DOCSLIB.ORG

The Importance of Cephalopods in the Diets of Marine Mammals and Other Top Predators

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Importance of Cephalopods in the Diets of Marine Mammals and Other Top Predators Not to be cited without prior reference to the authors THEME SESSION (M) Impact of Cephalopods in. the Food Chain and Their Interaction with the Environment ICES CM 19981M:8 The Importance of Cephalopods in the Diets of Marine Mammals and Other Top Predators M.R. Clarke, M.B. Santos and GJ. Pierce The importance of cephalopods in the diets of top predators is reviewed, with particular reference to studies by the authors on sperm whales (Physeter macrocephalus), common dolphins (Delphinus delphis), blue sharks (Prionace glauca) and swordfish (Xiphias gladius). The use of such data to estimate cephalopod consumption by top predator populations is illustrated, as is the potential for estimating cephalopod population biomass. Cephalopods have been shown to constitute an important part of the diet of many top predator species, although the importance of cephalopods varies with area (e.g. comparing the Antarctic and NE Atlantic). Quantifying the importance of cephalopods in diets presents some methodological problems due to, e.g., differing passage rates and digestibility of fish and cephalopods. These uncertainties and biases can significantly affect calculations of the amount of food consumed. Further problems are encountered when estimating population consumption, e.g. due to uncertainty in population size estimates. Confidence limits for consumption of cephalopods by sperm whales in the NE Atlantic are estimated using bootstrap procedures. Lower and upper 95% confidence limits, based on simple assumptions about likely random errors in parameter estimates, can differ by an order of magnitude. Computations such as those used here are useful in showing where data is most imperfect. At present, the multiplicity of potential errors in any but the most basic calculations will extend confidence limits beyond the point that their quantification is helpful. However, within distinctly prescribed geographic areas, where populations are well known, modelling of species interactions may be productive. <t KEYWORDS: cephalopods, top predators, marine mammals, diet, food consumption, fisheries MR Clarke: '~ncarva", Southdown, Millbrook, Torpoint, Cornwall, PLIO 1EZ, UK [e-mail: [email protected] ME. Santos and G.J. Pierce: Department of Zoology, University of Aberdeen, Tillydrone Avenue, AB24 2IZ, UK [tel: +44 1224 272459, fax: +44 1224272396, e-mail: [email protected]@abdn.ac.ukJ --~ Introduction Analyses of stomach contents of 'top marine predators can be useful for many different investigations. Besides indicating what a predator depends on for food, the predator's distribution, diving prowess etc., it can also tell us more about the ecology of the prey species, their distribution (Clarke, 1980), seasonal fluctuations and sometimes their growth (Clarke, 1993). Extensions of such analyses havepotential for giving information on the biomass of the prey (Clarke, 1987.), on the interaction of predators with other species such as commercial species offish (Smale, 1996.) and on fluctuations of what is present in an area. Here, we are mainly concerned with cephalopods in the diets of odontocetes although mention will be made of teuthophagous birds, seals and large fish. What can be deduced from the basic data derived from examining stomach contents very much depends on our knowledge of the cephalopods and predators concerned and whether the predator being considered also includes fish and/or crustaceans in the diet. The material we obtain from stomachs varies from complete prey animals to just eye lenses. Each type of material will help us to answer different questions and provide progress towards all or some of the aims outlined above. Each has different problems; usually there is little flesh left of many oceanic cephalopods since they are digested rapidly, more rapidly than fish muscle. Cephalopod beaks are largely undigested and .sometimes accumulate in the stomach while many otoliths and bones of fish are digested and are lost from the stomach before the beaks. Fish scales, finrays and teeth can all be used for identification. Cephalopod pens and spermatophores can aid identification but the former are usually broken up early in the digestive process and the latter have not been used. Eye lenses are digested only slowly although those of cephalopods break up much more quickly than those of fish and the ratio between them is not a good guide to the ratio in the diet (Clarke et