Eight Shark Species Swim in Maine Waters
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Sharks for the Aquarium and Considerations for Their Selection1 Alexis L
FA179 Sharks for the Aquarium and Considerations for Their Selection1 Alexis L. Morris, Elisa J. Livengood, and Frank A. Chapman2 Introduction The Lore of the Shark Sharks are magnificent animals and an exciting group Though it has been some 35 years since the shark in Steven of fishes. As a group, sharks, rays, and skates belong to Spielberg’s Jaws bit into its first unsuspecting ocean swim- the biological taxonomic class called Chondrichthyes, or mer and despite the fact that the risk of shark-bite is very cartilaginous fishes (elasmobranchs). The entire supporting small, fear of sharks still makes some people afraid to swim structure of these fish is composed primarily of cartilage in the ocean. (The chance of being struck by lightning is rather than bone. There are some 400 described species of greater than the chance of shark attack.) The most en- sharks, which come in all different sizes from the 40-foot- grained shark image that comes to a person’s mind is a giant long whale shark (Rhincodon typus) to the 2-foot-long conical snout lined with multiple rows of teeth efficient at marble catshark (Atelomycterus macleayi). tearing, chomping, or crushing prey, and those lifeless and staring eyes. The very adaptations that make sharks such Although sharks have been kept in public aquariums successful predators also make some people unnecessarily since the 1860s, advances in marine aquarium systems frightened of them. This is unfortunate, since sharks are technology and increased understanding of shark biology interesting creatures and much more than ill-perceived and husbandry now allow hobbyists to maintain and enjoy mindless eating machines. -
Porbeagle Oceanic Whitetip SCALLOPED Hammerhead VOTE YES Appendix II Endangered in Northwest Pacific
PORBEAGLE OCEANIC WHITETIP SCALLOPED HAMMERHEAD VOTE YES APPENDIX II Endangered in northwest Pacific. VOTE YES APPENDIX II VOTE YES APPENDIX II SPECIES FACTS n Hammerhead shark fins are some of the most Vulnerable globally. SPECIES NAME: Lamna nasus SPECIES NAME: SPECIES NAME: valuable on the market. FINS The warm-blooded porbeagle shark, caught Carcharhinus longimanus Sphyrna lewini SPECIES FACTS mostly for its fins for soup and its meat, is The oceanic whitetip is one of the The scalloped n Surveys in the northwest Atlantic document AT A GLANCE n The international demand for porbeagle fins distributed throughout the temperate North most widespread shark species, found hammerhead, with the hammerhead loss at up to 98 per cent, and meat has driven populations to very Atlantic Ocean throughout the world’s tropical and its distinctive head, is landings in the southwest Atlantic show low levels across their range. Studies show and Southern temperate seas. It is also one of the most one of the most recognizable sharks. It is also declines of up to 90 per cent, and declines declines of up to 90 per cent in places around Hemisphere. threatened. It is typically caught for its one of the most endangered shark species, of more than 99 per cent have occurred in the world, including the northwest Atlantic. valuable fins, which are used in soup. caught for its valuable fins to make soup. the Mediterranean. The three FIRST n Almost no international conservation or SPECIES FACTS hammerhead species DORSAL FIN FIRST DORSAL FIN FIRST DORSAL FIN management measures exist for n Studies have documented population (Sphyrna lewini, S. -
Can Threshold Foraging Responses of Basking Sharks Be Used to Estimate Their Metabolic Rate?
