scholarly journals Phylogeography of the widespread Caribbean spiny orb weaver Gasteracantha cancriformis

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8976
Author(s):  
Lisa Chamberland ◽  
Fabian C. Salgado-Roa ◽  
Alma Basco ◽  
Amanda Crastz-Flores ◽  
Greta J. Binford ◽  
...  

Background Modern molecular analyses are often inconsistent with pre-cladistic taxonomic hypotheses, frequently indicating higher richness than morphological taxonomy estimates. Among Caribbean spiders, widespread species are relatively few compared to the prevalence of single island endemics. The taxonomic hypothesis Gasteracantha cancriformis circumscribes a species with profuse variation in size, color and body form. Distributed throughout the Neotropics, G. cancriformis is the only morphological species of Gasteracantha in the New World in this globally distributed genus. Methods We inferred phylogenetic relationships across Neotropical populations of Gasteracantha using three target genes. Within the Caribbean, we estimated genetic diversity, population structure, and gene flow among island populations. Results Our findings revealed a single widespread species of Gasteracantha throughout the Caribbean, G. cancriformis, while suggesting two recently divergent mainland populations that may represent separate species, diverging linages, or geographically isolated demes. The concatenated and COI (Cytochrome c oxidase subunit 1) phylogeny supported a Caribbean clade nested within the New World. Genetic variability was high between island populations for our COI dataset; however, gene flow was also high, especially between large, adjacent islands. We found structured genetic and morphological variation within G. cancriformis island populations; however, this variation does not reflect genealogical relationships. Rather, isolation by distance and local morphological adaptation may explain the observed variation.


Zootaxa ◽  
2008 ◽  
Vol 1710 (1) ◽  
pp. 1 ◽  
Author(s):  
MOLLY G. RIGHTMYER

The cleptoparasitic bee genus Triepeolus is a widespread, species-rich group that has never been revised throughout its geographic range. Herein I review 103 species of Triepeolus, including all but those that belong to the newly defined Triepeolus verbesinae and Triepeolus simplex species groups (these will be the topic of a subsequent paper). I present three keys to the species, which together cover the genus throughout its range in the New World; the keys are to the females of North and Central America, the males and females from Eastern North America, and the males and females from South America and the Caribbean. I propose the following 37 new species: Triepeolus antiochensis, T. argentimus, T. argus, T. bimorulus, T. charlesi, T. circumculus, T. claytoni, T. cruciformis, T. diffusus, T. dilutus, T. edwardi, T. engeli, T. exilicurvus, T. flavigradus, T. fulgidus, T. griswoldi, T. interruptus, T. isohedrus, T. jennieae, T. joliae, T. lateralis, T. margaretae, T. mauropygus, T. melanarius, T. micheneri, T. nayaritensis, T. parkeri, T. partitus, T. parvidiversipes, T. parvus, T. perpictus, T. phaeopygus, T. punctoclypeus, T. quadratus, T. simulatus, T. vernus, and T. warriti, and propose the new combinations Triepeolus laticeps (Friese), Triepeolus tepanecus (Cresson) and Triepeolus zacatecus (Cresson). I newly synonymize 45 of the 169 previously proposed Triepeolus names, for a total of 51 synonymies: T. alachuensis Mitchell under T. rufithorax Graenicher; Epeolus albopictus Cockerell, E. costaricensis Friese, and E. flavocinctus Friese under T. aztecus (Cresson); T. alpestris Cockerell, T. amandus Cockerell, and T. vandykei Cockerell and Sandhouse under T. paenepectoralis Viereck; E. bardus Cresson, T. mesillae Cockerell, and T. pimarum Cockerell under T. distinctus (Cresson); T. brunneus Cockerell under T. balteatus Cockerell; T. charlottensis Mitchell under T. brittaini Cockerell; T. cirsianus Mitchell under T. donatus (Smith); T. concinnus Cockerell under T. townsendi Cockerell; T. coquilletti Cockerell, T. helianthi arizonensis Cockerell, T. helianthi pacificus Cockerell, T. lineatulus Cockerell and Sandhouse, and T. maculiventris Cockerell under T. helianthi (Robertson); T. dichropus Cockerell, T. eldredi Cockerell, T. helianthi grandior Cockerell, T. pallidiventris Cockerell and Sandhouse, T. rectangularis Cockerell, and T. wyomingensis Cockerell under T. texanus (Cresson); T. digueti Cockerell and E. nobilis Friese under T. intrepidus (Smith); T. floridanus Mitchellunder T. georgicus Mitchell; T. fortis Cockerell, T. insolitus Cockerell, and T. trilobatus Cockerell under T. martini (Cockerell); T. foxii Cockerell under T. rufoclypeus (Fox); T. lestes Cockerell under T. subalpinus Cockerell; T. loganensis Cockerell and T. sandhousae Cockerell under T. fraserae Cockerell; T. nautlanus Cockerell under T. lunatus (Say); E. nigriceps Smith under T. robustus (Cresson); E. oswegoensis Mitchell under T. pectoralis (Robertson); T. perelegans Cockerell and T. trichopygus Cockerell and Timberlake under T. penicilliferus (Brues); T. signatus Hedicke under T. ventralis (Meade-Waldo); T. stricklandi Cockerell under T. subalpinus Cockerell; E. superbus Provancher and E. texanus nigripes Cockerell under T. remigatus (Fabricius); and E. utahensis Cockerell under T. heterurus (Cockerell and Sandhouse).



