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Wednesday, November 24th, 2021
| Time | Event | ||||||
| 3:22a | [Invertebrate • 2021] Octopus djinda • A New Member of the Octopus vulgaris Group (Cephalopoda: Octopodidae) from southwest Australia
Abstract A new Octopus Cuvier, 1797 species, Octopus djinda Amor, 2021 (previously treated as O. cf. tetricus and O. aff. tetricus), is described from the shallow waters off southwest Australia. This species was classified as conspecific with O. tetricus Gould, 1852 from Australia’s east coast and New Zealand but is shown here to be morphologically and genetically distinct. This description is based on 25 individuals across three localities in southwest Australia, encompassing most of its distribution. Greater and non-overlapping sucker counts on the males hectocotylised arm delimit east and west coast forms. DNA barcoding using cytochrome c oxidase subunit I also successfully differentiates between these taxa; 13 polymorphisms along a 349 bp partial fragment (3.7% sequence divergence). A close relative of the O. vulgaris Cuvier, 1797 species-group, O. djinda, sp. nov. supports a highly productive fishery and is currently one of two octopod fisheries worldwide to have received sustainable certification from the Marine Stewardship Council. The taxonomic description presented here provides formal recognition of the taxonomic status of southwest Australia’s common octopus, O. djinda, sp. nov. and facilitates appropriate fisheries catch reporting and management. Keywords: Mollusca, Allopatric speciation, Bassian Isthmus, cryptic species, Octopus tetricus  Michael D. Amor and Anthony M. Hart. 2021. Octopus djinda (Cephalopoda: Octopodidae): A New Member of the Octopus vulgaris group from southwest Australia. Zootaxa. 5061(1); 145-156. DOI: 10.11646/zootaxa.5061.1.7 Mark Norman | ||||||
| 3:32a | [Ichthyology • 2021] Oxynoemacheilus nasreddini • A New Nemacheilid Loach (Teleostei: Nemacheilidae) from Central Anatolia
Abstract Oxynoemacheilus nasreddini, new species, from Lake Akşehir, Eber, Eğirdir, and Ilgın basins in Central Anatolia is distinguished from other species of Oxynoemacheilus in Central Anatolia by having irregularly shaped blotches on flank; 2–4 dark-brown bands on caudal fin; a slender body, and an emarginate caudal fin in which the shortest middle caudal-fin ray is 76–91% of the longest ray of the upper caudal-fin lobe. Molecular data suggest that the new species is closely related to O. mediterraneus from the Aksu and Köprüçay drainages. Although the two species are separated by only a minimum K2P distance of 1.2% in the mtDNA COI barcode region, they are well distinguished morphologically. The situation is complicated by loaches from Lake Eğirdir basin that are identified as O. nasreddini by their morphological character states but are only distinguished from O. mediterraneus by a minimum K2P distance of 0.2% in the mtDNA COI barcode region. Keywords: Pisces, Freshwater fish, taxonomy, Middle East   Baran Yoğurtçuoğlu, Cüneyt Kaya and Jörg Freyhof. 2021. Oxynoemacheilus nasreddini, A New Nemacheilid Loach from Central Anatolia (Teleostei: Nemacheilidae). Zootaxa. 4974(1); 135–150. DOI: 10.11646/zootaxa.4974.1.5 Yeni keşfedilen balık türüne Nasrettin Hoca'nın adı verildi | ||||||
| 3:41a | [Botany • 2021] Biancaea scabrida (Fabaceae: Caesalpinioideae) • A New Species of the Caesalpinia group from Peninsular Malaysia
Abstract The new species Biancaea scabrida, currently only known from Peninsular Malaysia, is described and illustrated. The new species most resembles B. parviflora and B. oppositifolia in its inflorescence, but can be distinguished from both species by its sepals which have short stiff scabrid hairs, and its pistil which has stiff and hispid hairs. It also has alternately arranged leaves and inflorescence branches, a lack of a persistent suborbicular stipule, few pinnae per rachis (2–6 pairs) and relatively fewer leaflets per pinna ((3–)5–9 pairs). A provisional IUCN conservation assessment and a taxonomic key to Biancaea is also provided here. Keywords: Caesalpinia, Caesalpinioideae, Kelantan, limestone hill, Perak, taxonomy
