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Full-Text Articles in Aquaculture and Fisheries

Utility Of Body And Otolith Morphometry To Discriminate Cryptic Juveniles Of Two Sympatric Red Snappers (Perciformes: Lutjanidae), Miwa Takahashi, Corey B. Wakefield, Stephen J. Newman, Kyle B. Hillcoat, Benjamin J. Saunders, Euan S. Harvey Aug 2023

Utility Of Body And Otolith Morphometry To Discriminate Cryptic Juveniles Of Two Sympatric Red Snappers (Perciformes: Lutjanidae), Miwa Takahashi, Corey B. Wakefield, Stephen J. Newman, Kyle B. Hillcoat, Benjamin J. Saunders, Euan S. Harvey

Fisheries Research Articles

The sympatric red snappers, Lutjanus erythropterus and Lutjanus malabaricus, are highly valued by commercial and recreational fishers along the tropical northern coasts of Australia and throughout their distribution. Studies on the life history and ecology of these congeners are confounded by difficulties in distinguishing the cryptic juveniles of each species (i.e., < 200 mm total length). This study aimed to validate a robust and cost-effective method to discriminate these juveniles using body and/or otolith morphometric data in a multivariate analysis. Juvenile samples were collected from the northwest (n = 71) and northeast (n = 19) coasts of Australia, and species identification was confirmed using DNA barcoding. The most parsimonious multivariate models achieved accurate species prediction rates of 98.8%, which consisted of just three body variables (dorsal fin length, the distance from the snout to the anterior edge of the eye, and either jaw length or distance from the snout to the preoperculum). The high level of discrimination for these cryptic juveniles highlights the robustness of this morphometric approach. The slightly lower rate of discrimination using otolith morphology (84.9%) was associated with greater regional variation in L. malabaricus between the northwest and northeast coasts. Slight variations in otolith shape are typically used to determine stock structure, which highlights the potential need to collect samples over a broader area of a species geographic range when using an otolith morphometric discrimination model. The method outlined in this study could be applied to distinguish other cryptic congeneric fish species, including from archived otolith collections. Moreover, this method has the potential to be utilized in assessing species compositions using body measurements from in situ stereo-video.


Age And Growth For Three Members Of The Family Gempylidae: Escolar (Lepidocybium Flavobrunnuem), Oilfish (Ruvettus Pretiosus), And Snake Mackerel (Gempylus Serpens), Sydney N. Daniels Apr 2023

Age And Growth For Three Members Of The Family Gempylidae: Escolar (Lepidocybium Flavobrunnuem), Oilfish (Ruvettus Pretiosus), And Snake Mackerel (Gempylus Serpens), Sydney N. Daniels

All HCAS Student Capstones, Theses, and Dissertations

Escolar, Lepidocybium flavobrunnuem (Smith, 1849), Oilfish, Ruvettus pretiosus (Cocco, 1829), and Snake Mackerel, Gempylus serpens (Cuvier, 1829) belong to the family Gempylidae and are bycatch of the tuna-targeting pelagic longline fishery. There is limited know life-history information on these mesopelagic fishes, especially regarding growth rates. Age estimates were assigned by counting pairs of increment bands formed on the sagittal otoliths of Escolar (n = 133), Oilfish (n = 49), and Snake Mackerel (n = 46) collected between 2007 and 2022. Marginal increment analyses were used to validate age estimates and periodicity of increment formation, but no significant trends were observed …


Otoliths Of South-Western Australian Fish: A Photographic Catalogue, Chris Dowling, Kim Smith, Elaine Lek, Joshua Brown Sep 2021

Otoliths Of South-Western Australian Fish: A Photographic Catalogue, Chris Dowling, Kim Smith, Elaine Lek, Joshua Brown

Fisheries research reports

Due to the species-specific nature of otoliths and given they are often the only part of the fish preserved when fish die, otolith catalogues can be used in numerous applications, such as diet studies in fish eating animals, including pinnipeds, fish and sea birds; archaeological purposes such as reconstructing indigenous people’s diets from otoliths found in middens or evolutionary history of fish species by comparing fossilized otoliths. Given the unique mixture of subtropical and temperate fish, including many endemic species that occur off the southwest corner of WA having a catalogue for this area is extremely important for people working …


