DOCSLIB.ORG

Food-Web Implications for Pelagic Top Predators: from Guts and Isotopes to Models

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Food-Web Implications for Pelagic Top Predators: from Guts and Isotopes to Models Food-web Implications for Pelagic Top Predators: from Guts and Isotopes to Models Robert J. Olson Inter-American Tropical Tuna Commission La Jolla, California Photo compliments of Dr. Frederic Menard, IRD, France Food webs and Ecosystem-based Fisheries Science • “Ecosystem” “Ecology”: multispecies approaches to management, reduction of bycatch, including environmental factors in stock assessment models. • Ecosystem: a geographically specified system of organisms, including humans, the environment, and the processes that control its dynamics (NOAA 2005). • “The time has come for community ecology to replace population ecology as the fundamental ecological science underlying fisheries” (Mangel and Levin 2005). • Communities are assemblages of species. Interactions makes the community more than the sum of its parts. • Communities interact via the food web. NOAA. 2005. New priorities for the 21st century: NOAA's strategic plan. NOAA, Washington, D.C. Mangel, M., and P.S. Levin. 2005. Regime, phase and paradigm shifts: making community ecology the basic science for fisheries. Phil. Trans. R. Soc. B, 360 (1453): 95-105. Why study food webs? • Trophic structure represented in food webs is thought to be the central organizing concept in ecology (Martinez 1995). • Knowledge of pelagic food webs is still rudimentary, in many aspects. Better food-web models are needed (preferably, spatially-explicit). • Review an assortment of information about food- web research in eastern Pacific, and (less-so) on modeling efforts. Eight ecosystem characteristics NMFS Ecosystem Principles Advisory Panel: 1. The ability to predict ecosystem behavior is limited 2. Ecosystems have thresholds and limits which, when exceeded, can effect major ecosystem restructuring 3. Once thresholds and limits have been exceeded, changes can be irreversible 4. Diversity is important to ecosystem functioning 5. Multiple scales interact within and among ecosystems 6. Components of ecosystems are linked 7. Ecosystem boundaries are open 8. Ecosystems change over time Components of ecosystems are linked How do we determine what the important components and linkages are? Critical food-web connections. •Keystone species •Dietary specialists •Models can help The tools for food-web research: •Diet studies (stomach-contents analysis) •Stable isotope analysis •Compound specific stable isotope analysis (amino-acids) •Fatty acid analysis Stomach-contents analysis (species identification) (and monitoring) V. Allain, SPC F. Galvan, CICIMAR IATTC, Manta, Ecuador Diet data for eastern Pacific predators (’92-’94) 100% 80% 60% weight 40% Percent 20% Dorado, Wahoo, R. Runner Billfishes 0% Sharks Dolphins Tunas Colleagues: •Felipe Galván-M, CICIMAR, La Paz, BCS, Mexico •Julio Martínez, Cumaná, Venezuela Diet data formulated food web (ETP) fico ó tr Nivel – Trophic level Trophic Olson, R.J., and G.M. Watters. 2003. A model of the pelagic ecosystem in the eastern tropical Pacific Ocean. Inter-American Tropical Tuna Commission, Bulletin 22 (3): 133-218. Yellowfin tuna stomach-contents (1990s, 2000s) Set Locations 1990s 2000s Feeding Ecology of Surface Migrating Myctophid Fishes in the eastern Tropical Pacific Joel Van Noord, Univ. of San Diego Jessica Redfern et al., NMFS SWFSC Trophic position: stable isotopes 15N 15 14 15 15 δ = [( N/ N) / Rstd – 1] x 1000 δ Npredator = 3.0 + δ Nprey (‰) Isotopic fractionation – the light 14N isotope is excreted more than the heavy 15N isotope, leaving the animal enriched by 3‰ in δ15N relative to its food source. Trophic position: stable isotopes, stomach contents 18 16 14 12 10 N (‰) 15 8 δ 6 Yellowfin tuna (5-deg areas) 