at., 1995) although their presence sometimes shows cephalopod presence in an otherwise heavily piscivorous diet. Here we shall co.nsider some of the sources of error in estimating the importance of cephalopods in the diet of cetaceans and other top predators. Our measure of "importance" will be biomass and our data will come from our own published and unpublished work. We hope to show limitations of present information and potential for further work. Dietary analysis can only provide representative results if the sample is representative. Since many current studies rely on strandings and by-catches, this is difficult to ensure (or even to test since, for some species, the only information on popUlation structure comes from strandings ). To assess 'importance" of cephalopods, in general and for species, requires first the identification of cephalopods and their beaks .. As few cephalopods are found in a sufficiently undigested state to be identified, the most efficient utilisation of samples involves identification of the beaks (as many as 18,000 beaks can be present in a sperm whale stomach, Clarke, 1980). Identification to as Iowa taxon as possible facilitates calculation of mass since size of beaks to mass relationships differ markedly according to.genus and sometimes species (and in a few families according to. sex, e.g. Onychoteuthidae). Identifying genera is usually possible from the lower beaks, for specified areas such as.the North Atlantic and many genera often include but one species in a region. Although some beaks remain unidentified in almost any oceanic region, these are not among the most numerous species and difficulties reflect taxonomic problems due to inadequacy in sampling cephalopods from oceanic waters. 2 Directly from identification we can assess frequency of occurrence and relative numerical occurrence (%) which give a 'feel' for the relative importance of the species. Estimates of the relationship between beak length (lower rostral length and lower crest or lower hood lengths- LRL, LCL, LHL, respectively) and body mass could be greatly improved for most genera. Particularly serious errors can arise from extrapolation from small animals (which are caught in nets and therefore available) to much larger animals in the food of the larger predators such as whales, seals or large fish (which are rarely caught by fishing gear, Clarke, 1983). Confidence limits have been published for few of these relationships and errors in these calculations lead to errors in the biomass percentage calculations even if only one of the species in the diet is significantly incorrect. When such biomass estimates are used to find population consumption in a geographic region these errors may be compounded by other factors such as errors in the estimation of the predator's population. Another factor in these calculations is the food requirement, usually expressed as a percentage of the mass of the predator per day (ranging from 2.0 - 3.5% for sharks and marine mammals, Clarke, 1979; Lockyer, 1981; R. Clarke et al., 1988 ; Clarke et al., 1996.). Estimates from calorific values is another way of calculating consumption but, at present, we have sufficient data for few families and any errors compound the errors of biomass estimates for each prey species. While all the above difficulties are serious when a predator under study only eats cephalopods, even more difficulties arise when the predator also eats fish because, at present, we have no effective way of quantifying cephalopods relative to fish. The latter are identified from calcareous parts, mainly otoliths, which dissolve rapidly in digestive juices while the beaks of cephalopods resist digestion and pass from the stomach at unknown intervals. Thus, they are lost from the stomach at different, unknown, intervals of time. This may lead to a considerable over estimation of the importance of cephalopods in the diet unless some way of recognising the intake during a particular time period can be found. This may be possible when feeding is restricted to dark hours and digestion during the day is followed by evacuation of remains from the stomach before the next feeding period (Clarke et a!., 1996). Statistical treatment of the computations based upon beak identifications and rostral measurements has not been popular largely because the data can so obviously only be considered a rough guide to reality due to the unknowns involved. Statistical analysis would suggest some confidence in the actual numbers given. Confidence limits can be difficult to calculate in dietary analysis for several reasons. Typically diets are described in terms of the overall proportion by weight of different prey species in a set of samples. The estimated importance of a species is thus a single number derived from the whole set of samples and does not have any confidence limits (unless we have several sets of samples and can calculate a mean and variance for sets). Furthermore, weights of prey are not measured directly, but estimated from measurements of hard parts (fish otoliths, cephalopod beaks) using previously established
