Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp
The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei ( Balaenoptera borea...
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ftunivcapetownir:oai:localhost:11427/18858 2023-05-15T13:32:17+02:00 Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp Best, Peter B Photopoulou, Theoni 2016 application/pdf http://hdl.handle.net/11427/18858 https://doi.org/10.1371/journal.pone.0152643 https://open.uct.ac.za/bitstream/11427/18858/1/Best_Identifying_the_demon_whale_biter_2016.pdf eng eng Public Library of Science University of Cape Town Faculty of Science Department of Statistical Sciences http://dx.doi.org/10.1371/journal.pone.0152643 http://hdl.handle.net/11427/18858 https://open.uct.ac.za/bitstream/11427/18858/1/Best_Identifying_the_demon_whale_biter_2016.pdf This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. http://creativecommons.org/licenses/by/4.0 © 2016 Best, Photopoulou CC-BY PLoS One http://journals.plos.org/plosone Sperm whales Whales Predation Sharks Sperm head Latitude Killer whales Stomach Journal Article 2016 ftunivcapetownir https://doi.org/10.1371/journal.pone.0152643 2022-09-13T05:53:15Z The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei ( Balaenoptera borealis ), fin ( B . physalus ), inshore and offshore Bryde's ( B . brydeii sp) and sperm whales ( Physeter macrocephalus ) examined at the Donkergat whaling station, Saldanha Bay, South Africa between March and October 1963. We then analyse the intensity and trends in its predation on large whales. Despite the scarcity of local records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion of unhealed bitemarks that were recent. We use day of the year; reproductive class, social grouping or sex; depth interval and body length as candidate covariates. The models with highest support for total counts of unhealed bitemarks involve the day of the year in all species. Depth was an important predictor in all species except offshore Bryde's whales. Models for the proportion of recent bites were only informative for sei and fin whales. We conclude that temporal scarring patterns support what is currently hypothesized about the distribution and movements of these whale species, given that Isistius does not occur in the Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales suggests that this group spends more time outside the area in which bites are incurred, providing a clue to one of the biggest gaps in our understanding of the movements of mature and maturing sperm males. Article in Journal/Newspaper Antarc* Antarctic Balaenoptera borealis Physeter macrocephalus University of Cape Town: OpenUCT Antarctic The Antarctic PLOS ONE 11 4 e0152643 |
institution |
Open Polar |
collection |
University of Cape Town: OpenUCT |
op_collection_id |
ftunivcapetownir |
language |
English |
topic |
Sperm whales Whales Predation Sharks Sperm head Latitude Killer whales Stomach |
spellingShingle |
Sperm whales Whales Predation Sharks Sperm head Latitude Killer whales Stomach Best, Peter B Photopoulou, Theoni Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp |
topic_facet |
Sperm whales Whales Predation Sharks Sperm head Latitude Killer whales Stomach |
description |
The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei ( Balaenoptera borealis ), fin ( B . physalus ), inshore and offshore Bryde's ( B . brydeii sp) and sperm whales ( Physeter macrocephalus ) examined at the Donkergat whaling station, Saldanha Bay, South Africa between March and October 1963. We then analyse the intensity and trends in its predation on large whales. Despite the scarcity of local records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion of unhealed bitemarks that were recent. We use day of the year; reproductive class, social grouping or sex; depth interval and body length as candidate covariates. The models with highest support for total counts of unhealed bitemarks involve the day of the year in all species. Depth was an important predictor in all species except offshore Bryde's whales. Models for the proportion of recent bites were only informative for sei and fin whales. We conclude that temporal scarring patterns support what is currently hypothesized about the distribution and movements of these whale species, given that Isistius does not occur in the Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales suggests that this group spends more time outside the area in which bites are incurred, providing a clue to one of the biggest gaps in our understanding of the movements of mature and maturing sperm males. |
format |
Article in Journal/Newspaper |
author |
Best, Peter B Photopoulou, Theoni |
author_facet |
Best, Peter B Photopoulou, Theoni |
author_sort |
Best, Peter B |
title |
Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp |
title_short |
Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp |
title_full |
Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp |
title_fullStr |
Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp |
title_full_unstemmed |
Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp |
title_sort |
identifying the "demon whale-biter": patterns of scarring on large whales attributed to a cookie-cutter shark isistius sp |
publisher |
Public Library of Science |
publishDate |
2016 |
url |
http://hdl.handle.net/11427/18858 https://doi.org/10.1371/journal.pone.0152643 https://open.uct.ac.za/bitstream/11427/18858/1/Best_Identifying_the_demon_whale_biter_2016.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Balaenoptera borealis Physeter macrocephalus |
genre_facet |
Antarc* Antarctic Balaenoptera borealis Physeter macrocephalus |
op_source |
PLoS One http://journals.plos.org/plosone |
op_relation |
http://dx.doi.org/10.1371/journal.pone.0152643 http://hdl.handle.net/11427/18858 https://open.uct.ac.za/bitstream/11427/18858/1/Best_Identifying_the_demon_whale_biter_2016.pdf |
op_rights |
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. http://creativecommons.org/licenses/by/4.0 © 2016 Best, Photopoulou |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1371/journal.pone.0152643 |
container_title |
PLOS ONE |
container_volume |
11 |
container_issue |
4 |
container_start_page |
e0152643 |
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