Biological Bulletin最新文献

{"title":"Variability in Toxicity of Plastic Leachates as a Function of Weathering and Polymer Type: A Screening Study with the Copepod <i>Nitocra spinipes</i>.","authors":"Berit Gewert,&nbsp;Matthew MacLeod,&nbsp;Magnus Breitholtz","doi":"10.1086/714506","DOIUrl":"https://doi.org/10.1086/714506","url":null,"abstract":"<p><p>AbstractThe production and use of plastic over many decades has resulted in its accumulation in the world's oceans. Plastic debris poses a range of potential risks to the marine environment and its biota. Especially, the potential hazards of small plastic debris and chemicals associated with plastic have not been extensively studied. When buoyant plastic is exposed to ultraviolet radiation, it will slowly degrade and leach chemicals into surrounding waters. These leachates can include additives, sorbed organic pollutants, and degradation products of the plastic polymers. While most hazard assessments have focused on studying adverse effects due to the uptake of plastic, toxicity studies of the leachates of plastics are less common. To begin to address this knowledge gap, we studied the acute toxicity of leachates from diverse plastics in the harpacticoid copepod <i>Nitocra spinipes</i>. Our results show that leachates caused a higher toxicity after plastic was exposed to ultraviolet light compared to leaching in darkness. We observed differences in toxicity for different polymer types: polyvinyl chloride and polypropylene resulted in the most toxic leachates, while polystyrene and poly[ethylene terephthalate] were least toxic. Furthermore, we observed increased toxicity of leachates from some plastics that had been weathered in the real marine environment compared to matching new materials. Our results indicate that both weathering condition and polymer type influence the toxicity of plastic leachates.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 3","pages":"191-199"},"PeriodicalIF":1.6,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/714506","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39233243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of a Novel Computer-Aided System to Monitor Cardiac Activity in a Mussel Undergoing Starfish Predation.","authors":"Igor Bakhmet,&nbsp;Dmitry Ekimov","doi":"10.1086/714361","DOIUrl":"https://doi.org/10.1086/714361","url":null,"abstract":"<p><p>AbstractWe explored a modified, computer-aided monitoring system for continuous, long-term recording of Bivalvia cardiac activity. To estimate the capabilities of this system, we used it to monitor the cardiac activity of a mussel (<i>Mytilus edulis</i>) under predation threat from a starfish (<i>Asterias rubens</i>). In addition, we used a web camera to track the behavioral responses of these animals. Compared to its state during normal feeding activity, the mussel's heart rate showed no significant changes when the mussel was near the starfish. However, when the mussel was attacked by the starfish, its heart rate and contraction power (<i>i.e.</i>, amplitude) increased and subsequently decreased down to the absence of any heartbeats within 2.5 hours. The results obtained in this study proved the usefulness of this new system as a stress-monitoring tool.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 3","pages":"200-204"},"PeriodicalIF":1.6,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/714361","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39233242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palatability and Physical and Chemical Defenses in Five Annelid Polychaetes from Tropical Brazilian Beaches.","authors":"Marina Cyrino Leal Coutinho,&nbsp;Valéria Laneuville Teixeira,&nbsp;Cinthya Simone Gomes Santos","doi":"10.1086/714505","DOIUrl":"https://doi.org/10.1086/714505","url":null,"abstract":"<p><p>AbstractAlthough researchers have examined numerous marine organisms' compensatory characteristics to minimize predation pressure, few have investigated the defensive mechanisms of polychaetes, despite their diversity. Thus, our study's aim was to evaluate the palatability and defensive strategies, both chemical and structural, in the polychaetes <i>Branchiomma luctuosum</i>, <i>Perinereis anderssoni</i>, <i>Phragmatopoma caudata</i>, <i>Eurythoe complanata</i>, and <i>Timarete</i> sp. Another twofold aim was to determine, by comparing our results with the literature, any latitudinal difference in the defensive strategies of <i>E. complanata</i> and to assess defensive mechanisms and palatability in relation to individuals' mobility, overtness, body regionalization, and color. Specimens were collected at Boa Viagem and Itaipu Beaches in Niterói, Rio de Janeiro, Brazil. In assays, a generalist consumer, the hermit crab <i>Calcinus tibicen</i>, was used to evaluate palatability and defenses. In palatability assays of live tissue of the polychaetes, consumers were offered a fresh piece of each polychaete to gauge their acceptance or rejection; in artificial food assays to test extracts of the polychaetes, artificial bait containing extracts of the polychaetes was offered to crabs to identify any chemical defense. Although the extracts of <i>B. luctuosum</i>, <i>E. complanata</i>, <i>P. caudata</i> (<i>i.e.