface and forming carbonic acid. Our knowledge is still scarce as to how these ocean environmental changes will affect marine life. The early studies on the impact of ocean acidification focused on corals aiming to clarify effects of high-CO2 seawater on their calcification processes. However, more recent studies have revealed that in fact ocean acidification, either alone or coupled with warming, could have detrimental impacts on a variety of biological processes in different taxa. We have shown that early development of marine bivalves (oysters and mussels) could be severely disrupted under elevated CO2 conditions (ca. 2,000 ppm). When a marine shrimp was exposed to seawater equilibrated with air containing 1,000 ppm CO2 for 30 weeks, survival was only 55% as compared with 90% in the control. Gonad maturation of a sea urchin was delayed by one month under the same CO2 conditions at ambient temperature, but when accompanied with increased temperature of 2 degree C above ambient, gonad maturation was not only delayed but also significantly suppressed; the number of eggs in the ovary was reduced to only 20% of the control. It has been shown that tropical animals already live near their thermal tolerant maxima, and therefore even small increases of environmental temperature could reduce their environmental fitness. These recent findings bear significant implication in aquaculture and fisheries production, in particular, in tropical countries. This paper will summarize recent data on these topics and discuss possible adaptation measures.