Age, Growth, And Mortality Of Atlantic Tripletail In The North-Central Gulf Of Mexico, Amanda E. Jefferson, Matthew B. Jargowsky, Meagan N. Schrandt, Pearce T. Cooper, Sean P. Powers, John Dindo, J. Marcus Drymon Jan 2021

Age, Growth, And Mortality Of Atlantic Tripletail In The North-Central Gulf Of Mexico, Amanda E. Jefferson, Matthew B. Jargowsky, Meagan N. Schrandt, Pearce T. Cooper, Sean P. Powers, John Dindo, J. Marcus Drymon

University Faculty and Staff Publications

In the southeastern USA and the Gulf of Mexico (GOM), Atlantic Tripletail Lobotes surinamensis are increasingly targeted by recreational anglers, indicating that stock status should be assessed. A critical need for such assessments is age-specific data; however, previous studies have drawn conflicting conclusions regarding the most appropriate structure for aging. Moreover, growth parameters and mortality rates for GOM Atlantic Tripletail are unknown. Therefore, the goals of this study were to (1) evaluate sagittal otoliths and first dorsal spines as aging structures; (2) model combined and sex-specific growth; and (3) estimate mortality rates for GOM Atlantic Tripletail. From 2012 to 2019, …


Evaluating Methods For Optimizing Classification Success From Otolith Tracers For Spotted Seatrout (Cynoscion Nebulosus) In The Chesapeake Bay, Stacy Kavita Beharry Jan 2011

Evaluating Methods For Optimizing Classification Success From Otolith Tracers For Spotted Seatrout (Cynoscion Nebulosus) In The Chesapeake Bay, Stacy Kavita Beharry

OES Theses and Dissertations

Identifying the natal sources of fish is an important step in understanding its population dynamics. Adult recruits are often sourced from multiple nursery areas, with good quality locations contributing disproportionately more fish to the adult stock. Because population persistence is strongly influenced by nursery habitat, methods that correctly identify the source of recruits are necessary for effective management. Within the last decade, otolith chemistry signatures have been increasingly used as a natural marker to delineate fish from a mixture of nursery sources. Despite the widespread use of otolith trace element and stable isotope ratios as habitat markers, the statistical approaches …


Otolith Chemistry Reflects Frontal Systems In The Antarctic Circumpolar Current, J. R. Ashford, A. I. Arkhipkin, C. M. Jones Jan 2007

Otolith Chemistry Reflects Frontal Systems In The Antarctic Circumpolar Current, J. R. Ashford, A. I. Arkhipkin, C. M. Jones

OES Faculty Publications

Pronounced environmental trends across fronts suggest that the otolith chemistry of oceanic fish can resolve zones on either side, promoting application to population questions at similar spatial scales. Trace and minor elements laid down immediately prior to capture - along the edges of otoliths from Patagonian toothfish Dissostichus eleginoides - discriminated frontal zones in the Antarctic Circumpolar Current in the Southwestern Atlantic Ocean. Mean values differentiated sampling areas by up to 2.6 standard deviations, suggesting: (1) otolith Mg/Ca enrichment related to fish activity around the Burdwood Bank; (2) Mn/Ca enrichment associated with South America; (3) Sr/Ca linked to the presence …


Age And Growth Of Scotia Sea Icefish, Chaenocephalus Aceratus, From The South Shetland Islands, M. La Mesa, J. Ashford, E. Larson, M. Vacchi Jan 2004

Age And Growth Of Scotia Sea Icefish, Chaenocephalus Aceratus, From The South Shetland Islands, M. La Mesa, J. Ashford, E. Larson, M. Vacchi

OES Faculty Publications

Samples of Chaenocephalus aceratus (Lönnberg) were collected during a trawl survey carried out around the South Shetland Islands in January–February 2002. Fish were caught by commercial bottom trawl fishing down to 500 m depth, using a stratified randomized sampling design. As observed in other recent surveys within the same area, C. aceratus represented one of the predominant species. Overall, 357 specimens ranging from 13 and 67 cm (TL) were selected for the present study. Ages were estimated by counting annuli present in the sagittal otoliths, exposed by grinding and polishing along their sagittal plane. To estimate the precision of age …


Fisheries Research Report No. 143 - Methods Used In The Collection, Preparation And Interpretation Of Narrow-Barred Spanish Mackerel (Scomberomorus Commerson) Otoliths For A Study Of Age And Growth In Western Australia, Paul Lewis, M. C. Mackie Dec 2002

