NEWSLETTER 06/2013 22. July 2013
|Please acknowledge use of the database www.shark-references.com in your publications, and cite:
Pollerspöck, J. 2013, Bibliography database of living/fossil sharks, rays and chimaeras (Chondrichtyes: Elasmobranchii, Holocephali), www.shark-references.com, World Wide Web electronic publication, Version 2013
3rd International Whale Shark Conference
Bringing the whale shark research and conservation community together
Registration and abstract submission information for the 3rd International Whale Shark Conference, to be held at the Georgia Aquarium in Atlanta USA, October 6-10, 2013
Abstracts will be considered as candidates for either oral or author-attended poster sessions. Authors should state their preference in the email accompanying the submission, but the Scientific Program Committee will make the final determination
For more information please visit: http://iwsc3.info/
THE DIVERSITY OF FISH OTOLITHS, PAST AND PRESENT by Dirk Nolf
The text includes:
1 – An introductory section, with a historical and nomenclatural overview, and with special emphasis on the great impact of otoliths for evaluating the fossil record of teleostean fishes.
2 – A systematic overview (with iconography) of the 1391 fossil species considered to be valid, and of all Recent species for which otoliths have been found as fossil. For every species, the stratigraphic and geographic origin of the type material is given, and where available, also the collection numbers and depository of the holotype. Fossil species based on skeletons with otoliths in situ, but which do not have exclusively otolith-based primary types, are also included.
3 – An alphabetic list of all the 1797 nominal otolith-based fossil fish species, with an evaluation of their validity and their actualized nomenclature.
The 395 plates show otoliths of over 2000 fossil and Recent fishes, often with growth or variability series. More than 50% of the species are illustrated by newly made drawings, with many of the fossil ones directly drawn from the holotypes. For many of the Recent families, the otoliths are illustrated here for the first time.
The book is not only of interest for otolith paleontologists and archeozoologists, but also for all those interested in the fossil record and first appearances of fish taxa, the interrelationships of fishes, and the study of feeding behaviour of predators, like marine mammals and birds, through analysis of their stomach content and rejection pellets.
New described species/Taxonomic News:
BORSA, P. & DURAND, J.-D. & SHEN, K.-N. & ARLYZA, I.S. & SOLIHIN, D.D. & BERREBI, P. (2013): Himantura tutul sp. nov. (Myliobatoidei: Dasyatidae), a new ocellated whipray from the tropical Indo-West Pacific, described from its cytochrome-oxidase I gene sequence. Comptes Rendus Biologies, 336 (2): 82-92
New species: Himantura tutul
Abstract: It has been previously established that the Leopard Whipray, Himantura leoparda, consists of two genetically isolated, cryptic species, provisionally designated as 'Cluster 1' and 'Cluster 4' (Arlyza et al., Mol. Phylogenet. Evol. 65 (2013) [11). Here, we show that the two cryptic species differ by the spotting patterns on the dorsal surface of adults: Cluster-4 individuals tend to have larger-ocellated spots, which also more often have a continuous contour than Cluster-1 individuals. We show that H. leopard a's holotype has the typical larger-ocellated spot pattern, designating Cluster 4 as the actual H. leoparda. The other species (Cluster 1) is described as Himantura tutul sp. nov. on the basis of the nucleotide sequence of a 655-base pair fragment of its cytochrome-oxidase I gene (GENBANK accession No. JX263335). Nucleotide synapomorphies at this locus clearly distinguish H. tutul sp. nov. from all three other valid species in the H. uarnak species complex, namely H. leoparda, H. uarnak, and H. undulata. H. tutul sp. nov. has a wide distribution in the Indo-West Pacific, from the shores of eastern Africa to the Indo-Malay archipelago. H. leoparda under its new definition has a similarly wide Indo-West Pacific distribution.
