[Herpetology • 2026] Stenocercus aguilari • Morphological and Genetic Evidence support New Species of Stenocercus (Iguania: Tropiduridae) from the Peruvian Andes

  

  Stenocercus aguilari  

Castillo-Urbina, Rios-Roque, Barrera-Moscoso & Mendoza, 2026

 

DOI: doi.org/10.11646/zootaxa.5796.2.5

Abstract

The genus Stenocercus comprises a diverse group of 80 recognized species distributed across South America, with approximately 65% (52 species) occurring in Peru. The Department of Ancash, situated in the central Andes and encompassing the Cordillera Negra and Cordillera Blanca, is a topographically complex region marked by prominent geographic barriers that may promote allopatric speciation and influence patterns of Andean biodiversity, particularly within Stenocercus lineages. Populations previously assigned to S. chrysopygus from the puna habitats of Ancash exhibit notable variation in diagnostic traits and coloration, suggesting that this taxon may represent a species complex. However, inconsistent morphological diagnoses and limited genetic data have hindered accurate taxonomic resolution, underscoring the need for integrative approaches. Furthermore, a recent study showed that only populations from the Santa River Valley correspond to S. chrysopygus sensu stricto, while the other populations assigned to the distribution of S. chrysopygus constitute lineages of different species. In this study, we describe Stenocercus aguilari sp. nov. from Huari Province, Ancash Department, and present a phylogenetic hypothesis of its position based on the mitochondrial ND2 gene. We applied multivariate morphological analyses of scale counts using MANOVA and Gaussian Mixture Models, as well as molecular species delimitation approaches based on both distance-based and tree-based single-locus methods. All analyses support the taxonomic distinctiveness of S. aguilari sp. nov. Morphologically, the new species belongs to the group characterized by granular scales on the posterior surface of the thighs, vertebral scales similar in size and shape to adjacent rows, and three caudal whorls per autotomic segment. It is distinguished from other members of this group by the absence of a posthumeral mite pocket, the presence of a Type 1 postfemoral mite pocket, higher number of midbody scales and the presence of a distinct black patch on the pelvic region of the venter in adult males. Finally, the focal lineage is divergent from all nominal species in the Stenocercus genus for which respective data are available by >14.8% uncorrected pairwise distance in the ND2 gene.

Reptilia, Integrative taxonomy, multivariate analysis, molecular species delimitation, Cordillera Blanca

Stenocercus aguilari sp. nov. preserved holotype, adult female, SVL 71.54 mm (MUSM 41243):
 dorsal (A), lateral (B), and ventral (C) views of the head; dorsal (D) and ventral (E) views of the entire specimen.

Photographs by E. Castillo-Urbina. Scale bar = 10 mm.

(A–C) Lateral, ventral, and dorsal views in life of the adult female holotype of Stenocercus aguilari sp. nov.(MUSM 41243), SVL 71.5 mm.
(D) Panoramic view of the type locality in Ancash, San Marcos. (E–F) Shrubs and rocky microhabitats used for foraging and basking.

Stenocercus aguilari sp. nov.

 

ERNESTO CASTILLO-URBINA, SHARY RIOS-ROQUE, DIEGO BARRERA-MOSCOSO, ALEJANDRO MENDOZA. 2026. Morphological and Genetic Evidence support New Species of Stenocercus (Iguania: Tropiduridae) from the Peruvian Andes. Zootaxa. 5796(2); 313-331. DOI: doi.org/10.11646/zootaxa.5796.2.5 [2026-04-21]

[Herpetology • 2025] Gerrhonotus occidentalis • Phylogenomic Analyses Reveal Hidden Diversity in Gerrhonotus (Anguidae: Gerrhonotinae) and Description of a New Species from Western Mexico

 Gerrhonotus occidentalis 

Nieto-Montes de Oca, Wiens & García-Vázquez, 2025 

 DOI: doi.org/10.1655/Herpetologica-D-24-00004 

 Researchgate.net/publication/394998957

 Abstract  

The genus Gerrhonotus has a wide geographic range, extending from Texas in the United States southward and eastward to Panamá. Despite this enormous distribution, only seven species are currently recognized within the genus. However, both morphological and molecular studies have provided evidence for the presence of an undescribed species in western Mexico that has historically been confused with G. liocephalus. This species remains undescribed. In addition, molecular studies have revealed significant genetic structuring within some of the most broadly distributed morphology-based species in the genus, including G. infernalis, G. liocephalus, and G. ophiurus. These findings suggest the potential for unrecognized species diversity. Here, we used double-digested restriction-site associated sequencing (ddRADseq) to construct a new phylogenomic data set for the genus Gerrhonotus. We performed maximum-likelihood analyses on concatenated matrices with varying minimum taxon coverage to assess the impact of different numbers of loci and proportions of missing data on matrix informativeness, and identified the optimal matrix. We then performed a maximum-likelihood analysis of this matrix. Based on the resulting tree, current taxonomy, and the geographic distribution of samples, we identified 10 potentially independent lineages (putative species) within the genus. Subsequently, we conducted species-tree analyses for these lineages and utilized the resulting topologies to estimate their genealogical divergence index (gdi), providing a preliminary assessment of their evolutionary distinctness. All of the analyses consistently corroborated the existence of an undescribed species from western Mexico. Moreover, gdi values indicated the potential presence of additional hidden species diversity within the genus. We describe the lineage from western Mexico as a distinct species, based on 18 adult specimens. The new species appears to be restricted to the western slopes of Mexico from southern Nayarit to central Guerrero, spanning elevations from sea level to about 1500 m. Its preferred habitats include tropical deciduous, tropical semideciduous, oak, and pine-oak forests.

