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Globally, potentially hundreds of Nylanderia species remain undescribed, hidden within several broadly distributed complexes of morphologically cryptic species. By integrating phylogenomics, geography, and morphology, we describe eight new Nylanderia species from southern Mexico and Mesoamerica, increasing the total number of known species in the genus to 131. In the Americas, Nylanderia is divided into two distantly related clades: American Clade I (AC1) and American Clade II (AC2). Within AC1, Nylanderia austroccidua (Trager) was originally described as a widespread and morphologically variable species distributed from Utah to Costa Rica. This species was diagnosed by a slight concavity in the anterior face of the pronotum and varying degrees of fine cuticular microsculpturing across the body that causes blue cuticular iridescence under microscopic examination. Using Ultraconserved Elements (UCEs) for molecular phylogenetic analysis, we found that taxa matching the original description of N. austroccidua are paraphyletic with respect to Nearctic Nylanderia species. We also found that AC1 includes a Neotropical subclade extending into Mesoamerica, the distribution of which overlaps with AC2, which is exclusively Neotropical. Along with an updated description of N. austroccidua, we also describe the following new species belonging to clade AC1: N. breviscapa, sp. nov., N. contraria, sp. nov., N. lazulina, sp. nov., N. luceata, sp. nov., N. mendax sp. nov., N. mosaica sp. nov., N. polita sp. nov., and N. usul, sp. nov. A dichotomous key and images of the worker caste of these species are included and, where available, images of queens and males are provided.
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Phenotypic variation across the range of the lined shore crab Pachygrapsus crassipes Randall, 1840 (Decapoda, Grapsidae)
Abstract Two isolated clades of the lined shore crab, Pachygrapsus crassipes , live on opposite sides of the northern Pacific, presenting an interesting opportunity for studies of range limits and divergence. Prior to this study, P. crassipes ’ Asian range was unclear; we confirmed that it is found throughout the main Japanese Archipelago, though sporadic or absent from the Ryukyu Archipelago. We examined phenotypic variation of this species’ chelae, which are conspicuously colored and larger in males, and found positive allometry for both sexes, which was stronger in males, a common feature of sexually selected ornaments and weapons. We also found that Asian and North American clades differ significantly in chela reflectance — in contrast to previous studies, which stated that these clades were phenotypically identical. We conclude that these clades are diverging phenotypically, but that these differences are not yet sufficient to warrant distinction as separate species.
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- PAR ID:
- 10329697
- Date Published:
- Journal Name:
- Crustaceana
- Volume:
- 92
- Issue:
- 4
- ISSN:
- 1568-5403
- Page Range / eLocation ID:
- 385 to 396
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1163/15685403-00003879