ROCHA, S. & CASAL, G. & AL-QURAISHY, S. & AZEVEDO, C. (2013): Morphological and Molecular Characterization of a New Myxozoan Species (Myxosporea) Infecting the Gall Bladder of Raja clavata (Chondrichthyes), from the Portuguese Atlantic Coast. Journal of Parasitology, 99 (2): 307-317
New species: Chloromyxum clavatum
Abstract: Microscopic and molecular procedures are used to describe a new myxosporean species, Chloromyxum clavatum n. sp., infecting the cartilaginous fish Raja clavata Linnaeus, 1758 (Chondrichthyes: Rajidae), collected from the northwest Atlantic coast of Portugal. Young plasmodia and mature spores were found floating free in the gall bladder of R. clavata . Spores were spherical to subspherical with a pointed anterior end, measuring14.4 +/- 0.5 mum (n = 25) in length, 11.9 +/- 0.5 mum (n = 25) in width, and 9.4 +/- 0.5 mum (n = 15) in thickness. The spore's wall was composed of 2 equally sized valves, each displaying 6-8 elevated surface ridges and a bundle of several tapering caudal filaments attached to the basal portion. Spores contained 4 pyriform equally sized polar capsules (5.5 +/- 0.4 mum x 2.9 +/- 0.5 mum) (n = 25), each possessing an obliquely arranged isofilar polar filament coiled in 7-8 coils. Morphological data, host specificity, tissue tropism, and molecular analysis of the SSU rDNA gene identify this parasite as a new species of Chloromyxum. Neighbor-joining and maximum likelihood further reveal the parasite clustering with other species of Chloromyxum infecting the gall bladder of marine cartilaginous fish to form a clade positioned at the base of the freshwater clade, therefore constituting an exception to the major division of the class Myxosporea into the freshwater and marine clades, while supporting the existence of a correlation between tissue tropism and myxosporean phylogeny.
KITAMURA, N. (2013): Description of a New Species of the Family Echinorhinidae (Chondrichthyes, Elasmobranchii) from the Upper Cretaceous Himenoura Group in Kumamoto Prefecture, Southwestern Japan. Paleontological Research, 17 (2): 189-195
New species: Echinorhinus wadanohanaensis
Abstract: Many species of the family Echinorhinidae are reported from the Cenozoic, but from the Cretaceous only a few species have been reported. In this paper, a new species, Echinorhinus wadanohanaensis of the family Echinorhinidae, is described from the Upper Cretaceous (Santonian) Hinoshima Formation of the Himenoura Group at Ryugatake-machi in Kumamoto Prefecture, Japan. The species differs from other congeners in having a distally inclined main cusp, the distally directed cusp apex not extending beyond the distal demarcation of the distal heel, no lateral cusplets (basal cusplets), a large principal cusp, no vertical groove in the root, few grooves below the boundary of the enameloid on the lingual face, and being markedly large in size. This is the first report of the family Echinorhinidae from the Santonian as well as the first report of the family Echinorhinidae from the Cretaceous of Japan.