Biancaea scabrida L.M.Choo, sp. nov. TYPE:—Peninsular Malaysia, Kelantan, Gua Musang, 23 Feb 1972, Loh Hoy Shing FRI 19256 (holotype SING! [SING0256191] (fl); isotype KEP [KEP136564] (fl); isotype L! [L1976278] (fl)). Diagnosis:—This species is the most similar to Biancaea parviflora and Biancaea oppositifolia in its small, compact flowers, borne on a long inflorescence, which are very much smaller than other species in the genus. However, it differs from both species by the sepals which have short, stiff scabrid hairs, and by the stiff and hispid hairs on the pistil, which is especially visible at the style where the hairs are sticking out, as compared to B. parviflora and B. oppositifolia where the hairs are soft and adpressed. It can be distinguished from B. parviflora by its larger and ovate-elliptic leaflets, fewer pinnae per rachis (2–6 pairs) and fewer leaflets per pinna ((3–)5–9 pairs). It can also be distinguished from B. oppositifolia by its alternately arranged leaves and inflorescence branches, and also by the lack of large, persistent and suborbicular stipules. Distribution:—Biancaea scabrida is known from two locations in Peninsular Malaysia, Gua Musang in the State of Kelantan and Tasik Temenggor in Perak. Habitat:—Limestone hill. Etymology:—The specific epithet is derived from the Latin word scaber, which means rough to the touch because of numerous minute projections. This refers to the hairs on the sepals which are short, stiff and scabrid on both surfaces. Le Min Choo. 2021. Biancaea scabrida, A New Species of the Caesalpinia group (Fabaceae) from Peninsular Malaysia. Phytotaxa. 525(4); 251-257. DOI: 10.11646/phytotaxa.525.4.1 | ||||||
| 2:10p | [Ichthyology • 2021] Speciation Dynamics and Extent of Parallel Evolution along A Lake-Stream Environmental Contrast in African Cichlid Fishes
Abstract Understanding the dynamics of speciation is a central topic in evolutionary biology. Here, we investigated how morphological and genomic differentiation accumulated along the speciation continuum in the African cichlid fish Astatotilapia burtoni. While morphological differentiation was continuously distributed across different lake-stream population pairs, we found that there were two categories with respect to genomic differentiation, suggesting a “gray zone” of speciation at ~0.1% net nucleotide divergence. Genomic differentiation was increased in the presence of divergent selection and drift compared to drift alone. The quantification of phenotypic and genetic parallelism in four cichlid species occurring along a lake-stream environmental contrast revealed parallel and antiparallel components in rapid adaptive divergence, and morphological convergence in species replicates inhabiting the same environments. Furthermore, we show that the extent of parallelism was higher when ancestral populations were more similar. Our study highlights the complementary roles of divergent selection and drift on speciation and parallel evolution.
  CONCLUSION: By examining the dynamics of differentiation in the African cichlid A. burtoni, we found that morphological differentiation was continuous along the speciation continuum. Contrastingly, we detected a gap in genomic differentiation that was only partially explained by geographic patterns. Our results, therefore, provide additional support for the hypothesis that there is a tipping point in genomic differentiation during the speciation process (5), suggesting that there might be a threshold of genomic differentiation to delimit species. We further showed that genomic differentiation was accelerated in the presence of both divergent selection and genetic drift, highlighting the combined effect of selective and neutral processes in speciation. To gain insights into the potential predictability of the speciation process, we investigated the extent of parallel evolution in nine population pairs from four cichlid species that diverged along a similar lake-stream environmental contrast. While pairwise comparisons failed to identify strong signatures of phenotypic and genomic parallelism, multivariate analyses uncovered major axes of shared evolutionary changes along the lake-stream contrast. Last, we found that levels of parallelism were higher between closely related and, hence, genetically more similar population pairs. While the speciation process is overall difficult to predict, our results support the view that evolution can be predictable to a certain extent if appropriate models and data are used (56). To conclude, our study corroborates that contingency plays an important role in speciation and that speciation is a complex product of differentiation trajectories through multivariate space and time.  Alexandra A.-T. Weber, Jelena Rajkov, Kolja Smailus, Bernd Egger and Walter Salzburger. 2021 Speciation Dynamics and Extent of Parallel Evolution along A Lake-Stream Environmental Contrast in African Cichlid Fishes. SCIENCE ADVANCES. 7: 45. DOI: 10.1126/sciadv.abg5391  | ||||||
