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Phylogenomic studies can provide insights into speciation, adaptation, and extinction, while providing a roadmap for conservation. Hawaiian tree snails are a model system for an adaptive radiation facing an extinction crisis. In the last 5 years, nearly all populations of Hawaiian tree snails across the 30 remaining species in the subfamily Achatinellinae (Achatinellidae) have declined from hundreds or thousands in the wild down to undetectable levels. Nearly 100 species historically occurred across dramatic environmental gradients on five of the Hawaiian Islands, but habitat loss, overcollection, and predation by invasive species have decimated populations. As such, this system offers the opportunity to integrate efforts to conserve evolutionary potential into conservation planning for a rapidly declining subfamily. Here, we used genome-wide, restriction-site associated DNA sequencing (RADseq), along with mitochondrial genome reconstruction, to resolve evolutionary relationships to inform conservation efforts. Phylogenetic analysis of nearly 400k genome-wide SNPs from 59 populations and 25 species across six genera in the family Achatinellidae, was generally concordant with taxonomy, geography, and mtDNA with several notable exceptions; mtDNA was unable to resolve some deeper nodes (e.g., the monophyly of Achatinella), while SNP data did not resolve as many shallow nodes. Both phylogenetic and coalescent analysis revealed deep divergences between populations within Achatinella mustelina that were consistent with species-level differences. Given cryptic species-level divergence within populations that are geographically proximate, they are at higher risk of extirpation from invasive predators and climate change than previously assumed. This study clarifies evolutionary relationships within this model system for adaptive radiation, forming the basis for conservation strategies such as translocation, captive rearing, and hybridization trials to prevent the loss of capacity to adapt to rapidly changing environmental conditions. [ABSTRACT FROM AUTHOR]

Species within the scleractinian genus Pocillopora Lamarck 1816 exhibit extreme phenotypic plasticity, making identification based on morphology difficult. However, the mitochondrial open reading frame (mtORF) marker provides a useful genetic tool for identification of most species in this genus, with a notable exception of P. eydouxi and P. meandrina. Based on recent genomic work, we present a quick and simple, gel-based restriction fragment length polymorphism (RFLP) method for the identification of all six Pocillopora species occurring in Hawai'i by amplifying either the mtORF region, a newly discovered histone region, or both, and then using the restriction enzymes targeting diagnostic sequences we unambiguously identify each species. Using this approach, we documented frequent misidentification of Pocillopora species based on colony morphology. We found that P. acuta colonies are frequently mistakenly identified as P. damicornis in Kāne'ohe Bay, Oāhu. We also found that P. meandrina likely has a northern range limit in the Northwest Hawaiian Islands, above which P. ligulata was regularly mistaken for P. meandrina. [ABSTRACT FROM AUTHOR]

Aim To infer species identity, population isolation, and geographical variation in inter-specific hybridization among corals of the genus Porites from the central and eastern tropical Pacific, with a focus on the timing of separation between populations of P. evermanni and P. lobata divided by the Eastern Pacific Barrier. Location Hawaii, American Samoa, Panama and the Galapagos Islands of Ecuador. Methods Maximum likelihood gene trees were obtained for mitochondrial DNA ( COI), the internal transcribed spacer ( ITS), and 5 single-copy nuclear (scn) gene regions. Allelic networks were used to group multi-locus scn data into species clusters despite some allele sharing. Coalescent analyses ( IMa2) of the 5 scn markers were used to estimate the time of population divergence and test for introgression between P. evermanni and P. lobata. Results Allelic networks based on scn gene sequences agreed with mt COI and ITS designations. Divergence times between Hawaiian and eastern Pacific populations are consistent with an early Pleistocene recolonization of the eastern Pacific by P. evermanni followed by a more recent arrival of P. lobata. The two species were fully isolated in Hawaii/American Samoa populations, but introgression from P. evermanni into P. lobata was evident in the eastern Pacific. Main conclusions These results are consistent with a scenario where a bout of introgression with P. evermanni, an early-arriving colonizer of the eastern Pacific suited to marginal environmental conditions, facilitated the later colonization of the more sensitive P. lobata. [ABSTRACT FROM AUTHOR]

In this study, we report the complete mitochondrial genome sequence ofAchatinella sowerbyana, an endangered Hawaiian tree snail. The mitogenome is 15,374 bp in length and has a base composition of A (36.4%), T (42.7%), C (9.1%), and G (11.8%). Similar to other pulmonates, it contains 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. The gene order is the same as its sister species,A. mustelina. To our knowledge, this is the second mitochondrial genome sequenced within the superfamily Achatinelloidea, and will aid in the examination of the genusAchatinella, part of a spectacular radiation in the Hawaiian Islands. [ABSTRACT FROM PUBLISHER]

The mitochondrial genome of the coralPorites lobatawas sequenced using ezRAD. The assembled genome consists of 18,647 bp, including 13 protein-coding genes, two ribosomal RNA genes and two transfer RNA genes. The gene arrangement was consistent with other scleractinian coral mitochondrial genomes. The sequence was strikingly similar toPorites okinawensis, indicating the necessity for further systematic work to resolve phylogenetic relationships in the genusPorites. [ABSTRACT FROM PUBLISHER]

In this study, we report the complete mitochondrial genome sequence ofAchatinella mustelina, an endangered Hawaiian tree snail. The mitogenome is 16 323 bp in length and has a base composition of A (34.7%), T (42.6%), C (12.7%) and G (10.0%). Similar to other Pulmonates, it contains 13 protein-coding genes, 2 rRNA genes and 22 tRNA genes. To our knowledge, this is the first mitochondrial genome sequenced within the Achatinelloidea superfamily, which contains a high number of endangered species. As such, this mitogenome will be useful in conservation genetics studies. [ABSTRACT FROM PUBLISHER]

We compare the complete mitochondrial genomes of Achatinella fulgens, A. mustelina, A. sowerbyana, Partulina redfieldi, and Perdicella helena, five species of Hawaiian tree snails across three genera. Mitogenomes ranged in length from 15,187 to 16,793 base pairs, with a base composition of A (36.4-37.4%); T (42.2-42.7%); C (8.8-9.2%); and G (11.3-11.8%). Similar with other pulmonates, these mitogenomes contain 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes, with the order conserved among genera. Our study suggests polyphyly in the current arrangement of the subfamily Achatinellinae, part of a spectacular radiation in the Hawaiian Islands. [ABSTRACT FROM AUTHOR]

In this study, we sequenced the complete mitochondrial genome of Porites harrisoni using ezRAD and Illumina technology. Genome length consisted of 18,630 bp, with a base composition of 25.92% A, 13.28% T, 23.06% G, and 37.73% C. Consistent with other hard corals, P. harrisoni mitogenome was arranged in 13 protein-coding genes, 2 rRNA, and 2 tRNA genes. nad5 and cox1 contained embedded Group I Introns of 11,133 bp and 965 bp, respectively. [ABSTRACT FROM AUTHOR]

Corals in the genus Porites are among the major framework builders of reef structures worldwide, yet the genus has been challenging to study due to a lack of informative molecular markers. Here, we used ezRAD sequencing to reconstruct the complete mitochondrial genome of Porites fontanesii (GenBank accession number MG754069), a widespread coral species endemic to the Red Sea and Gulf of Aden. The gene arrangement of P. fontanesii did not differ from other Scleractinia and consisted of 18,658 bp, organized in 13 protein-coding genes, 2 rRNA genes, and 2 tRNA genes. This mitochondrial genome contributes essential data to work towards a better understanding of evolutionary relationships within Porites. [ABSTRACT FROM AUTHOR]