DOCSLIB.ORG

Northern Shrimp, Pandalus Borealis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Northern Shrimp, Pandalus Borealis Northern shrimp, Pandalus borealis Background Pandalus borealis is one of about 20 Pandalus species world-wide (Komai 1999). While officially known as the northern shrimp (Williams et al. 1989), it is also recognized under several other common names, including pink shrimp (Shumway et al. 1985), deep-sea shrimp (Ito 1976), as well as a prawn rather than shrimp. More local names, such as Maine shrimp (Czapp, 2005), also exist. Until recently it has been regarded as a widely ranging circumarctic species (Williams and Wigley 1977) that extends into northern Pacific and Atlantic regions, here referred to as P. borealis sensu lato. Western populations from the Bering Sea and further south in the Pacific can now be considered a separate species (Squires 1992) based on distinct traits of larvae and adults, here referred to as P. borealis sensu stricto. However, this change has not yet been universally adopted in the literature (Bergström 2000). Within the North Atlantic, P. borealis is known from northern Europe in the eastern Atlantic, and in the western Atlantic from Greenland to about 40ºN latitude (Squires, 1990), just south of the Gulf of Maine. The species is typically found at depths ranging from 10-500 m (Squires, 1990; Pohle, 1988), but is also known from deeper waters (Bergström 1992). Usually these schooling shrimp live on or near soft bottom with high organic content but do exhibit diurnal vertical migration (Shumway et al. 1985). They are found at temperatures ranging from 2 – 14ºC, but occurrences in areas below 0ºC are known (Squires 1968). In Atlantic waters, P. borealis is one of three recognized species of Pandalus that overlap geographically and bathymetrically, but is the only one amongst these with a major commercial fishery (Williams and Wigley 1977). Attaining a total length of over 18 cm in females, it is also the largest of these species (Bergström 1992). This shrimp is an important link in marine food chains, feeding on sea-bed invertebrates and plankton, such as krill, amphipods, and copepods, while being consumed in turn by such fish as cod, halibut, redfish, silver and white hake (Squires 1965; 1990). Life cycle Like its congeners, Pandalus borealis has a protandric life cycle, starting life as males that, through transitional stages, change to females at about 4 to 7 years of age. In this species some individuals may also develop directly into ‘primary females’, in which male characteristics never appear. Environmental temperatures have a considerable effect on sex determination in terms of timing and duration (Squires 1990). The ability to vary timing of sex change is seen as a strategy to maximize reproductive success (Bergström 1992). Generally, mating and oviposition of fertilized eggs occur within 36 hours during late summer to fall (July-October), with developing embryos being carried by the female on pleopods until hatching the following spring (March – June) (Bergström 2000). The colder the environment, the earlier the spawning and the longer the incubation period. The latter ranges 5-11 months. During that time ovigerous females migrate from deeper waters offshore to shallow areas inshore (Haynes and Wigley 1969) where spawning occurs. Fecundity may vary from 300-4300 eggs (Squires 1990), averaging about 2000 for a typical-size female (Shumway et al. 1985). Pelagic larvae hatch as a stage I zoea, followed by an additional four or more zoeal stages and a megalopa, before entering the juvenile stage (Squires 1993, Wienberg 1982). Larval development may take 45-120 days, depending largely on temperature (Stickney and Perkins 1977). Larval dispersion should largely be determined by local current conditions but larvae tend to stay in shallow water, being able of some vertical movement (Shumway et al. 1985). Juveniles tend to remain inshore for more than a year before migrating offshore as they mature. In the Gulf of Maine age at 50% maturity is about 3.5 years in females (Idoine 2001). Fishery Among all shrimp species of the pandalid family, the fishery for Pandalus borealis is the largest one (Balsiger, 1981) and thus of considerable economic importance. In the northwestern Atlantic primary fishery areas for P. borealis s.s. are concentrated off Greenland, Labrador, Scotian Shelf, Gulf of St. Lawrence, Bay of Fundy and Gulf of Maine, as far south as Gloucester Mass (Parsons and Fréchette 1989; Koeller et al 1999). Yields are higher for more northern fishing areas, the Davis Strait fishery peaking at about 41,000 tonnes in the 1980’s. Areas around Iceland and further east along the coast of Norway are also important fishing zones (Holthuis 1980). Worldwide, the Pandalus borealis s.l. fishery has been steadily increasing from a few thousand tonnes in the 1950’s to over 350,000 tonnes in recent years, with Canada reporting the largest catches (http://www.fao.org/figis/servlet/species?fid=3425). However, stock