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<!DOCTYPE html> <html lang="en" dir="ltr" xmlns="http://www.w3.org/1999/xhtml" xmlns:mml="http://www.w3.org/1998/Math/MathML"> <head prefix="og: http://ogp.me/ns# article: http://ogp.me/ns/article# book: http://ogp.me/ns/book#" >  <link rel="dns-prefetch" href="//d33xdlntwy0kbs.cloudfront.net" /> <link rel="dns-prefetch" href="//www.google.com" /> <link rel="dns-prefetch" href="//scholar.google.com" /> <link rel="dns-prefetch" href="//www.googletagmanager.com" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <link rel="shortcut icon" href="https://www.biorxiv.org/sites/default/files/images/favicon.ico" type="image/vnd.microsoft.icon" /> <meta name="viewport" content="width=device-width, initial-scale=1" /> <link rel="alternate" type="application/pdf" title="Full Text (PDF)" href="/content/10.1101/2024.08.23.609377v3.full.pdf" /> <link rel="alternate" type="text/plain" title="Full Text (Plain)" href="/content/10.1101/2024.08.23.609377v3.full.txt" /> <meta name="article_thumbnail" content="https://www.biorxiv.org/content/biorxiv/early/2024/11/18/2024.08.23.609377/embed/graphic-2.gif" /> <meta name="type" content="article" /> <meta name="category" content="article" /> <meta name="HW.identifier" content="/biorxiv/early/2024/11/18/2024.08.23.609377.atom" /> <meta name="HW.pisa" content="biorxiv;2024.08.23.609377v3" /> <meta name="DC.Format" content="text/html" /> <meta name="DC.Language" content="en" /> <meta name="DC.Title" content="Growth patterns of theoretical bite force and jaw musculature in southern sea otters (Enhydra lutris nereis)" /> <meta name="DC.Identifier" content="10.1101/2024.08.23.609377" /> <meta name="DC.Date" content="2024-11-18" /> <meta name="DC.Publisher" content="Cold Spring Harbor Laboratory" /> <meta name="DC.Rights" content="© 2024, Posted by Cold Spring Harbor Laboratory. This pre-print is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), CC BY-NC 4.0, as described at http://creativecommons.org/licenses/by-nc/4.0/" /> <meta name="DC.AccessRights" content="restricted" /> <meta name="DC.Description" content="The transition from milk to solid food requires drastic changes in the morphology of the feeding apparatus and its performance. As durophagous mammals, southern sea otters exhibit significant ontogenetic changes in cranial and mandibular morphology to presumably enable them to feed on a variety of hard-shelled invertebrate prey. Juvenile sea otters begin feeding independently by 6 –8 months of age, but how quickly they reach sufficient maturity in biting performances remains unknown. Here, I found that theoretical bite force of southern sea otters does not reach full maturation until during the adult stage at 3.6 and 5.0 years of age in females and males, respectively. The slow maturation of biting performance can be directly attributed to the slow growth and development of the cranium and the primary jaw adductor muscle (i.e., the temporalis) and may ultimately impact the survival of newly weaned juveniles by limiting their ability to process certain hard-shelled prey. Alterative foraging behaviors such as tool use, however, may mitigate the disadvantages of delayed maturation of biting performance. In analyses of sexual dimorphism, I found that female otters reached bite force maturation earlier whereas male otters exhibit initial rapid growth in bite force to quickly reach sufficient biting performances needed to process prey early in life followed by a slower growth phase towards bite force maturation that coincides with sexual maturity. This biphasic growth in bite force suggests that male to male competition for resources and mates exhibits strong selection in the growth and development of skull form and function in male otters. Overall, this study demonstrates how the analysis of anatomical data can provide insight on the foraging ecologies and life histories of sea otters across ontogeny. ### Competing Interest Statement The authors have declared no competing interest." /> <meta name="DC.Contributor" content="Chris J. Law" /> <meta name="article:published_time" content="2024-11-18" /> <meta name="article:section" content="New Results" /> <meta name="citation_title" content="Growth patterns of theoretical bite force and jaw musculature in southern sea otters (Enhydra lutris nereis)" /> <meta