4 Yellowfin tuna (outside 5-deg areas) Mesozooplankton (5-deg areas) 2 Mesozoopl. (outside 5-deg areas) CSIA samples 0 -15 -10 -5 0 5 10 15 20 25 30 Latitude (degrees) Mean TP = 4.5 PFRP, B. Popp, B. Graham, C. Hannides, F. Galván, G. López, B. Fry Yellowfin trophic position (TP) YFT δ15N = 13-16‰ Copepods δ15N = 6-12‰ ΔYFT-COP = 4.0 – 7.6 ‰ Gladis Lopez-I., CICIMAR, Mexico TP ≈ 4.3 - 5.3, spanning ~ 1 trophic level B. Popp, UH B. Graham, UH F. Galvan-Magana, CICIMAR C. Lennert-Cody, IATTC PFRP Popp, B.N., B.S. Graham, R.J. Olson, C.C.S. Hannides, M.J. Lott, G.A. López-Ibarra, F. Galván-Magaña, and B. Fry. 2007. Insight into the trophic ecology of yellowfin tuna, Thunnus albacares, from compound-specific nitrogen isotope analysis of proteinaceous amino acids. In Dawson, T.E., and R.T.W. Siegwolf (eds.), Stable Isotopes as Indicators of Ecological Change. Elsevier-Academic Press, Terrestrial Ecology Series, San Diego: 173-190. Yellowfintuna δ Bulk white muscle 15 N of Amino Amino of Acids N – eastern tropical Pacific (“Source” AA) (“Trophic” AA)(“Trophic” TL 4.5 TL E-W shift in trophic position in ETP TP shift≈1 Lipids as Dietary Tracers Traditional techniques problematic, e.g. gut content analysis Prey species have unique lipid / fatty acid compositions Many fatty acids readily transferred from prey to predator with minimal modification Constituent fatty acids therefore represent, to some extent, a temporal integration of diet Can be quantitative and allows temporal integration (cf gut content analysis) Signature fatty acids: combinations of fatty acids preserved as they pass up the food chain Complements other approaches * Jock Young, CSIRO Eight ecosystem characteristics NMFS Ecosystem Principles Advisory Panel: 1. The ability to predict ecosystem behavior is limited 2. Ecosystems have thresholds and limits which, when exceeded, can effect major ecosystem restructuring 3. Once thresholds and limits have been exceeded, changes can be irreversible 4. Diversity is important to ecosystem functioning 5. Multiple scales interact within and among ecosystems 6. Components of ecosystems are linked 7. Ecosystem boundaries are open 8. Ecosystems change over time Can models predict ecosystem behavior? • Nature is seldom linear, and often unpredictable (Francis et al. 2007) . • Ecosystem resilience depends on “stability domain” of existing food web: how broad is it, how resistant is it to change, how close is it to reorganizing? (Francis et al. 2007) Models are required. • How should components of the food web be represented in models? • Can models highlight key areas for field/lab studies? Francis, R.C., M.A. Hixon, M.E. Clarke, S.A. Murawski, and S. Ralston. 2007. Ten commandments for ecosystem-based fisheries scientists. Fisheries, 32 (5): 217-233. Taxonomy in models fico ó tr Nivel – Trophic level Trophic (Olson, R.J., and G.M. Watters. 2003. A model of the pelagic ecosystem in the eastern tropical Pacific Ocean. Inter-American Tropical Tuna Commission, Bulletin 22 (3): 133-218.) Functional groups in models Epipelagic Epi Epi-Meso Meso Epi- Bathy Meso Bathy Meso-Bathy Bathy Qualitative analysis of Pacific Ocean predators 20 N South-Western Pacific Ocean Central-Eastern Pacific Ocean 5.0 77 5.0 76 169 106 75 124 74 43 44 115 121 165 65 170 122 110 168 134 77 152 4.5 33 109 108 159 31 45 157 32 160 154 126 125 4.5 74 75 76 124 106 169 121 115 44 211 85 198 127 173 215 66 70 65 122 165 168 149 172 83 155 163 156 157 114 108 112 126 167 120 161 23 219 37 36 24 12 151 14 2 13 68 4.0 26 4.0 210 212 174 215 116 177 119 117 127 209 38 5 4 147 123 3 113 28 20 18 197 193 37 192 219 196 191 195 25 69 153 27 15 35 34 52 3.5 57 60 51 59 58 64 56 194 178 Food webs 3.5 238 204 153 27 118 63 180 179 64 98 95 89 91 88 79 53 81 80 82 47 78 9 6 103 203 199 201 202 200 206 207 205 3.0 3.0 95 142 49 100 9396 140 92 72 105 102 94 23690 39 