Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classification
The Trinity bristle snail (Monadenia setosa) is listed as a threatened species under the California Endangered Species Act (CESA). In northern California, populations of this endemic terrestrial gastropod occur in rare, isolated, and highly fragmented locations within the greater Trinity Basin. Sinc...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
California Department of Fish and Wildlife
2021-07-01
|
| Series: | California Fish and Wildlife Journal |
| Subjects: |
| _version_ | 1818729508015964160 |
|---|---|
| author | Robert M. Sullivan |
| author_facet | Robert M. Sullivan |
| author_sort | Robert M. Sullivan |
| collection | DOAJ |
| description | The Trinity bristle snail (Monadenia setosa) is listed as a threatened species under the California Endangered Species Act (CESA). In northern California, populations of this endemic terrestrial gastropod occur in rare, isolated, and highly fragmented locations within the greater Trinity Basin. Since 1952 when it was originally described, the taxonomic status of the Trinity bristle snail has been questioned based on unpublished information limited in geographic scope and sample size, which resulted in the taxon being reduced from species status (M. setosa) to subspecific status (M. i. setosa) within the Redwood sideband (M. infumata) species complex. Primary objectives of the present study were to: 1) use DNA extraction and PCR sequencing to gain insight into patterns of genetic variation and phylogenetic relationships among a larger sample of endemic populations of the Trinity bristle snail; 2) re-evaluate the systematic and taxonomic status of the species using outgroup analysis and references samples from sympatric ecologically co-occurring taxa within the genus Monadenia; and 3) evaluate the potential biogeographic effects of major riverine systems on genetic differentiation among relic and disjunct populations within the Trinity Basin. Results of the DNA sequence analysis using several different tree re-construction methods revealed that subspecies of the Redwood sideband (M. i. subcarinata), Yellow-based sideband (M. i. ochromphalus), and the Trinity bristle (M. i. setosa) exhibited a phylogenetic signal at > 95% species probability. Except for the Yellow-based sideband, molecular evidence detected the presence of several morphologically cryptic subclades within each species clade formerly undescribed by the scientific community. Syntopic ecological relationships between subclades of the Trinity bristle snail and the Redwood sideband occurred in several areas within the geographic range of the Trinity bristle snail, which indicated that these subclades were conservatively differentiated at the subspecific level. A Bayesian coalescent tree showed that genetic variation among allopatric subclades of the Trinity bristle snail and the Redwood sideband were congruent with hydrological discontinuities associated with site-specific riparian stream corridors and the primary river systems within the Trinity Basin. Correlation analysis revealed a pattern of area effects, wherein sparsely bristled Trinity bristle snails were generally found to the northwest and more abundantly bristled individuals to the southeast in relation to primary river corridors that bisect the central Trinity Basin. A similar but opposite trend was observed in the directional pattern of banding. Here the most conspicuously banded individuals were found in samples distributed to the northwest while individuals with less conspicuous banding patterns occurred in a more southeasterly direction in relation to primary riverine corridors. These geographic patterns of bristles and bands appeared to reflect shallow clines that were evident in samples of both the Trinity bristle snail and the Redwood sideband. Parsimony character state reconstructions revealed that the presence of bristles and conspicuousness of bands was widespread among genetic samples, but these attributes did not provide a definitive morphological character that could be used to distinguish among co-occurring taxa. |
| first_indexed | 2024-12-17T22:47:00Z |
| format | Article |
| id | doaj.art-c6b7549f4f854ed1b332579f2d0652c7 |
| institution | Directory Open Access Journal |
| issn | 2689-419X 2689-4203 |
| language | English |
| last_indexed | 2024-12-17T22:47:00Z |
| publishDate | 2021-07-01 |
| publisher | California Department of Fish and Wildlife |
| record_format | Article |
| series | California Fish and Wildlife Journal |