name="citation_abstract" lang="en" content="<h3>Abstract</h3> <p>The transition from milk to solid food requires drastic changes in the morphology of the feeding apparatus and its performance. As durophagous mammals, southern sea otters exhibit significant ontogenetic changes in cranial and mandibular morphology to presumably enable them to feed on a variety of hard-shelled invertebrate prey. Juvenile sea otters begin feeding independently by 6 –8 months of age, but how quickly they reach sufficient maturity in biting performances remains unknown. Here, I found that theoretical bite force of southern sea otters does not reach full maturation until during the adult stage at 3.6 and 5.0 years of age in females and males, respectively. The slow maturation of biting performance can be directly attributed to the slow growth and development of the cranium and the primary jaw adductor muscle (i.e., the temporalis) and may ultimately impact the survival of newly weaned juveniles by limiting their ability to process certain hard-shelled prey. Alterative foraging behaviors such as tool use, however, may mitigate the disadvantages of delayed maturation of biting performance. In analyses of sexual dimorphism, I found that female otters reached bite force maturation earlier whereas male otters exhibit initial rapid growth in bite force to quickly reach sufficient biting performances needed to process prey early in life followed by a slower growth phase towards bite force maturation that coincides with sexual maturity. This biphasic growth in bite force suggests that male to male competition for resources and mates exhibits strong selection in the growth and development of skull form and function in male otters. Overall, this study demonstrates how the analysis of anatomical data can provide insight on the foraging ecologies and life histories of sea otters across ontogeny.</p>" /> <meta name="citation_journal_title" content="bioRxiv" /> <meta name="citation_publisher" content="Cold Spring Harbor Laboratory" /> <meta name="citation_publication_date" content="2024/01/01" /> <meta name="citation_mjid" content="biorxiv;2024.08.23.609377v3" /> <meta name="citation_id" content="2024.08.23.609377v3" /> <meta name="citation_public_url" content="https://www.biorxiv.org/content/10.1101/2024.08.23.609377v3" /> <meta name="citation_abstract_html_url" content="https://www.biorxiv.org/content/10.1101/2024.08.23.609377v3.abstract" /> <meta name="citation_full_html_url" content="https://www.biorxiv.org/content/10.1101/2024.08.23.609377v3.full" /> <meta name="citation_pdf_url" content="https://www.biorxiv.org/content/biorxiv/early/2024/11/18/2024.08.23.609377.full.pdf" /> <meta name="citation_doi" content="10.1101/2024.08.23.609377" /> <meta name="citation_num_pages" content="34" /> <meta name="citation_article_type" content="Article" /> <meta name="citation_section" content="New Results" /> <meta name="citation_firstpage" content="2024.08.23.609377" /> <meta name="citation_author" content="Chris J. 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Lett. 10:20140484–20140484." /> <meta name="twitter:title" content="Growth patterns of theoretical bite force and jaw musculature in southern sea otters (Enhydra lutris nereis)" /> <meta name="twitter:site" content="@biorxivpreprint" /> <meta name="twitter:card" content="summary" /> <meta name="twitter:image" content="https://www.biorxiv.org/sites/default/files/images/biorxiv_logo_homepage7-5-small.png" /> <meta name="twitter:description" content="The transition from milk to solid food requires drastic changes in the morphology of the feeding apparatus and its performance. As durophagous mammals, southern sea otters exhibit significant ontogenetic changes in cranial and mandibular morphology to presumably enable them to feed on a variety of hard-shelled invertebrate prey. Juvenile sea otters begin feeding independently by 6 –8 months of age, but how quickly they reach sufficient maturity in biting performances remains unknown. Here, I found that theoretical bite force of southern sea otters does not reach full maturation until during the adult stage at 3.6 and 5.0 years of age in females and males, respectively. The slow maturation of biting performance can be directly attributed to the slow growth and development of the cranium and the primary jaw adductor muscle (i.e., the temporalis) and may ultimately impact