BORSA, P. & DURAND, J.-D. & SHEN, K.-N. & ARLYZA, I.S. & SOLIHIN, D.D. & BERREBI, P. (2013): Himantura tutul sp. nov. (Myliobatoidei: Dasyatidae), a new ocellated whipray from the tropical Indo-West Pacific, described from its cytochrome-oxidase I gene sequence Comptes Rendus Biologies, 336 (2): 82-92 http://dx.doi.org/10.1016/j.crvi.2013.01.004
BUSTAMANTE, C. & KYNE, P.M. & BENNETT, M.B. (2013): Comparative morphology of the egg cases of Asymbolus analis, Asymbolus rubiginosus and Figaro boardmani (Carcharhiniformes: Scyliorhinidae) from southern Queensland, Australia. Journal of Fish Biology, 83 (1): 133-143 http://dx.doi.org/10.1111/jfb.12155
CHEN, X. & AI, W. & XIANG, D. & CHEN, Y. & CHEN, S. (2013): Complete mitogenome of the pale-edged stingray Dasyatis zugei (Myliobatiformes: Dasyatidae). Mitochondrial DNA, 24 (3): 196-198 http://dx.doi.org/10.3109/19401736.2012.744982
CHIN, C.-P. & LIU, K.-M. (2013): Estimate of the intrinsic rate of population increase for the blue shark in the North Pacific. ISC Shark Working Group Workshop: ISC/13/SHARKWG-2/04; NOAA/NMFS, Southwest Fisheries Science Center
CLARKE, C.R. & LEA, J.S.E. & ORMOND, R.F.G. (2013): Changing relative abundance and behaviour of silky and grey reef sharks baited over 12 years on a Red Sea reef.Marine and Freshwater Research, in press http://dx.doi.org/10.1071/MF12144
COMPAGNUCCI, C. & DEBIAIS-THIBAUD, M. & COOLEN, M. & FISH, J. & GRIFFIN, J.N. & BERTOCCHINI, F. & MINOUX, M. & RIJLI, F.M. & BORDAY-BIRRAUX, V. & CASANE, D. & MAZAN, S. & DEPEW, M.J. (2013): Pattern and Polarity in the Development and Evolution of the Gnathostome Jaw: Both Conservation and Heterotopy in the Branchial Arches of the Shark, Scyliorhinus canicula. Developmental Biology, 377 (2): 428-448 http://dx.doi.org/10.1016/j.ydbio.2013.02.022
CUEVAS-ZIMBRÓN, E. & SOSA-NISHIZAKI, O. & PÉREZ-JIMÉNEZ, J.C. & O'SULLIVAN, J.B. (2013): An analysis of the feasibility of using caudal vertebrae for ageing the spinetail devilray, Mobula japanica (Müller and Henle, 1841). Environmental Biology of Fishes, 96 (8): 907-914 http://dx.doi.org/10.1007/s10641-012-0086-2
DEL RAYE, G. & JORGENSEN, S.J. & KRUMHANSL, K. & EZCURRA, J.M. & BLOCK, B.A. (2013): Travelling light: white sharks (Carcharodon carcharias) rely on body lipid stores to power ocean-basin scale migration. Proceedings of the Royal Society of London, Series B, 280 (1766): 8pp http://dx.doi.org/10.1098/rspb.2013.0836
DEWAR, H. & EGUCHI, T. & HYDE, J. & KINZEY, D. & KOHIN, S. & MOORE, J. & TAYLOR, B.L. & VETTER, R. (2013): Status Review of the Northeastern Pacific Population of White Sharks (Carcharodon carcharias) under the Endangered Species Act. National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center: 153 pp
DOMINGUES, R.R. & DE AMORIM, A.F. & HILSDORF, A.W.S. (2013): Genetic identification of Carcharhinus sharks from the southwest Atlantic Ocean (Chondrichthyes: Carcharhiniformes). Journal of Applied Ichthyology, 29 (4): 738–742 http://dx.doi.org/10.1111/jai.12154
EL KAMEL-MOUTALIBI, O. & MNASRI, N. & BOUMAIZA, M. & REYNAUD, C. & CAPAPÉ, C. (2013): Diet of common torpedo Torpedo torpedo (Chondrichthyes: Torpedinidae) from the Lagoon of Bizerte (northeastern Tunisia, central Mediterranean).Cahiers de Biologie Marine, 54 (2): 209-220