71 9 composed of 200+ 229 143 226 223 239 231 235 239 145 234 2.5 2.5 41 taxa level Trophic 245 242 222 247 237 244 246 217 216 2.0 2.0 182 241 232 185 228 1.5 1.5 183 1.0 1.0 243 Aggregated food webs composed of 24 nodes with similar predator prey relationships Can models highlight research needs? Sensitivity analysis of ETP Ecopath model Large marlinsLarge Marlins (5.5) Small sharksSmall Sharks (5.4) Small marlinsSmall Marlins (5.4) Toothed whalesToothed Whales (5.4) LargeLarge bigeye Bigeye Tuna (5.3) Spotted dolphinsSpotted Dolphins (5.2) Large sharksLarge Sharks (5.2) Large wahooLarge Wahoo (5.1) Large swordfishLarge Swordfish (5.1) Large sailfishLarge Sailfish (5.1) PursuitPursuit birds Birds (4.9) Small mahimahiSmall Mahimahi (4.8) Small sailfishSmall Sailfish (4.8) Large mahimahiLarge Mahimahi (4.8) Large Largeyellowfin Yellowfin Tuna (4.8) MesopelagicMesopelagic dolphins Dolphins (4.8) Small wahooSmall Wahoo (4.7) SmallSmall bigeye Bigeye Tuna (4.7) Small Smallyellowfin Yellowfin Tuna (4.7) SkipjackSkipjack Tuna (4.7) CephalopodsCephalopods (4.6) Small swordfishSmall Swordfish (4.6) Misc. piscivoresMisc. Piscivores (4.5) BluefinBluefin tuna Tuna (4.5) Auxis spp.Auxis spp. (4.1) Baleen whalesBaleen Whales (4.1) RaysRays (3.9) GrazingGrazing birds Birds (3.9) Sea turtlesSea Turtles (3.8) CrabsCrabs (3.6) Cephalopods Misc. mesopelagicMisc. Mesopelagic fishes Fishes (3.6) FlyingfishesFlyingfishes (3.6) Auxis spp. Misc. epipelagicMisc. Epipelagic fishes Fishes (3.3) Secondary consumersSecondary Consumers (3.0) Primary consumersPrimary Consumers (2.0) ProducersProducers (1.0) 0 20 40 60 80 100 120 140 160 Index of Sensitivity Eight ecosystem characteristics NMFS Ecosystem Principles Advisory Panel: 1. The ability to predict ecosystem behavior is limited 2. Ecosystems have thresholds and limits which, when exceeded, can effect major ecosystem restructuring 3. Once thresholds and limits have been exceeded, changes can be irreversible 4. Diversity is important to ecosystem functioning 5. Multiple scales interact within and among ecosystems 6. Components of ecosystems are linked 7. Ecosystem boundaries are open 8.
Load more

Recommended publications
  • <I>Sthenoteuthis Oualaniensis</I>
    BULLETIN OF MARINE SCIENCE, 71(2): 1105–1108, 2002 THE AGE AND GROWTH OF STHENOTEUTHIS OUALANIENSIS (CEPHALOPODA: OMMASTREPHIDAE) IN THE PACIFIC OCEAN Kaori Takagi, Takeru Kitahara, Naoki Suzuki, Junta Mori and Akihiko Yatsu Sthenoteuthis oualaniensis is distributed in the tropical and subtropical areas of the Pacific and the Indian Oceans. According to Nesis (1993), there is a complex population structure in S. oualaniensis, as is the case in many other ommastrephids and some loliginids. In the Pacific Ocean, there is the middle-sized squid which is a widespread and typical one (Nesis, 1993). Arkhipkin and Bizikov (1991) examined the statoliths of middle-sized female in the Indian Ocean and determined its growth. S. oualaniensis is, though, one of the most difficult species in the Ommastrephidae for the observation of statolith incre- ments due to the numerous occulting crystals and weak contrast in the increments (Uozumi, 1993). Using a newly developed heating technique in processing statoliths, we estimated the age and growth of S. oualaniensis, assuming the daily deposition of increments. MATERIALS AND METHODS Samples of S. oualaniensis were collected between September and December 1993 in the Pa- cific Ocean around the Hawaii and the Ogasawara (Bonin) Islands. We used the statoliths of 53 adults (112–284 mm in mantle length (ML), 21 males and 32 females) and 112 paralarvae (0.7– 13.5 mm in ML). The adults were captured by drift nets and jigs. The paralarvae were captured by bongo nets and a larval net. To examine the relationship between ML and age, we also used 6 other juveniles (39–50 mm in ML) captured using a dip net.