MARINE ECOLOGY PROGRESS SERIES Vol. 200: 289-296,2000 Published July 14 Mar Ecol Prog Ser ~ NOTE Can threshold foraging responses of basking sharks be used to estimate their metabolic rate? David W. Sims* Department of Zoology, University of Aberdeen. Tillydrone Avenue. Aberdeen AB24 2TZ. United Kingdom ABSTRACT: Empirical and theoretical determinations of There are 3 species of filter-feeding shark, the whale minimum threshold prey densities for filter-feeding basking shark ~hi~~~d~~typus of warm-temperate and tropical sharks Cetorhinus maximus were used to test the idea that threshold foraging behaviour could provide a means for esti- seas worldwide, the basking shark Cetorhinus max- mating oxygen consumption (a proxy for metabolic rate). The im~~that inhabits warm-temperate to boreal waters threshold feeding levelrepres&nts the prey density at which circumglobally, and the megamouth shark Mega- there will be no net energy gain (energy intake equals expen- chasms pelagjos occurs in the Pacific and At- diture). Basking sharks were observed to cease feeding at lantic, primarily in deep water (Compagno 1984, Yano their theoretical threshold; thus, the assumption underpin- ning the concept presented here was that over the narrow et They are the largest marine verte- range of zooplankton prey densities that induce 'switching' brates attaining body lengths of up to 14, 10 and 6 m re- between feeding and non-feeding in basking sharks, the spectively. Comparatively little is known about the bi- energetic value of the minimum threshold prey density is ology of planktivorous sharks despite the fact that they equivalent to the shark's instantaneous level of energy expen- diture. -
Lamna Nasus) Inferred from a Data Mining in the Spanish Longline Fishery Targeting Swordfish (Xiphias Gladius) in the Atlantic for the 1987-2017 Period
SCRS/2020/073 Collect. Vol. Sci. Pap. ICCAT, 77(6): 89-117 (2020) SIZE AND AREA DISTRIBUTION OF PORBEAGLE (LAMNA NASUS) INFERRED FROM A DATA MINING IN THE SPANISH LONGLINE FISHERY TARGETING SWORDFISH (XIPHIAS GLADIUS) IN THE ATLANTIC FOR THE 1987-2017 PERIOD J. Mejuto1, A. Ramos-Cartelle1, B. García-Cortés1 and J. Fernández-Costa1 SUMMARY A total of 5,136 size observations of porbeagle were recovered for the period 1987-2017. The GLM results explained very moderately the variability of the sizes considering three main factors, suggesting minor but significant differences in some cases especially for the year factor and non-significant differences in other factors depending on the analysis. The greatest differences in the standardized mean length between some zones were caused by some large fish of unidentified sex. The standardized mean length data for the northern zones showed stability throughout the time series, very stable range of mean values and very few differences between sexes. The size distribution for northern areas indicated an FL-overall mean of 158 cm. The size showed a normal distribution confirming that a small fraction of individuals of this stock/s is available in the oceanic areas where the North Atlantic fleet is regularly fishing and the fishes are not fully recruited to those areas and / or this fishing gear up to 160 cm. The data suggests that some individuals could sporadically reach some intertropical areas of the eastern Atlantic. RÉSUMÉ Un total de 5.136 observations de taille de requins-taupes communs ont été récupérées pour la période 1987-2017. Les résultats du GLM expliquent très modérément la variabilité des tailles en tenant compte de trois facteurs principaux, ce qui suggère des différences mineures mais significatives dans certains cas, notamment pour le facteur année et des différences non significatives pour d'autres facteurs selon le type d’analyse. -
SHARKS (From Page 24) There Are Close to 500 Species of Sharks
SHARKS (from page 24) There are close to 500 species of sharks worldwide, Wetherbee Blue shark. These oceanic sharks are long and skinny and said. They range in size from the 8-inch dwarf dogshark to the 60- can grow to be 13 feet in length and weigh 450 pounds. These foot whale shark. Their habitat ranges from coastal areas to the “beautiful” sharks are excellent swimmers. Mating between males open ocean, from Arctic waters to tropical seas, from surface and females is waters to abyssal depths. violent, as the males often bite Spiny and smooth dogfish. Despite sharing the same surname, the females. To these two coastal shark species aren’t closely related. Dogfish withstand the get their violence of name mating, the because female's skin is they often three times as thick as that of their male counterparts. Although travel and not good to eat, blues are the world’s most fished shark species. hunt in They are harvested for their fins, skin, tails and flesh. Their teeth packs. Both and jaws are also harvested for commercial uses. species migrate into the area in the warmer months, and a few remain Mako shark. This oceanic species is one of the fastest fish in through the winter. They have little teeth, and can grow to be 5 the ocean, with speeds up to 40 mph or so. They also are a feet long. Spiny dogfish can arch their backs and inject venom popular seafood into predators from their dorsal spines. Thousands are harvested worldwide. They can annually for use in U.K. -
Case Reports for Species & Habitats on the Initial Draft