the survival of newly weaned juveniles by limiting their ability to process certain hard-shelled prey. Alterative foraging behaviors such as tool use, however, may mitigate the disadvantages of delayed maturation of biting performance. In analyses of sexual dimorphism, I found that female otters reached bite force maturation earlier whereas male otters exhibit initial rapid growth in bite force to quickly reach sufficient biting performances needed to process prey early in life followed by a slower growth phase towards bite force maturation that coincides with sexual maturity. This biphasic growth in bite force suggests that male to male competition for resources and mates exhibits strong selection in the growth and development of skull form and function in male otters. Overall, this study demonstrates how the analysis of anatomical data can provide insight on the foraging ecologies and life histories of sea otters across ontogeny. ### Competing Interest Statement The authors have declared no competing interest." /> <meta name="og-title" property="og:title" content="Growth patterns of theoretical bite force and jaw musculature in southern sea otters (Enhydra lutris nereis)" /> <meta name="og-url" property="og:url" content="https://www.biorxiv.org/content/10.1101/2024.08.23.609377v3" /> <meta name="og-site-name" property="og:site_name" content="bioRxiv" /> <meta name="og-description" property="og:description" content="The transition from milk to solid food requires drastic changes in the morphology of the feeding apparatus and its performance. As durophagous mammals, southern sea otters exhibit significant ontogenetic changes in cranial and mandibular morphology to presumably enable them to feed on a variety of hard-shelled invertebrate prey. Juvenile sea otters begin feeding independently by 6 –8 months of age, but how quickly they reach sufficient maturity in biting performances remains unknown. Here, I found that theoretical bite force of southern sea otters does not reach full maturation until during the adult stage at 3.6 and 5.0 years of age in females and males, respectively. The slow maturation of biting performance can be directly attributed to the slow growth and development of the cranium and the primary jaw adductor muscle (i.e., the temporalis) and may ultimately impact the survival of newly weaned juveniles by limiting their ability to process certain hard-shelled prey. Alterative foraging behaviors such as tool use, however, may mitigate the disadvantages of delayed maturation of biting performance. In analyses of sexual dimorphism, I found that female otters reached bite force maturation earlier whereas male otters exhibit initial rapid growth in bite force to quickly reach sufficient biting performances needed to process prey early in life followed by a slower growth phase towards bite force maturation that coincides with sexual maturity. This biphasic growth in bite force suggests that male to male competition for resources and mates exhibits strong selection in the growth and development of skull form and function in male otters. Overall, this study demonstrates how the analysis of anatomical data can provide insight on the foraging ecologies and life histories of sea otters across ontogeny. ### Competing Interest Statement The authors have declared no competing interest." /> <meta name="og-type" property="og:type" content="article" /> <meta name="og-image" property="og:image" content="https://www.biorxiv.org/sites/default/files/images/biorxiv_logo_homepage7-5-small.png" /> <meta name="citation_date" content="2024-11-18" /> <link rel="alternate" type="application/vnd.ms-powerpoint" title="Powerpoint" href="/content/10.1101/2024.08.23.609377v3.ppt" /> <meta name="description" content="bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution" /> <meta name="generator" content="Drupal 7 (http://drupal.org)" /> <link rel="canonical" href="https://www.biorxiv.org/content/10.1101/2024.08.23.609377v3" /> <link rel="shortlink" 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class="highwire-article-citation highwire-citation-type-highwire-article node4231004" data-node-nid="4231004" id="node-4231004--2614418483" data-pisa="biorxiv;2024.08.23.609377v3" data-pisa-master="biorxiv;2024.08.23.609377" data-apath="/biorxiv/early/2024/11/18/2024.08.23.609377.atom" data-hw-author-tooltip-instance="highwire_author_tooltip"><div