Zootaxa ◽  
2021 ◽  
Vol 4951 (3) ◽  
pp. 434-460
Author(s):  
BRITTANY A. MISTRETTA ◽  
CHRISTINA M. GIOVAS ◽  
MARCELO WEKSLER ◽  
SAMUEL T. TURVEY

The Lesser Antillean island chain in the eastern Caribbean formerly supported a diverse rodent fauna including multiple endemic genera of oryzomyine rice rats. The Caribbean rice rats are now all extinct, with most island populations known only from Holocene palaeontological and zooarchaeological material and with many remaining taxonomically undescribed. Rice rat material is reported from several pre-Columbian Ceramic Age (late Holocene) archaeological sites on the Grenada Bank, including sites on Grenada and Carriacou, but the taxonomic identity and diversity of the Grenada Bank rice rats has remained uncertain. We provide a morphology-based description of rice rats from Grenada and Carriacou, and analyze their phylogenetic and biogeographical affinities to other Caribbean and mainland Neotropical oryzomyines. We recognize two taxa from the Grenada Bank: we describe the new species Megalomys camerhogne from Pearls (Grenada), representing the largest-bodied member of the extinct endemic Caribbean genus Megalomys, and we refer smaller-bodied oryzomyine material from Pearls and Sabazan (Carriacou) to the widespread extant Neotropical species Zygodontomys brevicauda. Body size variation within Megalomys correlates with island bank area and might thus reflect historical rather than modern biogeography. Zygodontomys specimens from the Grenada Bank fall within the upper end of size variation in extant populations and may constitute an example of ‘island gigantism’, but it is possible that occurrence of this widespread species on the Grenada Bank might reflect prehistoric human-mediated translocation. We predict further endemic Caribbean rice rat taxa remain to be discovered, including a possible species of Megalomys on the neighbouring island of St. Vincent. 



2019 ◽  
Vol 66 (3) ◽  
pp. 227-237
Author(s):  
Paula C Rodríguez-Flores ◽  
Ernesto Recuero ◽  
Yolanda Jiménez-Ruiz ◽  
Mario García-París

Abstract Anostraca are known by their ability for long-distance dispersal, but the existence in several species of deep, geographically structured mtDNA lineages suggests their populations are subjected to allopatric differentiation, isolation, and prevalence of local scale dispersion. Tanymastix stagnalis is one of the most widespread species of Anostraca and previous studies revealed an unclear geographical pattern of mtDNA genetic diversity. Here, we analyze populations from the Iberian and Italian Peninsulas, Central Europe, and Scandinavia, with the aim to characterize the patterns of genetic diversity in a spatio-temporal framework using mtDNA and nuclear markers to test gene flow among close populations. For these aims we built a time-calibrated phylogeny and carried out Bayesian phylogeographic analyses using a continuous diffusion model. Our results indicated that T. stagnalis presents a deeply structured genetic diversity, including 7 ancient lineages, some of them even predating the Pleistocene. The Iberian Peninsula harbors high diversity of lineages, with strong isolation and recent absence of gene flow between populations. Dispersal at local scale seems to be the prevailing dispersal mode of T. stagnalis, which exhibits a pattern of isolation-by-distance in the Iberian Peninsula. We remark the vulnerability of most of these lineages, given the limited known geographic distribution of some of them, and the high risk of losing important evolutionary potential for the species.



2020 ◽  
Author(s):  
Di Cui ◽  
Cuifeng Tang ◽  
Hongfeng Lu ◽  
Jinmei Li ◽  
Xiaoding Ma ◽  
...  

