Vulnerabilities and Fisheries Impacts: the Uncertain Future of Manta and Devil Rays

Total Page:16

File Type:pdf, Size:1020Kb

Vulnerabilities and Fisheries Impacts: the Uncertain Future of Manta and Devil Rays University of Groningen Vulnerabilities and fisheries impacts Croll, Donald A.; Dewar, Heidi; Dulvy, Nicholas K.; Fernando, Daniel; Francis, Malcolm P.; Galván-Magaña, Felipe; Hall, Martin; Heinrichs, Shawn; Marshall, Andrea; Mccauley, Douglas Published in: Aquatic Conservation DOI: 10.1002/aqc.2591 IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 2016 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Croll, D. A., Dewar, H., Dulvy, N. K., Fernando, D., Francis, M. P., Galván-Magaña, F., Hall, M., Heinrichs, S., Marshall, A., Mccauley, D., Newton, K. M., Notarbartolo-Di-Sciara, G., O'Malley, M., O'Sullivan, J., Poortvliet, M., Roman, M., Stevens, G., Tershy, B. R., & White, W. T. (2016). Vulnerabilities and fisheries impacts: The uncertain future of manta and devil rays. Aquatic Conservation, 26(3), 562-575. https://doi.org/10.1002/aqc.2591 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Download date: 27-09-2021 AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS Aquatic Conserv: Mar. Freshw. Ecosyst. 26: 562–575 (2016) Published online 3 November 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/aqc.2591 Vulnerabilities and fisheries impacts: the uncertain future of manta and devil rays DONALD A. CROLLa,*, HEIDI DEWARb, NICHOLAS K. DULVYc, DANIEL FERNANDOd,e, MALCOLM P. FRANCISf, FELIPE GALVÁN-MAGAÑAg, MARTIN HALLh, SHAWN HEINRICHSi, ANDREA MARSHALLj, DOUGLAS MCCAULEYk, KELLY M. NEWTONa, GIUSEPPE NOTARBARTOLO-DI-SCIARAl, MARY O’MALLEYe,m, JOHN O’SULLIVANn, MARLOES POORTVLIETa,o, MARLON ROMANh, GUY STEVENSe,p, BERNIE R. TERSHYa and WILLIAM T. WHITEq aCoastal Conservation Action Lab, University of California, Santa Cruz bSouthwest Fisheries Science Center, NOAA Fisheries cBiological Sciences, Simon Fraser University dDepartment of Biology and Environmental Science, Linnaeus University eManta Trust fFisheries, National Institute of Water and Atmospheric Research gCentro Interdisciplinario de Ciencias Marinas hInter-American Tropical Tuna Commission iBlue Sphere Media LLC jMarine Megafauna Foundation kDepartment of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara lTethys Research Institute mWildAid nMonterey Bay Aquarium oDepartment of Marine Benthic Ecology and Evolution, Centre for Ecological and Evolutionary Studies, University of Groningen pEnvironment Department, University of York qMarine and Atmospheric Research, Commonwealth Scientific and Industrial Research Organization ABSTRACT 1. Manta and devil rays of the subfamily Mobulinae (mobulids) are rarely studied, large, pelagic elasmobranchs, with all eight of well-evaluated species listed on the IUCN Red List as threatened or near threatened. 2. Mobulids have life history characteristics (matrotrophic reproduction, extremely low fecundity, and delayed age of first reproduction) that make them exceptionally susceptible to overexploitation. 3. Targeted and bycatch mortality from fisheries is a globally important and increasing threat, and targeted fisheries are incentivized by the high value of the global trade in mobulid gill plates. 4. Fisheries bycatch of mobulids is substantial in tuna purse seine fisheries. 5. Thirteen fisheries in 12 countries specifically targeting mobulids, and 30 fisheries in 23 countries with mobulid bycatch were identified. 6. Aside from a few recently enacted national restrictions on capture, there is no comprehensive monitoring, assessment or control of mobulid fisheries or bycatch. Recent listing through the Convention on the *Correspondence to: Donald A. Croll, Coastal Conservation Action Lab, University of California, Santa Cruz, 100 Shaffer Road. Santa Cruz, CA 95060 USA. Email: [email protected] # 2016 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons, Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. THE UNCERTAIN FUTURE OF MANTA AND DEVIL RAYS 563 International Trade in Endangered Species (CITES) may benefit mobulids of the genus Manta (manta rays), but none of the mobulids in the genus Mobula (devil rays) are protected. 