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Meyer III WM, Hayes KA, Yeung NW, Crane III EJ, Turvey A, LeBlanc C, Cavalcanti ARO. The trail less traveled: Envisioning a new approach to identifying key food resources for threatened Hawaiian arboreal snails. NATURE CONSERVATION 2023. [DOI: 10.3897/natureconservation.51.94952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Our understanding of Hawaiian arboreal snails’ diets remains rudimentary, hindering the development of effective conservation strategies. To identify important food resources, we tested the hypothesis that epiphytic microbial assemblages differ on plant species preferred and avoided by snails at Mt. Kaala Natural Area Reserve, where snail plant preferences are known from previous studies. Comparing microbial assemblages on plants that snails both prefer and avoid was identified as a potentially key step to moving research away from characterizing which microbes snails encounter, towards testing if microbial assemblages are driving snail plant preferences. We found that fungal and bacterial assemblages differed between plant species preferred and avoided by snails, indicating that Hawaiian arboreal snails may be selecting plants based on their epiphytic microbial assemblages. Previous microbes thought to be important, Cladosporium spp., propagated in captive rearing facilities, and Botryosphaeria spp., preferred fungi in a feeding experiment, were both rare and had similar abundances on preferred and avoided plant species in Mt. Kaala. Our approach, conducting preference studies before isolating microbes, is key to identifying arboreal snail food resources and improves our ability to identify microbes that form the foundation of Hawaiian arboreal snails’ diet. If we can identify important food resources, it greatly expands our ability to: (1) assess and monitor habitat quality, (2) make informed restoration recommendations, and (3) improve rearing efforts for highly endangered captive reared populations.
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Strouse E, Price MR, Sischo DR. Dietary effects on fitness in captive-reared Hawaiian tree snails. PeerJ 2021; 9:e11789. [PMID: 34631305 PMCID: PMC8466071 DOI: 10.7717/peerj.11789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 06/25/2021] [Indexed: 11/20/2022] Open
Abstract
The native terrestrial snail fauna of the Hawaiian Islands faces numerous threats that have led to severe range reductions, population declines, and extinction of species. With the continued declines of many wild populations, a crucial component of preserving Hawaiian terrestrial snail biodiversity is through captive rearing programs, like that implemented by the Hawai‘i Department of Land and Natural Resources Snail Extinction Prevention Program. Rare and endangered tree snails in the family Achatinellidae, which feed on epiphytic microbial communities, are maintained in captivity with a diet that includes native vegetation brought in from nearby forests, as well as a cultured fungus originally isolated from native host trees. Recent mortality events in lab populations have been attributed to wild-gathered vegetation. These events have increased interest in developing a completely manufactured or cultured diet that would eliminate the need for exposure to wild-gathered plants. This study compared survival and egg production in Auriculella diaphana provided with lab-cultured fungus, and those provided with wild vegetation. We compared the number of eggs laid and number of deaths among three treatments: (1) wild collected vegetation only; (2) wild vegetation supplemented with laboratory-cultured fungus; and (3) laboratory cultured fungus only. Mortality did not significantly differ among treatments, but the number of eggs laid was significantly higher in snails provided wild vegetation and cultured fungus (F = 24.998; P < 0.001), compared with those provided with only wild vegetation (t = 1.88, P = 0.032) or only cultured fungus (t = 4.530, P = 0.004). Our results suggest: (1) the existing strain of cultured fungus alone is not sufficient to maintain captive-reared snail populations; (2) the additional energy or calcium provided by the cultured fungus appears to enhance egg reproduction in captive-reared populations; (3) the presence or absence of live vegetation influences snail behavior, including aestivation and egg laying. These results highlight the importance of ongoing research to culture additional species of fungi at a rate that could support captive-reared populations, as the diversity of fungi present in wild epiphytic microbial communities may be important for snail reproductive health.