biomass in some fishing areas, such as the Gulf of Maine, have experienced periods of significant decline in the 1970’s and late 1990’s (Idoine 2001) that included a fishery closure during the former period (Clark et al. 2000). Temperature limits The northern shrimp is a cold water stenothermal species with a preferred temperature range of 1-6ºC (Shumway et al 1985). Based on the current northwest Atlantic distribution of P. borealis, SSTs range from a February minimum of -2.1ºC to an August maximum of 23.1ºC, considerably outside the preferred temperature range. However, in their review of temperature ranges for P. borealis, Shumway et al. (1985) reported northern shrimps in waters with temperatures from -1.6ºC to 12ºC, with Squires (1990) reporting temperatures as high as 14ºC. Larvae indicate possible tolerance of still higher temperatures, as laboratory work on specimens acclimated at 10ºC showed 89% and 77% survival at 16º and 18ºC after 22 hours exposure, respectively (Stickney and Perkins 1977). This may be an adaptation of this phase, as larvae hatch and are more prevalent in shallow waters. Nevertheless, while low SSTs agree with reported temperature ranges, the max. SST’s exceed what is known for the species. Likely, the shrimp occur in deeper locations or further offshore within those areas or are not found there at those times of year. The former appears to be the case at southern limits, where Squires (1990) reports records at 40º latitude as offshore near the continental shelf. Impacts: Temperature, together with depth, substratum and salinity, are all major physical determinants of the distribution of P. borealis (Bergström 2000), but temperature seems most closely correlated with changes in abundance (Shumway et al. 1985). Temperature also appears to have an effect on sex ratio, and therefore reproduction, but this does not seem to be well understood, may vary by location (Shumway et al. 1985) or be related to differences between Atlantic and Pacific taxa. A 4ºC rise in global temperature will impact the future distribution of P. borealis in the western Atlantic. Results from all four models under both scenarios agree in a predicted loss in the southern range of the species. The affected waters are south and north of Cape Cod, including portions of the Gulf of Maine, with the CSSR model showing the widest affected area. These losses may extend further offshore beyond areas not covered in this study. Two models predict potential habitat losses elsewhere. Under scenario A2 for CCSR and GFDL models, this includes the southwestern Gulf of St. Lawrence near Prince Edward Island. Within the Gulf these are areas with relatively warmer waters. While those may not represent prime shrimp habitat, it nevertheless indicates that there is potential for a fisheries impact within the Gulf of St. Lawrence. The CSSR model predicts impacts elsewhere, including the Scotian Shelf and offshore on portions of the Grand Banks off Newfoundland under scenario A2. As well, both scenarios of the CCSR model predict possible impacts in areas off Labrador. Although the latter CCSR scenarios are perhaps less likely to occur than the others, it indicates that regions other than southern ones can be potentially impacted under a 4ºC warming scenario. No northward gain of habitat into arctic waters being present-day occurrence is predicted in our study, but this is not necessarily so as the study did not extend to these areas. In the southern range of the species increasing water temperatures resulting from global warming consistently predict a loss of habitat, areas where P. borealis is not widely abundant today. A northern distributional shift will likely result in suboptimal fishery conditions of P. borealis in the adjacent Gulf of Maine. In that area, significant declines in landings have already been linked to increases in water temperature (Dow 1981). Studies on Pacific pandalid shrimp have also corroborated impacts of climate change, having found that populations declined to near extinction in shallow water and low population levels in deeper water, following an abrupt water column warming after 1977 (Anderson 2000). It is reasonable to assume similar effects in the Atlantic, and particularly the Gulf of Maine, under the proposed warming scenario. References Anderson, P.J. 2000. Pandalid shrimp as indicators of ecosystem regime shift. Journal of Northwest Atlantic Fisheries Science, 27:1-10. Balsiger, J.W. 1981. A review of pandalid shrimp fisheries in the northern hemisphere. In: “Proceedings of the international pandalid shrimp symposium, Kodiak, Alaska, February 13-15, 1979” (T. Frady, ed.). Sea Grant Reports, 3:7-35. University of Alaska, Kodiak, Alaska. Bergström, B.I. 1992. Growth, growth modelling and age determination of Pandalus borealis. Marine Ecology Progress Series, 83:167-183. Bergström, B.I. 2000. The biology of Pandalus. Advances in Marine Biology, 38: 55-245. Clark, S.H., Cadrin, S.X., Schick, D.F., Diodati, P.J., Armstrong, M.P, and D.
