Dark Blotches Research Articles

Reallocation of the magnificent catshark Proscyllium magnificum Last & Vongpanich, 2004 to the genus Ctenacis Compagno, 1973 (Carcharhiniformes: Proscylliidae).

The magnificent catshark Proscyllium magnificum was described in 2004 based off five specimens collected in the Andaman Sea off Myanmar. It was originally allocated to the genus Proscyllium, but recent molecular analyses suggested it was more closely related to the harlequin catshark Ctenacis fehlmanni from the western Indian Ocean. This study incorporated meristics and external and internal morphology, together with molecular data to reclassify the magnificent catshark as Ctenacis magnificum and provides revised diagnoses for the genera Ctenacis and Proscyllium. Ctenacis consists of two allopatric Indian Ocean species, while Proscyllium is monotypic genus confined to the northwest Pacific. The revised Ctenacis can be distinguished from Proscyllium in having a broader and longer head (head length 21%-23% vs. 16%-18% of total length), distance between pectoral and pelvic bases shorter than head length (vs. greater than head length), more teeth (upper jaw with 80-86 vs. 46-62 tooth files), and a complex colour pattern of dark reddish-brown blotches and saddles (vs. colour pattern of small black spots). A revised key to the genera of proscylliids and species of Ctenacis is provided.

Integrative taxonomy reveals a new species of Characidium (Characiformes: Crenuchidae) shared by tributaries of upper Tapajós and Xingu river basins, Brazil

AbstractA new species of Characidium shared by adjacent tributaries of the upper portions of the Tapajós and Xingu river basins is described. Characidium varii, new species, can be distinguished from the congeners by having distinctly speckled pattern of colouration, including dark blotches on cheek and ventral surface of head, by having conspicuous dark marks on fins, along with a single row of dentary teeth, isthmus completely covered by scales, 14 circumpeduncular scales, and swimbladder reduced. Molecular data reinforce the validation of the new species. The distribution of C. varii supports the hypothesis of the existence of a faunistic mixing between Tapajós and Xingu river basins, corresponding to the region of the Serra do Cachimbo and surrounding areas, previously proposed in the literature.

A Tale of Three Oceans—Taxonomy of the Holothuria (Thymiosycia) arenicola Semper, 1868 complex (Echinodermata: Holoturoidea: Holothuriidae)

The ubiquitous sea cucumber Holothuria (Thymiosycia) arenicola Semper, 1868, externally characterized by a double row of dark blotches of various sizes on its dorsal body wall and a cryptic behaviour, is generally assumed to have a wide tropical distribution, although it has not been reported from the Eastern Atlantic. Careful morphological examination, with emphasis on the ossicle assemblage, of type and non-type H. arenicola specimens sampled in the Indian, Pacific and Atlantic Ocean, its subjective synonyms and species with a similar colouration and habit, revealed that H. arenicola is often confused with other species. This paper formally separates the different species in the H. arenicola complex, one of them being a species new to science: Holothuria (Thymiosycia) kerriensis sp. nov. Additionally, we describe two other species that are often confused with H. arenicola: Holothuria (Lessonothuria) gracilis Semper, 1868 and H. (Thymiosycia) strigosa Selenka, 1867. The H. arenicola complex per se is keyed-out, with the ossicle assemblage of the musculature being recognised as an important, previously largely neglected, guide. This contribution highlights the importance of building and curating well-maintaned natural history collections to understand biodiversity through time and space.

Effect of <i>Bacillus subtilis</i> in combination with chitosan salicylate on peroxidase and catalase activity in <i>B. sorokiniana</i> infected wheat

