DOI: 10.3897/asp.83.e153079

Authors: Edvanda A. Souza-Carvalho, Célio Magalhães, Fabrício L. Carvalho, Fernando L. Mantelatto

Abstract: Abstract The generic system of the Neotropical crabs of the subfamily Trichodactylinae H. Milne Edwards, 1853 has remained quite stable over the last 30 years, but the recognition or not of the genus Mikrotrichodactylus Pretzmann, 1968 has been a matter of debate: erected as a subgenus, it was treated with generic status in Rodríguez’ classificatory system but some subsequent works considered it a junior synonym of Trichodactylus Latreille, 1828. Based on this scenario, an integrative analysis based on molecular (using two mitochondrial, 16S rRNA and COI, and one nuclear, Histone 3, genes) and morphological (using diagnostic characters traditionally used on the identification of the family) data was performed in order to clarify the phylogenetic position of the genera within Trichodactylinae. The inferred phylogeny recovered three great lineages within Trichodactylinae with high support values in both Bayesian Inference and Maximum Likelihood phylogenetic analyses, corroborated the non-monophyletic status of Trichodactylus, and confirmed the full generic status of Mikrotrichodactylus. A taxonomic rearrangement of Trichodactylinae is proposed but the positioning of “Trichodactylus” quinquedentatus Rathbun, 1893 remains doubtful and was treated herein as a taxon inquirendum et incertae sedis. This taxon seems to be closer related to Rodriguezia Bott, 1969, and Avotrichodactylus Pretzmann, 1968; however, more data are needed before additional taxonomic adjustments concerning its positioning within the subfamily is proposed. In the current proposal, Trichodactylus is composed by four species, Mikrotrichodactylus by six species, Avotrichodactylus and Rodriguezia by three each, in addition to “Trichodactylus” quinquedentatus.

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DOI: 10.3897/asp.83.e116160

Authors: Dieter Weber, Martin Wendt, Thomas Schmitt

Abstract: The biogeography, taxonomy and systematics of ground water organisms is still poorly understood. This is partly due to the difficult accessibility of the habitats and the expert knowledge required for identification. Nevertheless, due to the large distribution range and limited dispersal possibilities of amphipods such as the genus Niphargus, important insights can be gained into biogeographical patterns and evolutionary processes in subterranean ecosystems. Niphargus is the most species-rich genus of freshwater amphipods worldwide and holds great potential for cryptic species whose identification is important for the reconstruction of biogeographic patterns and events. Therefore, we assessed the genetic patterns of Niphargus fontanus Spence Bate, 1859 (Amphipoda: Niphargidae). We sampled the species all over its current distribution and sequenced one mitochondrial and three nuclear gene fragments. We discovered that most records from France were probably misidentifications, and that the species does not occur in central and southern France. Nevertheless, the distribution area extends from Wales to Bavaria, which could make it one of the largest distribution areas within the genus. Compared with other Niphargus, the genetic diversity and differentiation of N. fontanus is low and most likely evolved since the mid-Pleistocene Transition, but reflects a clear phylogeographic pattern with about 13 genetic lineages. These apparently stand for a number of extra-Mediterranean glacial refugia from which postglacial expansion was low to moderate. However, few cases of disjunction within these genetic lineages exist, most likely resulting from rapid expansions along river Rhine which otherwise mostly acted as a dispersal barrier.

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DOI: 10.3897/asp.82.e113041

Authors: Jin Wang, Chong-Hui Yao, Chao Jiang, Wei-Chun Li

Abstract: The genus Lucasioides Kwon, 1993 (Isopoda: Oniscidea: Agnaridae) occurs in Asia, but confined only to China, Japan, Korea, and Russian Siberia. The ambiguously morphological differences among some members of the genus make a dilemma: the species recognition, whether morphologically similar or different, is uncertain. In this paper, we present first morphometric and molecular data for the genus from a broad sample. DNA sequences (mitochondrial COI, nuclear 18S rRNA, 28S rRNA, and NaK) were generated and integrated with morphological evidence to reveal the cryptic species and delimit the new species within the genus. Seven species are described as new to science: Lucasioides digitatus sp. nov., L. dissectus sp. nov., L. dianensis sp. nov., L. formosus sp. nov., L. gracilentus sp. nov., L. schmidti sp. nov. and L. subcurvatus sp. nov. To date, Lucasioides species from China are 44.4% as many as all the known congeners worldwide, showing the exceptional species diversity of Lucasioides species from China. The results demonstrate that the integrative taxonomy is especially important to reveal the cryptic species among the high morphological similarity of taxa, as well as providing an effective way for species identification to accelerate the exploration of woodlice biodiversity.

