PeerJ:Taxonomyhttps://peerj.com/articles/index.atom?journal=peerj&subject=2700Taxonomy articles published in PeerJFilling the gaps in ecology of tropical tiger beetles (Coleoptera: Cicindelidae): first quantitative data of sexual dimorphism in semi-arboreal Therates from the Philippine biodiversity hotspothttps://peerj.com/articles/169562024-03-132024-03-13Dale Ann AcalAnna Sulikowska-DrozdRadomir Jaskuła
Background
Sexual dimorphism, driven by sexual selection, leads to varied morphological distinctions in male and female insects, providing insights into selection pressures across species. However, research on the morphometric variability within specific taxa of tiger beetles (Coleoptera: Cicindelidae), particularly arboreal and semi-arboreal species, remains very limited.
Methods
We investigate sexual dimorphism in six semi-arboreal Therates tiger beetle taxa from the Philippines, focusing on morphological traits. We employed morphometric measurements and multivariate analyses to reveal patterns of sexual dimorphism between sexes within the taxa.
Results
Our results indicate significant sexual dimorphism in elytra width, with females consistently displaying broader elytra, potentially enhancing fecundity. Notable sexual size dimorphism was observed in Therates fulvipennis bidentatus and T. coracinus coracinus, suggesting heightened sexual selection pressures on male body size. Ecological factors, mating behavior, and female mate choice might contribute to the observed morphological variation. These findings emphasize the need for further studies to comprehend mating dynamics, mate choice, and ecological influences on morphological variations in semi-arboreal and arboreal tiger beetles.
Background
Sexual dimorphism, driven by sexual selection, leads to varied morphological distinctions in male and female insects, providing insights into selection pressures across species. However, research on the morphometric variability within specific taxa of tiger beetles (Coleoptera: Cicindelidae), particularly arboreal and semi-arboreal species, remains very limited.
Methods
We investigate sexual dimorphism in six semi-arboreal Therates tiger beetle taxa from the Philippines, focusing on morphological traits. We employed morphometric measurements and multivariate analyses to reveal patterns of sexual dimorphism between sexes within the taxa.
Results
Our results indicate significant sexual dimorphism in elytra width, with females consistently displaying broader elytra, potentially enhancing fecundity. Notable sexual size dimorphism was observed in Therates fulvipennis bidentatus and T. coracinus coracinus, suggesting heightened sexual selection pressures on male body size. Ecological factors, mating behavior, and female mate choice might contribute to the observed morphological variation. These findings emphasize the need for further studies to comprehend mating dynamics, mate choice, and ecological influences on morphological variations in semi-arboreal and arboreal tiger beetles.From caves to seamounts: the hidden diversity of tetractinellid sponges from the Balearic Islands, with the description of eight new specieshttps://peerj.com/articles/165842024-03-042024-03-04Julio A. DíazFrancesc OrdinesEnric MassutíPaco Cárdenas
The sponge fauna of the Western Mediterranean stands as one of the most studied in the world. Yet sampling new habitats and a poorly studied region like the Balearic Islands highlights once again our limited knowledge of this group of animals. This work focused on demosponges of the order Tetractinellida collected in several research surveys (2016–2021) on a variety of ecosystems of the Balearic Islands, including shallow caves, seamounts and trawl fishing grounds, in a broad depth range (0–725 m). Tetractinellid material from the North Atlantic and more than twenty type specimens were also examined and, for some, re-described in this work. All species were barcoded with the traditional molecular markers COI (Folmer fragment) and 28S (C1-C2 or C1-D2 fragment). A total of 36 species were identified, mostly belonging to the family Geodiidae (15 species), thereby bringing the number of tetractinellids recorded in the Balearic Islands from 15 to 39. Eight species from this study are new: Stelletta mortarium sp. nov., Penares cavernensis sp. nov., Penares isabellae sp. nov., Geodia bibilonae sp. nov., Geodia microsphaera sp. nov. and Geodia matrix sp. nov. from the Balearic Islands; Geodia phlegraeioides sp. nov. and Caminus xavierae sp. nov. from the North East Atlantic. Stelletta dichoclada and Erylus corsicus are reported for the first time since their description in Corsica in 1983. Pachastrella ovisternata is documented for the first time in the Mediterranean Sea. Finally, after comparisons of type material, we propose new synonymies: Geodia anceps as a junior synonym of Geodia geodina, Erylus cantabricus as a junior synonym of Erylus discophorus and Spongosorites maximus as a junior synonym of Characella pachastrelloides.