Load more

Recommended publications
  • A Review of Southern Ocean Squids Using Nets and Beaks
    Marine Biodiversity (2020) 50:98 https://doi.org/10.1007/s12526-020-01113-4 REVIEW A review of Southern Ocean squids using nets and beaks Yves Cherel1 Received: 31 May 2020 /Revised: 31 August 2020 /Accepted: 3 September 2020 # Senckenberg Gesellschaft für Naturforschung 2020 Abstract This review presents an innovative approach to investigate the teuthofauna from the Southern Ocean by combining two com- plementary data sets, the literature on cephalopod taxonomy and biogeography, together with predator dietary investigations. Sixty squids were recorded south of the Subtropical Front, including one circumpolar Antarctic (Psychroteuthis glacialis Thiele, 1920), 13 circumpolar Southern Ocean, 20 circumpolar subantarctic, eight regional subantarctic, and 12 occasional subantarctic species. A critical evaluation removed five species from the list, and one species has an unknown taxonomic status. The 42 Southern Ocean squids belong to three large taxonomic units, bathyteuthoids (n = 1 species), myopsids (n =1),andoegopsids (n = 40). A high level of endemism (21 species, 50%, all oegopsids) characterizes the Southern Ocean teuthofauna. Seventeen families of oegopsids are represented, with three dominating families, onychoteuthids (seven species, five endemics), ommastrephids (six species, three endemics), and cranchiids (five species, three endemics). Recent improvements in beak identification and taxonomy allowed making new correspondence between beak and species names, such as Galiteuthis suhmi (Hoyle 1886), Liguriella podophtalma Issel, 1908, and the recently described Taonius notalia Evans, in prep. Gonatus phoebetriae beaks were synonymized with those of Gonatopsis octopedatus Sasaki, 1920, thus increasing significantly the number of records and detailing the circumpolar distribution of this rarely caught Southern Ocean squid. The review extends considerably the number of species, including endemics, recorded from the Southern Ocean, but it also highlights that the corresponding species to two well-described beaks (Moroteuthopsis sp.
    [Show full text]
  • Finding of Uncommon Cephalopods
    Cah. Biol. Mar. (1994),35: 339-345 Roscoff Finding of uncommon cephalopods (Ancistroteuthis lichtensteinii, Histioteuthis bonnellii, Histioteuthis reversa) and first record of Chiroteuthis veranyi in the Ionian Sea. A. Tursi, G. D'Onghia, A. Matarrese, P. Panetta, P. Maiorano Institute of Zoology and Comparative Anatomy - University - Via Orabona, 4 - 70125 Bari (ltaly) Abstract : Finding of some uncommon cephalopods. AnCÎslrolelilhis lichtensteinii, Histiotellthis bonne/Iii, H. rCl'ersa and the first record of Chirotellthis Feranyi in the Ionian Sea are reported here. Data were collected during a trawl survey carried out on red shrimp grounds during August 1993. Résumé : Dans ce travail, les auteurs analysent des espèces de Céphalopodes peu communes ou rares en Méditerranée, Ancislrotellthis Iichlensteinii, Histiotellthis bonnellii, H. reversa et ils signalent pour la première t"ois la présence de Chirotellthis l'eranyi en mer Ionienne. Les exemplaires ont été capturés au cours d'une campagne de chalutage expérimentale, sur des fonds ù crevettes rouges, au mois d'Août 1993. INTRODUCTION The SCal"CÎty of ecological knowledge on many species of cephalopods is certainly due to the technical problems of field observation and sampling. Information on distribution and abundance come mainly from CUITent research of biologi­ cal oceanography, fishing activities, analysis on stomach contents of mmine mammals and pelagic fishes. Recently, observations from submersibles have provided very interesting data about several aspects of the biology and ecology of cephalopods (Vecchione & Roper, 1991). Cephalopods are captured commercialy and for research purposes using a valiety of gears, primarily jigging machines, trawls and drift nets (Roper, 1991). While jigging, pela­ gic seining and potting are less destructive techniques that target specific sizes and species, trawling and drift netting are non-selective methods as far as size and specieS' are concer­ ned.