</i>, opercular crown), and <i>Timarete</i> sp. were not palatable to the consumers, extracts of <i>P. anderssoni</i> and <i>P. caudata</i> (<i>i.e.</i>, body) were. Moreover, the opercular crown of <i>P. caudata</i> and the branchial crown of <i>B. luctuosum</i> showed evidence of structural and chemical defenses. The results corroborate past findings, suggesting no latitudinal variation in the defensive strategies of <i>E. complanata</i>. In general, less motile and more exposed species, aposematic or dark in color, exhibited greater investment in defensive strategies and unpalatability.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 3","pages":"157-168"},"PeriodicalIF":1.6,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/714505","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39233244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Index to Volume 240","authors":"","doi":"10.1086/715102","DOIUrl":"https://doi.org/10.1086/715102","url":null,"abstract":"","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/715102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48297502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of the Accessory Nidamental Gland and Associated Bacterial Community in the Hawaiian Bobtail Squid, <i>Euprymna scolopes</i>.","authors":"Allison H Kerwin,&nbsp;Sarah J McAnulty,&nbsp;Spencer V Nyholm","doi":"10.1086/713965","DOIUrl":"https://doi.org/10.1086/713965","url":null,"abstract":"<p><p>AbstractThe Hawaiian bobtail squid, <i>Euprymna scolopes</i>, has a female reproductive organ called the accessory nidamental gland that contains a symbiotic bacterial consortium. These bacteria are deposited from the accessory nidamental gland into the squid's egg cases, where the consortium prevents microbial fouling. The symbiont community is environmentally transmitted and conserved across host populations, yet little is known about how the organ develops and is colonized by bacteria. In order to understand accessory nidamental gland development in <i>E. scolopes</i>, we characterized the gland during maturation by using histology and confocal and transmission electron microscopy. We found that an epithelial field formed first about four weeks after hatching, followed by the proliferation of numerous pores during what we hypothesize to be the initiation of bacterial recruitment (early development). Microscopy revealed that these pores were connected to ciliated invaginations that occasionally contained bacteria. During mid development, these epithelial fields expanded, and separate colonized tubules were observed below the epithelial layer that contained the pores and invaginations. During late development, the superficial epithelial fields appeared to regress as animals approached sexual maturity and were never observed in fully mature adults (about 2-3 months post-hatching), suggesting that they help facilitate bacterial colonization of the accessory nidamental gland. An analysis of <i>16S rRNA</i> gene diversity in accessory nidamental glands from females of varying size showed that the bacterial community changed as the host approached sexual maturity, increasing in community evenness and shifting from a Verrucomicrobia-dominated to an Alphaproteobacteria-dominated consortium. Given the host's relationship with the well-characterized light organ symbiont <i>Vibrio fischeri</i>, our work suggests that the accessory nidamental gland of <i>E. scolopes</i> may have similar mechanisms to recruit bacteria from the environment. Understanding the developmental and colonization processes of the accessory nidamental gland will expand the use of <i>E. scolopes</i> as a model organism for studying bacterial consortia in marine symbioses.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 3","pages":"205-218"},"PeriodicalIF":1.6,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/713965","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39233185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinct Phenotypes Associated with Mangrove and Lagoon Habitats in Two Widespread Caribbean Corals, <i>Porites astreoides</i> and <i>Porites divaricata</i>.","authors":"Karina Scavo Lord,&nbsp;Anna Barcala,&nbsp;Hannah E Aichelman,&nbsp;Nicola G Kriefall,&nbsp;Chloe Brown,&nbsp;Lauren Knasin,&nbsp;Riley Secor,&nbsp;Cailey Tone,&nbsp;Laura Tsang,&nbsp;John R Finnerty","doi":"10.1086/714047","DOIUrl":"https://doi.org/10.1086/714047","url":null,"abstract":"<p><p>AbstractAs coral reefs experience dramatic declines in coral cover throughout the tropics, there is an urgent need to understand the role that non-reef habitats, such as mangroves, play in the ecological niche of corals. Mangrove habitats present a challenge to reef-dwelling corals because they can differ dramatically from adjacent reef habitats with respect to