| 2:11p | [Herpetology • 2021] Achalinus dehuaensis • A New Species of the Achalinus rufescens Complex (Serpentes :Xenodermidae) from Fujian Province, China
Abstract A new species of the xenodermid snake genus Achalinus Peters, 1869 is described from Fujian Province, China, based on six specimens. Bayesian inference and maximum likelihood analyses based on a mitochondrial DNA fragment (CO1) indicated the new taxon is different from its congeners (p–distance ≥ 18.5%). Morphologically, the new species can be diagnosed from the other species by a combination of following characters: (1) dorsal scales 23 rows throughout, strongly keeled, the most outer rows on both sides also keeled and slightly enlarged; (2) tail relatively longer, TaL/TL ratio 0.26–0.29 in males, 0.21–0.22 in females; (3) maxillary teeth 30–33; (4) length of suture between internasals significantly longer than that between prefrontals; (5) nasal divided into two sections by nasal cleft; (6) a single loreal; (7) SPO 1, seldom 2; (8) SPL 6, the fourth and fifth contacting eye; (9) IFL5, rarely 6, the first three touching the first pair of chin shields; (10) TMP 7–9, arranged in three rows; (11) VS 142–149 in males, VS 152–154 in females; (12) SC 74–81 in males, SC 63–65 in females, arranged in a single row; (13) cloacal entire; (14) greyish brown above, pale yellow beneath; (15) dorsum with an indistinct longitudinal vertebral stripe. The description of the new species brings the total species of Achalinus to 19. Keywords: Reptilia, Achalinus dehuaensis sp.nov., morphology, molecular phylogeny, taxanomy, snake
Ke Li, Ya-Yong Wu, Rui-Ying Xu, Fei Zhu, Jin-Long Ren, Peng Guo and Bing-Jun Dong. 2021. A New Species of the Achalinus rufescens Complex (Xenodermidae: Achalinus) from Fujian Province, China. Zootaxa. 5026(2); 239-254. DOI: 10.11646/zootaxa.5026.2.5 | ||||||
| 2:11p | [Herpetology • 2021] Gastrotheca guentheri • Re-evaluating the Morphological Evidence for the Re-evolution of Lost Mandibular Teeth in Frogs
Abstract Dollo's law of irreversibility states that once a complex structure is lost, it cannot be regained in the same form. Several putative exceptions to Dollo's law have been identified using phylogenetic comparative methods, but the anatomy and development of these traits are often poorly understood. Gastrotheca guentheri is renowned as the only frog with teeth on the lower jaw. Mandibular teeth were lost in the ancestor of frogs more than 200 million years ago and subsequently regained in G. guentheri. Little is known about the teeth in this species despite being a frequent example of trait “re-evolution,” leaving open the possibility that it may have mandibular pseudoteeth. We assessed the dental anatomy of G. guentheri using micro-computed tomography and histology and confirmed the longstanding assumption that true mandibular teeth are present. Remarkably, the mandibular teeth of G. guentheri are nearly identical in gross morphology and development to upper jaw teeth in closely related species. The developmental genetics of tooth formation are unknown in this possibly extinct species. Our results suggest that an ancestral odontogenic pathway has been conserved but suppressed in the lower jaw since the origin of frogs, providing a possible mechanism underlying the re-evolution of lost mandibular teeth. Keywords: Anura, dentition, Dollo's law, Hemiphractidae, trait reversal 