    [Show full text]
  • Redalyc.Subcutaneous Photophores in the Jumbo Squid Dosidicus Gigas
    Revista de Biología Marina y Oceanografía ISSN: 0717-3326 [email protected] Universidad de Valparaíso Chile Lohrmann, Karin B. Subcutaneous photophores in the jumbo squid Dosidicus gigas (d'Orbigny, 1835) (Cephalopoda: Ommastrephidae) Revista de Biología Marina y Oceanografía, vol. 43, núm. 2, agosto, 2008, pp. 275-284 Universidad de Valparaíso Viña del Mar, Chile Disponible en: http://www.redalyc.org/articulo.oa?id=47943205 Cómo citar el artículo Número completo Sistema de Información Científica Más información del artículo Red de Revistas Científicas de América Latina, el Caribe, España y Portugal Página de la revista en redalyc.org Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Revista de Biología Marina y Oceanografía 43(2): 275-284, agosto de 2008 Subcutaneous photophores in the jumbo squid Dosidicus gigas (d’Orbigny, 1835) (Cephalopoda: Ommastrephidae) Fotóforos subcutáneos en el calamar gigante Dosidicus gigas (d’Orbigny, 1835) (Cephalopoda: Ommastrephidae) Karin B. Lohrmann1 1Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile. Larrondo 1281, Coquimbo, Chile [email protected] Resumen.- En Dosidicus gigas se observaron pequeñas Abstract.- In Dosidicus gigas small pale yellow ovoid inclusiones de color amarillo pálido embebidas a distintas inclusion bodies corresponded to subcutaneous photophores, profundidades en el músculo del manto, las que corresponden which were embedded in the mantle muscle, at differing depths. a fotóforos. A nivel histológico los fotóforos están formados At the histological level the photophores were composed of a por un tejido fotogenerador, que se tiñe de color naranja intenso photogenic tissue, which stained bright orange with Mallory con tinción tricrómica de Mallory y un tejido vacuolar, que lo triple stain.
    [Show full text]
  • Breeding in an Oceanic Population of Pleuroncodes Planipes (Crustacea, Galatheidae) 1 ALAN R
    Breeding in an Oceanic Population of Pleuroncodes planipes (Crustacea, Galatheidae) 1 ALAN R. LONGHURST2 AND DON L. R. SEIBERT'l ABSTRACT: The pelagic population of Pleuroncodes planipes known to occur in the California Current Extension is partly recruited by drift of megalopas from neritic regions and partly, as demonstrated by EASTROPAC samples, by breeding in situ , THE DISTRIBUTION of pelagic adults and larvae samples; only size frequencies of night samples of the galatheid crab Pleuroncodes planipes in are used here. the California Current has been described re­ Adults of Pleuroncodes planipes, none of cently (Boyd, 1963, 1967; Longhurst, 1967, which had carapace lengths exceeding 15 mm, 1968). These studies showed the regular occur­ were found early in the year in northern Area 1. rence of an oceanic population of small adults This population (carapace length 9 to 13 mm) far beyond the normal neritic habitat and indi­ shifted its locus in late summer until, at the end cated how this expatriate population might be of the year, all occurrences were south of 14° recruited from megalopas derived from the N ; the second winter cruise (February-March neritic population along the west coast of Baja 1968) showed that the population had shifted California. north again to a locus between 14° to 20° N. The Eastern Tropical Pacific (EASTROPAC) In Area 2, adults were present only after Au­ expeditions (February 1967 to March 1968 gust-September, when a population of very from 20° N to 20° S and from the American small (6 to 8 mm) . adults appeared in the sam­ continent out to 126° W) afforded an oppor­ ples and remained through the end of the year.