KEYWORDS: Alligator lizard, biodiversity, Gerrhonotus, phylogenomics, species delimitation, systematics, taxonomy

 Gerrhonotus occidentalis in life.
 (A) Adult male (MZFZ 4951). (B) Adult female (MZFZ 4950). (C) Adult specimen from Colima, Cerro Alcomú n. The latter photograph was taken by J. Jones on 29 December 2023. The specimen was released.

  Gerrhonotus occidentalis sp. nov.

Adrián Nieto-Montes de Oca, John J. Wiens and Uri Omar García Vázquez. 2025. Phylogenomic Analyses Reveal Hidden Diversity in Gerrhonotus (Anguidae: Gerrhonotinae) and Description of a New Species from Western Mexico. Herpetologica. 81(3); 303-321. DOI: doi.org/10.1655/Herpetologica-D-24-00004 (5 August 2025)  

Researchgate.net/publication/394998957_Phylogenomic_Analyses_in_Gerrhonotus_and_a_New_Species_from_Mexico

[Botany • 2025] Hyoscyamus labiatus (Solanaceae: Hyoscyameae) • A New Species from Henan, China: Implications for the Delimitation of Hyoscyamus

 

Hyoscyamus labiatus Y. Y. Liu, Q. R. Wang and J. M. Li, 

in Liu, Wang, Mi et Li, 2025. 

DOI: doi.org/10.1111/njb.04525

 facebook.com/NordicJBotany

Abstract

Hyoscyamus labiatus Y. Y. Liu, Q. R. Wang and J. M. Li, a new species of Hyoscyamus (Solanaceae) from Henan province, China, is described and illustrated here. It is morphologically similar to the known species of Hyoscyamus and Archihyoscyamus, but can be distinguished by corolla 2-lipped, adaxial lip 3-lobed and much longer than abaxial lips, tube slender at base, and stamens 5, inserted on inner side of disk, free, obviously unequal, and exceeding corolla. To infer the systematic position of this new species, phylogenetic analysis was performed based on four chloroplast markers, viz rbcL, ndhF, trnC-psbM and trnL-F. According to the phylogenetic tree, Hyoscyamus labiatus is strongly supported as sister to a monophyletic group containing all species of Hyoscyamus and Archihyoscyamus previously described. Morphological comparison and molecular phylogeny confirmed the identity of the species as a new taxon, and that Archihyoscyamus should be included in Hyoscyamus.

Keywords: Archihyoscyamus, Hyoscyameae, phylogeny, Solanaceae, taxonomy

Hyoscyamus labiatus Y. Y. Liu, Q. R. Wang and J. M. Li, sp. nov. 

Yan-Yan Liu, Qi-Rui Wang, Zeng-Lu Mi and Jia-Mei Li. 2025. Hyoscyamus labiatus sp. nov. (Solanaceae) from Henan, China: Implications for the Delimitation of Hyoscyamus. Nordic J. Botany.  e04525. DOI: doi.org/10.1111/njb.04525 [10 December 2024]

 facebook.com/NordicJBotany/posts/1163808125748415

 Researchgate.net/publication/355837769_Hyoscyamus_labiatus_sp_nov_from_Henan_China

[Arachnida • 2024] Hamataliwa cordivulva, Tapponia auriola, T. rarobulbus, ... • Integrative Species Delimitation and Five New Species of Lynx Spiders (Araneae: Oxyopidae) in Taiwan

 

[A] Hamadruas hieroglyphica (Thorell, 1887);

[B], Hamataliwa cordivulva sp. nov. Lo, Cheng & Lin, 2024;

[C] Oxyopes macilentus L. Koch, 1878; [D] Peucetia latikae Tikader, 1970, 

in Lo, Cheng & Lin, 2024 

DOI: doi.org/10.1371/journal.pone.0301776

Abstract

An accurate assessment of species diversity is a cornerstone of biology and conservation. The lynx spiders (Araneae: Oxyopidae) represent one of the most diverse and widespread cursorial spider groups, however their species richness in Asia is highly underestimated. In this study, we revised species diversity with extensive taxon sampling in Taiwan and explored species boundaries based on morphological traits and genetic data using a two-step approach of molecular species delimitation. Firstly, we employed a single COI dataset and applied two genetic distance-based methods: ABGD and ASAP, and two topology-based methods: GMYC and bPTP. Secondly, we further analyzed the lineages that were not consistently delimited, and incorporated H3 to the dataset for a coalescent-based analysis using BPP. A total of eight morphological species were recognized, including five new species, Hamataliwa cordivulva sp. nov., Hamat. leporauris sp. nov., Tapponia auriola sp. nov., T. parva sp. nov. and T. rarobulbus sp. nov., and three newly recorded species, Hamadruas hieroglyphica (Thorell, 1887), Hamat. foveata Tang & Li, 2012 and Peucetia latikae Tikader, 1970. All eight morphological species exhibited reciprocally monophyletic lineages. The results of molecular-based delimitation analyses suggested a variety of species hypotheses that did not fully correspond to the eight morphological species. We found that Hamat. cordivulva sp. nov. and Hamat. foveata showed shallow genetic differentiation in the COI, but they were unequivocally distinguishable according to their genitalia. In contrast, T. parva sp. nov. represented a deep divergent lineage, while differences of genitalia were not detected. This study highlights the need to comprehensively employ multiple evidence and methods to delineate species boundaries and the values of diagnostic morphological characters for taxonomic studies in lynx spiders.