7. The relative economic costs of catch mitigation are minimal, particularly compared with a broad range of other, more complicated, marine conservation issues. Copyright # 2015 John Wiley & Sons, Ltd. Received 06 February 2015; Revised 28 July 2015; Accepted 13 August 2015 KEY WORDS: coastal; ocean; conservation evaluation; endangered species; fish; fishing INTRODUCTION LIFE HISTORY Marine organisms are subject to multiple Like many elasmobranchs, mobulids have anthropogenic threats (Stevens et al., 2000; Lewison K-selected life history traits including delayed, et al., 2004; Dulvy et al., 2014), and long-lived matrotrophic (ovoviparous) reproduction and low species with low fecundity (e.g. whales, seabirds, sea annual fecundity. The life history parameter that sets turtles, and sharks) are particularly vulnerable mobulids apart from other elasmobranchs and (Owens and Bennett, 2000). Pelagic elasmobranchs makes them vulnerable to overexploitation is their tend to be even more vulnerable because they have extremely low fecundity – among the lowest of all exceptionally low population growth rates, are fishes (Dulvy et al., 2014). Mobulid litter size is only often subject to targeted and bycatch in multiple one (Hoenig and Gruber, 1990, Stevens et al., 2000), fisheries, and the quantification of catch and and interbirth intervals are estimated at 1–3years management is limited or non-existent (Stevens (Notarbartolo-di-Sciara, 1988; Compagno and Last, et al., 2000; Dulvy et al., 2008, 2014). 1999; Homma et al., 1999; Marshall and Bennett, Of the pelagic elasmobranchs, the 11 species of 2010). Marshall and Bennett (2010) estimated Manta manta and devil rays, subfamily Mobulinae alfredi gestation period at 12 months with a mix of (mobulids) are among the most vulnerable. In annual and biennial pregnancies while Stevens addition to their K-selected life history traits, they (unpublished data) estimated one gestation every have been directly targeted in small-scale fisheries 5years in M. alfredi off the Maldives. Although (Notarbartolo-di-Sciara, 1988; White et al., 2006a; variable across mobulids, most annual fecundities are Rohner et al., 2013) and captured as bycatch in ~0.5 pups per year, particularly for larger species industrial fisheries (Paulin et al., 1982; White (e.g. 0.56 pregnancies per adult female per year for et al., 2006a). Between 1998 and 2009, mobulid M. alfredi;Deakoset al., 2011). landings increased more than an order of Maximum rate of mobulid population increase is magnitude (from 200 to 5000 metric tons yearÀ1) also limited by delayed age at maturation. Pups are (Ward-Paige et al., 2013). All eight of the mobulid relatively large at birth, ranging from 27 to 49% of species effectively evaluated for the IUCN Red maternal size (Notarbartolo-di-Sciara, 1988; White List are threatened (endangered or vulnerable) or et al., 2006b; Marshall et al., 2009). Information near threatened, with the remaining three listed as on age of maturation is limited, however, using data deficient (Table 1). Four species are classified unvalidated age/growth data from Cuevas-Zimbron as declining, and the population trajectory of the (2007) and size at maturity from Serrano-López remaining seven species is unknown (IUCN, 2012) (2009), Mobula japanica appear to attain sexual (Table 1). Given these concerns, a logical first step maturity at 5–6 years. Marshall et al. (2011a) to the conservation of mobulids is to evaluate their reported that M. alfredi matures at >8and>3years life history sensitivity and threats, and potential in females and males, respectively, while Clark (2010) management solutions. reported the age of maturity of M. alfredi as 3–6 years. Copyright # 2016 The Authors. Aquatic Conservation: Marine and Freshwater Aquatic Conserv: Mar. Freshw. Ecosyst. 26: 562–575 (2016) Ecosystems published by John Wiley & Sons, Ltd. 564 D. A. CROLL ET AL. Table 1. Characteristics of the family Mobulidae (Couturier et al., 2012; IUCN, 2012) Scientific IUCN Maximum common name classification Distribution Habitat size (DW) Trend Fishery Manta alfredi vulnerable Circumglobal, tropical coastal 550 cm decreasing targeted bycatch Reef manta ray and subtropical Manta birostris vulnerable Circumglobal, tropical coastal pelagic 900 cm decreasing targeted bycatch Giant manta ray and subtropical Mobula eregoodootenkee near threatened Tropical Indo-West Pacific coastal 100 cm unknown bycatch Pygmy devil ray and Northern Indian Ocean Mobula hypostoma data deficient Western