class="highwire-cite highwire-cite-highwire-article highwire-citation-biorxiv-article-top clearfix has-author-tooltip" > <span class="biorxiv-article-type"> New Results </span> <h1 class="highwire-cite-title" id="page-title">Growth patterns of theoretical bite force and jaw musculature in southern sea otters (<em>Enhydra lutris nereis</em>)</h1> <div class="highwire-cite-authors" ><span class="highwire-citation-authors"><span class="highwire-citation-author first hw-author-orcid-logo-wrapper" data-delta="0"><a href="http://orcid.org/0000-0003-1575-7746" target="_blank" class="hw-author-orcid-logo link-icon-only link-icon"><span class="hw-icon-orcid hw-icon-color-orcid"></span> <span class="title element-invisible">View ORCID Profile</span></a><span class="nlm-given-names">Chris J.</span> <span class="nlm-surname">Law</span></span></span></div> <div class="highwire-cite-metadata" ><span class="highwire-cite-metadata-doi highwire-cite-metadata"><span class="label">doi:</span> https://doi.org/10.1101/2024.08.23.609377 </span></div> </div> <div id="hw-article-author-popups-node-4231004--2614418483" style="display: none;"><div class="author-tooltip-0"><div class="author-tooltip-name">Chris J. Law </div><div class="author-tooltip-affiliation"><span class="author-tooltip-text"><div class='author-affiliation'><span class='nlm-sup'>1</span><span class='nlm-institution'>Burke Museum and Department of Biology, University of Washington</span></div><div class='author-affiliation'><span class='nlm-sup'>2</span><span class='nlm-institution'>Department of Integrative Biology, University of California Berkeley</span></div></span></div><ul class="author-tooltip-find-more"><li class="author-tooltip-gs-link first"><a href="/lookup/google-scholar?link_type=googlescholar&gs_type=author&author%5B0%5D=Chris%2BJ.%2BLaw%2B" target="_blank" class="" data-icon-position="" data-hide-link-title="0">Find this author on Google Scholar</a></li><li class="author-tooltip-pubmed-link"><a href="/lookup/external-ref?access_num=Law%20CJ&link_type=AUTHORSEARCH" target="_blank" class="" data-icon-position="" data-hide-link-title="0">Find this author on PubMed</a></li><li class="author-site-search-link"><a href="/search/author1%3AChris%2BJ.%2BLaw%2B" rel="nofollow" class="" data-icon-position="" data-hide-link-title="0">Search for this author on this site</a></li><li class="author-orcid-link"><a href="http://orcid.org/0000-0003-1575-7746" target="_blank" class="" data-icon-position="" data-hide-link-title="0">ORCID record for Chris J. Law</a></li><li class="author-corresp-email-link last"><span>For correspondence: <a href="/cdn-cgi/l/email-protection#e4878e888593a49193ca818091" class="" data-icon-position="" data-hide-link-title="0"><span class="__cf_email__" data-cfemail="e4878e888593a49193ca818091">[email protected]</span></a></span></li></ul></div></div></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-highwire-panel-tabs pane-panels-ajax-tab-tabs" > <div class="pane-content"> <div class="item-list"><ul class="tabs inline panels-ajax-tab"><li class="first"><a href="/content/10.1101/2024.08.23.609377v3" class="panels-ajax-tab-tab" data-panel-name="biorxiv_tab_art" data-target-id="highwire_article_tabs" data-entity-context="node:4231004" data-trigger="" data-url-enabled="1">Abstract</a><a href="/panels_ajax_tab/biorxiv_tab_art/node:4231004/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li><li><a href="/content/10.1101/2024.08.23.609377v3.full-text" class="panels-ajax-tab-tab" data-panel-name="article_tab_full_text" data-target-id="highwire_article_tabs" data-entity-context="node:4231004" data-trigger="full-text" data-url-enabled="1">Full Text</a><a href="/panels_ajax_tab/article_tab_full_text/node:4231004/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li><li><a href="/content/10.1101/2024.08.23.609377v3.article-info" class="panels-ajax-tab-tab" data-panel-name="biorxiv_tab_info" data-target-id="highwire_article_tabs" data-entity-context="node:4231004" data-trigger="article-info" data-url-enabled="1">Info/History</a><a href="/panels_ajax_tab/biorxiv_tab_info/node:4231004/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li><li><a href="/content/10.1101/2024.08.23.609377v3.article-metrics" class="panels-ajax-tab-tab" data-panel-name="article_tab_metrics" data-target-id="highwire_article_tabs" data-entity-context="node:4231004" data-trigger="article-metrics" data-url-enabled="1">Metrics</a><a