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First Record of Selenops submaculosus Bryant (Araneae, Selenopidae; a flattie spider) from Louisiana
Sarah C. Crews, Aimée K. Thomas, Shannon Hester

Southeastern Naturalist, Volume 17, Issue 1 (2018): N10–N14

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2018 Southeastern Naturalist Notes Vol. 17, No. 1 N10 S.C. Crews, A.K. Thomas, S. Hester First Record of Selenops submaculosus Bryant (Araneae, Selenopidae; a flattie spider) from Louisiana Sarah C. Crews1,*, Aimée K. Thomas2, Shannon Hester2 Abstract - Selenops submaculosus, a species of flattie spider distributed in the Bahamas, Cuba, and Florida, was collected in New Orleans, LA. Selenopids are large, but they often go undetected due to their speed and secretive lifestyles. Thus, although not previously found in the area, it is possible selenopids naturally occur in the region. However, because some selenopids can travel long distances on ocean flotsam and other items transported by humans, we compared molecular data from this specimen with sequences of other specimens and closely related species from throughout its range. Results indicate that the specimen represents a distinct population. Future efforts will be aimed at locating more specimens from Louisiana and the area between Louisiana and the northernmost record of the family in Florida. In July 2017, A.K. Thomas collected an adult female Selenops submaculosus Bryant, a species of flattie spider, in the Marlyville/Broadmoor neighborhood in New Orleans, LA, from an urban backyard environment with a mixture of native and non-native plant species. Published records (Crews 2011) indicate that the species has been collected as far north as Fort Myers, on the Gulf Coast of Florida. After examining records on citizen-science websites, the northernmost records on the Gulf Coast of Florida were found to be Rotonda West (bugguide.net) and Palmetto (inaturalist.org) (Fig. 1). Although this last locality extends the distribution by more than 100 km, New Orleans is more than 700 km from Palmetto. There is a published record of closely related S. aissus Walckenaer from Montgomery, AL, collected in the winter of 1946 (Muma 1953), but after examining this specimen from the American Museum of Natural History (New York, NY), we have identified it as Philodromus barrowsi Gertsch. Selenops submaculosus was first described by Bryant in 1940 and was known to occur in Cuba. Muma’s revision of the genus (1953) expanded the distribution to include the Bimini Islands in the Bahamas. Muma also mentioned this species’ close relationship with S. simius Muma, S. vinalesi Muma, and S. alemani Muma, the former only found in the Biminis and the latter 2 endemic to Cuba. Alayón-Garcia (2005) mentioned that S. submaculosus is found in Florida and noted the presence of S. simius in Cuba. He also mentioned the difficulty in separating S. simius and S. submaculosus, concluding that the former is smaller and noted some genitalic characters useful for separation. Crews (2011) examined many specimens of both S. simius and S. submaculosus, adding the Cayman Islands to the distribution of the former and several localities in the Bahamas and Florida to the distribution of the latter. After measuring several specimens, she noted that S. simius is not always smaller than S. submaculosus and that specific genitalic characters can be used to separate the species. Despite difficulties of morphological separation, a molecular analysis supported 2 separate species that are sister taxa (Crews and Gillespie 2010). Selenops vinalesi could not be included in this previous analysis. 1California Academy of Sciences, Department of Entomology, 55 Music Concourse Drive, San Francisco, CA 94118. 