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DOI: 10.3897/asp.82.e115268

Authors: Nielson Felix Caetano França, Célio Magalhães, Fernando Luis Mantelatto

Abstract: The taxonomic status of the freshwater crab Dilocarcinus septemdentatus (Herbst, 1783) is still not well established. Currently, the main issue involves synonymization with D. spinifer H. Milne Edwards, 1853, based on a variation of the angulation of the gonopod apex. These species are distributed along rivers and lakes in northern South America, with disjunct occurrences in central-west Brazil and Argentina. Due to these inconsistencies, an integrative approach was performed to elucidate these questions, with morphological (including NanoCT-Scan) and molecular analysis (Maximum Likelihood Trees, Bayesian Inference, Genetics Distance Matrix, and Haplotype Network), based on mitochondrial markers COI and 16S rRNA. Both analysis revealed and supported the existence of a species complex under the name of D. septemdentatus. Based on the results obtained, we propose the revalidation of D. spinifer, the description of a new species, and the redescription of D. septemdentatus s. str., with a neotype designation for this species. The hypothesis that this species complex originated in the Pebas System, an extensive mega wetland system that existed along the lowlands of Western Amazonia from late Oligocene to late Miocene (c. 23–11 mya) is discussed.

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DOI: 10.3897/asp.82.e105740

Authors: Atefe Kalate, Alireza Keikhosravi, Reza Nasrabadi, Elahe Parvizi, Christoph D. Schubart, Reza Naderloo

Abstract: The current patterns of biodiversity have significantly been affected by glacial-interglacial cycles during the Pleistocene period. True freshwater crabs are considered as poor dispersers and terrestrial barriers restrict gene flow between their local populations. Recent studies, however, suggest that certain environmental conditions, such as periods of heavy rainfall and humidity, can facilitate their between-drainage dispersal and will result in the evolution of homogenous genetic patterns among different drainage systems. Here we tested this hypothesis by comparing populations of the endemic freshwater crab Potamon elbursi Pretzmann, 1962 distributed in two drainage systems, the Caspian Sea and Namak Lake, in northern Iran. Our results based on the genetic analysis of 70 new and 61 previously published sequences of the mitochondrial cytochrome oxidase subunit I gene revealed a substantial haplotype diversity in some populations and high levels of local population structuring in others. Initially, we found mixed evidence of genetic differentiation and connectivity among drainages and populations. Genetic differentiation between the two drainages only became apparent after the Sepirdood population (which belongs to the Caspian Sea drainage) was excluded. Subsequently, the two drainages showed significant genetic distinctions, with a limited gene flow between them. Our demographic analyses supported recent population bottlenecks, followed by a rapid demographic and/or spatial expansion dating back to the Pleistocene climatic fluctuations. Species distribution modelling suggests that precipitation during warm weather conditions profoundly affects the distribution of P. elbursi. This study indicates that freshwater crabs can override short land barriers under favorable weather conditions and will have conservation implications in the face of contemporary climatic fluctuations.