Load more

Recommended publications
  • The Fishery for Northern Shrimp (Pandalus Borealis) Off West Greenland, 1970–2019
    NOT TO BE CITED WITHOUT PRIOR REFERENCE TO THE AUTHOR(S) Northwest Atlantic Fisheries Organization Serial No. N7008 NAFO SCR Doc. 19/044 NAFO/ICES PANDALUS ASSESSMENT GROUP—November 2019 The Fishery for Northern Shrimp (Pandalus borealis) off West Greenland, 1970–2019 by AnnDorte Burmeister and Frank Rigét Greenland Institute of Natural Resources Box 570, 3900 Nuuk, Greenland Abstract The Northern shrimp (Pandalus borealis) occurs on the continental shelf off West Greenland in NAFO Divisions 0A and 1A–1F in depths between approximately 150 and 600 m. Greenland fishes this stock in Subarea 1, Canada in Div. 0A. The species is assessed in these waters as a single stock and managed by catch control. The fishery has been prosecuted over time by four fleets: Greenland small-vessel inshore; Greenland KGH offshore; Greenland recent offshore, and Canadian offshore. Catch peaked in 1992 at 105 000 tons but then decreased to around 80 000 tons by 1998 owing to management measures. Increases in allowed takes were subsequently accompanied by increased catches. The logbook recorded catches in 2005 and 2006, around 157 000 tons, were the highest recorded. Since then catches has decreased to a recent low level in 2015 at 72 256 tons. In the following years, both TACs and catches increased, and the total catches was 94 878 tons in 2018. The enacted TAC for Greenland in 2019 is set at 103 383 tons and a TAC of 1 617 tons were set for Canada, by the Greenland Self-government. The projected catch for 2019 is set at 100 000 tons.
    [Show full text]
  • Shrimp: Wildlife Notebook Series
    Shrimp Five species of pandalid shrimp of various commercial and subsistence values are found in the cool waters off the coast of Alaska. Pink shrimp (Pandalus borealis) are the foundation of the commercial trawl shrimp fishery in Alaska. Pinks are circumpolar in distribution, though greatest concentrations occur in the Gulf of Alaska. Ranging from Puget Sound to the Arctic coast of Alaska, the humpy shrimp (P. goniurus) is usually harvested incidentally to pink shrimp. In some cases, however, the humpy constitutes the primary species caught. Both pink and humpy shrimp are usually marketed as cocktail or salad shrimp. Known for its sweet flavor, the sidestripe shrimp (Pandalopsis dispar) is also caught incidentally to pinks; however, there are small trawl fisheries in Prince William Sound and Southeast Alaska which target on this deeper water species. The coonstripe shrimp (Pandalus hypsinotis) is the prized target of various pot shrimp fisheries around the state. Coonstripe shrimp can be found from the Bering Sea to the Strait of Juan de Fuca while sidestripes range from the Bering Sea to Oregon. Spot shrimp (P. platyceros) is the largest shrimp in the North Pacific. Ranging from Unalaska Island to San Diego, this species is highly valued by commercial pot fishers and subsistence users alike. Most of the catch from the sidestripe, coonstripe, and spot fisheries is sold fresh in both local and foreign markets. General description: Pandalid shrimp can be characterized by a long, well-developed spiny rostrum and are medium to large in size. The body is generally slender and there are five pairs of "swimmerets" located on the underside of the abdomen.