2Loyola University New Orleans, Department of Biological Sciences, 6363 St. Charles Avenue, New Orleans, LA 70118. *Corresponding author - screws@calacademy.org. Manuscript Editor: Richard Brown Notes of the Southeastern Naturalist, Issue 17/1, 2018 N11 2018 Southeastern Naturalist Notes Vol. 17, No. 1 S.C. Crews, A.K. Thomas, S. Hester Figure 1. Map showing records for Selenops vinalesi, S. simius, and S. submaculosus. White triangles = S. vinalesi, white squares = S. submaculosus, black-filled squares = S. submaculosus records form inaturalist.org and bugguide.net that we could confirm to species (the range overlaps with S. insularis in parts of Florida), and white circles = S. simius. NOLA = New Orleans, LA; FL = Florida; CU = Cuba; CI = Cayman Islands; and BA = Bahamas. The goal of this research was to determine whether the spider found in New Orleans represents an accidental introduction or an undiscovered population. The climate along the coast may be mild enough to harbor selenopids, and although it may seem unlikely that they have not previously been collected from the region, they generally aren’t well-represented in collections due to their speed and habits, despite being quite common (Crews 2011, Muma 1953). However, some species of selenopids are known to travel with humans. Selenops insularis Keyserling, S. candidus Muma, and S. mexicanus Keyserling have been found in Wisconsin, Arizona, and Washington, DC on Musa spp. (bananas) (Muma 1953). Selenops mexicanus also has been found in St. Maarten on palms (unkown species) from Florida that originated in Chiapas, Mexico (Crews 2011). This species was also transported by humans to the Galapagos Islands, where it has become established during the last 500 y (Crews et al. 2016). Therefore, to determine whether the New Orleans specimen represented an introduction or an unknown population, we sequenced 3 genes from this specimen and added the sequences to 2 larger datasets: 1 that includes both S. simius Muma and S. vinalesi Muma, and 1 that includes only S. simius. We used both datasets because unpublished analyses of a larger dataset including >50 species indicate support for ([S. simius + S. vinalesi] + S. submaculosus) as well as support for (S. simius + S. submaculosus) with S. vinalesi elsewhere (see inset in Fig. 2). Figure 2 (following page). Phylogenetic tree showing placement of the New Orleans specimen of Selenops submaculosus among other specimens from throughout the range. Numbers on nodes are bayesian posterior probabilities. Inset trees show relationships and support values with and without the inclusion of S. vinalesi (see text). The intraspecific relationships of S. submaculosus did not change with the exclusion of this species. 2018 Southeastern Naturalist Notes Vol. 17, No. 1 N12 S.C. Crews, A.K. Thomas, S. Hester N13 2018 Southeastern Naturalist Notes Vol. 17, No. 1 S.C. Crews, A.K. Thomas, S. Hester We followed the manufacturer’s protocol to extract DNA with a Qiagen DNEasy kit (Qiagen, Inc., Germantown, MD). We amplified DNA for the histone-3 nuclear gene and partial fragments of the 16S-ND1 and CO1 mitochondrial genes. The DNA was cleaned with Exo-SAP IT, and sequenced on an ABI 3130 in the Center for Comparative Genomics at the California Academy of Sciences, San Francisco, CA. See Crews and Gillespie (2010) for details of the molecular methods. We examined chromatograms and combined forward and reverse sequences with SeqTrace (Stucky 2012). The genes were concatenated using SequenceMatrix (Vaidya et al. 2011) and aligned with the full dataset using the online version of MAFFT, v. 7 (Katoh and Standley 2013, Katoh et al. 2002). We assembled 2 datasets of 2093 base pairs: one with 67 samples consisting only of S. simius and S. submaculosus, and another with 73 samples that aslo included S. vinalesi. We employed PartitionFinder2 (Lanfear et al. 2016) to find the best partitioning scheme and the best models for each partition using the BIC (models available from the authors). We conducted bayesian analyses in MrBayes 3.2 (Ronquist and Huelsenbeck 2003, Ronquist et al. 2012) on the CIPRES Science Gateway (Miller et al. 2010). We ran analyses for 50 million generations using default parameters. We employed Tracer v1.6 (Rambaut et al. 2014) to examine convergence. We combined runs from each analysis and created consensus trees using the default burn-in. Previously published sequences are available on GenBank, and new sequences are currently available from the authors. We deposited the specimen at the California Academy of Sciences (CASENT9078015). Our results indicate that the specimen from New Orleans morphologically