 

Maternal egg-guarding behavior of oxyopids.
A, Hamadruas hieroglyphica, 2014 Oct. 28, Fuyang National Park, Taipei; B, Hamataliwa cordivulva sp. nov., 2014 Aug. 18, Taichung;
C, Oxyopes macilentus, 2014 Oct. 20, Qipan village, Yunlin; D, Peucetia latikae, 2018 Oct. 09, Dakeng, Taichung (photo by Sung-Yan Wei)

Hamataliwa cordivulva sp. nov., 

Hamataliwa leporauris sp. nov., 

Tapponia auriola sp. nov., 

T. parva sp. nov. 

T. rarobulbus sp. nov.

Ying-Yuan Lo, Ren-Chung Cheng and Chung-Ping Lin. 2024. Integrative Species Delimitation and Five New Species of Lynx Spiders (Araneae, Oxyopidae) in Taiwan. PLoS ONE. 19(5): e0301776. DOI: doi.org/10.1371/journal.pone.0301776 [May 9, 2024]

 

[Mammalogy • 2024] Callosciurus concolor & Tamiops barbei • Lost in Synonymy: Integrative Species Delimitation reveals Two unrecognized Species of Southern Asian Tree Squirrels (Rodentia: Sciuridae: Callosciurinae)

  

 the skins of (A) Callosciurus caniceps (NHMUK 41.1817, lectotype);
live images of (B) C. caniceps caniceps taken by Natthaphat Chotjuckdikul (Te’) in Bangkok, Thailand;
(C) C. caniceps bimaculatus taken by Pattaraporn Vangtal in Railay Bay Beach, Krabi, Thailand; and
(D) C. concolor taken by Cheong Weng Chun in Fraser’s Hill, Pahang, Malaysia.

in Hinckley, Maldonado, Tamura, Leonard & Hawkins, 2024. 

DOI: doi.org/10.3897/vz.74.e133467

Abstract

We present a comprehensive integrative taxonomic review of Callosciurus caniceps and Tamiops mcclellandii as they are currently defined. This review combines published molecular evidence, craniodental morphometrics, pelage and bacular variation, evaluations of potential hybrid zones using museum specimens and citizen science photographs, and, for C. caniceps, bioacoustic evidence. Our findings lead to the recognition of two species that had been lost in synonymy and highlight future perspectives on species delimitation in Sciuridae. By comparing phenotypic differentiation across climatic and vegetation transitions and contextualizing our results with the evolutionary history of our study systems, we provide insights into distribution, ecogeographical patterns, and speciation drivers in Southeast Asian vertebrates.

Keywords: Baculum, bioacoustics, biodiversity, citizen science, Mammalia, morphometrics, Southeast Asia, speciation, taxonomy

Taxonomic revision: 

Based on our findings, which unite molecular phylogenetic (Hinckley et al. 2023a), morphological evidence described below and in previous studies (Pocock 1923; Moore and Tate 1965; Hayashida et al. 2006), and bioacoustic data (in C. caniceps sensu lato), we conclude that the populations of Callosciurus caniceps sensu lato inhabiting Sundaland, and Tamiops mcclellandii sensu lato populations to the east of the Himalayas and Arakan range, should be recognized as distinct species. We revalidate the specific status of Callosciurus concolor (Blyth, 1855) and Tamiops barbei (Blyth, 1847), as these names represent the earliest descriptions of these separately evolving lineages. Additionally, we provide emended diagnoses and detailed species comparisons for both taxa and their sister species.

Dorsal and ventral views of the skins of (A) Callosciurus caniceps (NHMUK 41.1817, lectotype); live images of (B) C. caniceps caniceps taken by Natthaphat Chotjuckdikul (Te’) in Bangkok, Thailand; (C) C. caniceps bimaculatus taken by Pattaraporn Vangtal in Railay Bay Beach, Krabi, Thailand; and (D) C. concolor taken by Cheong Weng Chun in Fraser’s Hill, Pahang, Malaysia.