 Daniel J. Paluh, Wesley A. Dillard, Edward L. Stanley, Gareth J. Fraser and David C. Blackburn. 2021. Re-evaluating the Morphological Evidence for the Re-evolution of Lost Mandibular Teeth in Frogs. Evolution. DOI: 10.1111/evo.14379 Underbite regained: Species feared extinct is the only frog with true teeth on its lower jaw Frogs have lacked teeth on their lower jaw since their first appearance in the fossil record more than 200 million years ago. But scientists were finally able to verify one species defies the standard -- a large marsupial frog named Gastrotheca guentheri. For decades, no one was sure whether the structures on G. guentheri’s lower jaw were bones masquerading as teeth or the genuine article. “They’re incredibly small, each about the size of a grain of sand,” said lead author Daniel Paluh, a doctoral candidate in the University of Florida’s department of biology. “There’s no way to confirm the presence of dentin and enamel in frog teeth without using high-resolution techniques.” | ||||||
| 2:18p | [Entomology • 2021] Diastolembia thailandensis • A Remarkable New Genus and Species of Embiids (Embioptera: Embiidae) from Thailand
Abstract This research aimed at the morphological and molecular characterization of specimens collected in Thailand to extend the available information on webspinners (Embioptera). The purpose of this article is to describe Diastolembia thailandensis n. gen., n. sp. (Embiidae) from Tak and Chiang Mai provinces. Alate males of this new species are distinguished by having a large lobe of basal segment of left cercus, expansion as angular and echinulate at the apex. Hind basitarsus is short with a single papilla. Meanwhile, apterous females are without distinctive characters. This discovery brings a total of 89 species under 24 genera worldwide for this insect family. Additionally, part of the mtDNA-COI gene of a peculiar new taxon and other Thai webspinner species was reconstructed for a phylogenetic position using the Maximum Likelihood method. Keywords: Diastolembia thailandensis, Embiidae, Embioptera, new genus and species, Thailand.    Diastolembia thailandensis n. gen., n. sp. Pisit Poolprasert, Keerati Tanruen, Sinlaprachai Senarat and Janice S. Edgerly. 2021. Diastolembia thailandensis, A Remarkable New Genus and Species of Embiids (Embioptera: Embiidae) from Thailand. Journal of Hunan University Natural Sciences. 48 (10). http://JoNUNS.com/index.php/journal/article/view/768  | ||||||
| 3:02p | [Mollusca • 2021] Neolepetopsid True Limpets (Gastropoda: Patellogastropoda) from Indian Ocean Hot Vents shed light on Relationships Among Genera
Abstract Neolepetopsidae is a family of true limpets restricted to deep-sea chemosynthesis-based ecosystems. It is a small and little-studied family with about a dozen species in three genera, namely Eulepetopsis, Neolepetopsis and Paralepetopsis, and all named species were from the Pacific or Atlantic Oceans. Here, we describe three new species from Indian Ocean vents, namely Eulepetopsis crystallina sp. nov. found across three ridges, Neolepetopsis ardua sp. nov. from the Southwest Indian Ridge and Neolepetopsis prismatica sp. nov. from the Carlsberg Ridge. Given that Neolepetopsis appears to specialize on inactive sulfide deposits, the apparent wider distribution of E. crystallina is probably attributable to bias in sampling effort at inactive chimneys. The molecular phylogeny of Patellogastropoda, reconstructed using the COI gene, supported the monophyly of Neolepetopsidae. These are the first molecular data available for Neolepetopsis, confirming that the three genera are genetically distinct. Eulepetopsis appears to be adapted to active vents, and its derived position compared with Paralepetopsis indicates a possible ‘stepping-stone’ evolutionary pathway from seeps and organic falls to vents. Our results provide new insights into this enigmatic family and highlight the importance of surveying the vent periphery, especially given that inactive vents are being eyed as a replacement for active ones in deep-sea mining. Keywords: deep sea, deep, sea vents, Mollusca, molecular phylogeny 
Chong Chen, Yadong Zhou, Hiromi Kayama Watanabe, Ruiyan Zhang and Chunsheng Wang. 2021. Neolepetopsid True Limpets (Gastropoda: Patellogastropoda) from Indian Ocean Hot Vents shed light on Relationships Among Genera. Zoological Journal of the Linnean Society. zlab081, DOI: 10.1093/zoolinnean/zlab081 | ||||||
| 3:02p | [Paleontology • 2021] Kyhytysuka sachicarum • Re-appearance of Hypercarnivore Ichthyosaurs in the Cretaceous with Differentiated Dentition: Revision of ‘Platypterygius’ sachicarum (Ichthyosauria, Ophthalmosauridae) from Colombia