Abstract Background Understanding and identifying the factors responsible for genetic differentiation is of fundamental importance for efficient utilization and conservation of traditional rice landraces. In this study, we examined the spatial genetic differentiation of 594 individuals sampled from 28 locations in Yunnan Province, China, covering a wide geographic distribution and diverse growing conditions. All 594 accessions were studied using ten unlinked target genes and 48 microsatellite loci, and the representative 108 accessions from the whole collection were sampled for resequencing. Results The genetic diversity of rice landraces was quite different geographically and exhibited a geographical decline from south to north in Yunnan, China. Population structure revealed that the rice landraces could be clearly differentiated into japonica and indica groups, respectively. In each group, the rice accessions could be further differentiated corresponded to their geographic locations, including three subgroups from northern, southern and middle locations. We found more obvious internal geographic structure in the japonica group than in the indica group. In the japonica group, we found that genetic and phenotypic differentiation were strongly related to geographical distance, suggesting a pattern of isolation by distance (IBD); this relationship remained highly significant when we controlled for environmental effects, where the likelihood of gene flow is inversely proportional to the distance between locations. Moreover, the gene flow also followed patterns of isolation by environment (IBE) whereby gene flow rates are higher in similar environments. We detected 314 and 216 regions had been differentially selected between Jap-N and Jap-S, Ind-N and Ind-S, respectively, and thus referred to as selection signatures for different geographic subgroups. We also observed a number of significant and interesting associations between loci and environmental factors, which implies adaptation to local environment. Conclusion Our findings highlight the influence of geographical isolation and environmental heterogeneity on the pattern of the gene flow, and demonstrate that both geographical isolation and environment drives adaptive divergence play dominant roles in the genetic differentiation of the rice landraces in Yunnan, China as a result of limited dispersal.



Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Di Cui ◽  
Cuifeng Tang ◽  
Hongfeng Lu ◽  
Jinmei Li ◽  
Xiaoding Ma ◽  
...  

Abstract Background Understanding and identifying the factors responsible for genetic differentiation is of fundamental importance for efficient utilization and conservation of traditional rice landraces. In this study, we examined the spatial genetic differentiation of 594 individuals sampled from 28 locations in Yunnan Province, China, covering a wide geographic distribution and diverse growing conditions. All 594 accessions were studied using ten unlinked target genes and 48 microsatellite loci, and the representative 108 accessions from the whole collection were sampled for resequencing. Results The genetic diversity of rice landraces was quite different geographically and exhibited a geographical decline from south to north in Yunnan, China. Population structure revealed that the rice landraces could be clearly differentiated into japonica and indica groups, respectively. In each group, the rice accessions could be further differentiated corresponded to their geographic locations, including three subgroups from northern, southern and middle locations. We found more obvious internal geographic structure in the japonica group than in the indica group. In the japonica group, we found that genetic and phenotypic differentiation were strongly related to geographical distance, suggesting a pattern of isolation by distance (IBD); this relationship remained highly significant when we controlled for environmental effects, where the likelihood of gene flow is inversely proportional to the distance between locations. Moreover, the gene flow also followed patterns of isolation by environment (IBE) whereby gene flow rates are higher in similar environments. We detected 314 and 216 regions had been differentially selected between Jap-N and Jap-S, Ind-N and Ind-S, respectively, and thus referred to as selection signatures for different geographic subgroups. We also observed a number of significant and interesting associations between loci and environmental factors, which implies adaptation to local environment. Conclusions Our findings highlight the influence of geographical isolation and environmental heterogeneity on the pattern of the gene flow, and demonstrate that both geographical isolation and environment drives adaptive divergence play dominant roles in the genetic differentiation of the rice landraces in Yunnan, China as a result of limited dispersal.



2018 ◽  
Author(s):  
Klemen Čandek ◽  
Ingi Agnarsson ◽  
Greta J. Binford ◽  
Matjaž Kuntner

AbstractThe Caribbean archipelago offers one of the best natural arenas for testing biogeographic hypotheses. The intermediate dispersal model of biogeography (IDM) predicts variation in species richness among lineages on islands to relate to their dispersal potential. To test this model, one would need background knowledge of dispersal potential of lineages, which has been problematic as evidenced by our prior biogeographic work on the Caribbean tetragnathid spiders. In order to investigate the biogeographic imprint of an excellent disperser, we study the American Trichonephila, a nephilid genus that contains globally distributed species known to overcome long, overwater distances. Our results reveal that the American T. clavipes shows a phylogenetic and population genetic structure consistent with a single species over the Caribbean, but not over the entire Americas. Haplotype network suggests that populations maintain lively gene flow between the Caribbean and North America. Combined with prior evidence from spider genera of different dispersal ability, these patterns coming from an excellent disperser (Trichonephila) that is species poor and of a relatively homogenous genetic structure, support the IDM predictions.



2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Maysa Tiemi Motoki ◽  
Dina Madera Fonseca ◽  
Elliott Frederic Miot ◽  
Bruna Demari-Silva ◽  
Phoutmany Thammavong ◽  
...  