    [Show full text]
  • HMS App a August 2003
    APPENDIX F U.S. WEST COAST HIGHLY MIGRATORY SPECIES: LIFE HISTORY ACCOUNTS AND ESSENTIAL FISH HABITAT DESCRIPTIONS (Originally Appendix A to the FMP) U.S. West Coast Highly Migratory Species Plan Development Team Pacific Fishery Management Council Originally Available January 16, 2003 HMS FMP - Appendix Fi June 2007 TABLE OF CONTENTS REVIEW OF METHODS AND DEFINITIONS.............................................F-1 1.0SHARKS ....................................................................F-1 1.1Common Thresher ...........................................................F-1 1.1.8 Essential Fish Habitat for Common Thresher ................................F-4 1.2Pelagic Thresher.............................................................F-5 1.2.8 Essential Fish Habitat for Pelagic Thresher..................................F-6 1.3Bigeye Thresher .............................................................F-7 1.3.8 Essential Fish Habitat for Bigeye Thresher ..................................F-9 1.4Shortfin Mako ...............................................................F-9 1.4.8 Essential Fish Habitat for Shortfin Mako ...................................F-12 1.5Blue Shark.................................................................F-12 1.5.8 Essential Fish Habitat for Blue Shark......................................F-16 2.0TUNAS.......................................................................F-16 2.1Albacore ..................................................................F-16 2.1.8 Essential Fish Habitat for Albacore .......................................F-20
    [Show full text]
  • The Pelagic Phase of Pleuroncodes Planipes Stimpson (Crustacea, Galatheidae) in the California Current
    THE PELAGIC PHASE OF PLEURONCODES PLANIPES STIMPSON (CRUSTACEA, GALATHEIDAE) IN THE CALIFORNIA CURRENT ALAN R. LONGHURST' Institute of Marine Resources and Scripps Institution of Oceanography La Jolla, California INTRODUCTION 140 meters with a 1-meter zooplankton net; details of the sampling procedure and of the location of sta­ The planktonic habit may be prolonged into or re­ tions are described elsewhere (e.g. Ahlstrom, 1948; cur in the adults of two species of Galatheidae. Harri­ son Matthews (1932) uses the terms "lobster-krill" CalCOFI, 1963). or "whale feed" in reference to these: Munida gre- The data consist of records of the numbers of garia (Fabricus) of southern South America and pelagic crabs removed in the laboratory from each of New Zealand, and Pleuroncodes planipes Stimpson zooplankton sample before voluming, and these num­ the red or pelagic crab of California and Mexico. bers were extracted for the present study from the Both occur at times as conspicuous concentrations of original data sheets. The actual specimens had neither apparently adult crabs on which baleen whales are been measured nor were subsequently retained except known to browse (Harrison Matthews, 1932) ; in addi­ during 8 months of 1960 when the whole catch of tion, the studies of Me Hugh (1952) and Alverson pelagic crabs was measured by Boyd (1963) who (1963) on the tuna Thunnus alalunga, Katsuwonus recorded a range in standard carapace length of from pelamis and Thunnus albacares have shown that 7 to 20 mm; it has been assumed here that the Cal­ Pleuroncodes is a significant food item during their COFI data to be discussed refer only to subadult and summer migration into the California Current; for adult crabs within this size range.