Callosciurus caniceps (Gray, 1842)

Common name: Northern gray-bellied squirrel

กระรอกปลายหางดำเหนือ

Callosciurus concolor (Blyth, 1855)

Common name: Southern gray-bellied squirrel

กระรอกปลายหางดำใต้

Tamiops mcclellandii (Horsfield, 1839)

Common name. Himalayan striped squirrel

กระเล็นขนปลายหูสั้น

Tamiops barbei (Blyth, 1847)

Common name. Southeast Asian striped squirrel

กระเล็น

 Arlo Hinckley, Jesús E. Maldonado, Noriko Tamura, Jennifer A. Leonard and Melissa T. R. Hawkins. 2024. Lost in Synonymy: Integrative Species Delimitation reveals Two unrecognized Species of Southern Asian Tree Squirrels (Rodentia: Sciuridae: Callosciurinae). Vertebrate Zoology. 74: 683-707. DOI: doi.org/10.3897/vz.74.e133467

[Herpetology • 2024] Incorporating New Datatypes to Enhance Species Delimitation: A Case Study in Rice Paddy Snakes (Homalopsidae: Hypsiscopus)

 

Hypsiscopus Rice Paddy Snakes 

in Bernstein, Murphy, Lathrop, Nguyen, Orlov et Stuart. 2024. 

DOI: 10.11646/zootaxa.5501.1.2 

 Researchgate.net/publication/383526819

 

Abstract

Homalopsids (Old World Mud Snakes) include 59 semiaquatic species in Asia and Australasia that display an array of morphological adaptations, behaviors, and microhabitat preferences. These attributes make homalopsids an ideal model system for broader questions in evolutionary biology, but the diversity of this understudied group of snakes is still being described. Recognized species diversity in rice paddy snakes (Hypsiscopus) has recently doubled after nearly 200 years of taxonomic stability. However, the evolutionary distinctiveness of some populations remains in question. In this study, we compare mainland Southeast Asian populations of Hypsiscopus east and west of the Red River Basin in Vietnam, a known biogeographic barrier in Asia, using an iterative approach with molecular phylogenetic reconstruction, machine-learning morphological quantitative statistics, and ecological niche modeling. Our analyses show that populations west of the Red River Basin represent an independent evolutionary lineage that is distinct in genetics, morphospace, and habitat suitability, and so warrants species recognition. The holotype of H. wettsteini, a species originally described in error from Costa Rica, grouped morphometrically with the population at the Red River Basin and eastward, and those west of the Red River Basin are referred to the recently described H. murphyi. The two species may have diversified due to a variety of geological and environmental factors, and their recognition exemplifies the importance of multifaceted approaches in taxonomy for downstream biogeographic studies on speciation scenarios.

Reptilia, China, east Asia, mud snakes, phylogenetics, systematics, red river, Vietnam

Justin M. Bernstein, Robert W. Murphy, Amy Lathrop, Sang Ngoc Nguyen, Nikolai L. Orlov and Bryan L. Stuart. 2024. Incorporating New Datatypes to Enhance Species Delimitation: A Case Study in Rice Paddy Snakes (Homalopsidae: Hypsiscopus).  Zootaxa. 5501(1); 39-55. DOI: doi.org/10.11646/zootaxa.5501.1.2 

 Researchgate.net/publication/383526819_Incorporating_New_Datatypes_to_Enhance_Species_Delimitation_Hypsiscopus

[Ichthyology • 2024] Aequidens pirilampo • A New Species of Aequidens (Cichliformes: Cichlidae) from the rio Paraguai basin, Brazil

Aequidens pirilampo

R.C. Oliveira, Tencatt, Deprá, Britzke, C. Oliveira & Graça, 2024

 DOI: 10.1590/1982-0224-2023-0106   

 

Abstract

Morphological and molecular data support the description of a new Aequidens species from the upper rio Correntes, considered herein as endemic to the upper rio Paraguai basin in the Cerrado biome in Brazil. The new species is distinguished from all congeners, except from A. plagiozonatus by having anteriorly oblique dark brown flank bars vs. vertical flank bars, and is additionally distinguished from some congeners by showing a discontinuous lateral band and presence of a dark cheek spot. The new species differs from Aequidens plagiozonatus by having the profile of the dorsal part of head almost straight (in lateral view), with a conspicuous concavity at the interorbital, and by the longer length of upper and lower jaws. Furthermore, delimitation analyses based on mitochondrial data provide additional support for the validity of the species. Our study data also revealed the occurrence, and consequently the first record, of A. plagiozonatus in the upper rio Araguaia basin, which was most likely driven by headwater capture events.

Keywords: Cerrado biome; DNA barcode; Molecular data; Morphological data; Species delimitation

Aequidens pirilampo, living specimens photographed just after capture in the rio Comprido, rio Paraguai River basin, 17°32’04.8”S 54°25’36.6”W, uncatalogued. Photos by L. F. C. Tencatt.

Aequidens pirilampo, new species

Diagnosis. Aequidens pirilampo is distinguished from all congeners, except A. plagiozonatus, by having anteriorly oblique dark brown flank bars (vs. vertical). The new species differs from A. plagiozonatus by having the dorsal head contour, from the tip of the snout to the vertical through the posterior margin of the eye, almost straight, except for a conspicuous concavity at the interorbital region (Fig. 2) (vs. dorsal head contour convex, with a subtle concavity at the interorbital region in occasional specimens), by having longer lower jaw (40.2–46.9% HL and 16.7–18.5% SL vs. 35.2–39.3% HL and 13.2–15.2% SL in A. plagiozonatus), and longer upper jaw, (12.2–15.1% SL vs. 9.3–12.1% SL in A. plagiozonatus). Additionally, A. pirilampo is distinguished from its congeners, except A. chimantanus Inger, 1956, A. diadema, A. epae, A. mauesanus Kullander, 1997, A. michaeli, A. patricki Kullander, 1984, A. plagiozonatus, A. potaroensis Eigenmann, 1912, and A. tubicen Kullander & Ferreira, 1991, by having a discontinuous lateral band in fixed specimens (vs. continuous). ...