Recommended publications
  • Lesser Devil Rays Mobula Cf. Hypostoma from Venezuela Are Almost Twice Their Previously Reported Maximum Size and May Be a New Sub-Species
    Journal of Fish Biology (2017) 90, 1142–1148 doi:10.1111/jfb.13252, available online at wileyonlinelibrary.com Lesser devil rays Mobula cf. hypostoma from Venezuela are almost twice their previously reported maximum size and may be a new sub-species N. R. Ehemann*†‡§, L. V. González-González*† and A. W. Trites‖ *Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, Apartado Postal 592, La Paz, Baja California Sur C.P. 23000, Mexico, †Escuela de Ciencias Aplicadas del Mar (ECAM), Boca del Río, Universidad de Oriente, Núcleo Nueva Esparta (UDONE), Boca del Río, Nueva Esparta, C.P. 06304, Venezuela, ‡Proyecto Iniciativa Batoideos (PROVITA), Caracas, Venezuela and ‖Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada (Received 8 September 2016, Accepted 23 November 2016) Three rays opportunistically obtained near Margarita Island, Venezuela, were identified as lesser devil rays Mobula cf. hypostoma, but their disc widths were between 207 and 230 cm, which is almost dou- ble the reported maximum disc width of 120 cm for this species. These morphometric data suggest that lesser devil rays are either larger than previously recognized or that these specimens belong to an unknown sub-species of Mobula in the Caribbean Sea. Better data are needed to describe the distribu- tion, phenotypic variation and population structure of this poorly known species. © 2017 The Fisheries Society of the British Isles Key words: batoids; by-catch; Caribbean Sea; Chondrichthyes; Myliobatiformes. There is limited biological and fisheries information about the body size at maturity, population size, stock, maximum age and length–mass relationships of Mobula hypos- toma (Bancroft, 1831), better known as the lesser devil ray.
    [Show full text]
  • First Record of Mobula Japonica (Muller Et Hentle), a Little Known Devil Ray from the Gulf of Thailand (Pisces : Mobulidae)
    FIRST RECORD OF MOBULA JAPONICA (MULLER ET HENTLE), A LITTLE KNOWN DEVIL RAY FROM THE GULF OF THAILAND (PISCES : MOBULIDAE) Thosaporn Wongratana* Abstract A specimen of young Mobulajaponica (Muller & Henle), measured 661 rom across wings, is here described together with a note on the sight­ ing of 12 big specimens from Koh Chang, Trat Province, in the Gulf of Thailand. This is the first documentary report of the family Mobulidae for Thailand and of. the species for the South China Sea. Previously, the species were occasionally recorded from Japan, Honolulu, Samoa, Korea and Taiwan waters. Its inferior mouth with a band of teeth in both jaws, the very long whip-liked tail, and a prominent serrated caudal spine pro­ vide the main distinct characteristics and separate it from other related species. The full measurements of this young specimen and of the Naga Expedition's specimen of Mobula diabolus (Shaw), taken from Cambodian water, are also given. Introduction Jn order to update the knowledge of marine fish fauna of Thailand, regular observation of fish landing and occasional procurement of fish specimens are made at the Bangkok Wholesale Fish Market, operated by the Fish Marketing Organization of the Ministry of Agriculture and Cooperatives. On 4 December 1973, the author came across a young devil ray or sea devil, known in Thai "Pia rahu" (uom»). The fish measured 661 mm across the width. He has no hesitati~ns to make a further look for other specimens. And this led him to spot other 8 big males and 3 females of about the same size.