The sponge fauna of the Western Mediterranean stands as one of the most studied in the world. Yet sampling new habitats and a poorly studied region like the Balearic Islands highlights once again our limited knowledge of this group of animals. This work focused on demosponges of the order Tetractinellida collected in several research surveys (2016–2021) on a variety of ecosystems of the Balearic Islands, including shallow caves, seamounts and trawl fishing grounds, in a broad depth range (0–725 m). Tetractinellid material from the North Atlantic and more than twenty type specimens were also examined and, for some, re-described in this work. All species were barcoded with the traditional molecular markers COI (Folmer fragment) and 28S (C1-C2 or C1-D2 fragment). A total of 36 species were identified, mostly belonging to the family Geodiidae (15 species), thereby bringing the number of tetractinellids recorded in the Balearic Islands from 15 to 39. Eight species from this study are new: Stelletta mortarium sp. nov., Penares cavernensis sp. nov., Penares isabellae sp. nov., Geodia bibilonae sp. nov., Geodia microsphaera sp. nov. and Geodia matrix sp. nov. from the Balearic Islands; Geodia phlegraeioides sp. nov. and Caminus xavierae sp. nov. from the North East Atlantic. Stelletta dichoclada and Erylus corsicus are reported for the first time since their description in Corsica in 1983. Pachastrella ovisternata is documented for the first time in the Mediterranean Sea. Finally, after comparisons of type material, we propose new synonymies: Geodia anceps as a junior synonym of Geodia geodina, Erylus cantabricus as a junior synonym of Erylus discophorus and Spongosorites maximus as a junior synonym of Characella pachastrelloides.MicroCT illuminates the unique morphology of Shiinoidae (Copepoda: Cyclopoida), an unusual group of fish parasiteshttps://peerj.com/articles/169662024-03-042024-03-04James P. BernotGeoffrey A. BoxshallFreya E. GoetzAnna J. Phillips
The copepod family Shiinoidae Cressey, 1975 currently comprises nine species of teleost parasites with unusual morphology and a unique attachment mechanism. Female shiinoids possess greatly enlarged antennae that oppose a rostrum, an elongate outgrowth of cuticle that originates between the antennules. The antennae form a moveable clasp against the rostrum which they use to attach to their host. In this study, we use micro-computed tomography (microCT) to examine specimens of Shiinoa inauris Cressey, 1975 in situ attached to host tissue in order to characterize the functional morphology and specific muscles involved in this novel mode of attachment and to resolve uncertainty regarding the segmental composition of the regions of the body. We review the host and locality data for all reports of shiinoids, revise the generic diagnoses for both constituent genera Shiinoa Kabata, 1968 and Parashiinoa West, 1986, transfer Shiinoa rostrata Balaraman, Prabha & Pillai, 1984 to Parashiinoa as Parashiinoa rostrata (Balaraman, Prabha & Pillai, 1984) n. comb., and present keys to the females and males of both genera.