Etymology. The specific epithet “pirilampo” means firefly in the popular Portuguese naming in the region the new species occurs. It is a bioluminescent Coleoptera very common in this region. These insects emit an intense green light, which alludes to the color pattern in life displayed by the new species. A noun in apposition.

Collecting sites of Aequidens pirilampo, showing (A) the ribeirão Comprido, its type-locality, (B) a stream with unknown name, and (C) the córrego de Cima, all tributaries of the rio Correntes in the border region of Mato Grosso and Mato Grosso do Sul states, Central Brazil. Photo (A) by LFCT, (B) by Heriberto Gimênes Jr., and (C) by Hans Evers.

Rianne Caroline de Oliveira, Luiz Fernando Caserta Tencatt, Gabriel de Carvalho Deprá, Ricardo Britzke, Claudio Oliveira and Weferson Júnio da Graça. 2024. A New Species of Aequidens (Cichliformes: Cichlidae) from the rio Paraguai basin, Brazil.  Neotrop. ichthyol. 22 (2); DOI: doi.org/10.1590/1982-0224-2023-0106   

Resumo: Dados morfológicos e moleculares apoiam a descrição de uma nova espécie de Aequidens do alto rio Correntes, considerada aqui como uma espécie endêmica da bacia do alto rio Paraguai, no bioma Cerrado no Brasil. A nova espécie distingue-se de todas as congêneres, exceto de Aequidens plagiozonatus, por apresentar barras laterais marrom-escuras oblíquas em direção anterodorsal vs. barras verticais nos flancos. Além disso, distingue-se de algumas espécies por apresentar uma faixa lateral descontínua e pela presença de uma mancha escura na porção entre a órbita e a margem preopercular. A nova espécie difere de A. plagiozonatus por apresentar o perfil da parte dorsal da cabeça (em vista lateral) aproximadamente reta, com uma concavidade conspícua na porção interorbital, e pelo maior comprimento das maxilas superior e inferior. Além disso, análises de delimitação baseadas em dados mitocondriais oferecem evidência a favor da validade da espécie. Nossos dados também revelaram a ocorrência e, consequentemente, o primeiro registro de A. plagiozonatus na bacia do alto rio Araguaia, provavelmente devido a eventos de captura de cabeceiras.

Palavras chave: Bioma Cerrado; Dados moleculares; Dados morfológicos; Delimitação de espécies; DNA barcode

[Crustacea • 2020] Macrobrachium naiyanetri, M. palmopilosum et M. puberimanus • Molecular Phylogeny and Species Delimitation of the Freshwater Prawn Macrobrachium pilimanus Species Group (Decapoda: Palaemonidae), with Descriptions of Three New Species from Thailand

Live habitus specimens of three new Macrobrachium species in the M. pilimanus group from Thailand.
Macrobrachium naiyanetri Siriwut; 
Macrobrachium palmopilosum Siriwut; 
Macrobrachium puberimanus Siriwut; 

in Siriwut, Jeratthitikul, Panha, Chanabun & Sutcharit​, 2020. 

DOI: 10.7717/peerj.10137 

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Abstract 

Specific status and species boundaries of several freshwater prawns in the Macrobrachium pilimanus species group remain ambiguous, despite the taxonomic re-description of type materials and additional specimens collected to expand the boundaries of some species. In this study, the “pilimanus” species group of Macrobrachium sensu Johnson (1958) was studied using specimens collected from montane streams of Thailand. Molecular phylogenetic analyses based on sequences of three molecular markers (COI, 16S and 18S rRNA) were performed. The phylogenetic results agreed with morphological identifications, and indicated the presence of at least nine putative taxa. Of these, six morphospecies were recognised as M. malayanum, M. forcipatum, M. dienbienphuense, M. hirsutimanus, M. eriocheirum, and M. sirindhorn. Furthermore, three morphologically and genetically distinct linages were detected, and are described herein as Macrobrachium naiyanetri Siriwut sp. nov., M. palmopilosum Siriwut sp. nov. and M. puberimanus Siriwut sp. nov. The taxonomic comparison indicated wide morphological variation in several species and suggested additional diagnostic characters that are suitable for use in species diagnoses, such as the shape and orientation of fingers, the rostrum form, and the presence or absence of velvet pubescence hairs and tuberculated spinulation on each telopodite of the second pereiopods. The “pilimanus” species group was portrayed as non-monophyletic in both ML and BI analyses. The genetic structure of different geographical populations in Thailand was detected in some widespread species. The species delimitation based on the four delimitation methods (BIN, ABGD, PTP and GMYC) suggested high genetic diversity of the “pilimanus” species group and placed the candidate members much higher than in previous designations based on traditional morphology. This finding suggests that further investigation of morphological and genetic diversity of Southeast Asian freshwater prawns in the genus Macrobrachium is still required to provide a comprehensive species list to guide efforts in conservation and resource management.

