2018 Southeastern Naturalist Notes Vol. 17, No. 1
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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
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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
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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.
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