href="/panels_ajax_tab/article_tab_metrics/node:4231004/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li><li class="last"><a href="/content/10.1101/2024.08.23.609377v3.full.pdf+html" class="panels-ajax-tab-tab" data-panel-name="biorxiv_tab_pdf" data-target-id="highwire_article_tabs" data-entity-context="node:4231004" data-trigger="full.pdf+html" data-url-enabled="1"><i class="icon-file-alt"></i> Preview PDF</a><a href="/panels_ajax_tab/biorxiv_tab_pdf/node:4231004/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li></ul></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-highwire-panel-tabs-container" > <div class="pane-content"> <div data-panels-ajax-tab-preloaded="biorxiv_tab_art" id="panels-ajax-tab-container-highwire_article_tabs" class="panels-ajax-tab-container"><div class="panels-ajax-tab-loading" style ="display:none"><img class="loading" src="https://www.biorxiv.org/sites/all/modules/contrib/panels_ajax_tab/images/loading.gif" alt="Loading" title="Loading" /></div><div class="panels-ajax-tab-wrap-biorxiv_tab_art"><div class="panel-display panel-1col clearfix" > <div class="panel-panel panel-col"> <div><div class="panel-pane pane-highwire-markup" > <div class="pane-content"> <div class="highwire-markup"><div xmlns="http://www.w3.org/1999/xhtml" data-highwire-cite-ref-tooltip-instance="highwire_reflinks_tooltip" class="content-block-markup" xmlns:xhtml="http://www.w3.org/1999/xhtml"><div class="article abstract-view "><span class="highwire-journal-article-marker-start"></span><div class="section abstract" id="abstract-1"><h2 class="">Abstract</h2><p id="p-2">The transition from milk to solid food requires drastic changes in the morphology of the feeding apparatus and its performance. As durophagous mammals, southern sea otters exhibit significant ontogenetic changes in cranial and mandibular morphology to presumably enable them to feed on a variety of hard-shelled invertebrate prey. Juvenile sea otters begin feeding independently by 6 –8 months of age, but how quickly they reach sufficient maturity in biting performances remains unknown. Here, I found that theoretical bite force of southern sea otters does not reach full maturation until during the adult stage at 3.6 and 5.0 years of age in females and males, respectively. The slow maturation of biting performance can be directly attributed to the slow growth and development of the cranium and the primary jaw adductor muscle (i.e., the temporalis) and may ultimately impact the survival of newly weaned juveniles by limiting their ability to process certain hard-shelled prey. Alterative foraging behaviors such as tool use, however, may mitigate the disadvantages of delayed maturation of biting performance. In analyses of sexual dimorphism, I found that female otters reached bite force maturation earlier whereas male otters exhibit initial rapid growth in bite force to quickly reach sufficient biting performances needed to process prey early in life followed by a slower growth phase towards bite force maturation that coincides with sexual maturity. This biphasic growth in bite force suggests that male to male competition for resources and mates exhibits strong selection in the growth and development of skull form and function in male otters. Overall, this study demonstrates how the analysis of anatomical data can provide insight on the foraging ecologies and life histories of sea otters across ontogeny.</p></div><h3>Competing Interest Statement</h3><p id="p-3">The authors have declared no competing interest.</p><div class="section fn-group" id="fn-group-1"><h2>Footnotes</h2><ul><li class="fn-update fn-group-summary-of-updates" id="fn-1"><p id="p-4">revised manuscript based on comments from reviewers</p></li></ul></div><span class="highwire-journal-article-marker-end"></span></div><span class="related-urls"></span></div></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-biorxiv-copyright" > <div class="pane-content"> <div class="field field-name-field-highwire-copyright field-type-text field-label-inline clearfix"><div class="field-label">Copyright </div><div class="field-items"><div class="field-item even">The copyright holder for this preprint is the author/funder, who has granted bioRxiv 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