Abstract Microbial diversity and community function are related, and can be highly specialized in different gut regions. The cloacal microbiome ofSceloporus virgatusfemales provides antifungal protection to eggshells, a specialized function that suggests a specialized microbiome. Here, we describe the cloacal, intestinal, and oviductal microbiome fromS.virgatusgravid females, adding to growing evidence of microbiome localization in reptiles and other taxa. We further assessed whether common methods for sampling gastrointestinal (GI) microbes – cloacal swabs and faeces – provide accurate representations of these microbial communities. We found that different regions of the gut had unique microbial communities. The cloacal microbiome showed extreme specialization averaging 99% Proteobacteria (Phylum) and 83%Enterobacteriacaea(Family).Enterobacteriacaeadecreased up the GI and reproductive tracts. Cloacal swabs recovered communities similar to that of lower intestine and cloacal tissues. In contrast, faecal samples had much higher diversity and a distinct composition (common Phyla: 62% Firmicutes, 18% Bacteroidetes, 10% Proteobacteria; common families: 39%Lachnospiraceae, 11%Ruminococcaceae, 11%Bacteroidaceae) relative to all gut regions. The common families in faecal samples made up <1% of cloacal tissue samples, increasing to 43% at the upper intestine. Similarly, the common families in gut tissue (EnterobacteriaceaeandHelicobacteraceae) made up <1% of the faecal microbiome. Further, we found that cloacal swabs taken shortly after defaecation may be contaminated with faecal matter. Our results serve as a caution against using faeces as a proxy for GI microbes, and may help explain high between‐sample variation seen in some studies using cloacal swabs.
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Fecal and cloacal microbiomes of cold-stunned loggerhead Caretta caretta, Kemp’s ridley Lepidochelys kempii, and green sea turtles Chelonia mydas
Investigating animal gut microbiomes can lead to a better understanding of their foraging preferences and their overall health. In this study, the fecal and cloacal microbiomes of 4 cold-stunned, frozen loggerhead Caretta caretta, 9 Kemp’s ridley Lepidochelys kempi , and 5 green sea turtles Chelonia mydas that stranded on beaches in Massachusetts, USA, were surveyed. Cloacal swabs and in situ fecal samples were collected from each turtle. From the extracted DNA, the hypervariable V1-V3 regions of the 16S rRNA gene were amplified with PCR, then sequenced using next generation Illumina MiSeq technology. Fecal and cloacal microbiomes were primarily composed of the phyla Proteobacteria , Bacteroidetes , and Firmicutes . Microbial communities varied significantly based on location of the gut sampled. Cloacal samples were largely dominated by Proteobacteria , while fecal samples appeared to have a greater distribution of taxa and higher alpha diversity. Green turtles had a higher abundance of Firmicutes and Bacteroidetes than Kemp’s ridley and loggerhead turtles, but a lower abundance of Proteobacteria . The information gained from this study contributes to knowledge of cold-stunned sea turtle gut microbiomes and may eventually be applied to rehabilitation efforts.
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- Award ID(s):
- 1655221
- PAR ID:
- 10437652
- Date Published:
- Journal Name:
- Endangered Species Research
- Volume:
- 50
- ISSN:
- 1863-5407
- Page Range / eLocation ID:
- 93 to 105
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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