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Affiliation(s)
- Evan Strouse
- Department of Natural Resources and Environmental Management, University of Hawai'i, Honolulu, Hawai'i, United States
| | - Melissa R Price
- Department of Natural Resources and Environmental Management, University of Hawai'i, Honolulu, Hawai'i, United States
| | - David R Sischo
- Department of Land and Natural Resources, Division of Forestry and Wildlife, Honolulu, Hawai'i, United States
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Zemanova MA. Towards more compassionate wildlife research through the 3Rs principles: moving from invasive to non-invasive methods. WILDLIFE BIOLOGY 2020. [DOI: 10.2981/wlb.00607] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Miriam A. Zemanova
- M. A. Zemanova (https://orcid.org/0000-0002-5002-3388) ✉ , Dept of Philosophy, Univ. of Basel, Steinengraben 5, CH-4051 Basel, Switzerland
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Carroll EL, Gallego R, Sewell MA, Zeldis J, Ranjard L, Ross HA, Tooman LK, O'Rorke R, Newcomb RD, Constantine R. Multi-locus DNA metabarcoding of zooplankton communities and scat reveal trophic interactions of a generalist predator. Sci Rep 2019; 9:281. [PMID: 30670720 PMCID: PMC6342929 DOI: 10.1038/s41598-018-36478-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 11/22/2018] [Indexed: 01/26/2023] Open
Abstract
To understand the ecosystem dynamics that underpin the year-round presence of a large generalist consumer, the Bryde's whale (Balaenoptera edeni brydei), we use a DNA metabarcoding approach and systematic zooplankton surveys to investigate seasonal and regional changes in zooplankton communities and if whale diet reflects such changes. Twenty-four zooplankton community samples were collected from three regions throughout the Hauraki Gulf, New Zealand, over two temperature regimes (warm and cool seasons), as well as 20 samples of opportunistically collected Bryde's whale scat. Multi-locus DNA barcode libraries were constructed from 18S and COI gene fragments, representing a trade-off between identification and resolution of metazoan taxa. Zooplankton community OTU occurrence and relative read abundance showed regional and seasonal differences based on permutational analyses of variance in both DNA barcodes, with significant changes in biodiversity indices linked to season in COI only. In contrast, we did not find evidence that Bryde's whale diet shows seasonal or regional trends, but instead indicated clear prey preferences for krill-like crustaceans, copepods, salps and ray-finned fishes independent of prey availability. The year-round presence of Bryde's whales in the Hauraki Gulf is likely associated with the patterns of distribution and abundance of these key prey items.
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Affiliation(s)
- E L Carroll
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.
| | - R Gallego
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - M A Sewell
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - J Zeldis
- National Institute of Water and Atmospheric Research, Christchurch, New Zealand
| | - L Ranjard
- Research School of Biology, the Australian National University, Canberra, ACT, Australia
| | - H A Ross
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - L K Tooman
- The Institute for Plant & Food Research, Auckland, New Zealand
| | - R O'Rorke
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - R D Newcomb
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- The Institute for Plant & Food Research, Auckland, New Zealand
| | - R Constantine
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Institute of Marine Science, University of Auckland, Auckland, New Zealand
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Carroll EL, Bruford MW, DeWoody JA, Leroy G, Strand A, Waits L, Wang J. Genetic and genomic monitoring with minimally invasive sampling methods. Evol Appl 2018; 11:1094-1119. [PMID: 30026800 PMCID: PMC6050181 DOI: 10.1111/eva.12600] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/02/2018] [Indexed: 12/12/2022] Open
Abstract
The decreasing cost and increasing scope and power of emerging genomic technologies are reshaping the field of molecular ecology. However, many modern genomic approaches (e.g., RAD-seq) require large amounts of high-quality template DNA. This poses a problem for an active branch of conservation biology: genetic monitoring using minimally invasive sampling (MIS) methods. Without handling or even observing an animal, MIS methods (e.g., collection of hair, skin, faeces) can provide genetic information on individuals or populations. Such samples typically yield low-quality and/or quantities of DNA, restricting the type of molecular methods that can be used. Despite this limitation, genetic monitoring using MIS is an effective tool for estimating population demographic parameters and monitoring genetic diversity in natural populations. Genetic monitoring is likely to become more important in the future as many natural populations are undergoing anthropogenically driven declines, which are unlikely to abate without intensive adaptive management efforts that often include MIS approaches. Here, we profile the expanding suite of genomic methods and platforms compatible with producing genotypes from MIS, considering factors such as development costs and error rates. We evaluate how powerful new approaches will enhance our ability to investigate questions typically answered using genetic monitoring, such as estimating abundance, genetic structure and relatedness. As the field is in a period of unusually rapid transition, we also highlight the importance of legacy data sets and recommend how to address the challenges of moving between traditional and next-generation genetic monitoring platforms. Finally, we consider how genetic monitoring could move beyond genotypes in the future. For example, assessing microbiomes or epigenetic markers could provide a greater understanding of the relationship between individuals and their environment.