    [Show full text]
  • The Mediterranean Decapod and Stomatopod Crustacea in A
    ANNALES DU MUSEUM D'HISTOIRE NATURELLE DE NICE Tome V, 1977, pp. 37-88. THE MEDITERRANEAN DECAPOD AND STOMATOPOD CRUSTACEA IN A. RISSO'S PUBLISHED WORKS AND MANUSCRIPTS by L. B. HOLTHUIS Rijksmuseum van Natuurlijke Historie, Leiden, Netherlands CONTENTS Risso's 1841 and 1844 guides, which contain a simple unannotated list of Crustacea found near Nice. 1. Introduction 37 Most of Risso's descriptions are quite satisfactory 2. The importance and quality of Risso's carcino- and several species were figured by him. This caused logical work 38 that most of his names were immediately accepted by 3. List of Decapod and Stomatopod species in Risso's his contemporaries and a great number of them is dealt publications and manuscripts 40 with in handbooks like H. Milne Edwards (1834-1840) Penaeidea 40 "Histoire naturelle des Crustaces", and Heller's (1863) Stenopodidea 46 "Die Crustaceen des siidlichen Europa". This made that Caridea 46 Risso's names at present are widely accepted, and that Macrura Reptantia 55 his works are fundamental for a study of Mediterranean Anomura 58 Brachyura 62 Decapods. Stomatopoda 76 Although most of Risso's descriptions are readily 4. New genera proposed by Risso (published and recognizable, there is a number that have caused later unpublished) 76 authors much difficulty. In these cases the descriptions 5. List of Risso's manuscripts dealing with Decapod were not sufficiently complete or partly erroneous, and Stomatopod Crustacea 77 the names given by Risso were either interpreted in 6. Literature 7S different ways and so caused confusion, or were entirely ignored. It is a very fortunate circumstance that many of 1.
    [Show full text]
  • Pandalus Borealis (Krøyer, 1838)
    Food and Agriculture Organization of the United Nations Fisheries and for a world without hunger Aquaculture Department Species Fact Sheets Pandalus borealis (Krøyer, 1838) Black and white drawing: (click for more) Synonyms Dymas typus Krøyer, 1861 Pandalus borealis typica Retovsky, 1946 FAO Names En - Northern prawn, Fr - Crevette nordique, Sp - Camarón norteño. 3Alpha Code: PRA Taxonomic Code: 2280400203 Scientific Name with Original Description Pandalus borealis Kroyer, 1838, Naturhist.Tidsskr., 2:254. Geographical Distribution FAO Fisheries and Aquaculture Department Launch the Aquatic Species Distribution map viewer North Atlantic: Spitsbergen and Greenland south to the North Sea and to Massachusetts (U.S.A.). North Pacific: Bering Sea to S.E. Siberia, Japan and Oregon (U.S.A.).The taxonomic status of the North Pacific form, usually considered a subspecies Pandalus borealis eous Makarov, 1935, is not fully clear yet. Habitat and Biology Depth 20 to 1 330 m.Bottom clay and mud. Marine. Size Maximum total length 120 mm (male), 165 mm (female). Interest to Fisheries Commercially this is one of the most important carideans of the North Atlantic; only Crangon crangon may be more important. Longhurst (1970:258) called it the principal product of the prawn fisheries of the northwestern Atlantic, being concentrated off Greenland, while in more recent years also more to the south fisheries for the species have started, e.g., in the Gulf of St. Lawrence, the Bay of Fundy and the Gulf of Maine (as far south as Gloucester, Mass.). There is an intensive fishery around Iceland and a most important one off the Norwegian coast. In the Kattegat and Skagerak it is fished for by Danish trawlers.