    [Show full text]
  • Conservation and Population Ecology of Manta Rays in the Maldives
    Conservation and Population Ecology of Manta Rays in the Maldives Guy Mark William Stevens Doctor of Philosophy University of York Environment August 2016 2 Abstract This multi-decade study on an isolated and unfished population of manta rays (Manta alfredi and M. birostris) in the Maldives used individual-based photo-ID records and behavioural observations to investigate the world’s largest known population of M. alfredi and a previously unstudied population of M. birostris. This research advances knowledge of key life history traits, reproductive strategies, population demographics and habitat use of M. alfredi, and elucidates the feeding and mating behaviour of both manta species. M. alfredi reproductive activity was found to vary considerably among years and appeared related to variability in abundance of the manta’s planktonic food, which in turn may be linked to large-scale weather patterns such as the Indian Ocean Dipole and El Niño-Southern Oscillation. Key to helping improve conservation efforts of M. alfredi was my finding that age at maturity for both females and males, estimated at 15 and 11 years respectively, appears up to 7 – 8 years higher respectively than previously reported. As the fecundity of this species, estimated at one pup every 7.3 years, also appeared two to more than three times lower than estimates from studies with more limited data, my work now marks M. alfredi as one of the world’s least fecund vertebrates. With such low fecundity and long maturation, M. alfredi are extremely vulnerable to overfishing and therefore needs complete protection from exploitation across its entire global range.
    [Show full text]
  • Keeping the Balance.Pdf
    Contents Caribbean reef shark (Carcharhinus perezi). Jardines de la Reina, Cuba, March 2008. © OCEANA/ Carlos Suárez IUCN Status: Near Threatened. Executive Summary ..................................................................................................................1 1. Introduction ...........................................................................................................................2 2. Shark status according to the IUCN Red List of Threatened Species .....5 3. United Nations Convention on the Law of the Sea ..........................................7 4. International multilateral biodiversity conventions ......................................8 5. European regional environmental conventions .............................................12 6. Shark protection under EU biodiversity regulations ..................................16 7. Conclusions ..........................................................................................................................17 Annex I. Existing multilateral and regional conventions under international environmental law and their provisions for shark protection...................................18 Annex II. Elasmobranch species listed under existing multilateral and regional environmental conventions ...................................................................................19 References ...................................................................................................................................21 Recommendations .................................................................................................................26
    [Show full text]
  • Atlantic Ocean)
    Marine Stewardship Council fisheries assessments Lloyd’s Register 6 Redheughs Rigg South Gyle Edinburgh, EH12 9DQ United Kingdom T +44 (0)13 1619 2100 E [email protected] www.lr.org AGAC four oceans Integral Purse Seine Tropical Tuna Fishery (Atlantic Ocean) Risk-Based Framework Stakeholder Consultation Document Conformity Assessment Body (CAB) Lloyd’s Register Jo Akroyd, Carola Kirchner, Kevin McLoughlin, Rob Blyth- Assessment team Skyrme, Stewart Norman and David Japp Fishery client AGAC Assessment Type Initial Assessment LR RBF Stakeholder Consultation document AGAC four oceans Integral Purse Seine Tropical Tuna Fishery – Atlantic Ocean AGAC four oceans Integral Purse Seine Tropical Tuna Fishery (Atlantic Ocean) Assessment Background The AGAC four oceans Integral Purse Seine Tropical Tuna Fishery targets three species yellowfin, bigeye and skipjack tuna in four areas of operation, namely the Western Central Pacific, Eastern Pacific, Indian and Atlantic oceans and is currently being assessed against the Marine Stewardship Council (MSC) Standard for sustainable fisheries. The fishery is being assessed as 12 separate Units of Assessment (UoAs) but the focus of this document is the three UoAs in the jurisdiction of the Atlantic Ocean and specifically the area under ICCAT management, as shown in Table 1, below: Table 1: UoAs for the AGAC four oceans Integral Purse Seine Tropical Tuna Fishery (Atlantic Ocean) UoA Location Gear Type Target Species 1 Atlantic Ocean – FAO areas 34 and 47 Purse Seine (FAD and FSC) Yellowfin tuna 2 Atlantic Ocean – FAO areas 34 and 47 Purse Seine (FAD and FSC) Bigeye tuna Purse Seine (FAD and FSC) Skipjack tuna East Atlantic and West Atlantic Ocean – FAO areas 34 and 47 Atlantic, scored as two elements with (East Atlantic skipjack tuna element), 3 UoA 3 and 31 and 41 (West Atlantic skipjack tuna element) An Assessment Team of independent experts from Lloyd’s Register produced the Announcement Comment Draft Report on 21 August 2020 and is preparing to carry out a remote site visit commencing 21 October 2020.