Live habitus specimens of three new Macrobrachium species in the M. pilimanus group from Thailand. (A) Macrobrachium naiyanetri sp. nov. (B) Macrobrachium palmopilosum sp. nov. (C) Macrobrachium puberimanus sp. nov.

Warut Siriwut, Ekgachai Jeratthitikul, Somsak Panha, Ratmanee Chanabun and Chirasak Sutcharit​. 2020. Molecular Phylogeny and Species Delimitation of the Freshwater Prawn Macrobrachium pilimanus Species Group, with Descriptions of Three New Species from Thailand. PeerJ. 8:e10137. DOI: 10.7717/peerj.10137

กุ้งก้ามขนชนิดใหม่ของโลก สกุล 𝘔𝘢𝘤𝘳𝘰𝘣𝘳𝘢𝘤𝘩𝘪𝘶𝘮 3 ชนิด จากประเทศไทย

สัตว์สกุลใหม่และชนิดใหม่ของโลกประจำปี 2020 ของ ASRU 

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[Botany • 2023] Spiranthes minamitaniana (Orchidaceae) • A New Orchid Species from Japan based on Morphological and Phylogenetic Data

Spiranthes minamitaniana Suetsugu,

in Suetsugu, Hirota et Suyama, 2023. 

オスズネジバナ  ||  DOI: 10.11646/phytotaxa.599.3.1 

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Abstract

The delimitation of species within the genus Spiranthes (Orchidaceae) is problematic due to the intricate interplay of phenotypic plasticity, ecological variation, and hybridization, making identification that relies solely on morphology inadequate. In light of morphological and phylogenetic data, we have described a self-pollinating species, Spiranthes minamitaniana within the Spiranthes sinensis species complex. Spiranthes minamitaniana shares several morphological features with S. hachijoensis, such as glabrous inflorescence rachis, ovaries, and sepals, a degenerated rostellum, pollinia without a viscidium, and papillate lip basal callosities. However, it can be distinguished by several morphological traits, including semicircular, weakly- or non-3-lobed stigma, and more conspicuous anther cap. Although S. minamitaniana is morphologically most similar to S. hachijoensis, phylogenetic analysis strongly suggested that S. minamitaniana has independently acquired a selfing reproductive mode and constitutes a separate genetic cluster from it. As such, this taxon is morphologically and phylogenetically distinct from other closely related species. Consequently, this taxon is morphologically and phylogenetically distinct from other closely related species.

Key words: Orchidaceae, integrative taxonomy, reproductive isolation, SNP data, species delimitation, Spiranthes sinensis species complex

 Spiranthes minamitaniana in its type locality.
(A) Habit. (B) Inflorescence with whitish cleistogamous flower. (C–D) Flower.

Scale bars: 30 mm (A) and 5 mm (B–D).

Spiranthes minamitaniana with reddish pink normal flower (Tadashi Minamitani Ss146, KYO).
(A) Inflorescence. (B) Flower, lateral view. (C) Flower, dorsal view. (D) Dorsal sepal. (E) Petal. (F) Lateral sepal. (G) Labellum. (H) Close-up of basal callosities of labellum. (I) Ovary and column. (J) Column, ventral view. (K) Column, dorsal view. (L) Pollinarium.

Scale bars: 20 mm (A), 3 mm (B–G), 0.5 mm (H) and 1 mm (I–M).

Spiranthes minamitaniana Suetsugu, sp. nov.

Japanese name. 「オスズネジバナ」 Osuzu-neji-bana 

Diagnosis. Spiranthes minamitaniana is morphologically most similar to S. hachijoensis but differs from S. hachijoensis by semicircular, weakly- or non-3-lobed stigma, and more conspicuous anther cap.

Comparison between Spiranthes hachijoensis (Nahoko Fukudome Ss203, KYO: left) and Spiranthes minamitaniana  (Tadashi Minamitani Ss204, KYO: right).
(A) Habit. (B) Inflorescence. (C) Flower. (D) Column, dorsal view. (E) Column, lateral view. (F) Column, ventral view.

Scale bars: 50 mm (A), 10 mm (B), 3 mm (C) and 1 mm (D–F). 

Photographed by Kenji Suetsugu

Kenji Suetsugu, Shun K. Hirota and Yoshihisa Suyama. 2023. Spiranthes minamitaniana (Orchidaceae), A New Orchid Species from Japan based on Morphological and Phylogenetic Data.  Phytotaxa. 599(3); 139-149. DOI: 10.11646/phytotaxa.599.3.1

  facebook.com/KenjiSuetsugu5/posts/2609032339254113

[Ichthyology • 2023] Phenacogaster lucenae • Molecular Species Delimitation and Description of A New Species of Phenacogaster (Characiformes: Characidae) from the southern Amazon Basin

 