The aim of the work was to study the effect of Bacillus subtilis strains VKM B‑2604D and VKM B‑2605D which form the basis of the Vitaplan biological product, and their combinations with chitosan salicylate on antioxidant defense enzymes in the process of formation of resistance of wheat plants to infection with the dark brown blotch pathogen Bipolaris sorokiniana. In wheat plants treated with B. subtilis strains and their combinations with chitosan salicylate, upon subsequent infection, catalase and peroxidase are activated, which regulate the intensity of oxidative stress induced by the introduction of the pathogen. Taking into account the data obtained by us, it can be assumed that the increase in plant resistance to the pathogen is realized through the control of the activity of antioxidant enzymes (inparticular, catalase, peroxidase), which maintain the concentration of H2O2 at the level necessary for the neutralization of the phytopathogen in tissues, including the direct destruction of the invading pathogen and / or activation of crosslinking and lignification of the cell wall. These processes strengthen the cell wall and help contain the spread of the pathogen in the plant. At the same time, protective reactions are also switched on, leading to the development of induced resistance in wheat plants to dark brown spotting, which manifests itself in a decrease in the development of the disease by 25–45% relative to the infected control in the treated plants. The obtained results indicate that the combination of active strains of microorganisms-antagonists of plant pathogens and chitosan salicylate is promising for increasing the biological efficiency and expanding the spectrum of action of the developed prescription forms of biological products.

Bisecting the type series of Leporinus paranensis Garavello and Britski, 1987 (Characiformes, Anostomidae)

The type series of Leporinus paranensis includes two distinct species, one of which is herein described as new. Leporinus paranensis is redescribed based on its holotype, two paratypes, and additional specimens recently sampled in tributaries of the Grande river, in the north portion of the upper Paraná basin in Brazil. A new species of Leporinus is described based on specimens collected in all major tributaries of the upper Paraná basin in Brazil, and tributaries of the Paraná river in Paraguay. Both species share the presence of three unicuspid teeth on the premaxillary and four on dentary, terminal mouth and three dark midlateral blotches on the body. The new species is distinguished from L. paranensis based on the number of scale series around the caudal peduncle (12 vs. 16). The variation in the body shape of both species were compared through a Principal Component Analysis and showed that they share a similar body shape. Species delimitation analyses using DNA Barcode were applied to compare samples of the new species to congeners and corroborated the uniqueness of the new species. In addition, molecular data revealed that L. bahiensis, L. octofasciatus, and L. taeniatus are possibly closely related to the new species. The conservation status of L. paranensis and the new species are discussed using the IUCN criteria.

Integrative Metabolomic and Transcriptomic Analyses Reveal the Mechanism of Petal Blotch Formation in Rosa persica.

Petal blotch is a specific flower color pattern commonly found in angiosperm families. In particular, Rosa persica is characterized by dark red blotches at the base of yellow petals. Modern rose cultivars with blotches inherited the blotch trait from R. persica. Therefore, understanding the mechanism for blotch formation is crucial for breeding rose cultivars with various color patterns. In this study, the metabolites and genes responsible for the blotch formation in R. persica were identified for the first time through metabolomic and transcriptomic analyses using LC-MS/MS and RNA-seq. A total of 157 flavonoids were identified, with 7 anthocyanins as the major flavonoids, namely, cyanidin 3-O-(6″-O-malonyl) glucoside 5-O-glucoside, cyanidin-3-O-glucoside, cyanidin 3-O-galactoside, cyanidin O-rutinoside-O-malonylglucoside, pelargonidin 3-O-glucoside, pelargonidin 3,5-O-diglucoside, and peonidin O-rutinoside-O-malonylglucoside, contributing to pigmentation and color darkening in the blotch parts of R. persica, whereas carotenoids predominantly influenced the color formation of non-blotch parts. Zeaxanthin and antheraxanthin mainly contributed to the yellow color formation of petals at the semi-open and full bloom stages. The expression levels of two 4-coumarate: CoA ligase genes (Rbe014123 and Rbe028518), the dihydroflavonol 4-reductase gene (Rbe013916), the anthocyanidin synthase gene (Rbe016466), and UDP-flavonoid glucosyltransferase gene (Rbe026328) indicated that they might be the key structural genes affecting the formation and color of petal blotch. Correlation analysis combined with weighted gene co-expression network analysis (WGCNA) further characterized 10 transcription factors (TFs). These TFs might participate in the regulation of anthocyanin accumulation in the blotch parts of petals by modulating one or more structural genes. Our results elucidate the compounds and molecular mechanisms underlying petal blotch formation in R. persica and provide valuable candidate genes for the future genetic improvement of rose cultivars with novel flower color patterns.