    [Show full text]
  • Pandalus Platyceros Range: Spot Prawn Inhabit Alaska to San Diego
    Fishery-at-a-Glance: Spot Prawn Scientific Name: Pandalus platyceros Range: Spot Prawn inhabit Alaska to San Diego, California, in depths from 150 to 1,600 feet (46 to 488 meters). The areas where they are of higher abundance in California waters occur off of the Farallon Islands, Monterey, the Channel Islands and most offshore banks. Habitat: Juvenile Spot Prawn reside in relatively hard-bottom kelp covered areas in shallow depths, and adults migrate into deep water of 60.0 to 200.0 meters (196.9 to 656.2 feet). Size (length and weight): The Spot Prawn is the largest prawn in the North Pacific reaching a total length of 25.3 to 30.0 centimeters (10.0 to 12.0 inches) and they can weigh up to 120 grams (0.26 pound). Life span: Spot Prawn have a maximum observed age estimated at more than 6 years, but there are considerable differences in age and growth of Spot Prawns depending on the research and the area. Reproduction: The Spot Prawn is a protandric hermaphrodite (born male and change to female by the end of the fourth year). Spawning occurs once a year, and Spot Prawn typically mate once as a male and once or twice as a female. At sexual maturity, the carapace length of males reaches 1.5 inches (33.0 millimeters) and females 1.75 inches (44.0 millimeters). Prey: Spot Prawn feed on other shrimp, plankton, small mollusks, worms, sponges, and fish carcasses, as well as being detritivores. Predators: Spot Prawn are preyed on by larger marine animals, such as Pacific Hake, octopuses, and seals, as well as humans.
    [Show full text]
  • Current Ocean Wise Approved Canadian MSC Fisheries
    Current Ocean Wise approved Canadian MSC Fisheries Updated: November 14, 2017 Legend: Blue - Ocean Wise Red - Not Ocean Wise White - Only specific areas or gear types are Ocean Wise Species Common Name Latin Name MSC Fishery Name Gear Location Reason for Exception Clam Clearwater Seafoods Banquereau and Banquereau Bank Artic surf clam Mactromeris polynyma Grand Banks Arctic surf clam Hydraulic dredges Grand Banks Crab Snow Crab Chionoecetes opilio Gulf of St Lawrence snow crab trap Conical or rectangular crab pots (traps) North West Atlantic - Nova Scotia Snow Crab Chionoecetes opilio Scotian shelf snow crab trap Conical or rectangular crab pots (traps) North West Atlantic - Nova Scotia Snow Crab Chionoecetes opilio Newfoundland & Labrador snow crab Pots Newfoundland & Labrador Flounder/Sole Yellowtail flounder Limanda ferruginea OCI Grand Bank yellowtail flounder trawl Demersal trawl Grand Banks Haddock Trawl Bottom longline Gillnet Hook and Line CAN - Scotian shelf 4X5Y Trawl Bottom longline Gillnet Atlantic haddock Melangrammus aeglefinus Canada Scotia-Fundy haddock Hook and Line CAN - Scotian shelf 5Zjm Hake Washington, Oregon and California North Pacific hake Merluccius productus Pacific hake mid-water trawl Mid-water Trawl British Columbia Halibut Pacific Halibut Hippoglossus stenolepis Canada Pacific halibut (British Columbia) Bottom longline British Columbia Longline Nova Scotia and Newfoundland Gillnet including part of the Grand banks and Trawl Georges bank, NAFO areas 3NOPS, Atlantic Halibut Hippoglossus hippoglossus Canada
    [Show full text]
  • Articles and Detrital Matter