Phenacogaster lucenae

Souza, Mattox, Vita, Ochoa, Melo & Oliveira, 2023

DOI: 10.3897/zookeys.1164.102436

Abstract

Phenacogaster is the most species-rich genus of the subfamily Characinae with 23 valid species broadly distributed in riverine systems of South America. Despite the taxonomic diversity of the genus, little has been advanced about its molecular diversity. A recent molecular phylogeny indicated the presence of undescribed species within Phenacogaster that is formally described here. We sampled 73 specimens of Phenacogaster and sequenced the mitochondrial cytochrome c oxidase subunit I (COI) gene in order to undertake species delimitation analyses and evaluate their intra- and interspecific genetic diversity. The results show the presence of 14 species, 13 of which are valid and one undescribed. The new species is known from the tributaries of the Xingu basin, the Rio das Mortes of the Araguaia basin, and the Rio Teles Pires of the Tapajós basin. It is distinguished by the incomplete lateral line, position of the humeral blotch near the pseudotympanum, and shape of the caudal-peduncle blotch. Meristic data and genetic differentiation relative to other Phenacogaster species represent strong evidence for the recognition of the new species and highlight the occurrence of an additional lineage of P. franciscoensis.

Keywords: Biodiversity, Characinae, mitochondrial DNA, Neotropical freshwater fishes, Phenacogasterini

Phenacogaster lucenae
A MZUSP 126754, holotype, 26.7 mm SL, Brazil, Pará, Novo Progresso, Xingu basin, stream affluent of Rio Curuá
 B LBP 30738, paratype, 38.1 mm SL, Brazil, Mato Grosso, Primavera do Leste, Xingu basin, Rio Culuene, Córrego Xavante
C LBP 25217, paratype, 30.6 mm SL, Brazil, Pará, Altamira, Xingu basin, Rio Treze de Maio.

 Phenacogaster lucenae sp. nov.

Phenacogaster sp. Xingu: Souza et al. 2022: 9, figs 3, 5 

[molecular phylogeny; cited in figures also as Phenacogaster sp. Xingu].

Diagnosis: Phenacogaster lucenae is distinguished from all congeners except P. tegata (Eigenmann, 1911), P. carteri (Norman, 1934), P. napoatilis Lucena & Malabarba, 2010, and P. capitulata Lucena & Malabarba, 2010 by having an incomplete lateral line (vs. complete lateral line). It differs from P. tegata by the presence of a round or slightly longitudinal oval humeral blotch near the pseudotympanum and distant from the vertical through dorsal-fin origin (vs. humeral blotch longitudinally elongated distant from pseudotympanum, closer to vertical through dorsal-fin origin). The new species differs from P. carteri by having a humeral blotch in males and females (vs. absence of humeral blotch in both sexes) and from P. napoatilis and P. capitulata by having a humeral blotch in both sexes (vs. absence of humeral blotch in males). In addition to the incomplete lateral line (vs. complete), P. lucenae differs from P. retropinna Lucena & Malabarba, 2010 by the anal-fin origin at vertical through base of first or second dorsal-fin branched ray (vs. anal-fin origin located posteriorly to that point), and from P. ojitata Lucena & Malabarba, 2010 by the round caudal peduncle blotch slightly reaching over the middle caudal-fin rays (vs. a diamond-shaped caudal peduncle blotch and further extending over the middle caudal-fin rays).

Etymology: Phenacogaster lucenae is named in honor of Dr. Zilda Margarete Seixas de Lucena, an eminent ichthyologist who has significantly contributed to our knowledge of Phenacogaster taxonomy. A noun in genitive case.

 Camila S. Souza, George M. T. Mattox, George Vita, Luz E. Ochoa, Bruno F. Melo and Claudio Oliveira. 2023. Molecular Species Delimitation and Description of A New Species of Phenacogaster (Teleostei, Characidae) from the southern Amazon Basin. ZooKeys. 1164: 1-21. DOI: 10.3897/zookeys.1164.102436

[Ichthyology • 2023] Etheostoma xanthovum • A New Species of Spottail Darter (Percidae: Etheostomatinae: Etheostoma) Endemic to the Clarks River in Kentucky and Tennessee

[A] Etheostoma xanthovum

Wood, Harrington, Alley, Thomas, Simmons & Near, 2023

[C] E. oophylax, 

[D] E. chienense 

DOI: 10.3374/014.064.0102 

twitter.com/TJNear

 Abstract  

Etheostoma xanthovum, the Clarks Darter, is described as a new species endemic to the Clarks River drainage in Kentucky and Tennessee, USA. Etheostoma xanthovum was previously recognized as Etheostoma oophylax based on morphological characters. Subsequent to the description of E. oophylax, molecular phylogenetic analyses consistently resolved specimens from the Clarks River drainage and E. chienense as sister species, which together formed a sister clade to all other sampled populations of E. oophylax. Our analyses of morphological trait data, mitochondrial DNA, and genomic sampling using double digest restriction-site associated DNA sequencing support the distinctiveness of E. xanthovum. Morphologically, E. xanthovum differs slightly from E. oophylax in the modal number of dorsal fin rays (12 versus 11) and in the average number of scale rows around the caudal peduncle (21.8 versus 20.4). Etheostoma xanthovum does not share mitochondrial DNA haplotypes with E. oophylax or E. chienense. Phylogenomic analysis of an average of 28,448 double digest restriction-site associated DNA loci per sampled specimen resolves E. xanthovum and E. chienense as sister species, and assessment of genomic divergence supports the hypothesis that each of these two species represents a distinct and independently evolving lineage. In addition, we report a range extension of E. oophylax in the Obion River drainage, a direct tributary of the Mississippi River.