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DOI: 10.3897/asp.81.e111799

Authors: Hossein Ashrafi, Kristin M. Hultgren

Abstract: Abstract The alpheid snapping shrimp genus Synalpheus Spence Bate, 1888, is a prominent component of arthropod diversity found in coral reefs. Notably, Synalpheus is the only genus of marine organisms known to exhibit eusocial behavior. Although eusociality has evolved at least four times independently in Synalpheus, all described eusocial species are from the West Atlantic, with only a single study documenting possibly eusocial species from Indonesia. In 2008, during an expedition to Madagascar organized by the Florida Museum of Natural History (FLMNH), a diverse array of sponge-dwelling species was collected, including two species of Synalpheus exhibiting colonial behavior. Through detailed examination of these specimens, we have confirmed that these two species are eusocial and represent new eusocial species of Synalpheus outside of the West Atlantic. Consequently, we provide the first official documentation of eusocial species from the Western Indian Ocean and present their taxonomic descriptions and their phylogenetic relationships with other species of the genus in this study.

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DOI: 10.3897/asp.81.e96839

Authors: Sana Sharifian, Ehsan Kamrani, Maria A. Nilsson, Hanieh Saeedi

Abstract: Brachyuran crabs constitute the dominant fauna in intertidal and supratidal coasts of mangrove forests. We sampled the most commonly occurring crab species from the biodiversity rich Persian Gulf mangrove forest. We identified crabs from Camptandriidae, Dotillidae, Ocypodidae, Macrophthalmidae, and Sesarmidae as the most common species in the sampled regions. Molecular barcoding was applied to determine 11 species (29 specimens) of the mangrove crabs. Two mitochondrial genes were used to barcode the specimens and these were included in a larger phylogenetic data set. Many of the analyzed species showed a close phylogenetic relationship with species from the Northern Arabian Sea. The results provide the first steps to study the genetic diversity of the mangrove crab community along the Iranian coasts to support protection and management of mangrove ecosystems and its associated taxa.

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DOI: 10.3897/asp.80.e79498

Authors: Analisa Waller, Exequiel R. González, Ana Verdi, Ivanna H. Tomasco

Abstract: Hyalella is a genus of epigean freshwater amphipods endemic to the Americas. The study of morphological characters alone has traditionally dominated the description of new species. Recently, molecular systematics tools have contributed to identifying many cryptic species and a high level of convergent evolution in species complexes from North America and the South American highlands. In this study, we evaluate for the first time the molecular diversity in Hyalella spp. in Uruguay, a country located in the humid pampa ecoregion, based on four molecular markers. Thus, we investigate the systematic position of H. curvispina in the context of the available phylogenetic hypothesis for the genus. Phylogenetic and morphological analyses confirm that there is a “curvispina complex”. This complex includes H. curvispina and several similar morphological forms but is paraphyletic in relation to some altiplano species. In addition, we found one provisional new species. The results obtained are contrasted with previous studies to help understand the mechanisms of genetic differentiation and speciation of the genus, which seems to have a strong tendency towards morphological convergence.

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DOI: 10.3897/asp.79.e70234

Authors: Lucas A. Jennings, April M. H. Blakeslee, Krista A. McCoy, Donald C. Behringer, Jamie Bojko

Abstract: Abstract This study provides a broad phylogenetic analysis for the Eubrachyura, with the inclusion of three new Panopeidae mitochondrial genomes: Eurypanopeus depressus (flatback mud crab) (15,854bp), Panopeus herbstii (Atlantic mud crab) (15,812bp) and Rhithropanopeus harrisii (Harris, or ‘white-fingered’ mud crab) (15,892bp). These new mitogenomes were analyzed alongside all available brachyuran mitochondrial genomes (n = 113), comprising 80 genera from 29 families, to provide an updated phylogenetic analysis of the infra-order Brachyura (“true crabs”). Our analyses support the subsection Potamoida within the Eubrachyura as the sister group to Thoracotremata. The family Panopeidae aligns with the family Xanthidae to form the Xanthoidea branch, which is supported by current morphological and genetic taxonomy. A unique gene arrangement termed ‘XanGO’ was identified for the panopeids and varies relative to other members of the subsection Heterotremata (within the Eubrachyura) via a transposition of the trnV gene. This gene arrangement is novel and is shared between several Xanthoidea species, including Etisus anaglyptus (hairy spooner crab), Atergatis floridus (brown egg crab), and Atergatis integerrimus (red egg crab), suggesting that it is a conserved gene arrangement within the Xanthoidea superfamily. Our study further reveals a need for taxonomic revision of some brachyuran groups, particularly the Sesarmidae. The inclusion of panopeid mitogenomes into the greater brachyuran phylogeny increases our understanding of crab evolution and higher level Eubrachyuran systematics.