The copepod family Shiinoidae Cressey, 1975 currently comprises nine species of teleost parasites with unusual morphology and a unique attachment mechanism. Female shiinoids possess greatly enlarged antennae that oppose a rostrum, an elongate outgrowth of cuticle that originates between the antennules. The antennae form a moveable clasp against the rostrum which they use to attach to their host. In this study, we use micro-computed tomography (microCT) to examine specimens of Shiinoa inaurisCressey, 1975in situ attached to host tissue in order to characterize the functional morphology and specific muscles involved in this novel mode of attachment and to resolve uncertainty regarding the segmental composition of the regions of the body. We review the host and locality data for all reports of shiinoids, revise the generic diagnoses for both constituent genera Shiinoa Kabata, 1968 and Parashiinoa West, 1986, transfer Shiinoa rostrataBalaraman, Prabha & Pillai, 1984 to Parashiinoa as Parashiinoa rostrata (Balaraman, Prabha & Pillai, 1984) n. comb., and present keys to the females and males of both genera.Plectronoceratids (Cephalopoda) from the latest Cambrian at Black Mountain, Queensland, reveal complex three-dimensional siphuncle morphology, with major taxonomic implicationshttps://peerj.com/articles/170032024-02-292024-02-29Alexander PohlePeter JellChristian Klug
The Plectronoceratida includes the earliest known cephalopod fossils and is thus fundamental to a better understanding of the origin and early evolution of this group of molluscs. The bulk of described material comes from the late Cambrian Fengshan Formation in North China with isolated occurrences in South China, Laurentia, Kazakhstan and Siberia. Knowledge of their morphology and taxonomy is limited in that most specimens were only studied as longitudinal sections, which are prone to misinterpretations due to variations in the plane of section. We describe more than 200 new specimens, which exceeds the entire hitherto published record of plectronoceratids. The material was collected by Mary Wade and colleagues during the 1970s and 1980s, from the lower Ninmaroo Formation at Black Mountain (Mount Unbunmaroo), Queensland, Australia. Despite the collecting effort, diverse notes and early incomplete drafts, Mary Wade never published this material before her death in 2005. The specimens provide novel insights into the three-dimensional morphology of the siphuncle based on abundant material, prompting a general revision of the order Plectronoceratida. We describe Sinoeremoceras marywadeae sp. nov. from numerous, well-preserved specimens, allowing investigation of ontogenetic trajectories and intraspecific variability, which in turn enables improved interpretations of the three-dimensional siphuncle morphology. The siphuncle of S. marywadeae sp. nov. and other plectronoceratids is characterised by highly oblique segments, an elongated middorsal portion of the septal neck (= septal flap) and laterally expanded segments that extend dorsally relative to the septal flap (= siphuncular bulbs). We show that this complex siphuncular structure has caused problems of interpretation because it was studied mainly from longitudinal sections, leading to the impression that there were large differences between specimens and supposed species. We revise the order Protactinoceratida and the families Protactinoceratidae and Balkoceratidae as junior synonyms of the Plectronoceratida and Plectronoceratidae, respectively. We reduce the number of valid genera from eighteen (including one genus formerly classified as an ellesmeroceratid) to three: Palaeoceras Flower, 1954, Plectronoceras Kobayashi, 1935 and Sinoeremoceras Kobayashi, 1933. We accept 10 valid species to which the 68 previously established species may be assigned. Sinoeremoceras contains 8 of the 10 plus the new species. Two species, previously referred to ellesmeroceratid genera, are transferred to Sinoeremoceras. This revised scheme groups plectronoceratids into distinct geographically and stratigraphically separated species, which better reflects biological realities and removes bias caused by preparation techniques. North China remains important containing the highest known diversity and was likely a centre of cephalopod diversification.
