Diet of bonnethead shark in eastern Gulf of Mexico
To examine variation in diet and daily ration of the bonnethead, Sphyrna tiburo (Linnaeus, 1758), sharks were collected from three areas in the eastern Gulf of Mexico: northwest Florida (29o40N, 85o13W), Anclote Key near Tampa Bay (28o10N, 82o42.5W), and Florida Bay (24o50N, 80o48W) from March through September, 1998-2000. In each area, diet was assessed by life stage (young-of-the year, juveniles, and adults) and quantified using five indices: percent by number (N), percent by weight (W), frequency of occurrence (O), index of relative importance expressed on a percent basis (IRI), and IRI based on diet category (IRIDC). Diet could not be assessed for young-of-the-year in Tampa Bay or Florida Bay owing to low sample size. Diet analysis showed an ontogenetic shift in northwest Florida. Young-of-the-year stomachs from northwest Florida (n68, 1 empty) contained a mix of seagrass and crustaceans while juvenile stomachs (n82, 0 empty) contained a mix of crabs and seagrass and adult stomachs (n39, 1 empty) contained almost exclusively crabs. Crabs made up the majority of both juvenile and adult diet in Tampa Bay (n79, 2 empty, and n88, 1 empty, respectively). Juvenile stomachs from Florida Bay (n72, 0 empty) contained seagrass and a mix of crustaceans while adult stomachs contained more shrimp and cephalopods (n82, 3 empty). Diets in northwest Florida and Tampa Bay were similar. The diet in Florida Bay was different from those in the other two areas, consisting of fewer crabs and more cephalopods and lobsters. Plant material was found in large quantities in all stomachs examined from all locations (15 IRIDC in 6 of the 7 life stage-area combinations, 30 IRIDC in 4 of the 7 combinations, and 62 IRIDC in young-of-the-year diet in northwest Florida). Using species- and area-specific inputs, a bioenergetic model was constructed to estimate daily ration. Models were constructed under two scenarios: assuming plant material was and was not part of the diet. Overall, daily ration was significantly different by sex, life stage, and region. The bioenergetic model predicted increasing daily ration with decreasing latitude and decreasing daily ration with ontogeny regardless of the inclusion or exclusion of plant material. These results provide evidence that bonnetheads continuously exposed to warmer temperatures have elevated metabolism and require additional energy consumption to maintain growth and reproduction.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | non-public |
| contactPoint |
{
"fn": "Carlson, John",
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| description | To examine variation in diet and daily ration of the bonnethead, Sphyrna tiburo (Linnaeus, 1758), sharks were collected from three areas in the eastern Gulf of Mexico: northwest Florida (29o40N, 85o13W), Anclote Key near Tampa Bay (28o10N, 82o42.5W), and Florida Bay (24o50N, 80o48W) from March through September, 1998-2000. In each area, diet was assessed by life stage (young-of-the year, juveniles, and adults) and quantified using five indices: percent by number (N), percent by weight (W), frequency of occurrence (O), index of relative importance expressed on a percent basis (IRI), and IRI based on diet category (IRIDC). Diet could not be assessed for young-of-the-year in Tampa Bay or Florida Bay owing to low sample size. Diet analysis showed an ontogenetic shift in northwest Florida. Young-of-the-year stomachs from northwest Florida (n68, 1 empty) contained a mix of seagrass and crustaceans while juvenile stomachs (n82, 0 empty) contained a mix of crabs and seagrass and adult stomachs (n39, 1 empty) contained almost exclusively crabs. Crabs made up the majority of both juvenile and adult diet in Tampa Bay (n79, 2 empty, and n88, 1 empty, respectively). Juvenile stomachs from Florida Bay (n72, 0 empty) contained seagrass and a mix of crustaceans while adult stomachs contained more shrimp and cephalopods (n82, 3 empty). Diets in northwest Florida and Tampa Bay were similar. The diet in Florida Bay was different from those in the other two areas, consisting of fewer crabs and more cephalopods and lobsters. Plant material was found in large quantities in all stomachs examined from all locations (15 IRIDC in 6 of the 7 life stage-area combinations, 30 IRIDC in 4 of the 7 combinations, and 62 IRIDC in young-of-the-year diet in northwest Florida). Using species- and area-specific inputs, a bioenergetic model was constructed to estimate daily ration. Models were constructed under two scenarios: assuming plant material was and was not part of the diet. Overall, daily ration was significantly different by sex, life stage, and region. The bioenergetic model predicted increasing daily ration with decreasing latitude and decreasing daily ration with ontogeny regardless of the inclusion or exclusion of plant material. These results provide evidence that bonnetheads continuously exposed to warmer temperatures have elevated metabolism and require additional energy consumption to maintain growth and reproduction. |
| distribution |
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| identifier | gov.noaa.nmfs.inport:24912 |
| isPartOf | Diet of scalloped hammerhead shark in eastern Gulf of Mexico |
| issued | 2017-01-01T00:00:00.000+00:00 |
| keyword |
[
"EARTH SCIENCE > BIOLOGICAL CLASSIFICATION",
"EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > WATER DEPTH",
"EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE",
"0163192",
"163192",
"US DOC; NOAA; NMFS; Southeast Fisheries Science Center; Panama City, FL Laboratory",
"ANIMALS - INDIVIDUAL - Stomach Contents",
"BIOLOGICAL DATA",
"STOMACH CONTENTS",
"STOMACH CONTENTS - CONTENT WEIGHT",
"STOMACH CONTENTS - PREY COUNT",
"STOMACH CONTENTS - PREY TAXONOMY",
"WATER TEMPERATURE",
"water depth",
"biological",
"laboratory analyses",
"US DOC; NOAA; NMFS; Southeast Fisheries Science Center",
"oceanography",
"Coastal Waters of Florida",
"Gulf of Mexico",
"North Atlantic Ocean",
"YSI - handheld multi-parameter instrumentYSI - handheld multi-parameter instrument",
"scale",
"bonnethead",
"diet",
"fishery-dependent",
"young-of-the-year",
"1998-2005",
"Anclote Key",
"Florida Bay",
"Gulf of Mexico",
"Tampa Bay",
"depth sounder",
"measuring board",
"ruler",
"DOC/NOAA/NMFS/SEFSC > Southeast Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Department of Commerce",
"A Comparison of the foraging ecology and bioenergetics of the early life-stages of two sympatric hammerhead sharks from 1998-07-12 to 2005-07-27 (NCEI Accession 0163192)"
]
|
| landingPage | https://www.fisheries.noaa.gov/inport/item/24912 |
| language |
[]
|
| license | https://creativecommons.org/publicdomain/zero/1.0/ |
| modified | 2017-01-01T00:00:00.000+00:00 |
| publisher |
{
"name": "Southeast Fisheries Science Center",
"@type": "org:Organization"
}
|
| references |
[
"https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/sefsc/dmp/pdf/24912.pdf"
]
|
| rights | otherRestrictions, unclassified |
| spatial | -82.063,25.056,-85.292,29.978 |
| temporal | 2001-01-01T00:00:00+00:00/2002-01-01T00:00:00+00:00 |
| title | Diet of bonnethead shark in eastern Gulf of Mexico |