    [Show full text]
  • Fish Bulletin 152. Food Habits of Albacore, Bluefin Tuna, and Bonito in California Waters
    UC San Diego Fish Bulletin Title Fish Bulletin 152. Food Habits of Albacore, Bluefin Tuna, and Bonito In California Waters Permalink https://escholarship.org/uc/item/7t5868rd Authors Pinkas, Leo Oliphant, Malcolm S Iverson, Ingrid L.K. Publication Date 1970-06-01 eScholarship.org Powered by the California Digital Library University of California STATE OF CALIFORNIA THE RESOURCES AGENCY DEPARTMENT OF FISH AND GAME FISH BULLETIN 152 Food Habits of Albacore, Bluefin Tuna, and Bonito In California Waters By Leo Pinkas , Malcolm S. Oliphant, and Ingrid L. K. Iverson 1971 1 2 ABSTRACT The authors investigated food habits of albacore, Thunnus alalunga, bluefin tuna, Thunnus thynnus, and bonito, Sarda chiliensis, in the eastern North Pacific Ocean during 1968 and 1969. While most stomach samples came from fish caught commercially off southern California and Baja California, some came from fish taken in central Califor- nia, Oregon, and Washington waters. Standard procedures included enumeration of food items, volumetric analysis, and measure of frequency of occur- rence. The authors identified the majority of forage organisms to the specific level through usual taxonomic methods for whole animals. Identification of partially digested animals was accomplished through the use of otoliths for fish, beaks for cephalopods, and the exoskeleton for invertebrates. A pictorial guide to beaks of certain eastern Pacific cephalopods was prepared and proved helpful in identifying stomach contents. This guide is presented in this publication. The study indicates the prominent forage for bluefin tuna, bonito, and albacore in California waters is the northern anchovy, Engraulis mordax. 3 ACKNOWLEDGMENTS The Food Habits Study of Organisms of the California Current System, (Project 6–7-R), was an investigation estab- lished under contract between the U.S.
    [Show full text]
  • Feeding Habits of the Common Thresher Shark (Alopias Vulpinus) Sampled from the California-Based Drift Gill Net Fishery, 1998-1 999
    PRETI ET AL.: FEEDING HABITS OF COMMON THRESHER SHARK CalCOFl Rep., Vol. 42, 2001 FEEDING HABITS OF THE COMMON THRESHER SHARK (ALOPIAS VULPINUS) SAMPLED FROM THE CALIFORNIA-BASED DRIFT GILL NET FISHERY, 1998-1 999 ANTONELLA PRETI SUSAN E. SMITH AND DARLENE A. RAMON California Department of Fish and Game National Marine Fisheries Service, NOM 8604 La Jolla Shores Dnve Southwest Fisheries Science Center La Jolla, California 92037 P.O. Box 271 sharksharkshark@hotniail coni La Jolla, California 92038 ABSTRACT (Compagno 1984). It is epipelagic, gregarious, and cos- The diet of common thresher shark (Alopius vulpinus) mopolitan, and in the northeastern Pacific seems to be from US. Pacific Coast waters was investigated by means most abundant within 40 miles of shore (Strasburg 1958). of frequency of occurrence, gravimetric and numerical Its known range extends from Clarion Island, Mexico, methods, and calculating the geometric index of im- north to British Columbia; it is common seasonally from portance (GII) of prey taxa taken from stoniachs col- mid-Baja California, Mexico, to Washington state.' It lected by fishery observers from the California-based is the leading commercial shark taken in California, drift gill net fishery. Sampling was done from 16 August where it is highly valued in the fresh fish trade (Holts et 1998 to 24 January 1999, a time when the California al. 1998). It is also sought by recreational anglers for its Current was undergoing rapid change from El Niiio to fighting ability as well as food value, especially in south- La Niiia conhtions. Of the 165 stomachs examined, 107 ern California.
    [Show full text]
  • Diet of Oceanic Loggerhead Sea Turtles (Caretta Caretta) in the Central North Pacific
    Diet of oceanic loggerhead sea turtles (Caretta caretta) in the central North Pacific Item Type article Authors Parker, Denise M.; Cooke, William J.; Balazs, George H. Download date 29/09/2021 11:03:34 Link to Item http://hdl.handle.net/1834/26255 ART & EQUATIONS ARE LINKED Preflight Good 142 Abstract — Diet analysis of 52 log- gerhead sea turtles (Caretta caretta) Diet of oceanic loggerhead sea turtles collected as bycatch from 1990 to 1992 (Caretta caretta) in the central North Pacific in the high-seas driftnet fishery oper- ating between lat. 29.5°N and 43°N and between long. 150°E and 154°W Denise M. Parker demonstrated that these turtles fed Joint Institute for Marine and Atmospheric Research predominately at the surface; few 8604 La Jolla Shores Drive deeper water prey items were pres- La Jolla, California 92037 ent in their stomachs. The turtles Present address: Northwest Fisheries Science Center ranged in size from 13.5 to 74.0 cm National Marine Fisheries Service, NOAA curved carapace length. Whole tur- Newport, Oregon 97365-5275 tles (n=10) and excised stomachs E-mail address: [email protected] (n=42) were frozen and transported to a laboratory for analysis of major faunal components. Neustonic species William J. Cooke accounted for four of the five most AECOS, Inc. common prey taxa. The most common 970 N. Kalaheo Avenue, Suite C311 prey items were Janthina spp. (Gas- Kailua, Hawaii 96734 tropoda); Carinaria cithara Benson 1835 (Heteropoda); a chondrophore, Velella velella (Hydrodia); Lepas spp. George H. Balazs (Cirripedia), Planes spp. (Decapoda: Pacific Islands Fisheries Science Center, Honolulu Laboratory Grapsidae), and pyrosomas (Pyrosoma National Marine Fisheries Service spp.).