FILMALTER, J.D. & CAPELLO, M. & DENEUBOURG, J.-L. & COWLEY, P.D. & DAGORN, L. (2013): Looking behind the curtain: quantifying massive shark mortality in fish aggregating devices. Frontiers in Ecology and the Environment, in press http://dx.doi.org/10.1890/130045
GASPER, J.R. & KRUSE, G.H. (2013): Modeling of the Spatial Distribution of Spiny Dogfish (Squalus suckleyi) in the Gulf of Alaska using Generalized Additive and Generalized Linear Models. Canadian Journal of Fisheries and Aquatic Sciences, in press http://dx.doi.org/10.1139/cjfas-2012-0535
GILLOTEAUX, J. & OTT, D.W. & OLDHAM-OTT, C.K. (2013): The gallbladder of the electric ray Torpedo marmorata Risso displays excrescent cholecystocytes with merocrine and apocrine-like secretions. Anatomical Record, 296 (1): 79-95 http://dx.doi.org/10.1002/ar.22621
GUISANDE, C. & PATTI, B. & VAAMONDE, A. & MANJARRÉS-HERNÁNDEZ, A. & PELAYO-VILLAMIL, P. & GARCÍA-ROSELLÓ, E. & GONZÁLEZ-DACOSTA, J. & HEINE, J. & GRANADO-LORENCIO, C. (2013): Factors affecting species richness of marine elasmobranchs. Biodiversity and Conservation, 22 (8): 1703-1714 http://dx.doi.org/10.1007/s10531-013-0507-3
HANNAN, K.M. & FOGG, A.Q. & DRIGGERS, W.B. & HOFFMAYER, E.R. & INGRAM, G.W. & GRACE, M.A. (2013): Size selectivity and catch rates of two small coastal shark species caught on circle and J hooks in the northern Gulf of Mexico. Fisheries Research, 147: 145-149 http://dx.doi.org/10.1016/j.fishres.2013.05.005
HOLT, R.E. & FOGGO, A. & NEAT, F.C. & HOWELL, K.L. (2013): Distribution patterns and sexual segregation in chimaeras: implications for conservation and management.ICES Journal of Marine Science, in press http://dx.doi.org/10.1093/icesjms/fst058
JEWELL, O.J.D. & JOHNSON, R.L. & GENNARI, E. & BESTER, M.N (2013): Fine scale movements and activity areas of white sharks (Carcharodon carcharias) in Mossel Bay, South Africa. Environmental Biology of Fishes, 96 (7): 881-894 http://dx.doi.org/10.1007/s10641-012-0084-4
JUNG, S.-M. & KIM, D.S. & SHIN, H.S. (2013): Primary cell culture from the nose of a marine organism, the banded houndshark, Triakis scyllium. Biotechnology and Bioprocess Engineering, 18 (2): 413-418 http://dx.doi.org/10.1007/s12257-012-0494-3
KEMPSTER, R.M. & GARZA-GISHOLT, E. & EGEBERG, C.A. & HART, N.S. & O’SHEA, O.R. & COLLIN, S.P. (2013): Sexual Dimorphism of the Electrosensory System: A Quantitative Analysis of Nerve Axons in the Dorsal Anterior Lateral Line Nerve of the Blue-Spotted Fantail Stingray (Taeniura lymma). Brain, Behavior and Evolution, 81 (4): http://dx.doi.org/10.1159/000351700
LI, S. & KATO, A. & TAKABE, S. & CHEN, A.-P. & ROMERO, M.F. & UMEZAWA, T. & NAKADA, T. & HYODO, S. & HIROSE, S. (2013): Expression of a novel isoform of Na+/H+ exchanger 3 in the kidney and intestine of banded houndshark, Triakis scyllium.American Journal of Physiology - Regulatory Integrative and Comparative Physiology, 304 (10): R865-R876 http://dx.doi.org/10.1152/ajpregu.00417.2012
LIEW, H.J. & DE BOECK, G. & WOOD, C.M. (2013): An in vitro study of urea, water, ion and CO2/HCO3− transport in the gastrointestinal tract of the dogfish shark (Squalus acanthias): the influence of feeding. Journal of Experimental Biology, 216 (11): 2063-2072 http://dx.doi.org/10.1242/jeb.082313