The Plectronoceratida includes the earliest known cephalopod fossils and is thus fundamental to a better understanding of the origin and early evolution of this group of molluscs. The bulk of described material comes from the late Cambrian Fengshan Formation in North China with isolated occurrences in South China, Laurentia, Kazakhstan and Siberia. Knowledge of their morphology and taxonomy is limited in that most specimens were only studied as longitudinal sections, which are prone to misinterpretations due to variations in the plane of section. We describe more than 200 new specimens, which exceeds the entire hitherto published record of plectronoceratids. The material was collected by Mary Wade and colleagues during the 1970s and 1980s, from the lower Ninmaroo Formation at Black Mountain (Mount Unbunmaroo), Queensland, Australia. Despite the collecting effort, diverse notes and early incomplete drafts, Mary Wade never published this material before her death in 2005. The specimens provide novel insights into the three-dimensional morphology of the siphuncle based on abundant material, prompting a general revision of the order Plectronoceratida. We describe Sinoeremoceras marywadeae sp. nov. from numerous, well-preserved specimens, allowing investigation of ontogenetic trajectories and intraspecific variability, which in turn enables improved interpretations of the three-dimensional siphuncle morphology. The siphuncle of S. marywadeae sp. nov. and other plectronoceratids is characterised by highly oblique segments, an elongated middorsal portion of the septal neck (= septal flap) and laterally expanded segments that extend dorsally relative to the septal flap (= siphuncular bulbs). We show that this complex siphuncular structure has caused problems of interpretation because it was studied mainly from longitudinal sections, leading to the impression that there were large differences between specimens and supposed species. We revise the order Protactinoceratida and the families Protactinoceratidae and Balkoceratidae as junior synonyms of the Plectronoceratida and Plectronoceratidae, respectively. We reduce the number of valid genera from eighteen (including one genus formerly classified as an ellesmeroceratid) to three: Palaeoceras Flower, 1954, Plectronoceras Kobayashi, 1935 and Sinoeremoceras Kobayashi, 1933. We accept 10 valid species to which the 68 previously established species may be assigned. Sinoeremoceras contains 8 of the 10 plus the new species. Two species, previously referred to ellesmeroceratid genera, are transferred to Sinoeremoceras. This revised scheme groups plectronoceratids into distinct geographically and stratigraphically separated species, which better reflects biological realities and removes bias caused by preparation techniques. North China remains important containing the highest known diversity and was likely a centre of cephalopod diversification.Halichoeres sanchezi n. sp., a new wrasse from the Revillagigedo Archipelago of Mexico, tropical eastern Pacific Ocean (Teleostei: Labridae)https://peerj.com/articles/168282024-02-282024-02-28Benjamin C. VictorBenjamin W. FrableWilliam B. Ludt
A new labrid fish species, Halichoeres sanchezi n. sp., is described from eight specimens collected in the Revillagigedo Archipelago in the tropical eastern Pacific Ocean, off the coast of Mexico. The new species belongs to the Halichoeres melanotis species complex that is found throughout the region, differing by 2.4% in the mtDNA cytochrome c oxidase I sequence from its nearest relative, H. melanotis from Panama, and 2.9% from Halichoeres salmofasciatus from Cocos Island, off Costa Rica. The complex is distinguished from others in the region by having a black spot on the opercular flap and a prominent black area on the caudal fin of males. The juveniles and initial phase of the new species closely resemble those of H. salmofasciatus and Halichoeres malpelo from Malpelo Island of Colombia, differing in having an oblong black spot with a yellow dorsal margin on the mid-dorsal fin of initial-phase adults as well as on juveniles. In contrast, the terminal-phase male color pattern is distinct from other relatives, being vermilion to orangish brown with dark scale outlines, a white patch on the upper abdomen, and a prominent black band covering the posterior caudal peduncle and base of the caudal fin. The new species adds to the list of endemic fish species for the isolated archipelago and is an interesting case of island endemism in the region. The discovery was made during the joint 2022 collecting expedition to the archipelago, which featured a pioneering collaborative approach to an inventory of an island ichthyofauna, specifically including expert underwater photographers systematically documenting specimens in situ, before hand-collection, and then photographed fresh, tissue-sampled, and subsequently vouchered in museum collections.