    [Show full text]
  • Manta Ray Critical Habitat Determination Bibliography
    Manta Ray Critical Habitat Determination Bibliography Adams D, Amesbury E (1998) Occurrence of the manta ray, Manta birostris, in the Indian River Lagoon, Florida. Florida Scientist 61: 7-9 Armstrong AO, Armstrong AJ, Jaine FRA, Couturier LIE, Fiora K, Uribe-Palomino J, Weeks SJ, Townsend KA, Bennett MB, Richardson AJ (2016) Prey Density Threshold and Tidal Influence on Reef Manta Ray Foraging at an Aggregation Site on the Great Barrier Reef. PLoS ONE 11: 1-18 doi 10.1371/journal.pone.0153393 Beebe W, Tee-Van J (1941) Eastern Pacific expeditions of the New York Zoological Society. XXVIII. Fishes from the tropical eastern Pacific. [From Cedros Island, Lower California, south to the Galápagos Islands and northern Peru.] Part 3. Rays, Mantas and Chimaeras. Zoologica, Scientific Contributions of the New York Zoological Society 26: 245-280, PIs. 241-244 Bigelow HB, Schroeder WC (1953) Sawfishes, guitarfishes, skates and rays. Fishes of the Western North Atlantic. Memoirs of Sears Foundation for Marine Research 1: 514 Burgess KB (2017) Feeding ecology and habitat use of the giant manta ray Manta birostris at a key aggregation site off mainland Ecuador. Faculty of Medicine Burgess KB, Couturier LI, Marshall AD, Richardson AJ, Weeks SJ, Bennett MB (2016) Manta birostris, predator of the deep? Insight into the diet of the giant manta ray through stable isotope analysis. R Soc Open Sci 3: 160717 doi 10.1098/rsos.160717 Carpenter KE, Niem VH (2001) FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 5. Bony fishes part 3 (Menidae to Pomacentridae).
    [Show full text]
  • FAO Expert Advisory Panel for Assessment of CITES Marine and Aquatic Proposals (Rome, Italy
    CoP17 Doc. 88. 3 Annex 11 (English only / Únicamente en inglés / Seulement en anglais) FAO Expert Advisory Panel for Assessment of CITES Marine and Aquatic Proposals (Rome, Italy. 6-10 June 2016) Submission by SPRFMO Secretariat The Secretariat of the South Pacific Regional Fisheries Management Organisation (SPRFMO) is pleased to be able to provide the following information for consideration by the CITES Expert Advisory Panel for the assessment of proposals to amend CITES Appendices II for fishery species (June 2016). 1. Conservation and Management Measures (CMMs) SPRFMO while still being a relatively young RFMO has implemented very detailed reporting requirements. These requirements are fully described in CMM 4.02 (Data Standards; 2016). Briefly, CMM 4.02 requires that all Members and Cooperating non-Contracting Parties (CNCPs) annually submit data on fishing activities and the impacts of fishing to the SPRFMO Secretariat. These submissions can be grouped into the following categories: a) Annual catch totals for all species caught during the year; b) Data on fishing activities by fishing method and; c) Observer collected information. Annual catch data contains a total “”live weight” for each species caught within each FAO statistical area. Fishing activities data contains information on the date, time and location of estimated catches and discards (for all target, bycatch and other species of concern). Observer information generally contains similar information as fishing activity data and additionally includes biological and scientific information. Along with marine mammals, seabirds and reptiles, and since January 2015, captures of other species of concern must be specifically identified and recorded in both fishing activity and observer information submissions.
    [Show full text]
  • Ecology and Natural History of the Manta Ray (Manta Birostris)
    Ecology and natural history of the Manta Ray (Manta birostris). Robert D. Rubin, Ph.D. Pacific Manta Research Group The manta ray is one of the most intriguing and unique animals found in the world’s oceans. Its large size and unusual shape, coupled with the strange horn-like fins used in feeding, make it one of the natural world’s most spectacular animals. Rarely in nature does one encounter free-living animals that display a tolerance of their human onlookers. Moreover, animals that seem to have a genuine interest and curiosity about humans may be limited to a few species worldwide. The Pacific Manta Ray represents this unique combination of great size coupled with a gentle grace and a curious approach to the humans who come to share, if only for a moment its silent world. Large pelagic animals of any species are poorly known because they are few in number, range widely in the world's oceans and spend most of their life in a solitary remoteness that makes them inaccessible to humans. As pressures for recreational and commercial fishing sites have expanded, so have the inevitable interactions resulting from human use and invasion of the natural world. In the past decade an animal that is almost unknown to science has all but disappeared from areas of the world where it was once commonplace. This charismatic animal, once thought of as 'the devil fish' and feared by seafaring people, begs for an increased understanding of its behavior and ecological status in the sea. Over the past three decades only a handful of scientific papers have been devoted to any aspect of this species’ ecology.