A new species of Hemiphyllodactylus (Squamata, Gekkonidae) from southwest Yunnan, China.

A new species of gekkonid, Hemiphyllodactylusgengmaensissp. nov., is described based on six specimens from Gengma Dai and Wa Autonomous County, Yunnan, China. The new species can be distinguished from its congeners by a significant genetic divergence of greater than 9.7% in the mitochondrial ND2 gene and a combination of the following characters: a maximum SVL of 43.24mm; 8 or 9 chin scales; six circumnasal scales; 2 or 3 internasal scales; 9-11 supralabial scales; 8 or 9 infralabial scales; 11-18 dorsal scales; 8-10 ventral scales; a manual lamellar formula of 5-5-5-4 or 5-6-5-4 and a pedal lamellar formula of 5-5-6-5; 20-25 precloacal and femoral pore-bearing scales contiguous in males; dark postorbital stripes or striping on body; dark dorsal transverse blotches present; and a brown postsacral mark bearing anteriorly projecting arms. The discovery of this new species brings the number of Hemiphyllodactylus species in China to 15.

A new distinctively striped species of bushynose catfish (Siluriformes: Loricariidae: Ancistrus) from the Pachitea River drainage, Pasco, Peru.

With 76 currently valid species, the bushynose catfish genus Ancistrus is the fourth most species-rich catfish genus, yet Ancistrus diversity remains underestimated, with many species still undescribed. This is especially true of the Peruvian Andean headwaters of the Amazon, which are rich in unnamed Ancistrus species but have received little recent taxonomic attention. We describe a distinctively striped new Ancistrus species from tributaries of the Palcazú River, in the Pachitea-Ucayali-Amazonas drainage basin. The new species differs from all congeners by having black, vermiculated lines covering the head and two to four distinct black, parallel, lateral body stripes from head to caudal fin (vs. body uniformly colored or with dark or light spots or blotches over head and body, or black vermiculate lines on flanks). The new species is the fifth valid species of Ancistrus described from the rich Ucayali River ichthyofauna. It has previously been recognized in the aquarium fish trade as L267.

Description of a New Species Named Cabillus wui of Genus Cabillus (Teleostei: Gobiiformes: Gobiidae) from Southeastern China Sea

A tiny goby collected from Taiwan Strait which has been identified as a member of genus Cabillus seems individual, named Cabillus wui sp. nov.. Many pieces of evidence point to it as a new species. This species could be distinguished as follows. There is a dark blotch on the first-dorsal-fin membrane; predorsal scales 6; the first dorsal spine very depressed, is the longest, and is very close to the second dorsal spine; pelvic sucker is emarginated; median predorsal scales is present; all pectoral-fin elements are 20 branched soft rays; every fin nearly completely patternless and transparent except slightly patterned first dorsal fin; dorsal fin possesses 10 soft rays. This species is described in this article with the comparison of the other species in the genus Cabillus. An overview of this genus is also given. Besides, a key for distinguishing the species in this genus is also provided.

A new species of pit-viper from the Ayeyarwady and Yangon regions in Myanmar (Viperidae, Trimeresurus).

In a genomic study by Chan and colleagues, pit-vipers of the Trimeresuruserythrurus-purpureomaculatus complex from the Ayeyarwady and Yangon regions in Myanmar were demonstrated to be a distinct species based on robust population genetic and species delimitation analyses. Here, we provide morphological characterizations and a formal description of those populations as a new species. The new species, Trimeresurusayeyarwadyensissp. nov., is most closely related to T.erythrurus and T.purpureomaculatus and shares morphological characteristics with both of those species. Some specimens of T.ayeyarwadyensissp. nov. have green dorsal coloration and no distinct dorsal blotches (a trait shared with T.erythrurus but not T.purpureomaculatus), while others have dark dorsal blotches (a trait shared with T.purpureomaculatus but not T.erythrurus). The distinct evolutionary trajectory of the new species, coupled with the lack of obvious morphological differentiation, represents a classic example of the cryptic nature of species commonly found in the Trimeresurus group of Asian pit-vipers and underscores the need for data-rich analyses to verify species' boundaries more broadly within this genus.