OSPAR Commission, 2008: Case reports for the OSPAR List of Threatened and/or Declining Species and Habitats ___________________________________________________________________________________________________ Nomination Rarity Lamna nasus, Porbeagle shark This species is very seriously depleted and only rarely encountered over most of its former OSPAR Porbeagle shark (Lamna nasus) (Bonnaterre, range although, because of its aggregating nature, 1788) seasonal target fisheries are still possible. It is not possible to estimate its population size in the OSPAR Area, and there is no guidance for the application of this criterion to highly mobile species. Sensitivity Very Sensitive. Lamna nasus is relatively slow growing, late maturing, and long-lived, bears small litters of pups and has a generation period of 20–50 years and an intrinsic rate of population increase of Geographical extent 5–7% per annum. It is also of high commercial • OSPAR Regions: I, II, III, IV, V value at all age classes (mature and immature). These factors, combined with its aggregating habit, • Biogeographic zones: make it highly vulnerable to over-exploitation and 8,9,10,11,12,13,14,15,16,17,22,23 population depletion by target and incidental • Region & Biogeographic zones specified for fisheries. Its resilience is also very low. The decline and/or threat: as above Canadian Recovery Assessment Report for the Northwest Atlantic stock of Lamna nasus (DFO Lamna nasus is a wide-ranging, coastal and 2005) projected that a recovery to maximum oceanic shark, but with apparently little exchange sustainable yield would take some 25 to 55 years if between adjacent populations. It has an antitropical the fishery is closed, or over 100 years if fisheries distribution in the North Atlantic and Mediterranean mortality remained at 4%. -
1 a Petition to List the Oceanic Whitetip Shark
A Petition to List the Oceanic Whitetip Shark (Carcharhinus longimanus) as an Endangered, or Alternatively as a Threatened, Species Pursuant to the Endangered Species Act and for the Concurrent Designation of Critical Habitat Oceanic whitetip shark (used with permission from Andy Murch/Elasmodiver.com). Submitted to the U.S. Secretary of Commerce acting through the National Oceanic and Atmospheric Administration and the National Marine Fisheries Service September 21, 2015 By: Defenders of Wildlife1 535 16th Street, Suite 310 Denver, CO 80202 Phone: (720) 943-0471 (720) 942-0457 [email protected] [email protected] 1 Defenders of Wildlife would like to thank Courtney McVean, a law student at the University of Denver, Sturm college of Law, for her substantial research and work preparing this Petition. 1 TABLE OF CONTENTS I. INTRODUCTION ............................................................................................................................... 4 II. GOVERNING PROVISIONS OF THE ENDANGERED SPECIES ACT ............................................. 5 A. Species and Distinct Population Segments ....................................................................... 5 B. Significant Portion of the Species’ Range ......................................................................... 6 C. Listing Factors ....................................................................................................................... 7 D. 90-Day and 12-Month Findings ........................................................................................ -
Electrosensory Pore Distribution and Feeding in the Basking Shark Cetorhinus Maximus (Lamniformes: Cetorhinidae)
Vol. 12: 33–36, 2011 AQUATIC BIOLOGY Published online March 3 doi: 10.3354/ab00328 Aquat Biol NOTE Electrosensory pore distribution and feeding in the basking shark Cetorhinus maximus (Lamniformes: Cetorhinidae) Ryan M. Kempster*, Shaun P. Collin The UWA Oceans Institute and the School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia ABSTRACT: The basking shark Cetorhinus maximus is the second largest fish in the world, attaining lengths of up to 10 m. Very little is known of its sensory biology, particularly in relation to its feeding behaviour. We describe the abundance and distribution of ampullary pores over the head and pro- pose that both the spacing and orientation of electrosensory pores enables C. maximus to use passive electroreception to track the diel vertical migrations of zooplankton that enable the shark to meet the energetic costs of ram filter feeding. KEY WORDS: Ampullae of Lorenzini · Electroreception · Filter feeding · Basking shark Resale or republication not permitted without written consent of the publisher INTRODUCTION shark Rhincodon typus and the megamouth shark Megachasma pelagios, which can attain lengths of up Electroreception is an ancient sensory modality that to 14 and 6 m, respectively (Compagno 1984). These 3 has evolved independently across the animal kingdom filter-feeding sharks are among the largest living in multiple groups (Scheich et al. 1986, Collin & White- marine vertebrates (Compagno 1984) and yet they are head 2004). Repeated independent evolution of elec- all able to meet their energetic costs through the con- troreception emphasises the importance of this sense sumption of tiny zooplankton. -
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. -
4 Thresher Shark, Alopias Vulpinus