    [Show full text]
  • DIET of FREE-RANGING and STRANDED SPERM WHALES (Physeter
    DIET OF FREE-RANGING AND STRANDED SPERM WHALES (Physeter macrocephalus) FROM THE GULF OF MEXICO NATIONAL MARINE FISHERIES SERVICE CONTRACT REPORT Submitted to: Dr. Keith D. Mullin National Marine Fisheries Service Southeast Fisheries Science Center PO. Drawer 1207 Pascagoula, MS 39568-1207 Submitted by: Dr. Nelio B. Barros Mote Marine Laboratory Center for Marine Mammal and Sea Turtle Research 1600 Ken Thompson Parkway Sarasota, FL 34236-1096 (941) 388-4441 x 443 (941) 388-4317 FAX May 2003 Mote Marine Laboratory Technical Report Number 895 ABSTRACT Sperm whales are common inhabitants of the deep waters of the Gulf of Mexico. To date, no information is available on the diet of sperm whales in the Gulf. This study sheds light into the feeding habits ofthese whales by examining data collected from free-ranging and stranded animals. Prey species included a minimum of 13 species within 10 families of cephalopods, the only prey type observed. The most important prey was Histioteuthis, a midwater squid important in the diet of sperm whales worldwide. Most species of cephalopods consumed by Gulf sperm whales are meso to bathypelagic in distribution, being found in surface to waters 2,500 deep. Some of these prey are also vertical migrators. The diet of Gulf sperm whales does not include species targeted by the commercial fisheries. INTRODUCTION Until fairly recently, little was known about the species of whales and dolphins (cetaceans) inhabiting the deep waters of the Gulf of Mexico. Most of the information available came from opportunistic sightings and occasional strandings. In the early 1990' s large-scale dedicated surveys were initiated to study the distribution and abundance of marine mammals in the deep Gulf.
    [Show full text]
  • <I>Teuthowenia</I> (Oegopsida)
    BULLETIN OF MARINE SCIENCE, 36(1): 1-85, 1985 SYSTEMATICS, BIOLOGY AND BIOGEOGRAPHY OF THE CRANCHIID CEPHALOPOD GENUS TEUTHOWENIA (OEGOPSIDA) Nancy A. Voss ABSTRACT Teuthowenia is comprised of three discrete, closely related, allopatric species. Synonymies, definitions, diagnoses and keys to all developmental stages are presented, along with a review of the complex history of the genus and detailed illustrations. The discrete, ecologically distinct, distributional patterns of the three species reflect the influence ofa number of biological and physical factors. T. megalops (Prosch) is confined to the highly productive Atlantic subarctic and the highly productive areas of the North Atlantic temperate region. T. maculata (Leach) is restricted to the area of year-round, high productivity in the eastern tropical Atlantic. T. pellucida (Chun) is distributed circumglobally in the mixed and fringing waters of the Southern Subtropical Convergence. The species display similar patterns of ontogenetic descent from near-surface waters to midwater depths of about 1,000 m to in excess of 2,500 m where the animals mature, mate and spawn. Teuthowenia species have differentiated physiologically and developmentally as well as morphologically. Variations in the maturity-related morphological features among the species suggest differences in behavioral patterns for courtship and copulation. The genus displays a high rate of evolution in male and female secondary sexual characters. The relationships of Teuthowenia with Egea and Megalocranchia, which together comprise the monophyletic Megalocranchia group, and with the other taoniin genera are discussed. The taxonomic confusion surrounding the cranchiids was resolved in part by the familial revision of N. Voss (1980). The phylogenetic history of the family was reconstructed by N.
    [Show full text]
  • Cephalopoda: Histioteuthidae) in the Southern Tyrrhenian Sea (Western Mediterranean)
    NOT TO BE CITED WITHOUT PRIOR REFERENCE TO THE AUTHOR(S) Northwest Atlantic Fisheries Organization Serial No. N4560 NAFO SCR Doc. 01/165 SCIENTIFIC COUNCIL MEETING - SEPTEMBER 2001 (Deep-sea Fisheries Symposium – Poster) Occurrence of Histioteuthis bonnellii and Histioteuthis reversa (Cephalopoda: Histioteuthidae) in the Southern Tyrrhenian Sea (Western Mediterranean) by D. Giordano*, G. Florio*, T. Bottari*, and S. Greco** *Istituto Sperimentale Talassografico C.N.R., Spianata S. Raineri, 86 98100 Messina, Italy ** ICRAM, Istituto per la Ricerca Scientifica Applicata al Mare, Via dei Casalotti, 300 00166 Roma -Italy Abstract Data on occurrence of Histioteuthis bonnellii and Histioteuthis reversa collected in the southern Tyrrhenian Sea from 1994 to 1998 during five trawl surveys of the Medits eight trawl survey of the Grund project are reported. The International bottom trawl survey (the MEDITS programme) has been designed from a European Commission’s initiative to produce biological data on the demersal resources along the coasts of the four Mediterranean countries of the European Union (Spain, France, Italy and Greece). The main objective was to obtain independent knowledge useful for the fishery management, in an area where it is difficult to follow in detail the exploitation patterns of the fishing fleets. In Italian seas, before 1985, there was no research at national level on biological aspect and assessment of demersal resources. Within the framework of the first national plan (1985-1988) of the Law 41/82, three main research groups to assess demersal resources were organized: Tyrrhenyan group, Adriatic and Ionian group and Sicily group. All the seas were covered, with the exception of Ionian part of Sicily.