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Affiliation(s)
- Emma L. Carroll
- Scottish Oceans Institute and Sea Mammal Research UnitUniversity of St AndrewsSt AndrewsUK
| | - Mike W. Bruford
- Cardiff School of Biosciences and Sustainable Places Research InstituteCardiff UniversityCardiff, WalesUK
| | - J. Andrew DeWoody
- Department of Forestry and Natural Resources and Department of Biological SciencesPurdue UniversityWest LafayetteINUSA
| | - Gregoire Leroy
- Animal Production and Health DivisionFood and Agriculture Organization of the United NationsRomeItaly
| | - Alan Strand
- Grice Marine LaboratoryDepartment of BiologyCollege of CharlestonCharlestonSCUSA
| | - Lisette Waits
- Department of Fish and Wildlife SciencesUniversity of IdahoMoscowIDUSA
| | - Jinliang Wang
- Institute of ZoologyZoological Society of LondonLondonUK
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O'Rorke R, Tooman L, Gaughen K, Holland BS, Amend AS. Not just browsing: an animal that grazes phyllosphere microbes facilitates community heterogeneity. ISME JOURNAL 2017; 11:1788-1798. [PMID: 28452997 DOI: 10.1038/ismej.2017.52] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 02/18/2017] [Accepted: 03/03/2017] [Indexed: 01/10/2023]
Abstract
Although grazers have long been recognized as top-down architects of plant communities, animal roles in determining microbial community composition have seldom been examined, particularly in aboveground systems. To determine the extent to which an animal can shape microbial communities, we conducted a controlled mesocosm study in situ to see if introducing mycophageous tree snails changed phyllosphere fungal community composition relative to matched control mesocosms. Fungal community composition and change was determined by Illumina sequencing of DNA collected from leaf surfaces before snails were introduced, daily for 3 days and weekly for 6 weeks thereafter. Scanning electron microscopy was used to confirm that grazing had occurred, and we recorded 3.5 times more cover of fungal hyphae in control mesocosms compared with those containing snails. Snails do not appear to vector novel microbes and despite grazing, a significant proportion of the initial leaf phyllosphere persisted in the mesocosms. Within-mesocosm diversities of fungi were similar regardless of whether or not snails were added. The greatest differences between the snail-treated and control mesocosms was that grazed mesocosms showed greater infiltration of microbes that were not sampled when the experiment commenced and that the variance in fungal community composition (beta diversity) was greater between leaves in snail-treated mesocosms indicating increased community heterogeneity and ecosystem fragmentation.
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Affiliation(s)
- Richard O'Rorke
- Department of Botany, University of Hawaii, Honolulu, HI, USA.,Environmental Futures Research Institute, Griffith University, Nathan, Queensland, Australia
| | - Leah Tooman
- Department of Botany, University of Hawaii, Honolulu, HI, USA
| | - Kapono Gaughen
- Department of Botany, University of Hawaii, Honolulu, HI, USA
| | - Brenden S Holland
- Center for Conservation Research and Training, Pacific Biosciences Research Center, University of Hawaii, Honolulu, HI, USA
| | - Anthony S Amend
- Department of Botany, University of Hawaii, Honolulu, HI, USA
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