A new labrid fish species, Halichoeres sanchezi n. sp., is described from eight specimens collected in the Revillagigedo Archipelago in the tropical eastern Pacific Ocean, off the coast of Mexico. The new species belongs to the Halichoeres melanotis species complex that is found throughout the region, differing by 2.4% in the mtDNA cytochrome c oxidase I sequence from its nearest relative, H. melanotis from Panama, and 2.9% from Halichoeres salmofasciatus from Cocos Island, off Costa Rica. The complex is distinguished from others in the region by having a black spot on the opercular flap and a prominent black area on the caudal fin of males. The juveniles and initial phase of the new species closely resemble those of H. salmofasciatus and Halichoeres malpelo from Malpelo Island of Colombia, differing in having an oblong black spot with a yellow dorsal margin on the mid-dorsal fin of initial-phase adults as well as on juveniles. In contrast, the terminal-phase male color pattern is distinct from other relatives, being vermilion to orangish brown with dark scale outlines, a white patch on the upper abdomen, and a prominent black band covering the posterior caudal peduncle and base of the caudal fin. The new species adds to the list of endemic fish species for the isolated archipelago and is an interesting case of island endemism in the region. The discovery was made during the joint 2022 collecting expedition to the archipelago, which featured a pioneering collaborative approach to an inventory of an island ichthyofauna, specifically including expert underwater photographers systematically documenting specimens in situ, before hand-collection, and then photographed fresh, tissue-sampled, and subsequently vouchered in museum collections.Treemendous: an R package for integrating taxonomic information across backboneshttps://peerj.com/articles/168962024-02-282024-02-28Felix SpeckerAndrea PazThomas W. CrowtherDaniel S. Maynard
Standardizing and translating species names from different databases is key to the successful integration of data sources in biodiversity research. There are numerous taxonomic name-resolution applications that implement increasingly powerful name-cleaning and matching approaches, allowing the user to resolve species relative to multiple backbones simultaneously. Yet there remains no principled approach for combining information across these underlying taxonomic backbones, complicating efforts to combine and merge species lists with inconsistent and conflicting taxonomic information. Here, we present Treemendous, an open-source software package for the R programming environment that integrates taxonomic relationships across four publicly available backbones to improve the name resolution of tree species. By mapping relationships across the backbones, this package can be used to resolve datasets with conflicting and inconsistent taxonomic origins, while ensuring the resulting species are accepted and consistent with a single reference backbone. The user can chain together different functionalities ranging from simple matching to a single backbone, to graph-based iterative matching using synonym-accepted relations across all backbones in the database. In addition, the package allows users to ‘translate’ one tree species list into another, streamlining the assimilation of new data into preexisting datasets or models. The package provides a flexible workflow depending on the use case, and can either be used as a stand-alone name-resolution package or in conjunction with existing packages as a final step in the name-resolution pipeline. The Treemendous package is fast and easy to use, allowing users to quickly merge different data sources by standardizing their species names according to the regularly updated database. By combining taxonomic information across multiple backbones, the package increases matching rates and minimizes data loss, allowing for more efficient translation of tree species datasets to aid research into forest biodiversity and tree ecology.
Standardizing and translating species names from different databases is key to the successful integration of data sources in biodiversity research. There are numerous taxonomic name-resolution applications that implement increasingly powerful name-cleaning and matching approaches, allowing the user to resolve species relative to multiple backbones simultaneously. Yet there remains no principled approach for combining information across these underlying taxonomic backbones, complicating efforts to combine and merge species lists with inconsistent and conflicting taxonomic information. Here, we present Treemendous, an open-source software package for the R programming environment that integrates taxonomic relationships across four publicly available backbones to improve the name resolution of tree species. By mapping relationships across the backbones, this package can be used to resolve datasets with conflicting and inconsistent taxonomic origins, while ensuring the resulting species are accepted and consistent with a single reference backbone. The user can chain together different functionalities ranging from simple matching to a single backbone, to graph-based iterative matching using synonym-accepted relations across all backbones in the database. In addition, the package allows users to ‘translate’ one tree species list into another, streamlining the assimilation of new data into preexisting datasets