Abstract Background The Asian tiger mosquito, Aedes (Stegomyia) albopictus (Skuse) is an important worldwide invasive species and can be a locally important vector of chikungunya, dengue and, potentially, Zika. This species is native to Southeast Asia where populations thrive in both temperate and tropical climates. A better understanding of the population structure of Ae. albopictus in Lao PDR is very important in order to support the implementation of strategies for diseases prevention and vector control. In the present study, we investigated the genetic variability of Ae. albopictus across a north-south transect in Lao PDR. Methods We used variability in a 1337-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), to assess the population structure of Ae. albopictus in Lao PDR. For context, we also examined variability at the same genetic locus in samples of Ae. albopictus from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA. Results We observed very high levels of genetic polymorphism with 46 novel haplotypes in Ae. albopictus from 9 localities in Lao PDR and Thailand populations. Significant differences were observed between the Luangnamtha population and other locations in Lao PDR. However, we found no evidence of isolation by distance. There was overall little genetic structure indicating ongoing and frequent gene flow among populations or a recent population expansion. Indeed, the neutrality test supported population expansion in Laotian Ae. albopictus and mismatch distribution analyses showed a lack of low frequency alleles, a pattern often seen in bottlenecked populations. When samples from Lao PDR were analyzed together with samples from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA, phylogenetic network and Bayesian cluster analysis showed that most populations from tropical/subtropical regions are more genetically related to each other, than populations from temperate regions. Similarly, most populations from temperate regions are more genetically related to each other, than those from tropical/subtropical regions. Conclusions Aedes albopictus in Lao PDR are genetically related to populations from tropical/subtropical regions (i.e. Thailand, Singapore, and California and Texas in the USA). The extensive gene flow among locations in Lao PDR indicates that local control is undermined by repeated introductions from untreated sites.





The Auk ◽  
2021 ◽  
Author(s):  
Therese A Catanach ◽  
Matthew R Halley ◽  
Julie M Allen ◽  
Jeff A Johnson ◽  
Russell Thorstrom ◽  
...  

Abstract More than one-third of the bird species found in the Caribbean are endemic to a set of neighboring islands or a single island. However, we have little knowledge of the evolutionary history of the Caribbean avifauna, and the lack of phylogenetic studies limits our understanding of the extent of endemism in the region. The Sharp-shinned Hawk (Accipiter striatus) occurs widely across the Americas and includes 3 endemic Caribbean taxa: venator on Puerto Rico, striatus on Hispaniola, and fringilloides on Cuba. These island populations have undergone extreme declines presumably due to ecosystem changes caused by anthropogenic factors, as well as due to severe hurricanes. Sharp-shinned Hawks, in general, and Caribbean Sharp-shinned Hawks, in particular, have not been placed in a modern phylogenetic context. However, the island taxa have historically been presumed to have some ongoing gene flow with mainland populations. Here we sequenced ultraconserved elements (UCEs) and their flanking regions from 38 samples, focusing on Caribbean taxa. Using a combination of UCEs, mitochondrial genome sequences, and single-nucleotide polymorphisms, we investigated the phylogenetic relationships among Caribbean lineages and their relationships to mainland taxa. We found that Caribbean Sharp-shinned Hawks are reciprocally monophyletic in all datasets with regard to mainland populations and among island taxa (with no shared mtDNA haplotypes) and that divergence in the NADH dehydrogenase 2 gene (ND2) between these mainland and island groups averaged 1.83%. Furthermore, sparse non-negative matrix factorization (sNMF) analysis indicated that Hispaniola, Puerto Rico, and mainland samples each form separate populations with limited admixture. We argue that our findings are consistent with the recognition of the 3 resident Caribbean populations as species-level taxa because nuclear and mitochondrial genetic data indicate reciprocal monophyly and have species-level divergences, there is no sharing of mitochondrial haplotypes among or between island taxa and those on the mainland; and they are diagnosable by plumage.



Zootaxa ◽  
2021 ◽  
Vol 4938 (1) ◽  
pp. 145-147
Author(s):  
RUDOLF H. SCHEFFRAHN

Cryptotermes Banks, 1906 is the third most diverse kalotermitid genus worldwide after Glyptotermes Froggatt, 1897 and Neotermes Holmgren, 1911, with its greatest diversity found in the Neotropics (Krishna et al. 2013a). Furthermore, the greatest number of species of Cryptotermes are known from the Caribbean Basin (Scheffrahn & Křeček 1999, Casala et al. 2016, Scheffrahn 2019). Although Araujo (1977) and Bacchus (1987) list Cryptotermes domesticus (Haviland, 1898) from Trinidad (treated as mainland) and Panama, respectively, Scheffrahn & Křeček (1999) and Scheffrahn et al. (2009) doubt the existence of this Asian species in the New World. Without C. domesticus, the total extant Neotropical diversity of Cryptotermes is 29 endemic and three exotic species (Constantino 2020). 



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