and genetically falls within S. submaculosus, but does not belong to other sampled populations of S. submaculosus, including those from Florida (Fig. 2). It remains possible that the specimen represents an unsampled Caribbean population. However, it is more likely that the spider represents a population from Louisiana. We plan to try to locate additional specimens in New Orleans and in the intervening area from New Orleans to Florida’s Gulf Coast. This short communication highlights the utility of citizen-science efforts to document species’ distributions, shows that discoveries remain in areas thought to be well-collected, and that selenopids may go undetected even in areas that are densely pop ulated. Acknowledgments. We thank Scott Tedford (Florida State Parks) and Kraig Krum (Palm Beach County Department of Environmental Resources Management) for providing collecting permits, and Robin Rossmanith and Jeffrey Buck for providing field assistance. We also acknowledge the CarBio project for additional Caribbean specimens. We are grateful to Athena Lam, Boni Cruz, and Michael Pashkevich for assistance with lab work, and to Lauren Esposito and the Environment Program at Loyola University for funding. Literature Cited Alayón-Garcia, G. 2005. La familia Selenopidae (Arachnida: Araneae) en Cuba. Solenodon 5:10–52. Crews, S.C. 2011. A revision of the spider genus Selenops Latreille, 1819 (Arachnida, Araneae, Selenopidae) in North America, Central America and the Caribbean. ZooKeys 105:1–82. DOI:10.3897/zookeys.105.724. Crews, S.C., and R.G. Gillespie. 2010. Molecular systematics of Selenops spiders (Araneae: Selenopidae) from North and Central America: Implications for Caribbean biogeography. Biological Journal of the Linnean Society 101:288–322. DOI:10.1111/j.1095-8312.2010.01494.x. Crews, S.C., L. Baert, and A. Carmichael. 2016. Spider stowaways: Molecular data support the synonymization of Selenops galapagoensis with Selenops mexicanus (Araneae: Selenopidae) and indicate human-mediated introduction to the Galápagos Islands. Pacific Science 70:223–232. DOI:10.2984/70.2.8. Katoh, K., and D.M. Standley. 2013. MAFFT multiple sequence alignment software version 7: Improvements in performance and usability. Molecular Biology and Evolution 30:772–780. DOI:10.1093/molbev/mst010. 2018 Southeastern Naturalist Notes Vol. 17, No. 1 N14 S.C. Crews, A.K. Thomas, S. Hester Katoh, K., K. Misawa, K. Kuma, and T. Miyata. 2002. MAFFT: A novel method for rapid multiplesequence alignment based on fast Fourier transform. Nucleic Acids Research 30:3059–3066. doi:10.1093/nar/gkf436. Lanfear, R., P.B. Frandsen, A.M. Wright, T. Senfeld, and B. Calcott. 2016. PartitionFinder 2: New methods for selecting partitioned models of evolution for molecular and morphological phylogenetic analyses. Molecular Biology and Evolution 34:772–773. D OI:10.1093/molbev/msw260. Miller, M.A., W. Pfeiffer, and T. Schwartz. 2010. Creating the CIPRES Science Gateway for inference of large phylogenetic trees. Proceedings of the Gateway Computing Environments Workshop (GCE). 14 November 2010. New Orleans, LA. Pp. 1–8. Muma, M.H. 1953. A study of the spider family Selenopidae in North America, Central America, and the West Indies. American Museum Novitates 1619:1–55. Rambaut, A., M.A. Suchard, D. Xie, and A.J. Drummond. 2014. Tracer v1.6. Available online at http://beast.bio.ed.ac.uk/Tracer. Accessed August 2017. Ronquist, F., and J.P. Huelsenbeck. 2003. MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 19:1572–1574. DOI:10.1093/bioinformatics/btg180. Ronquist, F., M. Teslenko, P. van der Mark, D.L. Ayres, A. Darling, S. Höhna, B. Larget, L. Liu, M.A. Suchard, and J. P. Huelsenbeck. 2012. MrBayes 3.2: Efficient bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61:539–542. DOI:10:1093/ sysbio/sys029. Stucky, B.J. 2012. SeqTrace: A graphical tool for rapidly processing DNA sequencing chromatograms. Journal of Biomolecular Technology 23:90–93. DOI:10.7171/jbt.12-2303-004. Vaidya, G. D.J. Lohman, and R. Meier. 2011. SequenceMatrix: Concatenation software for the fast assembly of multi-gene datasets with character-set and codon information. Cladistics 27:171–180. DOI:10.1111/j.1096-0031.2010.00329.x.