    [Show full text]
  • Practical Manual in Zoology
    PRACTICAL MANUAL IN ZOOLOGY EDITOR Dr. A. AMSATH, Associate Professor & CONTRIBUTORS Dr. P. KUMARASAMY, HOD & Associate Professor Dr. S. RAVEENDRAN, Associate Professor Dr.K.MUTHUKUMARAVEL, Assistant Professor Dr.O.SATHICK, Assistant Professor Dr.V.GANAPIRIYA, Assistant Professor Dr.A.MAHARAJAN, Assistant Professor Dr.J.SUGUMARAN, Assistant Professor PG and Research Department of Zoology Khadir Mohideen College, Adirampattinam- 614 701 2014 M. M. A. PUBLICATIONS 6B/2 Ever Gold Complex, Selliamman Kovil Street, Adirampattinam-614 701,Thanjavur District, Tamil Nadu, India Title : PRACTICAL MANUAL IN ZOOLOGY Author : Dr. A. AMSATH Associate Professor and Research Advisor PG and Research Department of Zoology Adirampattinam - 614 701 First Edition : 2010 Revised Edition 2014 Pages : 10 + 313 Copy Right : Author Figures : 240 Page Setup : A4 Font : Arial Price : Rs. 360 Publisher : M. M. A. Publications 269-A Bharathisalai, Karikkadu Pattukkottai - 614 602. Cell: 9443717126 Phone: 04373-236469 Printed at : Hamidia Printers 170/3, Palaniappan Street Pattukkottai - 614601 ii PREFACE Animals have inhabited the earth for millions of years, growing from simple one-celled organisms to the diverse variety we see today. This manual encompasses an overview of the animal kingdom and classification suitable for both B.Sc. and M. Sc. Zoology. The collection of spotters and mountings related to the Functional Morphology and Paleontology of Invertebrates and Chordates. The spotters are presented in a simple way with taxonomical characters and salient features. It also emphasizes the microscopic study of live and preserved specimens. This manual is comprehensive in its representation of the major groups of animal phyla. The experimental parts related to the Genetics, Microbiology and Cell and Molecular Biology are presented in a simple way with a discussion on all subjects.
    [Show full text]
  • Encephalization and Brain Organization of Mobulid Rays (Myliobatiformes, Elasmobranchii) with Ecological Perspectives Csilla Ari*1,2,3
    The Open Anatomy Journal, 2011, .3, 1-13 1 Open Access Encephalization and Brain Organization of Mobulid Rays (Myliobatiformes, Elasmobranchii) with Ecological Perspectives Csilla Ari*1,2,3 USF Health Byrd Alzheimer`s Center and Research Institute, Tampa, Florida 33613, USA Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612, USA Semmelweis University, Department of Anatomy, Histology and Embryology, Budapest 1094, Hungary Abstract: In the present study the brain mass to body mass ratio and external morphological features of the brain of Mobula japanica, Mobula thurstoni and Manta birostris (devilrays) are described. The Mobulids extended the upper boundary of the minimum convex polygon described earlier by other authors for batoids, which is plotted on a double logarithmic scale of brain to body mass, causing some change in the allometric coefficient. The encephalization quotient of Mobulas was higher than unity, therefore it can be concluded that the actual brain mass is greater than expected by the given body mass. M. japanica had the highest percentage (61%) of telencephalic mass from all batoids, while the brain mass of M. birostris was the highest of all fish studied so far. The gross morphology of the enlarged Mobulid telencephalon and cerebellum prominently resembled to that of Sphyrna mokarran (great hammerhead shark). A structural dimorphism of the highly foliated cerebellum was detected between genders of the M. japanica, albeit with a small sample size. No such gender-related dimorphism was detected in brain mass/body mass ratio. Other brain parts were similar to those of other elasmobranch species. The data are discussed in terms of their ecological and evolutionary significance.