or models. The package provides a flexible workflow depending on the use case, and can either be used as a stand-alone name-resolution package or in conjunction with existing packages as a final step in the name-resolution pipeline. The Treemendous package is fast and easy to use, allowing users to quickly merge different data sources by standardizing their species names according to the regularly updated database. By combining taxonomic information across multiple backbones, the package increases matching rates and minimizes data loss, allowing for more efficient translation of tree species datasets to aid research into forest biodiversity and tree ecology.Revisiting the type material of two African Diplozoinae (Diplozoidae: Monogenea), with remarks on morphology, systematics and diplozoid specificityhttps://peerj.com/articles/170202024-02-282024-02-28Quinton Marco Dos SantosAnnemariè Avenant-Oldewage
The morphological characterisation of Diplozoidae spp. is highly reliant on the details of the sclerotised components of the hooks and clamps in the haptor. Only six species of Paradiplozoon (Diplozoinae) have been described from Africa, four of which have adequate morphological and even comparative ITS2 rDNA data available. However, the descriptions of Paradiplozoon ghanense (Thomas, 1957) and Paradiplozoon aegyptense (Fischthal & Kuntz, 1963) lack essential taxonomic information, specifically the details for their haptoral sclerites. As such, all available material from museum collections for these two species were studied using light microscopy to supplement the original morphometric descriptions. The holotype and paratypes of P. aegyptense were studied, but only voucher material for P. ghanense could be sourced. However, this voucher material for P. ghanense was deposited by the species authority and bore a striking resemblance to the illustrations and collection details from the original description. They were thus identified as the type series for the taxon, with a lectotype and paralectotype designated. Both P. ghanense and P. aegyptense could be readily distinguished from other taxa based on the supplementary data generated here, supporting their distinctness. The haptoral sclerites of P. aegyptense were most similar to those of Paradiplozoon krugerense Dos Santos & Avenant-Oldewage, 2016, also described from Labeo spp., while the sclerites of P. ghanense were most similar to Paradiplozoon bingolense Civáňová, Koyun & Koubková, 2013 and Paradiplozoon iraqense Al-Nasiri & Balbuena, 2016. Additionally, a voucher of P. aegyptense collected from the alestid type host of P. ghanense was reidentified as the latter species here. This greatly simplified the known host specificity for Paradiplozoon spp. in Africa, with P. aegyptense now exclusively reported from Cypriniformes (Cyprinidae and Danionidae), and P. ghanense restricted to Characiformes (Alestidae). The occurrence of all diplozoids from non-cyprinoid hosts was also investigated and several records of diplozoids occurring on non-cyprinoid hosts were collated and scrutinised. Excluding the two instances of diplozoids described and exclusively occurring on Characiformes fishes (P. ghanense and Paradiplozoon tetragonopterini (Sterba, 1957)), most other non-cyprinoid collections appear sporadic and unsubstantiated, but warrant further investigation supported by diligent taxonomic data. Even though the morphometric descriptions of both P. ghanense and P. aegyptense were fully reported on here, additional material will be needed to study their genetic profiles and phylogeny.
The morphological characterisation of Diplozoidae spp. is highly reliant on the details of the sclerotised components of the hooks and clamps in the haptor. Only six species of Paradiplozoon (Diplozoinae) have been described from Africa, four of which have adequate morphological and even comparative ITS2 rDNA data available. However, the descriptions of Paradiplozoon ghanense (Thomas, 1957) and Paradiplozoon aegyptense (Fischthal & Kuntz, 1963) lack essential taxonomic information, specifically the details for their haptoral sclerites. As such, all available material from museum collections for these two species were studied using light microscopy to supplement the original morphometric descriptions. The holotype and paratypes of P. aegyptense were studied, but only voucher material for P. ghanense could be sourced. However, this voucher material for P. ghanense was deposited by the species authority and bore a striking resemblance to the illustrations and collection details from the original description. They were thus identified as the type series for the taxon, with a lectotype and paralectotype designated. Both P. ghanense and P. aegyptense could be readily distinguished from other taxa based on the supplementary data generated here, supporting their distinctness. The haptoral sclerites of P. aegyptense were most similar to those of Paradiplozoon krugerense Dos Santos & Avenant-Oldewage, 2016, also described from Labeo spp., while the sclerites of P. ghanense were most similar to Paradiplozoon bingolense Civáňová, Koyun & Koubková, 2013 and Paradiplozoon iraqense Al-Nasiri & Balbuena, 2016. Additionally, a voucher of P. aegyptense collected from the alestid type host of P. ghanense was reidentified as the latter species here. This greatly simplified the known host specificity for Paradiplozoon spp. in Africa, with P. aegyptense now exclusively