    Biogeosciences, 7, 2851–2899, 2010 www.biogeosciences.net/7/2851/2010/ Biogeosciences doi:10.5194/bg-7-2851-2010 © Author(s) 2010. CC Attribution 3.0 License. Deep, diverse and definitely different: unique attributes of the world’s largest ecosystem E. Ramirez-Llodra1, A. Brandt2, R. Danovaro3, B. De Mol4, E. Escobar5, C. R. German6, L. A. Levin7, P. Martinez Arbizu8, L. Menot9, P. Buhl-Mortensen10, B. E. Narayanaswamy11, C. R. Smith12, D. P. Tittensor13, P. A. Tyler14, A. Vanreusel15, and M. Vecchione16 1Institut de Ciencies` del Mar, CSIC. Passeig Mar´ıtim de la Barceloneta 37-49, 08003 Barcelona, Spain 2Biocentrum Grindel and Zoological Museum, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany 3Department of Marine Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy 4GRC Geociencies` Marines, Parc Cient´ıfic de Barcelona, Universitat de Barcelona, Adolf Florensa 8, 08028 Barcelona, Spain 5Universidad Nacional Autonoma´ de Mexico,´ Instituto de Ciencias del Mar y Limnolog´ıa, A.P. 70-305 Ciudad Universitaria, 04510 Mexico,` Mexico´ 6Woods Hole Oceanographic Institution, MS #24, Woods Hole, MA 02543, USA 7Integrative Oceanography Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA 8Deutsches Zentrum fur¨ Marine Biodiversitatsforschung,¨ Sudstrand¨ 44, 26382 Wilhelmshaven, Germany 9Ifremer Brest, DEEP/LEP, BP 70, 29280 Plouzane, France 10Institute of Marine Research, P.O. Box 1870, Nordnes, 5817 Bergen, Norway 11Scottish Association for Marine Science, Scottish Marine Institute, Oban,
    [Show full text]
  • Shrimps, Lobsters, and Crabs of the Atlantic Coast of the Eastern United States, Maine to Florida
    SHRIMPS, LOBSTERS, AND CRABS OF THE ATLANTIC COAST OF THE EASTERN UNITED STATES, MAINE TO FLORIDA AUSTIN B.WILLIAMS SMITHSONIAN INSTITUTION PRESS Washington, D.C. 1984 © 1984 Smithsonian Institution. All rights reserved. Printed in the United States Library of Congress Cataloging in Publication Data Williams, Austin B. Shrimps, lobsters, and crabs of the Atlantic coast of the Eastern United States, Maine to Florida. Rev. ed. of: Marine decapod crustaceans of the Carolinas. 1965. Bibliography: p. Includes index. Supt. of Docs, no.: SI 18:2:SL8 1. Decapoda (Crustacea)—Atlantic Coast (U.S.) 2. Crustacea—Atlantic Coast (U.S.) I. Title. QL444.M33W54 1984 595.3'840974 83-600095 ISBN 0-87474-960-3 Editor: Donald C. Fisher Contents Introduction 1 History 1 Classification 2 Zoogeographic Considerations 3 Species Accounts 5 Materials Studied 8 Measurements 8 Glossary 8 Systematic and Ecological Discussion 12 Order Decapoda , 12 Key to Suborders, Infraorders, Sections, Superfamilies and Families 13 Suborder Dendrobranchiata 17 Infraorder Penaeidea 17 Superfamily Penaeoidea 17 Family Solenoceridae 17 Genus Mesopenaeiis 18 Solenocera 19 Family Penaeidae 22 Genus Penaeus 22 Metapenaeopsis 36 Parapenaeus 37 Trachypenaeus 38 Xiphopenaeus 41 Family Sicyoniidae 42 Genus Sicyonia 43 Superfamily Sergestoidea 50 Family Sergestidae 50 Genus Acetes 50 Family Luciferidae 52 Genus Lucifer 52 Suborder Pleocyemata 54 Infraorder Stenopodidea 54 Family Stenopodidae 54 Genus Stenopus 54 Infraorder Caridea 57 Superfamily Pasiphaeoidea 57 Family Pasiphaeidae 57 Genus
    [Show full text]
  • The Protandric Life History of the Northern Spot Shrimp Pandalus Platyceros: Molecular Insights and Implications for Fishery Management