    [Show full text]
  • Husbandry Manual for BLUE-RINGED OCTOPUS Hapalochlaena Lunulata (Mollusca: Octopodidae)
    Husbandry Manual for BLUE-RINGED OCTOPUS Hapalochlaena lunulata (Mollusca: Octopodidae) Date By From Version 2005 Leanne Hayter Ultimo TAFE v 1 T A B L E O F C O N T E N T S 1 PREFACE ................................................................................................................................ 5 2 INTRODUCTION ...................................................................................................................... 6 2.1 CLASSIFICATION .............................................................................................................................. 8 2.2 GENERAL FEATURES ....................................................................................................................... 8 2.3 HISTORY IN CAPTIVITY ..................................................................................................................... 9 2.4 EDUCATION ..................................................................................................................................... 9 2.5 CONSERVATION & RESEARCH ........................................................................................................ 10 3 TAXONOMY ............................................................................................................................12 3.1 NOMENCLATURE ........................................................................................................................... 12 3.2 OTHER SPECIES ...........................................................................................................................
    [Show full text]
  • Xiphias Gladius Stomach Content Analysis Is an in Zones a and B, Fish Were Stored Linnaeus, 1758, Is a Mesopelagic Important Tool in Ecological and in Ice
    The diet of the swordfish tained from a longline vessel between 1 and 15th March 1991 by using Xiphias gbdius Linnaeus, mackerel, Scomber spp., as bait. 1 758, in the central east Atlantic, Zone C Gulf of Guinea (3O09'- 0°36'N and 26O27'-4O17'W). Fifteen with emphasis on the role of swordfish (standard length [SL] between 140-209 cm) were selected cephalopods on the basis of the presence of cephalopods in their stomachs. Vicente Hernández-García These were taken from catches Dpto de Biología, Facultad de Ciencias del Mar made by a longliner between May Univ. de Las Palmas de G. Canaria and July of 1991 by using mackerel C P 350 1 7, Canary Islands, Spain and squid, Illex sp., as bait. Stomach preservation and analysis The swordfish Xiphias gladius Stomach content analysis is an In zones A and B, fish were stored Linnaeus, 1758, is a mesopelagic important tool in ecological and in ice. After landing, fish were mea- teleost with a cosmopolitan distri- fisheries biology studies. Oceanic sured from the tip of the lower jaw bution between 45"N anci 45"s iati- vertebrates are often more efficient to the fork of the taii (S¿). During tude. It is an opportunistic preda- collectors of cephalopods than any commercial operations the internal tor feeding mainly on pelagic ver- available sampling gear (Bouxin organs were removed before the tebrates and invertebrates (Palko and Legendre, 1936; Clarke, 1966). fish were weighed. The stomach et al., 1981). The diet. of the sword- The p'irpose nf thir st11dy was to rnntents nf earh fish, incli~dingal1 fish has been studied mainly in the expand knowledge of the diet of the hard parts found in the stomach western Atlantic Ocean (Tibbo et swordfish from the central east At- wall folds (otoliths, very small al., 1961; Scott and Tibbo, 1968, lantic Ocean, with special emphasis beaks, and lenses), were weighed 1974; Toll and Hess, 1981; Stillwell on the role of cephalopod species.