KEYWORDS: species delimitation, phylogeny, Teleostei

This new species was thought to be a population of the Guardian Darter, E. oophylax (C) but is the sister lineage of the endangered Relict Darter, E. chienense (D)

 

Julia E. Wood, Richard C. Harrington, Zachariah D. Alley, Matthew R. Thomas, Jeffrey W. Simmons and Thomas J. Near. 2023. A New Species of Spottail Darter Endemic to the Clarks River in Kentucky and Tennessee (Percidae: Etheostomatinae: Etheostoma). Bulletin of the Peabody Museum of Natural History. 64(1); 11-37. DOI: 10.3374/014.064.0102

 twitter.com/TJNear/status/1643209745224925185

 

[Mollusca • 2022] The First Phylogenetic and Species Delimitation Study of the Nudibranch Genus Gymnodoris (Gastropoda: Nudibranchia) reveals High Species Diversity

in Knutson & Gosliner, 2022. 

DOI: 10.1016/j.ympev.2022.107470

Highlights: 

• First phylogenetic study of the nudibranch genus Gymnodoris.

• Gymnodoris comprises three main clades and is most closely related to the genera Vayssierea and Lecithophorus.

• A linear gill arrangement appears to have evolved multiple times within Gymnodoris.

• Genus Analogium, defined by a linear gill arrangement, is maintained as a junior synonym of Gymnodoris.

• At least 81% of Gymnodoris is undescribed.

Abstract

Nudibranchs are charismatic marine gastropods that lack a shell in the adult stage. While most nudibranchs feed on sessile animals such as sponges, bryozoans, and cnidarians, the nudibranch genus Gymnodoris Stimpson, 1855 evolved a more active and predatory lifestyle, including sea slug predation, cannibalism, and oddly enough, fish-fin parasitism. At the beginning of our work, no phylogenetic hypothesis existed for the genus, nor a clear picture of how Gymnodoris is related to other nudibranchs. Here we set out to reconstruct Gymnodoris phylogeny, investigate species diversity, and clarify the status of the genus name Analogium, which had been proposed for members of the genus with a linear gill filament arrangement. We present the first phylogenetic hypothesis for Gymnodoris, reconstructed by maximum likelihood and Bayesian inference using two mitochondrial and two nuclear loci, with gill filament arrangement plotted on the phylogeny. The backbone of the phylogeny remains unresolved with theseloci, however, we found that Gymnodoris comprises three main well-supported clades, which we refer to as the “subornata”, “citrina” and “varied” clade, the latter two clades being comprised of several well-supported subclades. The sister group to Gymnodoris is a clade including the genera Vayssierea and Lecithophorus. Based on ABGD and PTP species delimitation methods, we conservatively estimate 65–70 species comprise our dataset. We further estimate that approximately 81% of the species we sampled are undescribed, and note that a linear gill filament arrangement has evolved multiple times within the genus. Gymnodoris is only monophyletic when the species with a linear gill arrangement are included. Therefore, at this time, we agree with the synonymy of Analogium striata with Gymnodoris striata by Rudman and Darvell (1990) and that the genus name Analogium is warranted as a junior synonym of Gymnodoris. Given the extensive undescribed diversity, and lack of resolution at some of the nodes in the phylogeny, patterns of diversification in diet are impossible to discern at this time and will require a large effort to both describe Gymnodoris species diversity and the diets of these candidate species.

 

Keywords: Opisthobranch, Heterobranchia, Cryptic diversity, Indo-Pacific, Polyceridae

Conservation statement and conclusion: 

Undescribed and undocumented diversity is cause for concern on many levels; it hinders our understanding of evolutionary and ecological processes and our ability to communicate that information within and outside of the scientific community. The latter is perhaps most pressing of all in today’s world, as this lack of data directly impacts conservation. Without a robust assessment of the diversity of species in many locations, coastal communities lack information that can inform conservation decisions. This is particularly true in developing regions with high pressure on marine resources, which is characteristic of the highly diverse Western Pacific and specifically the Coral Triangle, the center of marine diversity (Carpenter et al., 2010) where Gymnodoris and many of its relatives are found.

We provide here the first ever phylogenetic hypothesis for the genus Gymnodoris, which has enabled us to begin to clarify Gymnodoris taxonomy and provided evidence supporting the synonymy of Analogium with Gymnodoris. We can now begin to ask what the significance is, if any, of linear gill arrangement in this lineage, and continue to determine the diets of Gymnodoris species, including of all of the newly distinguished species we have identified here. The results of our species delimitations provide taxonomic hypotheses that will help researchers distinguish between and describe diversity within Gymnodoris and ultimately help us to study and understand the role that diet and feeding have played in the evolution of this highly diverse group of nudibranchs.

 

  

 Vanessa L. Knutson and Terrence M. Gosliner. 2022. The First Phylogenetic and Species Delimitation Study of the Nudibranch Genus Gymnodoris reveals High Species Diversity (Gastropoda: Nudibranchia). Molecular Phylogenetics and Evolution. 171; 107470. DOI: 10.1016/j.ympev.2022.107470