Yu-Jia Lin, Hua Hsun Hsu, Zahid Nazeer, Premlal Panickan, Rommel H. Maneja, Diego Lozano-Cortés, Ali Qasem, Antonio Delgado Huertas, Lotfi Jilani Rabaoui
{"title":"Resource use by Sphyrna mokarran and S. lewini (Chondrichthyes) neonates and juveniles in the western Arabian Gulf: a stable isotope analysis","authors":"Yu-Jia Lin, Hua Hsun Hsu, Zahid Nazeer, Premlal Panickan, Rommel H. Maneja, Diego Lozano-Cortés, Ali Qasem, Antonio Delgado Huertas, Lotfi Jilani Rabaoui","doi":"10.3354/esr01341","DOIUrl":null,"url":null,"abstract":"ABSTRACT: The great hammerhead shark <i>Sphyrna mokarran</i> and the scalloped hammerhead shark <i>S. lewini</i> are marine top predators with global distributions. However, limited information is available on the trophic ecology of hammerhead sharks in the Indian Ocean. In this study, we measured stable nitrogen and carbon isotopes in the muscle tissues of neonates and juveniles of <i>S. mokarran</i> and <i>S. lewini</i> from the waters of the western Arabian Gulf. In general, values of δ<sup>15</sup>N were lower in <i>S. mokarran</i> (10.8-18.7‰) than in <i>S. lewini</i> (12.2-18.7‰), indicating a reliance on food sources with low nitrogen values. Isotopic niche similarities were observed between female and male <i>S. mokarran</i>. We further observed considerable ontogenetic changes in the δ<sup>15</sup>N values of both <i>S. mokarran</i> and <i>S. lewini</i> neonates (a reduction from 19 to 12‰), reflecting the maternal effect. The effects of total length and sex on the nitrogen and stable isotope values were nonsignificant in <i>S. mokarran</i> juveniles. The western Arabian Gulf likely serves as a key feeding ground for both the neonates and the juveniles of <i>S. mokarran</i>. By contrast, <i>S. lewini</i> appears to have a low level of reliance on this region.","PeriodicalId":48746,"journal":{"name":"Endangered Species Research","volume":"19 1","pages":""},"PeriodicalIF":2.6000,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Endangered Species Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.3354/esr01341","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIODIVERSITY CONSERVATION","Score":null,"Total":0}
引用次数: 0
Abstract
ABSTRACT: The great hammerhead shark Sphyrna mokarran and the scalloped hammerhead shark S. lewini are marine top predators with global distributions. However, limited information is available on the trophic ecology of hammerhead sharks in the Indian Ocean. In this study, we measured stable nitrogen and carbon isotopes in the muscle tissues of neonates and juveniles of S. mokarran and S. lewini from the waters of the western Arabian Gulf. In general, values of δ15N were lower in S. mokarran (10.8-18.7‰) than in S. lewini (12.2-18.7‰), indicating a reliance on food sources with low nitrogen values. Isotopic niche similarities were observed between female and male S. mokarran. We further observed considerable ontogenetic changes in the δ15N values of both S. mokarran and S. lewini neonates (a reduction from 19 to 12‰), reflecting the maternal effect. The effects of total length and sex on the nitrogen and stable isotope values were nonsignificant in S. mokarran juveniles. The western Arabian Gulf likely serves as a key feeding ground for both the neonates and the juveniles of S. mokarran. By contrast, S. lewini appears to have a low level of reliance on this region.
期刊介绍:
ESR is international and interdisciplinary. It covers all endangered forms of life on Earth, the threats faced by species and their habitats and the necessary steps that must be undertaken to ensure their conservation. ESR publishes high quality contributions reporting research on all species (and habitats) of conservation concern, whether they be classified as Near Threatened or Threatened (Endangered or Vulnerable) by the International Union for the Conservation of Nature and Natural Resources (IUCN) or highlighted as part of national or regional conservation strategies. Submissions on all aspects of conservation science are welcome.