key environmental parameters, such as light. Because variation in light within reef habitats is known to drive intraspecific differences in coral phenotype, we hypothesized that coral species that can exploit both reef and mangrove habitats will exhibit predictable differences in phenotypes between habitats. To investigate how intraspecific variation, driven by either local adaptation or phenotypic plasticity, might enable particular coral species to exploit these two qualitatively different habitat types, we compared the phenotypes of two widespread Caribbean corals, <i>Porites divaricata</i> and <i>Porites astreoides</i>, in mangrove <i>versus</i> lagoon habitats on Turneffe Atoll, Belize. We document significant differences in colony size, color, structural complexity, and corallite morphology between habitats. In every instance, the phenotypic differences between mangrove prop root and lagoon corals exhibited consistent trends in both <i>P. divaricata</i> and <i>P. astreoides</i>. We believe this study is the first to document intraspecific phenotypic diversity in corals occupying mangrove prop root <i>versus</i> lagoonal patch reef habitats. A difference in the capacity to adopt an alternative phenotype that is well suited to the mangrove habitat may explain why some reef coral species can exploit mangroves, while others cannot.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 3","pages":"169-190"},"PeriodicalIF":1.6,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/714047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39233240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of Mud Blister Worm Infestation and Shell Repair by Oysters.","authors":"Kelly M Dorgan,&nbsp;Rachel D Moseley,&nbsp;Ellen Titus,&nbsp;Harrison Watson,&nbsp;Sarah M Cole,&nbsp;William Walton","doi":"10.1086/713145","DOIUrl":"https://doi.org/10.1086/713145","url":null,"abstract":"<p><p>AbstractMud blister worms bore into oyster shells; and oysters respond to shell penetration by secreting new layers of shell, resulting in mud blisters on inner surfaces of oyster shells. We conducted two experiments in off-bottom oyster farms along Alabama's coast in summer 2017 to explore the dynamics of worm infestation, blister formation, and shell repair. Results support our hypothesis that only a small proportion of worms that bore into oysters cause blisters. Triploid oysters had fewer blisters than diploids, likely because of faster growth and shell repair. We treated oysters to remove mud blister worms, redeployed them at intertidal and subtidal sites for nine weeks, and found that reinfestation by worms occurred only in subtidal oysters. Intertidally deployed oysters showed no visible blister coverage, indicating recovery, whereas blister coverage increased in subtidal oysters. Reinfestation of subtidal oysters was correlated with previous burrow damage, visualized with X-ray images, thus supporting our hypothesis that worms preferentially settle in previously infested shells. Forces required to break blisters, measured with a custom-built shucking knife with an integrated force sensor, were low relative to forces required to shuck oysters, possibly because our experiment was conducted when worm infestation was increasing. Higher forces were required to break smaller, lighter-colored blisters, consistent with blister recovery; but results were highly variable and not consistent across sites and sampling times, suggesting that size and color of blisters alone did not explain shell strength. Our results indicate that oysters repair shells slowly relative to more dynamic patterns of worm infestation.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 2","pages":"118-131"},"PeriodicalIF":1.6,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/713145","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38943515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare-Earth Magnets Influence Movement Patterns of the Magnetically Sensitive Nudibranch <i>Tritonia exsulans</i> in Its Natural Habitat.","authors":"Russell C Wyeth,&nbsp;Theora Holden,&nbsp;Hamed Jalala,&nbsp;James A Murray","doi":"10.1086/713663","DOIUrl":"https://doi.org/10.1086/713663","url":null,"abstract":"<p><p>AbstractThe nudibranch <i>Tritonia exsulans</i> (previously <i>Tritonia diomedea</i>) is known to have behaviors and neurons that can be modified by perturbations of the Earth's magnetic field. There is no definitive evidence for how this magnetic sense is used in nature. Using an exploratory approach, we tested for possible effects of magnetic perturbations based on underwater video of crawling patterns in the slugs' natural habitat, with magnets of varying strength deployed on the substrate. For analysis, we used a paired comparison of tracks of animals between segments 25-50 cm distant from the magnets and segments of the same tracks 0-25 cm from the magnets, to determine whether any differences depended on the strength of the magnet. Most track measurements (length, displacement, velocity, and tortuosity) showed no such differences. However, effects were observed for the changes in track headings between successive points. These results showed that tracks had relatively higher heading variability when they moved closer to stronger magnets. We suggest that this supports a hypothesis that <i>T. exsulans</i> continuously uses a magnetic sense to help maintain straight-line navigation. Further specific testing of the hypothesis is now needed to verify this new possibility for how animals can benefit from a compass sense.