    [Show full text]
  • Cephalopoda: Cranchiidae) from New Zealand Waters Aaron B
    Journal of Natural History, 2015 Vol. 49, Nos. 21–24, 1327–1349, http://dx.doi.org/10.1080/00222933.2013.840747 Ontogeny of the deep-sea cranchiid squid Teuthowenia pellucida (Cephalopoda: Cranchiidae) from New Zealand waters Aaron B. Evans* and Kathrin S.R. Bolstad Earth & Oceanic Sciences Research Institute, Auckland University of Technology, Auckland, New Zealand (Received 14 December 2012; accepted 19 July 2013; first published online 18 February 2014) Teuthowenia pellucida is a cosmopolitan southern sub-tropical species, and is abundantly represented in local New Zealand collections. However, because of the morphological similarities between this and other cranchiid genera at early ontogenetic stages, accurate identification of small specimens can be difficult. Herein, the morphological changes characterizing six pre-adult developmental stages (termed A–F) are reported in detail, as well as adult morphology; new information is provided on fecundity. These findings comprise a small contribution toward eventual resolution of the systematically unstable Cranchiidae. Keywords: Cranchiidae; ontogeny; New Zealand; squid Introduction Teuthowenia is a squid genus of the family Cranchiidae, whose largely transparent tissues have resulted in the common name “glass” squids; their crypsis is also aided by eye photophores (Herring et al. 2002), which counter-shade down-welling light from the surface (Young and Roper 1976; Voss 1985). Cranchiids have been reported from all oceans except the Arctic (Norman and Lu 2000), and are found primarily between the mesopelagic and bathypelagic zones; however, some species, including those of the genus Teuthowenia, migrate vertically within the water column depending on maturity and seasonality (Voss 1985; Moreno et al. 2009). Teuthowenia contains three species (Voss 1980, 1985): Teuthowenia maculata and Teuthowenia megalops are found in the central and northern Atlantic, and Teuthowenia pellucida lives circum-globally in the southern sub-tropical belt (Voss 1985).
    [Show full text]
  • Identification and Estimation of Size from the Beaks of 18 Species of Cephalopods from the Pacific Ocean
    17 NOAA Technical Report NMFS 17 Identification and Estimation of Size From the Beaks of 18 Species of Cephalopods From the Pacific Ocean Gary A. Wolff November 1984 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service NOAA TECHNICAL REPORTS NMFS The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance and geographic distribution of fishery resources, to understand and predict fluctuations in the quantity and distribution of these resources, and to establish levels for optimum use of the resources. NMFS is also charged with the development and implemen­ tation of policies for managing national fishing grounds, development and enforcement of domestic fisheries regulations, surveillance of foreign fishing off United States coastal waters, and the development and enforcement of international fishery agreements and policies. NMFS also assists the fishing industry through marketing service and economic analysis programs, and mortgage insurance and vessel construction subsidies. It collects, analyzes, and publishes statistics on various phases of the industry. The NOAA Technical Report NMFS series was established in 1983 to replace two subcategories of the Technical Reports series: "Special Scientific Report-Fisheries" and "Circular." The series contains the following types of reports: Scientific investigations that document long-term continuing programs of NMFS, intensive scientific reports on studies of restricted scope, papers on applied fishery problems, technical reports of general interest intended to aid conservation and management, reports that review in considerable detail and at a high technical level certain broad areas of research, and technical papers originating in economics studies and from management investigations.
    [Show full text]
  • The Diet of the Blue Shark (Prionace Glauca L.) in Azorean Waters
    THE DIET OF THE BLUE SHARK (PRIONACE GLAUCA L.) IN AZOREAN WATERS M.R. CLARKE, D.C. CLARKE, H.R. MARTINS & H.M. DA SILVA CLARKE,M.R., D.C. CLARKE, H.R. MARTINS & H.M. DA SILVA1996. The diet of the blue shark (Prionace gbauca L.) in Azorean waters. Arquipdago. Life and Marine Sciences 14A: 41-56. Ponta Delgada. ISSN 0873-4704. Stomach contents of 195 Prionace glauca caught off the Azores from October 1993 to July 1994 were studied. Eighty three had empty stomachs. Only 23 contained whole or fleshy parts of animals (other than bait) and all belonged to the fish Capros aper, Macrorhamphosus scolopax and Lepidopus caudatus and the squids Histioteuthis bonnellii and Taonius pavo. Seventy five fish otoliths and 207 cephalopod lower beaks were identified to genus or species. Considering all fragments from the stomachs, including otoliths, cephalopod beaks and eye lenses, a minimum of 1411 fish, 4 crustaceans and 261 cephalopods were represented. Approximately 386 of the fish were represented by eye lenses alone. There was a mean of 2.4 species (1.8 cephalopods and 0.6 fish) and 15.2 animals represented in each stomach. Fish rcmains occurred in 83.0% of the stomachs and contributed 84.5% of animals to the diet. Cephalopod remains occurred in 75.7% and contributed 15.5% of animals. Estimates of the weights of fish and cephalopods suggest that cephalopods are probably the most important in the diet and these were almost entirely meso- or bathypelagic, neutrally buoyant cephalopods. Small epipelagic shoaling fish were present with a few much larger near-bottom fish.