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DOI: 10.3897/asp.79.e62282

Authors: Hayato Tanaka, Hyunsu Yoo, Huyen Thi Minh Pham, Ivana Karanovic

Abstract: Abstract Keysercythere reticulata sp. nov. and Redekea abyssalis sp. nov., collected from the wood fall submerged in the Kuril-Kamchatka Trench (Northwestern Pacific), are only the second records of the naturally occurring, wood-associated ostracod fauna from a depth of over 5000 m. At the same time, K. reticulata is the second and R. abyssalis is the third representative of their respective genera. While Keysercythere Karanovic and Brandão, 2015 species are free-living, deep-sea taxa, all Redekea de Vos, 1953 live symbiotically on the body surface of wood-boring isopods, Limnoria spp. Since R. abyssalis is the only genus representative found in the deep sea, we hypothesize that its ancestor colonized this ecosystem as a result of the symbiotic relationship. Newly collected material enabled us to update molecular phylogeny of Cythreoidea based on 18S rRNA gene sequences, especially to clarify the current systematics of the families Keysercytheridae, Limnocytheridae, and Paradoxostomatidae. The resulting phylogenetic tree supports a close relationship between Keysercythere and Redekea and a distant relationship between two Limnocytheridae lineages, Timiriaseviinae and Limnocytherinae. Consequently, we propose a transfer of Redekea from Paradoxostomatidae to Keysercytheridae, and erecting of the two limnocytherid subfamilies onto the family level. The phylogenetic analysis also implies a close relationship between the nominal Limnocytherinae genus and Keysercythere+Redekea clade, albeit with a low posterior probability, requiring further studies to clarify this.

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DOI: 10.3897/asp.79.e66021

Authors: Vasily V. Grebennikov

Abstract: Abstract The weevil genus Typoderus is for the first time reported west of the Congo basin. Analysis of 2,136 aligned positions from one mitochondrial and two nuclear fragments revealed a moderately supported clade of five new Cameroonian species: T. amphion sp. nov. (Mt. Oku), T. canthus sp. nov. (Mt. Oku), T. clytius sp. nov. (Mt. Cameroon), T. iphitus sp. nov. (Mt. Kupe) and T. telamon sp. nov. (Mt. Kupe). Molecular clock analysis of 20 DNA barcode fragments using a fixed substitution rate estimated divergences within this clade to be during the Middle to Late Miocene (10.5–5.4 million years ago, MYA), which pre-dates the onset of the Pliocene-Pleistocene global climatic fluctuations and corresponding cycles of African forest size fluctuation. Such relatively old dates are unexpected and might reflect four unavoidable shortcomings of the temporal analysis: 1. undersampled ingroup, 2. scarcity of comparative temporal data for other animal clades from the Cameroon Volcanic Line, 3. oversimplification of a fixed-rate molecular clock approach using a single maternally-inherited protein-coding marker and 4. possible overestimation of comparatively old ages when using largely saturated mitochondrial sequences. Two obscure weevil species from the Republic of the Congo are hypothesized to belong to the genus Typoderus: T. distinctus (Hoffmann, 1968) comb. nov. (from Anchonidium subgenus Neoanchonidium) and T. baloghi (Hoffmann, 1968) comb. nov. (from Anchonidium subgenus Subanchonidium). Three genus-group names are newly synonymized under Typoderus: Entypoderus Voss, 1965 syn. nov. (the only non-nominative subgenus of Typoderus), Neoanchonidium Hoffmann, 1968 syn. nov. (subgenus of Anchonidium) and Subanchonidium Hoffmann, 1968 syn. nov. (subgenus of Anchonidium). Habitus images and other supplementary information of all sequenced specimens are available online at dx.doi.org/10.5883/DS-VGDS005 and dx.doi.org/10.5883/DS-VGDS006.

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