    The protandric life history of the Northern spot shrimp Pandalus platyceros: molecular insights and implications for fishery management. Item Type Article Authors Levy, Tom; Tamone, Sherry L; Manor, Rivka; Bower, Esther D; Sagi, Amir Citation Levy, T., Tamone, S.L., Manor, R. et al. The protandric life history of the Northern spot shrimp Pandalus platyceros: molecular insights and implications for fishery management. Sci Rep 10, 1287 (2020). https://doi.org/10.1038/s41598-020-58262-6 DOI 10.1038/s41598-020-58262-6 Publisher Nature Journal Scientific reports Download date 24/09/2021 06:45:06 Link to Item http://hdl.handle.net/11122/12052 www.nature.com/scientificreports OPEN The protandric life history of the Northern spot shrimp Pandalus platyceros: molecular insights and implications for fshery management Tom Levy 1, Sherry L. Tamone2*, Rivka Manor1, Esther D. Bower2 & Amir Sagi 1,3* The Northern spot shrimp, Pandalus platyceros, a protandric hermaphrodite of commercial importance in North America, is the primary target species for shrimp fsheries within Southeast Alaska. Fishery data obtained from the Alaska Department of Fish and Game indicate that spot shrimp populations have been declining signifcantly over the past 25 years. We collected spot shrimps in Southeast Alaska and measured reproductive-related morphological, gonadal and molecular changes during the entire life history. The appendix masculina, a major sexual morphological indicator, is indicative of the reproductive phase of the animal, lengthening during maturation from juvenile to the male phase and then gradually shortening throughout the transitional stages until its complete disappearance upon transformation to a female. This morphological change occurs in parallel with the degeneration of testicular tissue in the ovotestis and enhanced ovarian vitellogenesis.
    [Show full text]
  • Full Text in Pdf Format
    Vol. 78: 249–253, 2008 DISEASES OF AQUATIC ORGANISMS Published January 24 doi: 10.3354/dao01867 Dis Aquat Org Short- and long-term dietary effects on disease and mortality in American lobster Homarus americanus Michael F. Tlusty*, Anna Myers, Anita Metzler New England Aquarium, Central Wharf, Boston, Massachusetts 02110, USA ABSTRACT: The American lobster Homarus americanus fishery is heavily dependent on the use of fish as bait to entice lobsters into traps. There is concern that this food supplementation is nutrition- ally insufficient for lobsters, but previous experiments reported conflicting results. We conducted a long-term feeding experiment in which 1 yr old American lobsters were fed one of 7 diets for a period of 352 d, a time that allowed the lobsters to molt thrice. The diets consisted of fresh frozen herring, a ‘wild’ diet (rock crab, mussel, and Spirulina algae), a formulated artificial diet for shrimp, paired com- binations of these 3 diets or a diet formulated at the New England Aquarium (Artemia, fish and krill meal, Spirulina algae, soy lecithin, vitamins and minerals). The lobsters fed the diet of 100% fish had higher initial molting rates, but within the period of this experiment all either contracted shell disease or died. Mixed diets resulted in higher survival and a lower probability of mortality. This research demonstrated a critical time component to diet studies in lobsters. Short- and long-term impacts of diet differ. In the long term, continual high consumption rates of fish by the lobsters promote poor health in all lobsters, not just those of market size.