Abstract Early Cretaceous ichthyosaur diversity has markedly increased in recent years with the discovery of new taxa in the field and in museum collections. This has led to new characters, and a better understanding of taxonomically informative anatomy. Here, we re-describe the holotype of the ophthalmosaurid Platypterygius sachicarum from the Barremian–Aptian of Colombia and place these data in a phylogenetic context. The validity of the species is supported by several new characters of the narial region, mandible and dentition. The dentition is unique among ichthyosaurs in that it presents several discrete tooth morphologies that range from piercing to cutting to crushing. In combination, these cranial specializations imply a large vertebrate diet and make this taxon the first Cretaceous hypercarnivorous ichthyosaur. Differences from the type species of Platypterygius, P. platydactylus, include a suite of characters associated with differing feeding ecologies and the complex external nares. The large number of character differences and revised phylogenetic relationships are used to remove the Colombian taxon from Platypterygius and recognize it as a new genus, Kyhytysuka sachicarum comb. nov. A revised set of taxonomic definitions are proposed for Ophthalmosauria to maintain stability at this important node. Kyhytysuka sachicarum opens new questions regarding the diversity and paleobiogeography of Early Cretaceous ichthyosaurs from northern Gondwana and highlights the importance of individually assessing each ‘Platypterygius’ species and, potentially, specimen to better understand the diversity of this broadly distributed taxon. Keywords: Platypterygius sachicarum, Ophthalmosauridae, Early Cretaceous, South America, Colombia, Paja Formation      Dirley Cortés, Erin E. Maxwell and Hans C. E. Larsson. 2021. Re-appearance of Hypercarnivore Ichthyosaurs in the Cretaceous with Differentiated Dentition: Revision of ‘Platypterygius’ sachicarum (Reptilia: Ichthyosauria, Ophthalmosauridae) from Colombia. Journal of Systematic Palaeontology. DOI: 10.1080/14772019.2021.1989507  | ||||||
| 3:05p | [Ichthyology • 2021] Eleotris (Teleostei: Eleotridae) from Indonesia with Description of Three New Species within the ‘melanosoma’ Neuromast Pattern Group
Abstract The species of Eleotris from Indonesia are reviewed and compared to the known species described from the area. Nine species are recognized including three new species in the ‘melanosoma’ neuromast pattern group. These are described using genetic and morpho-meristic approaches. The new species differ by a high percentage of genetic divergence in partial COI gene (652 bp) and by several characters including the number of pectoral fin rays, the number of scales in lateral, predorsal, forward and zigzag series. The main characteristics of the other known species in the area in the ‘melanosoma’ group, Eleotris melanosoma Bleeker, 1853 and Eleotris macrolepis (Bleeker, 1875), both belonging to this group, are given for comparison. A key for Eleotris species from Indonesia is provided. Keywords: Eleotris, cryptic species, Indonesia  Marion I. Mennesson, Philippe Keith, Sopian Sauri, Frédéric Busson, Erwan Delrieu-Trottin, Gino Limmon, Tedjo Sukmono, Jiran, Renny Risdawati, Hadi Dahruddin and Nicolas Hubert. 2021. Eleotris (Teleostei: Eleotridae) from Indonesia with Description of Three New Species within the ‘melanosoma’ Neuromast Pattern Group. Pacific Science. 75(4); 469-495. DOI: 10.2984/75.4.2 Les espèces du genre Eleotris d’Indonésie sont passées en revues et comparées avec les espèces décrites dans cette zone. Neuf espèces sont dénombrées dont trois sont nouvelles pour le groupe de papilles sensorielles « melanosoma ». Ces dernières sont décrites à partir d’une analyse génétique combinée à une analyse morpho-méristique. Les nouvelles espèces différent entre elles par d’importants pourcentages de divergence sur le gène partiel COI (652 pb) et quelques caractères morphologiques incluant the nombre de rayons sur les nageoires pectorales, le nombre d’écailles sur la ligne latérale, les prédorsales, la série transverse antérieure et la série zig-zag. Les caractéristiques principales des autres espèces appartenant au groupe « melanosoma », Eleotris melanosoma Bleeker, 1853 et Eleotris macrolepis (Bleeker, 1875), sont données en comparaison. Une clé de détermination des espèces d’Eleotris d’Indonésie est donnée. |
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