| spelling | doaj.art-c6b7549f4f854ed1b332579f2d0652c72022-12-21T21:29:46ZengCalifornia Department of Fish and WildlifeCalifornia Fish and Wildlife Journal2689-419X2689-42032021-07-01107CESA Special Issue10714510.51492/cfwj.cesasi.6Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classificationRobert M. Sullivan0California Department of Fish and WildlifeThe Trinity bristle snail (Monadenia setosa) is listed as a threatened species under the California Endangered Species Act (CESA). In northern California, populations of this endemic terrestrial gastropod occur in rare, isolated, and highly fragmented locations within the greater Trinity Basin. Since 1952 when it was originally described, the taxonomic status of the Trinity bristle snail has been questioned based on unpublished information limited in geographic scope and sample size, which resulted in the taxon being reduced from species status (M. setosa) to subspecific status (M. i. setosa) within the Redwood sideband (M. infumata) species complex. Primary objectives of the present study were to: 1) use DNA extraction and PCR sequencing to gain insight into patterns of genetic variation and phylogenetic relationships among a larger sample of endemic populations of the Trinity bristle snail; 2) re-evaluate the systematic and taxonomic status of the species using outgroup analysis and references samples from sympatric ecologically co-occurring taxa within the genus Monadenia; and 3) evaluate the potential biogeographic effects of major riverine systems on genetic differentiation among relic and disjunct populations within the Trinity Basin. Results of the DNA sequence analysis using several different tree re-construction methods revealed that subspecies of the Redwood sideband (M. i. subcarinata), Yellow-based sideband (M. i. ochromphalus), and the Trinity bristle (M. i. setosa) exhibited a phylogenetic signal at > 95% species probability. Except for the Yellow-based sideband, molecular evidence detected the presence of several morphologically cryptic subclades within each species clade formerly undescribed by the scientific community. Syntopic ecological relationships between subclades of the Trinity bristle snail and the Redwood sideband occurred in several areas within the geographic range of the Trinity bristle snail, which indicated that these subclades were conservatively differentiated at the subspecific level. A Bayesian coalescent tree showed that genetic variation among allopatric subclades of the Trinity bristle snail and the Redwood sideband were congruent with hydrological discontinuities associated with site-specific riparian stream corridors and the primary river systems within the Trinity Basin. Correlation analysis revealed a pattern of area effects, wherein sparsely bristled Trinity bristle snails were generally found to the northwest and more abundantly bristled individuals to the southeast in relation to primary river corridors that bisect the central Trinity Basin. A similar but opposite trend was observed in the directional pattern of banding. Here the most conspicuously banded individuals were found in samples distributed to the northwest while individuals with less conspicuous banding patterns occurred in a more southeasterly direction in relation to primary riverine corridors. These geographic patterns of bristles and bands appeared to reflect shallow clines that were evident in samples of both the Trinity bristle snail and the Redwood sideband. Parsimony character state reconstructions revealed that the presence of bristles and conspicuousness of bands was widespread among genetic samples, but these attributes did not provide a definitive morphological character that could be used to distinguish among co-occurring taxa.biogeographydna sequence analysismonadenia setosanorthern californiaphylogeneticsriver systemstaxonomyterrestrial gastropodtrinity bristle snail |
| spellingShingle | Robert M. Sullivan Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classification California Fish and Wildlife Journal biogeography dna sequence analysis monadenia setosa northern california phylogenetics river systems taxonomy terrestrial gastropod trinity bristle snail |
| title | Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classification |
| title_full | Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classification |
| title_fullStr | Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classification |
| title_full_unstemmed | Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classification |
| title_short | Phylogenetic relationships among subclades within the Trinity bristle snail species complex, riverine barriers, and re-classification |
| title_sort | phylogenetic relationships among subclades within the trinity bristle snail species complex riverine barriers and re classification |
| topic | biogeography dna sequence analysis monadenia setosa northern california phylogenetics river systems taxonomy terrestrial gastropod trinity bristle snail |
| work_keys_str_mv | AT robertmsullivan phylogeneticrelationshipsamongsubcladeswithinthetrinitybristlesnailspeciescomplexriverinebarriersandreclassification |