MARCHAL, P. & VERMARD, Y. (2013): Evaluating deepwater fisheries management strategies using a mixed-fisheries and spatially explicit modelling framework. ICES Journal of Marine Science, 70 (4): 768-781 http://dx.doi.org/10.1093/icesjms/fst073
NAVIA, A.F. (2013): Función ecológica de tiburones y rayas en un ecosistema costero tropical del Pacífico colombiano. Tesis de doctorado, Centro Interdisciplinario de Ciencias Marinas
NOSAL, A.P. & CARTAMIL, D.C. & LONG, J.W. & LÜHRMANN, M. & WEGNER, N.C. & GRAHAM, J.B. (2013): Demography and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon along the open coast of southern California, USA. Environmental Biology of Fishes, 96 (7): 865-878 http://dx.doi.org/10.1007/s10641-012-0083-5
NOSAL, A.P. & CARTAMIL, D.C. & LONG, J.W. & LÜHRMANN, M. & WEGNER, N.C. & GRAHAM, J.B. (2013): Erratum to: Demography and movement patterns of leopard sharks (Triakis semifasciata ) aggregating near the head of a submarine canyon along the open coast of southern California, USA. Environmental Biology of Fishes, 96 (7): 879 http://dx.doi.org/10.1007/s10641-013-0128-4
OLIVER, S.P. & TURNER, J.R. & GANN, K. & SILVOSA, M. & D'URBAN JACKSON, T. (2013): Thresher Sharks Use Tail-Slaps as a Hunting Strategy. PLoS ONE, 8 (7): e67380 http://dx.doi.org/10.1371/journal.pone.0067380
O'MALLEY, M.P. & LEE-BROOKS, K. & MEDD, H.B. (2013): The Global Economic Impact of Manta Ray Watching Tourism. PLoS ONE, 8 (1): e65051 http://dx.doi.org/10.1371/journal.pone.0065051
PEÑAHERRERA, C. & LLERENA, Y. & KEITH, I. (2013): Perceptions of the economic value of sharks for single-day dive tourism and commerce in Santa Cruz Island. In: Galapagos Report 2011-2012. GNPS, GCREG, CDF and GC. Puerto Ayora, Galapagos, Ecuador: 114-120
POLO-SILVA, C. & NEWSOME, S.D. & GALVÁN-MAGAÑA, F. & GRIJALBA-BENDECK, M. & SANJUAN-MUÑOZ, A. (2013): Trophic shift in the diet of the pelagic thresher shark based on stomach contents and stable isotope analyses. Marine Biology Research, 9 (10): 958-971 http://dx.doi.org/10.1080/17451000.2013.793802
SIPPEL, T. & KOHIN, S. (2013): Catches of blue sharks from U.S. West Coast recreational fisheries during 1971-2011. ISC Shark Working Group Workshop: ISC/13/SHARKWG-2/01
SMITH, L.E. & O'CONNELL, C.P. (2013): The effects of neodymium-iron-boron permanent magnets on the behaviour of the small spotted catshark (Scyliorhinus canicula) and the thornback skate (Raja clavata). Ocean & Coastal Management, in press http://dx.doi.org/10.1016/j.ocecoaman.2013.05.010
SMITH, W.D. (2013): Vertebral Elemental Markers in Elasmobranchs: Potential for Reconstructing Environmental History and Population Structure. Dissertation, Oregon State University
SOSA-NISHIZAKI, O. (2013): Unofficial blue shark catch estimations for the Mexican Pacific (1976-2011). ISC Shark Working Group Workshop: ISC/13/SHARKWG-2/INFO-01
STEAD, N. (2013): Spiny dogfish saves urea for reuse. Journal of Experimental Biology, Inside 2013: III http://dx.doi.org/10.1242/jeb.088161
WELTZ, K. & KOCK, A.A. & WINKER, H. & ATTWOOD, C. & SIKWEYIYA, M. (2013):The Influence of Environmental Variables on the Presence of White Sharks, Carcharodon carcharias at Two Popular Cape Town Bathing Beaches: A Generalized Additive Mixed Model. PLoS ONE, 8 (7): e68554 http://dx.doi.org/10.1371/journal.pone.0068554