Fisheries Research Report No. 143 - Methods Used In The Collection, Preparation And Interpretation Of Narrow-Barred Spanish Mackerel (Scomberomorus Commerson) Otoliths For A Study Of Age And Growth In Western Australia, Paul Lewis, M. C. Mackie

Fisheries research reports

The narrow-barred Spanish mackerel (Scomberomorus commerson) is wide ranging throughout the Indo-West Pacific region where it has been the subject of various age and growth studies. Methods used in these studies have varied considerably and in some cases may have led to misleading conclusions. The purpose of this report, therefore, is to document in detail the methods used in determining the age and growth during a FRDC funded stock assessment of the species in the waters off Western Australia. These methods are considered to optimise the collection, processing, accuracy of microincrement counts, and interpretation of the annuli in both whole …


Fisheries Research Report No. 141 - A Guide To Good Otolith Cutting, Jerry Jenke Sep 2002

Fisheries Research Report No. 141 - A Guide To Good Otolith Cutting, Jerry Jenke

Fisheries research reports

This is a guide for embedding and sectioning fish otoliths. It is based on many years of otolith sectioning experience and is written as a recipe book for novice and expert alike. Included is a method for the enhancement of the clarity of small otoliths for improved sectioning, development of custom made tools, as well as a list of do’s and don’ts and hints to make the job easier. Use of this guide will assist in the most reliable interpretation of an otolith's internal structure, thereby improving ageing studies in general.


Radiocarbon From Nuclear Testing Applied To Age Validation Of Black Drum, Pogonias Cromis, Steven E. Campana, Cynthia M. Jones Aug 1998

Radiocarbon From Nuclear Testing Applied To Age Validation Of Black Drum, Pogonias Cromis, Steven E. Campana, Cynthia M. Jones

OES Faculty Publications

Radiocarbon ((14)C) in the world's oceans increased sharply between 1950 and 1970 as a result of the atmospheric testing of nuclear weapons. Through comparison with the (14)C time series reconstructed from atmospheric measurements and marine carbonates, Kalish, in 1993, used the (14)C concentration measured in fish otolith cores as a means of confirming the annulus-based age estimates for some South Pacific fish species. Here we report the pre-and postbomb (14)C chronology of North Atlantic adult black drum (Pogonias cronis), assumed to be between 15 and 42 yr of age on the basis of otolith annulus counts. According to …


Age And Growth Of Larval And Juvenile Atlantic Croaker, Micropogonias Undulatus, From The Middle Atlantic Bight And Estuarine Waters Of Virginia, Stephen W. Nixon, Cynthia M. Jones Jan 1997

Age And Growth Of Larval And Juvenile Atlantic Croaker, Micropogonias Undulatus, From The Middle Atlantic Bight And Estuarine Waters Of Virginia, Stephen W. Nixon, Cynthia M. Jones

OES Faculty Publications

Sagittal otoliths were used to determine age and growth of 605 larval and juvenile Atlantic croaker, Micropogonias undulatus, collected in the Middle Atlantic Bight and estuarine waters of Virginia. This study is the first to use age-based analysis for young Atlantic croaker collected in this region. A Laird-Gompertz model (r2=0.95) was used to describe the growth of Atlantic croaker up to 65 mm standard length (SL) and 142 days (t): SL((t)) = 2.657 exp (4.656 [1-exp (-0.0081t)]); where SL((t)) = standard length at day t. Spatial and temporal patterns in the size and age of Atlantic croaker showed a …


Response Of Otolith Microchemistry To Environmental Variations Experienced By Larval And Juvenile Atlantic Croaker (Micropogonias Undulatus), Simon R. Thorrold, Cynthia M. Jones, Steven E. Campana Jan 1997

Response Of Otolith Microchemistry To Environmental Variations Experienced By Larval And Juvenile Atlantic Croaker (Micropogonias Undulatus), Simon R. Thorrold, Cynthia M. Jones, Steven E. Campana

OES Faculty Publications

Minor and trace elements incorporated into otoliths during growth may permanently record environmental conditions experienced by fishes. To determine the validity of this approach, we used laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) to assay sectioned otoliths from juvenile Atlantic croaker (Micropogonias undulatus) collected from each of three sites in the Neuse River, North Carolina, and the Elizabeth River, Virginia. Elemental concentrations at the center of the otoliths did not differ between locations, although both Mg : Ca and Ba : Ca were significantly higher at the edge of otoliths from the Neuse River than from the …