4 Thresher Shark, Alopias vulpinus Thresher shark, Alopias vulpinus. Photo credit: Dale Sweetnam. History of the Fishery The common thresher shark, Alopias vulpinus, is the most common commercially landed shark in California. They are primarily caught using large mesh drift gill nets and hook and line gear, but are also caught incidentally with small mesh gill nets and harpoon. Prior to 1977, all sharks were reported in one market category and not separated by species, and it is assumed threshers were caught as bycatch in gears at levels similar or greater than today. The first significant fishery for thresher sharks began the late 1970s to early 1980s when drift gill net fishers began to target them close to the southern California coastline. The fishery expanded rapidly and, because of overfishing concerns, the California Department of Fish and Game (Department) as mandated by the State Legislature began an observer program, monitored landings and implemented a logbook program. A limited entry permit program for drift gill net gear was initiated in 1982, with permits issued to fishers rather than boats to prevent false inflation in value. The drift gill net fishery for thresher sharks peaked in 1981 when 113 Status of the Fisheries Report 2008 4-1 drift gill net boats landed nearly 600 tons (544 metric tons). However, total landings using all gears were highest the following year with a total of more than 1700 tons (1542 metric tons) taken by all gears (Figure 4-1). 2000 1500 1000 Landings (short tons) (short Landings 500 0 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 Year Figure 4-1. -
The Denticle Surface of Thresher Shark Tails: Three-Dimensional Structure and Comparison to Other Pelagic Species
Received: 3 April 2020 Revised: 14 May 2020 Accepted: 21 May 2020 DOI: 10.1002/jmor.21222 RESEARCH ARTICLE The denticle surface of thresher shark tails: Three-dimensional structure and comparison to other pelagic species Meagan Popp1 | Connor F. White1 | Diego Bernal2 | Dylan K. Wainwright1 | George V. Lauder1 1Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Abstract Massachusetts Shark skin denticles (scales) are diverse in morphology both among species and 2 Department of Biology, University of across the body of single individuals, although the function of this diversity is poorly Massachusetts Dartmouth, Dartmouth, Massachusetts understood. The extremely elongate and highly flexible tail of thresher sharks pro- vides an opportunity to characterize gradients in denticle surface characteristics Correspondence George V. Lauder, Museum of Comparative along the length of the tail and assess correlations between denticle morphology and Zoology, 26 Oxford Street, Cambridge, MA tail kinematics. We measured denticle morphology on the caudal fin of three mature 02138. Email: [email protected] and two embryo common thresher sharks (Alopias vulpinus), and we compared thresher tail denticles to those of eleven other shark species. Using surface Funding information National Oceanic and Atmospheric profilometry, we quantified 3D-denticle patterning and texture along the tail of Administration, Grant/Award Number: threshers (27 regions in adults, and 16 regions in embryos). We report that tails of NA16NMF4270231; National Science Foundation, Grant/Award Numbers: IOS- thresher embryos have a membrane that covers the denticles and reduces surface 1354593, GRF DGE-1144152; Office of Naval roughness. In mature thresher tails, surfaces have an average roughness of 5.6 μm Research, Grant/Award Numbers: N00014-09-1-0352, N000141410533 which is smoother than some other pelagic shark species, but similar in roughness to blacktip, porbeagle, and bonnethead shark tails. -
Porbeagle Shark Lamna Nasus
Porbeagle Shark Lamna nasus Lateral View (♀) Ventral View (♀) COMMON NAMES APPEARANCE Porbeagle Shark, Atlantic Mackerel Shark, Blue Dog, Bottle-nosed • Heavily built but streamlined mackerel shark. Shark, Beaumaris Shark, Requin-Taupe Commun (Fr), Marrajo • Moderately long conical snout with a relatively large eyes. Sardinero (Es), Tiburón Sardinero (Es), Tintorera (Es). • Large first dorsal fin with a conspicuous white free rear tip. SYNONYMS • Second dorsal fin and anal fin equal-sized and set together. Squalus glaucus (Gunnerus, 1758), Squalus cornubicus (Gmelin, 1789), • Lunate caudal fin with strong keel and small secondary keel. Squalus pennanti (Walbaum, 1792), Lamna pennanti (Desvaux, 1851), Squalus monensis (Shaw, 1804), Squalus cornubiensis (Pennant, 1812), • Dorsally dark blue to grey with no patterning. Squalus selanonus (Walker, 1818), Selanonius walkeri (Fleming, 1828), • Ventrally white. Lamna punctata (Storer, 1839), Oxyrhina daekyi (Gill, 1862), Lamna • Maximum length of 365cm, though rarely to this size. NE MED ATL philippi (Perez Canto, 1886), Lamna whitleyi (Phillipps, 1935). DISTRIBUTION The Porbeagle Shark is a large, streamlined mackerel shark with a In the northern conical snout and powerful body. The first dorsal fin is large and hemisphere, the originates above or slightly behind the pectoral fins. It has a free rear Porbeagle Shark tip which is white. The second dorsal fin is tiny and is set above the occurs only in the anal fin, to which it is comparable in size. The caudal fin is strong and North Atlantic and lunate with a small terminal notch. The caudal keel is strong and, Mediterranean, uniquely for the northeast Atlantic, a smaller secondary caudal keel is whilst in the present.