    [Show full text]
  • Dinburgh Encyclopedia;
    THE DINBURGH ENCYCLOPEDIA; CONDUCTED DY DAVID BREWSTER, LL.D. \<r.(l * - F. R. S. LOND. AND EDIN. AND M. It. LA. CORRESPONDING MEMBER OF THE ROYAL ACADEMY OF SCIENCES OF PARIS, AND OF THE ROYAL ACADEMY OF SCIENCES OF TRUSSLi; JIEMBER OF THE ROYAL SWEDISH ACADEMY OF SCIENCES; OF THE ROYAL SOCIETY OF SCIENCES OF DENMARK; OF THE ROYAL SOCIETY OF GOTTINGEN, AND OF THE ROYAL ACADEMY OF SCIENCES OF MODENA; HONORARY ASSOCIATE OF THE ROYAL ACADEMY OF SCIENCES OF LYONS ; ASSOCIATE OF THE SOCIETY OF CIVIL ENGINEERS; MEMBER OF THE SOCIETY OF THE AN­ TIQUARIES OF SCOTLAND; OF THE GEOLOGICAL SOCIETY OF LONDON, AND OF THE ASTRONOMICAL SOCIETY OF LONDON; OF THE AMERICAN ANTlftUARIAN SOCIETY; HONORARY MEMBER OF THE LITERARY AND PHILOSOPHICAL SOCIETY OF NEW YORK, OF THE HISTORICAL SOCIETY OF NEW YORK; OF THE LITERARY AND PHILOSOPHICAL SOClE'i'Y OF li riiECHT; OF THE PimOSOPHIC'.T- SOC1ETY OF CAMBRIDGE; OF THE LITERARY AND ANTIQUARIAN SOCIETY OF PERTH: OF THE NORTHERN INSTITUTION, AND OF THE ROYAL MEDICAL AND PHYSICAL SOCIETIES OF EDINBURGH ; OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA ; OF THE SOCIETY OF THE FRIENDS OF NATURAL HISTORY OF BERLIN; OF THE NATURAL HISTORY SOCIETY OF FRANKFORT; OF THE PHILOSOPHICAL AND LITERARY SOCIETY OF LEEDS, OF THE ROYAL GEOLOGICAL SOCIETY OF CORNWALL, AND OF THE PHILOSOPHICAL SOCIETY OF YORK. WITH THE ASSISTANCE OF GENTLEMEN. EMINENT IN SCIENCE AND LITERATURE. IN EIGHTEEN VOLUMES. VOLUME VII. EDINBURGH: PRINTED FOR WILLIAM BLACKWOOD; AND JOHN WAUGH, EDINBURGH; JOHN MURRAY; BALDWIN & CRADOCK J. M. RICHARDSON, LONDON 5 AND THE OTHER PROPRIETORS. M.DCCC.XXX.- .
    [Show full text]
  • Combined Effects of Ocean Acidification, Ocean Warming and Oil Spill on Aspects of Development of Marine Invertebrates
    University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 2016 COMBINED EFFECTS OF OCEAN ACIDIFICATION, OCEAN WARMING AND OIL SPILL ON ASPECTS OF DEVELOPMENT OF MARINE INVERTEBRATES Arnberg, maj http://hdl.handle.net/10026.1/5287 Plymouth University All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. COMBINED EFFECTS OF OCEAN ACIDIFICATION, OCEAN WARMING AND OIL SPILL ON ASPECTS OF DEVELOPMENT OF MARINE INVERTEBRATES by MAJ ARNBERG A thesis submitted to Plymouth University in partial fulfilment for the degree of DOCTOR OF PHILOSOPHY School of Marine Science and Engineering Faculty of Science and Technology In collaboration with; International Research Institute of Stavanger (IRIS) Stavanger, Norway. University of Gothenburg, Sweden. JANUARY 2016 1 COMBINED EFFECTS OF OCEAN ACIDIFICATION, OCEAN WARMING AND OIL SPILL ON ASPECTS OF DEVELOPMENT OF MARINE INVERTEBRATES By Maj Arnberg i. Abstract For decades, humans have impacted marine ecosystems in a variety of ways including contamination by pollution, fishing, and physical destruction of habitats. Global change has, and will, lead to alterations in in a number of abiotic factors of our ocean in particular reduced oxygen saturation, salinity changes, elevated temperature (ocean warming or OW) and elevated carbon dioxide (ocean acidification or OA). Now and in the future, OA and OW will operate together with local anthropogenic drivers such as oil pollution.
    [Show full text]