reported from Cypriniformes (Cyprinidae and Danionidae), and P. ghanense restricted to Characiformes (Alestidae). The occurrence of all diplozoids from non-cyprinoid hosts was also investigated and several records of diplozoids occurring on non-cyprinoid hosts were collated and scrutinised. Excluding the two instances of diplozoids described and exclusively occurring on Characiformes fishes (P. ghanense and Paradiplozoon tetragonopterini (Sterba, 1957)), most other non-cyprinoid collections appear sporadic and unsubstantiated, but warrant further investigation supported by diligent taxonomic data. Even though the morphometric descriptions of both P. ghanense and P. aegyptense were fully reported on here, additional material will be needed to study their genetic profiles and phylogeny.Discovering unknown Madagascar biodiversity: integrative taxonomy of raft spiders (Pisauridae: Dolomedes)https://peerj.com/articles/167812024-02-272024-02-27Kuang-Ping YuMatjaž Kuntner
Madagascar is a global biodiversity hotspot, but its biodiversity continues to be underestimated and understudied. Of raft spiders, genus Dolomedes Latreille, 1804, literature only reports two species on Madagascar. Our single expedition to humid forests of eastern and northern Madagascar, however, yielded a series of Dolomedes exemplars representing both sexes of five morphospecies. To avoid only using morphological diagnostics, we devised and tested an integrative taxonomic model for Dolomedes based on the unified species concept. The model first determines morphospecies within a morphometrics framework, then tests their validity via species delimitation using COI. It then incorporates habitat preferences, geological barriers, and dispersal related traits to form hypotheses about gene flow limitations. Our results reveal four new Dolomedes species that we describe from both sexes as Dolomedes gregoric sp. nov., D. bedjanic sp. nov., D. hydatostella sp. nov., and D. rotundus sp. nov. The range of D. kalanoro Silva & Griswold, 2013, now also known from both sexes, is expanded to eastern Madagascar. By increasing the known raft spider diversity from one valid species to five, our results merely scratch the surface of the true Dolomedes species diversity on Madagascar. Our integrative taxonomic model provides the framework for future revisions of raft spiders anywhere.
Madagascar is a global biodiversity hotspot, but its biodiversity continues to be underestimated and understudied. Of raft spiders, genus Dolomedes Latreille, 1804, literature only reports two species on Madagascar. Our single expedition to humid forests of eastern and northern Madagascar, however, yielded a series of Dolomedes exemplars representing both sexes of five morphospecies. To avoid only using morphological diagnostics, we devised and tested an integrative taxonomic model for Dolomedes based on the unified species concept. The model first determines morphospecies within a morphometrics framework, then tests their validity via species delimitation using COI. It then incorporates habitat preferences, geological barriers, and dispersal related traits to form hypotheses about gene flow limitations. Our results reveal four new Dolomedes species that we describe from both sexes as Dolomedes gregoricsp. nov., D. bedjanicsp. nov., D. hydatostellasp. nov., and D. rotundussp. nov. The range of D. kalanoro Silva & Griswold, 2013, now also known from both sexes, is expanded to eastern Madagascar. By increasing the known raft spider diversity from one valid species to five, our results merely scratch the surface of the true Dolomedes species diversity on Madagascar. Our integrative taxonomic model provides the framework for future revisions of raft spiders anywhere.The first gladius-bearing coleoid cephalopods from the lower Toarcian “Schistes Cartons” Formation of the Causses Basin (southeastern France)https://peerj.com/articles/168942024-02-262024-02-26Romain JattiotNathalie Coquel-PoussyIsabelle KrutaIsabelle RougetAlison J. RoweJean-David Moreau
The fossil record of gladius-bearing coleoids is scarce and based only on a few localities with geological horizons particularly favourable to their preservation (the so-called Konservat-Lagerstätten), which naturally leads to strongly limited data on geographical distributions. This emphasizes the importance of every new locality providing gladius-bearing coleoids. Here, we assess for the first time the gladius-bearing coleoid taxonomic diversity within the lower Toarcian “Schistes Cartons” of the Causses Basin (southeastern France). The material includes two fragmentary gladii, identified as Paraplesioteuthis sagittata and ?Loligosepia sp. indet. Just with these two specimens, two (Prototeuthina and Loligosepiina) of the three (Prototeuthina, Loligosepiina and Teudopseina) suborders of Mesozoic gladius-bearing coleoids are represented. Thus, our results hint at a rich early Toarcian gladius-bearing coleoid diversity in the Causses Basin and point out the need for further field investigations in the lower Toarcian “Schistes Cartons” in this area. This new record of Paraplesioteuthis sagittata is only the second one in Europe and the third in the world (western Canada, Germany and now France). Based on these occurrences, we tentatively suggest that P. sagittata originated in the Mediterranean domain and moved to the Arctic realm through the Viking Corridor to eventually move even farther to North America.