    [Show full text]
  • Tai.2021.66.241.Pdf
    Taiwania 66(2): 241‒250, 2021 DOI: 10.6165/tai.2021.66.241 Morphological, molecular, and ecological evidence in population determination and fishery management of purpleback flying squid Sthenoteuthis oualaniensis in the South China Sea Chunxu ZHAO1,2, Bin KANG3,*, Xiongbo HE2, Yunrong YAN2,4 1. Fishery College, Jimei University, Xiamen 361021, China. 2. Marine Resources Big Data Center of South China Sea, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524013, China. 3 Fisheries College, Ocean University of China, Qingdao 266003, China. 4 Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China. *Corresponding author’s Tel: +86-13012425395; E-mail: [email protected] (Manuscript received 13 May 2020; Accepted 8 May 2021; Online published 13 May 2021) ABSTRACT: Purpleback flying squid Sthenoteuthis oualaniensis has great potential to be an important fishery in the South China Sea, while its complex population structure causes difficulties for fishery management. In this study, specimens were sampled monthly throughout 2018 and identified at the population scale from the aspects of morphological, molecular, and ecological traits. Corresponding to the appearance of the photophore, the purpleback flying squid could be divided into two populations as the medium population and the dwarf population, also indicated by significant differences in mantle length. In the phylogenetic tree, all individuals fell into two lineages, and in each lineage, there was no sub-lineage corresponding to geological isolation or seasonal change. Fishes were the main food for purpleback flying squid, occupying approximately half of the total, followed by squid and crustaceans. Stable isotope analysis suggested that neither body size nor gender affected trophic niches.
    [Show full text]
  • Metabolic Suppression in the Pelagic Crab, Pleuroncodes Planipes, in Oxygen Minimum Zones T ⁎ Brad A
    Comparative Biochemistry and Physiology, Part B 224 (2018) 88–97 Contents lists available at ScienceDirect Comparative Biochemistry and Physiology, Part B journal homepage: www.elsevier.com/locate/cbpb Metabolic suppression in the pelagic crab, Pleuroncodes planipes, in oxygen minimum zones T ⁎ Brad A. Seibela, , Bryan E. Luub,1, Shannon N. Tessierc,1, Trisha Towandad, Kenneth B. Storeyb a College of Marine Science, University of South Florida, 830 1st St. S., St. Petersburg, FL 33701, USA b Institute of Biochemistry & Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada c BioMEMS Resource Center & Center for Engineering in Medicine, Massachusetts General Hospital & Harvard Medical School, 114 16th Street, Charlestown, MA 02129, USA d Evergreen State College, Olympia, WA, USA ARTICLE INFO ABSTRACT Keywords: The pelagic red crab, Pleuroncodes planipes, is abundant throughout the Eastern Tropical Pacific in both benthic Protein synthesis and pelagic environments to depths of several hundred meters. The oxygen minimum zones in this region Hypoxia reaches oxygen levels as low as 0.1 kPa at depths within the crabs vertical range. Crabs maintain aerobic me- Zooplankton tabolism to a critical PO2 of ~0.27 ± 0.2 kPa (10 °C), in part by increasing ventilation as oxygen declines. At Hypometabolism subcritical oxygen levels, they enhance anaerobic ATP production slightly as indicated by modest increases in Vertical migration lactate levels. However, hypoxia tolerance is primarily mediated via a pronounced suppression of aerobic me- tabolism (~70%). Metabolic suppression is achieved, primarily, via reduced protein synthesis, which is a major sink for metabolic energy. Posttranslational modifications on histone H3 suggest a condensed chromatin state and, hence, decreased transcription.