    [Show full text]
  • Longline Fishery (Central Mediterranean)
    SCRS/2009/059 Collect. Vol. Sci. Pap. ICCAT, 65(6): 2262-2269 (2010) NON-TARGET BY-CATCH IN THE MALTESE BLUEFIN TUNA (THUNNUS THYNNUS) LONGLINE FISHERY (CENTRAL MEDITERRANEAN) Emma Burgess,1 Mark Dimech2*, Raymond Caruana2, Michael Darmanin2, Helen Raine3, Alan Harrison,4 Patrick J. Schembri5 SUMMARY The bluefin tuna longline fishery is one of the most important pelagic fisheries in the Mediterranean but recently there has been increasing concern about the catches of non-target species. This study presents an assessment of the non-target by-catch from the Maltese bluefin tuna longline fleet and examines the effect of various environmental and spatio-temporal factors on non-target species catch rates. Field observations were made during 85 fishing days. In terms of number, bluefin tuna comprised a relatively small portion of the total catch while the loggerhead turtle (Caretta caretta) was the predominant by-catch species. Catch Per Unit Effort (CPUE) was calculated in terms of weight (kg/1000hooks/hr) and number (no/1000hooks/hr) for all the species caught. Generalized Linear Mixed Models (GLMMs) were applied to examine the effect of environmental and spatio-temporal variables on non-target by- catch CPUE. The model for CPUE (number) was not found to be significant. Date, lunar cycle, species and longitude were found to be significantly correlated with CPUE (weight). The results of this study suggests the need for the continual implementation of mitigation measures to minimise the impacts of fishing activities on threatened non-target species in the Mediterranean. RÉSUMÉ La pêcherie palangrière de thon rouge est une des pêcheries pélagiques les plus importantes en Méditerranée, mais récemment les captures d’espèces non-ciblées suscitent une inquiétude croissante.
    [Show full text]
  • Updated Checklist of the Extant Chondrichthyes Within the Exclusive Economic Zone of Mexico
    A peer-reviewed open-access journal ZooKeys 774: 17–39 (2018) Updated checklist of the extant Chondrichthyes... 17 doi: 10.3897/zookeys.774.25028 CHECKLIST http://zookeys.pensoft.net Launched to accelerate biodiversity research Updated checklist of the extant Chondrichthyes within the Exclusive Economic Zone of Mexico Nicolás Roberto Ehemann1, Lorem del Valle González-González1, Jorge Guillermo Chollet-Villalpando2, José De La Cruz-Agüero1 1 Instituto Politécnico Nacional – Centro Interdisciplinario de Ciencias Marinas (CICIMAR–IPN), Colección Ictiológica, Avenida IPN s/n, Colonia Playa Palo Santa Rita, La Paz, Baja California Sur, 23096, México 2 Instituto de Ecología, A.C. – INECOL, Biodiversidad y Sistemática, Carretera Antigua a Coatepec 351, Colonia El Haya, Xalapa, 91070, Veracruz, México Corresponding author: José De La Cruz-Agüero ([email protected]) Academic editor: N. Bogutskaya | Received 14 March 2018 | Accepted 22 May 2018 | Published 12 July 2018 http://zoobank.org/5C1CDCE3-B07A-4E15-B6B7-2C5F36F8C568 Citation: Ehemann NR, González-González LV, Chollet-Villalpando JG, Cruz-Agüero JDL (2018) Updated checklist of the extant Chondrichthyes within the Exclusive Economic Zone of Mexico. ZooKeys 774: 17–39. https://doi. org/10.3897/zookeys.774.25028 Abstract The checklist presented in this study includes the latest taxonomic and systematic modifications and updates (early 2018) for the Chondrichthyes that inhabit the Exclusive Economic Zone (EEZ) of Mexico. The list is based on a literature review of field-specific books, scientific publications and database information from collections and museums worldwide available online such as, the Ocean Biogeographic Information System (OBIS), Global Biodiversity Information Facility (GBIF), Encyclopedia of Life (EOL), iSpecies, FishBase and the National Biodiversity Information System (SNIB–CONABIO).
    [Show full text]