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 2","pages":"105-117"},"PeriodicalIF":1.6,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/713663","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38952931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Maternal Size on Offspring Traits in a Marine Gastropod with Direct Development and without Sibling Interaction.","authors":"María Soledad Avaca,&nbsp;Lorena Storero,&nbsp;Pablo Martín,&nbsp;Maite Narvarte","doi":"10.1086/713065","DOIUrl":"https://doi.org/10.1086/713065","url":null,"abstract":"<p><p>AbstractIn most animal taxa, large mothers (or those with high nutritional status) produce large offspring, leading to a maternal size-offspring size correlation, that is, a positive correlation between maternal size and offspring size. Here, we used the natural variation in maternal size between three natural populations of <i>Buccinanops deformis</i> (a marine snail with direct development, nurse egg feeding, and a single embryo per egg capsule) to study maternal investment and offspring size. The main objectives were to compare offspring size and maternal investment traits within and between populations and to evaluate the relationship between maternal size and offspring size. Although not supported in every population, our results show that maternal size was positively correlated with offspring size, thus representing an example of the maternal size-offspring size correlation in a species in which there is no competition for food between capsule mates because only one embryo develops per capsule. These findings also suggest that in <i>B. deformis</i> larger mothers produce more offspring and provide their offspring with more resources, and that this between-population variation in offspring size is related to differences in the number of nurse eggs allocated per egg capsule and in egg capsule size. The ubiquity of the maternal size-offspring size correlation in <i>B. deformis</i> needs to be tested further across populations, because factors other than maternal size could influence offspring size variation in this marine gastropod.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 2","pages":"95-104"},"PeriodicalIF":1.6,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/713065","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38943517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation and Function of the Primary Tube During Settlement and Metamorphosis of the Marine Polychaete <i>Hydroides elegans</i> (Haswell, 1883) (Serpulidae).","authors":"Megan J Huggett,&nbsp;Eugenio J Carpizo-Ituarte,&nbsp;Brian T Nedved,&nbsp;Michael G Hadfield","doi":"10.1086/713623","DOIUrl":"https://doi.org/10.1086/713623","url":null,"abstract":"<p><p>AbstractThe serpulid polychaete <i>Hydroides elegans</i> has emerged as a major model organism for studies of marine invertebrate settlement and metamorphosis and for processes involved in marine biofouling. Rapid secretion of an enveloping, membranous, organic primary tube provides settling larvae of <i>H. elegans</i> firm adhesion to a surface and a refuge within which to complete metamorphosis. While this tube is never calcified, it forms the template from which the calcified tube is produced at its anterior end. Examination of scanning and transmission electron micrographs of competent and settling larvae revealed that the tube is secreted from epidermal cells of the three primary segments, with material possibly transported through the larval cuticle <i>via</i> abundant microvilli. The tube is composed of complexly layered fibrous material that has an abundance of the amino acids that characterize the collagenous cuticle of other polychaetes, plus associated carbohydrates. The significance of the dependence on surface bacterial biofilms for stimulating settlement in this species is revealed as a complex interaction between primary tube material, as it is secreted, and the extracellular polymeric substances abundantly produced by biofilm-residing bacteria. This association appears to provide the settling larvae with an adhesion strength similar to that of bacteria in a biofilm and significantly less when larvae settle on a clean surface.</p>","PeriodicalId":55376,"journal":{"name":"Biological Bulletin","volume":"240 2","pages":"82-94"},"PeriodicalIF":1.6,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/713623","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38943519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}