    [Show full text]
  • Diet and Stable Isotope Analyses Reveal The
    RESEARCH ARTICLE Diet and stable isotope analyses reveal the feeding ecology of the orangeback squid Sthenoteuthis pteropus (Steenstrup 1855) (Mollusca, Ommastrephidae) in the eastern tropical Atlantic VeÂronique Merten1*, Bernd Christiansen2, Jamileh Javidpour1, Uwe Piatkowski1, Oscar Puebla1,3, Rebeca Gasca4, Henk-Jan T. Hoving1 a1111111111 a1111111111 1 GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, 2 UniversitaÈt Hamburg, Institute for Hydrobiology and Fishery Sciences, Hamburg, Germany, 3 Christian-Albrechts-UniversitaÈt zu Kiel, Kiel, a1111111111 Germany, 4 El Colegio de la Frontera Sur, Chetumal, Mexico a1111111111 a1111111111 * [email protected] Abstract OPEN ACCESS In the eastern tropical Atlantic, the orangeback flying squid Sthenoteuthis pteropus Citation: Merten V, Christiansen B, Javidpour J, (Steenstrup 1855) (Cephalopoda, Ommastrephidae) is a dominant species of the epipelagic Piatkowski U, Puebla O, Gasca R, et al. (2017) Diet nekton community. This carnivore squid has a short lifespan and is one of the fastest-grow- and stable isotope analyses reveal the feeding ecology of the orangeback squid Sthenoteuthis ing squids. In this study, we characterise the role of S. pteropus in the pelagic food web of pteropus (Steenstrup 1855) (Mollusca, the eastern tropical Atlantic by investigating its diet and the dynamics of its feeding habits Ommastrephidae) in the eastern tropical Atlantic. throughout its ontogeny and migration. During three expeditions in the eastern tropical PLoS ONE 12(12): e0189691. https://doi.org/ 10.1371/journal.pone.0189691 Atlantic in 2015, 129 specimens were caught by hand jigging. Stomach content analyses (via visual identification and DNA barcoding) were combined with stable isotope data (@15N Editor: Erik V. Thuesen, Evergreen State College, 13 UNITED STATES and @ C) of muscle tissue to describe diet, feeding habits and trophic ecology of S.
    [Show full text]
  • Behavior of Bluefin Tuna Schools in the Eastern North Pacific Ocean As Inferred from Fishermen's Logbooks
    BEHAVIOR OF BLUEFIN TUNA SCHOOLS IN THE EASTERN NORTH PACIFIC OCEAN AS INFERRED FROM FISHERMEN’S LOGBOOKS, 1960-67’ J. MICHAELSCOTT’ AND GLENNA. FLITTNER3 ABSTRACT Fishermen’s records of 8,059 purse-seine sets made on TILunnus thynnus (bluefin tuna) were examined for the period 1960-67. A total of 3,538 sets were identified as to school type. The majority of these sets were made within 90 miles of the beach off southern and Baja California from lat 23ON to 34ON. The region was divided into a northern and southern area on the basis of biological and oceanographic factors. Significant differences were observed in the occurrence of the six most common school types between the northern and southern most areas of the fishery. The difference in occurrence of the jumping, boiling, and shining schools was related to the relative absence of red crabs (Pleuroncodes planipes) in the northern area and to differences in the for- aging behavior of T. thynnus on baitfish and red crabs. Differences in vulnerability to capture and catch per successful set were noted among the five most common daytime schools as well as with respect to time of day. Purse-seine sets made with the assistance of airborne spotters had larger catches and a greater percentage success than did unassisted sets. In addition the percentage of a particular school type taken with aircraft assistance was inversely proportional to the visibility of the schools from the mast. The existence of different school types in scom- schools commonly encountered in the eastern broid fishes has been noted by several authors.
    [Show full text]