WOOD, C.M. & LIEW, H.J. & DE BOECK, G. & WALSH, P.J. (2013): A perfusion study of the handling of urea and urea analogues by the gills of the dogfish shark (Squalus acanthias). PeerJ, 1: e33 http://dx.doi.org/10.7717/peerj.33
YIGIN, C.C. & ISMEN, A. (2013): Reproductive Biology of Spiny Dogfish Squalus acanthias, in the North Aegean Sea. Turkish Journal of Fisheries and Aquatic Sciences, 13: 169-177 http://dx.doi.org/10.4194/1303-2712-v13_1_20
ROCHA, S. & CASAL, G. & AL-QURAISHY, S. & AZEVEDO, C. (2013): Morphological and Molecular Characterization of a New Myxozoan Species (Myxosporea) Infecting the Gall Bladder of Raja clavata (Chondrichthyes), from the Portuguese Atlantic Coast.Journal of Parasitology, 99 (2): 307-317 http://dx.doi.org/10.1645/GE-3150.1
ITANO, W.M. (2013): A tooth of Edestus from the early Pennsylvanian of Cheshire, UK.Proceedings of the Yorkshire Geological Society, 59 (3): 187-194 http://dx.doi.org/10.1144/pygs2013-325
KITAMURA, N. (2013): Description of a New Species of the Family Echinorhinidae (Chondrichthyes, Elasmobranchii) from the Upper Cretaceous Himenoura Group in Kumamoto Prefecture, Southwestern Japan. Paleontological Research, 17 (2): 189-195 http://dx.doi.org/10.2517/1342-8144-17.2.189
CASTRO, A. & CIONE, A.L. & CIVALERO, M.T. & DE NIGRIS, M. (2013): A Fossil Shark Tooth in Early Contexts of Cerro Casa de Piedra 7, Southwest Patagonia, Argentina. In: Southbound - Late Pleistocene Peopling of Latin America. MIOTTI, L. & SALEMME, M. & FLEGENHEIMER, N. & GOEBEL, T. (Eds.), Center for the Study of the First Americans, Texas, ISSN 8755–898X: 165-176
CARRILLO-BRICEÑO, J.D. & GONZÁLEZ-BARBA, G. & LANDAETA, M.F. & NIELSEN, S.N. (2013): Condrictios fósiles del Plioceno Superior de la Formación Horcón, Región de Valparaíso, Chile central. [Fossil Chondrichthyans from the Upper Pliocene Horcón Formation, Valparaíso Region, central Chile]. Revista Chilena de Historia Natural, 86: 191-206
GOVENDER, R. & CHINSAMY, A. (2013): Early Pliocene (5 Ma) Shark-Cetacean Trophic Interaction from Langebaanweg, Western Coast of South Africa. Palaios, 28 (5): 270-277http://dx.doi.org/10.2110/palo.2012.p12-058r
Sharks Stun Sardine Prey With Tail-Slaps
Thresher sharks hunt schooling sardines in the waters off a small coral island in the Philippines by rapidly slapping their tails hard enough to stun or kill several of the smaller fish at once, according to research published July 10 in the open access journal PLOS ONE by Simon Oliver of the Thresher Shark Research and Conservation Project, and colleagues from other institutions.
The researchers tracked shark activity with handheld video cameras and analyzed 25 instances of tail-slapping to stun prey. Sharks seemed to initiate the behavior by drawing their pectoral fins inward to lift their posteriors rapidly, followed by tail-slapping forceful enough to stun or kill several prey, and even cause dissolved gases to bubble out of the water. After a successful hunting event, sharks ate an average of 3.5 sardines.
For large marine predators, being able to stun more than one prey at a time is likely to be a more efficient means to hunt than chasing after many small fish in a school. Dolphins and killer whales are known to use tail-slaps to control or stun prey, while humpback and sperm whales use tail-slaps to communicate over long distances.