    [Show full text]
  • Underwater Photogrammetry for Close-Range 3D Imaging of Dry
    Underwater photogrammetry for close-range 3D imaging of dry-sensitive objects: The case study of cephalopod beaks Marjorie Roscian, Anthony Herrel, Raphaël Cornette, Arnaud Delapré, Yves Cherel, Isabelle Rouget To cite this version: Marjorie Roscian, Anthony Herrel, Raphaël Cornette, Arnaud Delapré, Yves Cherel, et al.. Underwa- ter photogrammetry for close-range 3D imaging of dry-sensitive objects: The case study of cephalopod beaks. Ecology and Evolution, Wiley Open Access, 2021, 11 (12), pp.7730-7742. 10.1002/ece3.7607. hal-03222274 HAL Id: hal-03222274 https://hal.sorbonne-universite.fr/hal-03222274 Submitted on 10 May 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Received: 22 September 2020 | Revised: 1 April 2021 | Accepted: 7 April 2021 DOI: 10.1002/ece3.7607 ORIGINAL RESEARCH Underwater photogrammetry for close- range 3D imaging of dry- sensitive objects: The case study of cephalopod beaks Marjorie Roscian1,2 | Anthony Herrel2 | Raphaël Cornette3 | Arnaud Delapré3 | Yves Cherel4 | Isabelle Rouget1 1Centre de Recherche en Paléontologie- Paris (CR2P), Muséum National d'Histoire Abstract Naturelle, CNRS, Sorbonne Université, Paris, • Technical advances in 3D imaging have contributed to quantifying and under- France standing biological variability and complexity.
    [Show full text]
  • Applying New Tools to Cephalopod Trophic Dynamics and Ecology: Perspectives from the Southern Ocean Cephalopod Workshop, February 2–3, 2006
    Rev Fish Biol Fisheries (2007) 17:79–99 DOI 10.1007/s11160-007-9055-9 RESEARCH PAPER Applying new tools to cephalopod trophic dynamics and ecology: perspectives from the Southern Ocean Cephalopod Workshop, February 2–3, 2006 G. D. Jackson Æ P. Bustamante Æ Y. Cherel Æ E. A. Fulton Æ E. P. M. Grist Æ C. H. Jackson Æ P. D. Nichols Æ H. Pethybridge Æ K. Phillips Æ R. D. Ward Æ J. C. Xavier Received: 30 October 2006 / Accepted: 14 February 2007 / Published online: 28 March 2007 Ó Springer Science+Business Media B.V. 2007 Abstract A two day workshop on Southern the ecosystem by incorporating squid data in Ocean cephalopods was held in Hobart, Tasmania, ecosystem models. Genetic barcoding is now of Australia prior to the triennial 2006 Cephalopod great value to fish taxonomy as well as other groups International Advisory Council (CIAC) sympo- and it is expected that a cephalopod barcoding sium. The workshop provided a second interna- initiative will be an important tool for cephalopod tional forum to present the current state of taxonomy. There is a current initiative to produce research and new directions since the last Southern a new cephalopod beak identification guide to Ocean cephalopod meeting held in 1993. A major assist predator biologists in identifying cephalopod focus of the workshop was trophic ecology and the prey items. There were also general discussions on use of a variety of tools that can be applied in specific taxonomic issues, Southern Ocean Ceph- Southern Ocean trophic studies for both cephalo- alopod paralarvae and parasites, and suggestions pod and predator researchers.
    [Show full text]