The fossil record of gladius-bearing coleoids is scarce and based only on a few localities with geological horizons particularly favourable to their preservation (the so-called Konservat-Lagerstätten), which naturally leads to strongly limited data on geographical distributions. This emphasizes the importance of every new locality providing gladius-bearing coleoids. Here, we assess for the first time the gladius-bearing coleoid taxonomic diversity within the lower Toarcian “Schistes Cartons” of the Causses Basin (southeastern France). The material includes two fragmentary gladii, identified as Paraplesioteuthis sagittata and ?Loligosepia sp. indet. Just with these two specimens, two (Prototeuthina and Loligosepiina) of the three (Prototeuthina, Loligosepiina and Teudopseina) suborders of Mesozoic gladius-bearing coleoids are represented. Thus, our results hint at a rich early Toarcian gladius-bearing coleoid diversity in the Causses Basin and point out the need for further field investigations in the lower Toarcian “Schistes Cartons” in this area. This new record of Paraplesioteuthis sagittata is only the second one in Europe and the third in the world (western Canada, Germany and now France). Based on these occurrences, we tentatively suggest that P. sagittata originated in the Mediterranean domain and moved to the Arctic realm through the Viking Corridor to eventually move even farther to North America.First case of a reversed Parabothus taiwanensis Amaoka & Shen, 1993 from Taiwan (Pleuronectiformes: Bothidae), with first evidence of situs inversus viscerum in bothidhttps://peerj.com/articles/168292024-02-232024-02-23Yo SuHsuan-Ching HoTah-Wei Chu
Background
Reversed condition is rarely found in most flatfishes in natural environment, except for some certain species. The mechanism controlling the reversals in flatfishes has been studied in some cultivated species, whereas some have only few cases for the entire family and remain unclear. Here, we report the first record of a dextral (reversed) specimen of Parabothus taiwanensis Amaoka & Shen, 1993 collected off southwestern Taiwan recently. It represents the second reversed case ever recorded in Bothidae. We aim to provide a detailed description of this dextral specimen and compared to the sinistral (normal) specimens collected from the vicinity.
Methods
Specimens were fixed in 4% formaldehyde and transferred to 70% ethanol for preservation. Meristic and morphometric characters were examined for both dextral and sinistral specimens. Dissections were made on specimens to confirm the position of internal organs. Lastly, X-radiographs were taken to elucidate the osteological features.
Results
As a result, no differences of both meristic and morphometric characters were observed between the dextral and sinistral specimens. Nevertheless, situs inversus viscerum is discovered in the dextral specimen for the first time in Bothidae and the sixth record within flatfishes.
Background
Reversed condition is rarely found in most flatfishes in natural environment, except for some certain species. The mechanism controlling the reversals in flatfishes has been studied in some cultivated species, whereas some have only few cases for the entire family and remain unclear. Here, we report the first record of a dextral (reversed) specimen of Parabothus taiwanensis Amaoka & Shen, 1993 collected off southwestern Taiwan recently. It represents the second reversed case ever recorded in Bothidae. We aim to provide a detailed description of this dextral specimen and compared to the sinistral (normal) specimens collected from the vicinity.
Methods
Specimens were fixed in 4% formaldehyde and transferred to 70% ethanol for preservation. Meristic and morphometric characters were examined for both dextral and sinistral specimens. Dissections were made on specimens to confirm the position of internal organs. Lastly, X-radiographs were taken to elucidate the osteological features.
Results
As a result, no differences of both meristic and morphometric characters were observed between the dextral and sinistral specimens. Nevertheless, situs inversus viscerum is discovered in the dextral specimen for the first time in Bothidae and the sixth record within flatfishes.