"This extraordinary story highlights the diversity of shark hunting strategies in an ocean where top predators are forced to adapt to the complex evasion behaviours of their ever declining prey," said Dr Simon Oliver the study's lead investigator.
A sequence of still images taken from an overhead tail-slap hunting event. (Credit: Oliver SP, Turner JR, Gann K, Silvosa M, D'Urban Jackson T (2013) Thresher Sharks Use Tail-Slaps as a Hunting Strategy. PLoS ONE 8(7): e67380. doi:10.1371/journal.pone.0067380)
Scottish shark tagging project to resume
The second year of a project to track basking sharks in Scottish waters is under way.
Scientists from Scottish Natural Heritage and the University of Exeter will attach satellite tracking tags to 27 sharks in the Inner Hebrides.
The tags will allow the public to follow the movements of 15 of the sharks online.
They will also collect data to give the team an insight into the sharks' behaviour during the summer months.
The work is part of a wider programme of marine research led by SNH and Marine Scotland, to help government and others plan for the sustainable management of the sea.
Results from the tagging project will help the Scottish government decide whether a Marine Protected Area should be put in place to safeguard the sharks and help balance environmental interests with industry and recreation.
The tagging project, which began last July, was set up to find out more about the life cycle of the large numbers of sharks that gather around the islands of Coll, Tiree and Canna every summer.
Some of the 20 sharks tagged last year stayed in the area between five and 57 days before the tags detached, the sharks moved deeper or they swam south.
Depth data collected so far has shown that sharks mainly occupy the top 250m of the water column, although two sharks were recorded down at 1,000m, off the edge of the continental shelf.
Dr Suzanne Henderson from SNH, who is managing the project, said: "The second year of tagging will build on last year's work, helping provide insights into shark behaviour year on year and identify any trends in the behaviour of sharks in this area.
"We're tagging more sharks this year to increase the confidence we have in the results and so we can look more closely at how behaviour differs among individuals.
"We hope the public will enjoy taking part again by following the progress of 15 of the sharks online.
"Last year half of the tags stayed on the sharks for over 90 days, with one detaching from its shark (Elgol) after 326 days to the south west of Portugal. We hope this year is just as successful."
The researchers have asked anyone who finds a tag around the shores of the UK to contact them.
The tags are silver/grey, torpedo or oval shaped, 15cm to 18cm long with a small antenna and may still have a plastic tether attached.
There is a reward available for each tag returned.The tags will help scientists learn more about the lives of basking sharks
Research by Cranfield University shows that sharks are quite clever
New behavioural research led by Cranfield ecological scientists shows that, contrary to historical beliefs, sharks are quick to learn and have good memories.
Drs Joel Kimber and Andrew Gill, who designed and conducted the study, suggest that this type of research will help improve the status of the much-misunderstood sharks. This is vitally important as many species are endangered and need protection and public support, because of dramatic population declines caused by unregulated fishing.
Sharks have historically been considered as relatively unintelligent predators. However, Cranfield University and the Marine Biological Association of the UK demonstrated that small-spotted catsharks (a common, sea-bed dwelling shark found around the entire British and NW European coast) possess impressively quick learning ability. They were also able to determine that the sharks possess a memory of between a day and a few weeks; significantly more than the 7-seconds that is, often incorrectly, associated with fish.
Sharks use a sense called electroreception to detect bio-electric fields emitted by their prey. The researchers recreated these electric fields to measure and analyse the behavioural response of the sharks, using experimental manipulation and food rewards. The rewarded sharks showed an impressive learned response of finding and biting the source of the electric fields significantly more quickly and intensely than their unrewarded counterparts. They would, however, forget these learned adaptations after three weeks when experiments were repeated.
It is thought these skills are adaptive and are ideally suited to a predator living in a complex, variable and unpredictable environment allowing them to adapt behaviour, ultimately improving their feeding efficiency.