Kourtney Barber, Michael Middlebrooks, Susan Bell, Sidney Pierce
{"title":"The Specialist Marine Herbivore <i>Elysia papillosa</i> Grows Faster on a Less Utilized Algal Diet.","authors":"Kourtney Barber, Michael Middlebrooks, Susan Bell, Sidney Pierce","doi":"10.1086/716508","DOIUrl":null,"url":null,"abstract":"<p><p>AbstractMany small specialist herbivores utilize their food resources both for nutrition and as a structural refuge or resource. Trophic linkage cannot solely be inferred from physical association of herbivores with a potential food item, because herbivores may temporarily inhabit algae or plants on which they do not feed. <i>Elysia papillosa</i>, a small sacoglossan sea slug, consumes and sequesters chloroplasts from the siphonaceous, chlorophytic alga <i>Penicillus capitatus</i>; it also maintains moderate densities on this alga. Recently, <i>E. papillosa</i> was also infrequently found in association with the alga <i>Penicillus lamourouxii</i>, which displays density similar to that of <i>P. capitatus</i>. After collecting <i>E. papillosa</i> from each of the two algal species from a shallow-water site along the west central coast of Florida, we used DNA barcoding of the <i>rbcL</i> gene sequences in order to determine whether the slug was consuming both algal species. The molecular data indicated that <i>E. papillosa</i> consumed and sequestered chloroplasts from the same algal species from which they were collected. A laboratory feeding experiment tested whether algal diet (<i>P. capitatus</i> or <i>P. lamourouxii</i>) had an impact on slug growth rate as measured by change in body size (mm). After 3 weeks <i>E. papillosa</i> fed <i>P. lamourouxii</i> achieved a mean body length that was 1.5-2 times that recorded for slugs fed <i>P. capitatus</i>, but maximum growth depended on the original field host. Thus, while the highest densities of <i>E. papillosa</i> in the field occurred on <i>P. capitatus</i>, slugs grew much faster on <i>P. lamourouxii</i> in the laboratory. The observed association of <i>E. papillosa</i> with <i>P. capitatus</i> must be related to other factors, such as foraging efficiency, algal morphology, algal biochemistry, or algal suitability as a refuge.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biological Bulletin","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1086/716508","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/9/22 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"BIOLOGY","Score":null,"Total":0}
引用次数: 2
Abstract
AbstractMany small specialist herbivores utilize their food resources both for nutrition and as a structural refuge or resource. Trophic linkage cannot solely be inferred from physical association of herbivores with a potential food item, because herbivores may temporarily inhabit algae or plants on which they do not feed. Elysia papillosa, a small sacoglossan sea slug, consumes and sequesters chloroplasts from the siphonaceous, chlorophytic alga Penicillus capitatus; it also maintains moderate densities on this alga. Recently, E. papillosa was also infrequently found in association with the alga Penicillus lamourouxii, which displays density similar to that of P. capitatus. After collecting E. papillosa from each of the two algal species from a shallow-water site along the west central coast of Florida, we used DNA barcoding of the rbcL gene sequences in order to determine whether the slug was consuming both algal species. The molecular data indicated that E. papillosa consumed and sequestered chloroplasts from the same algal species from which they were collected. A laboratory feeding experiment tested whether algal diet (P. capitatus or P. lamourouxii) had an impact on slug growth rate as measured by change in body size (mm). After 3 weeks E. papillosa fed P. lamourouxii achieved a mean body length that was 1.5-2 times that recorded for slugs fed P. capitatus, but maximum growth depended on the original field host. Thus, while the highest densities of E. papillosa in the field occurred on P. capitatus, slugs grew much faster on P. lamourouxii in the laboratory. The observed association of E. papillosa with P. capitatus must be related to other factors, such as foraging efficiency, algal morphology, algal biochemistry, or algal suitability as a refuge.
期刊介绍:
The Biological Bulletin disseminates novel scientific results in broadly related fields of biology in keeping with more than 100 years of a tradition of excellence. The Bulletin publishes outstanding original research with an overarching goal of explaining how organisms develop, function, and evolve in their natural environments. To that end, the journal publishes papers in the fields of Neurobiology and Behavior, Physiology and Biomechanics, Ecology and Evolution, Development and Reproduction, Cell Biology, Symbiosis and Systematics. The Bulletin emphasizes basic research on marine model systems but includes articles of an interdisciplinary nature when appropriate.