Skin transcriptomic correlates of cave-dwelling Sinocyclocheilus cavefish

IntroductionWith 78 species, Sinocyclocheilus cavefish constitute the largest cavefish radiation in the world. They exhibit remarkable morphological diversity across three habitat types: surface (surface morphs, normal-eyed, variably colored), exclusively-cave-dwelling (stygobitic morphs, eyeless, depigmented), and intermediate between cave and surface (stygophilic morphs, micro-eyed, partially depigmented). Distinctive traits of Sinocyclocheilus include variations in eye and skin conditions associated with their habitat, despite the role of the skin in sensing environmental changes, its habitat correlates are less understood, compared to the well-studied eye conditions.MethodsHere, we analyzed the correlation between Sinocyclocheilus skin morphology and its habitat, utilizing morphological and transcriptomics-based methods. We generated skin RNA-sequencing data for nine species and integrated those with existing data from five additional species. These 14 species represent the primary clades and major habitats of these cavefish.ResultWe identified 7,374 orthologous genes in the skin transcriptome data. Using a comparative transcriptomics approach, 1,348 differentially expressed genes (DEGs) were identified in the three morphotypes. GO and KEGG enrichment analyses suggested that these genes were mainly involved in energy metabolism, immunity and oxidative stress-related functions. Genes related to immune, apoptotic, and necrotic functions were identified through positive selection analysis of orthologous genes. The maximum likelihood phylogenetic tree, based on 1,369, single-copy orthologous genes of the species, was largely concordant with the currently established RAD-seq and mt-DNA based phylogenies. Species with higher cave dependence present lighter coloration, fewer dark blotches, and diminished scale morphology and coverage. We also found that differences in skin gene expression and positive selection effects may have contributed to the degradation of skin color and scales.DiscussionOur study highlights the significance of habitat in shaping skin metabolism, pigmentation variation, and morphology while offering insights into the molecular mechanisms driving these habitat-specific adaptations in Sinocyclocheilus. These findings underscore the transcriptional variation in adapting to diverse environments and contribute to future studies on the evolution and ecology of cavefish.

Description of a new species of Schizodon (Characiformes: Anostomidae) from the upper rio Tapajs basin, Brazil.

A new species of Schizodon with five dark transverse blotches on the body and a large black blotch at the end of the caudal peduncle is described from the rio Arinos, upper rio Tapajs basin, in the Brazilian Amazon. The new species shares a color pattern composed by transverse brown bars and a caudal fin blotch with Schizodon fasciatus and S. trivittatus but possess twelve rows of scales around the caudal peduncle, a unique character among the species of genus.

Characterizing the Dark Mahseer, Naziritor chelynoides (McClelland, 1839): A Morphological, Osteological, and Molecular Approach

Dark mahseer, Naziritor chelynoides is a vulnerable stream fish in several Asian countries, and developing an effective conservation strategy is impeded by incomplete information about its taxonomy. To address this research gap, in the current study dark mahseer collected from Himalayan stream in India (29°21`99.5` N and 79°33`23.9` E) were examined for their morphometric, meristic, osteological, and molecular characteristics. This study discovered unique features of dark mahseer, including its thin non-hypertrophied lower lip without median lobe, complete post-labial groove, 33 to 34 central perforated lateral line scales, a dark elliptical blotch at the angle of the operculum, and numerous fine black dots on a crescent pattern on scales. This species has 9 to 11 slender gill rakers (595.93±148.71 μm in length), 40 to 41 total vertebrae, 38 to 39 neural spines, 14 to 15 hemal spines, and fused first to fourth abdominal vertebrae. Molecular analysis of cytochrome c oxidase subunit 1 gene (cox1), cytochrome b (cytb), and ATPase subunit 6&8 (ATPase 6&8) genes revealed the genetic distance of 0.08 to 0.10, 0.12 to 0.13, and 0.01 to 0.11 respectively from other Tor species. Our study enhances knowledge of dark mahseer's taxonomy, supporting conservation strategies for this valuable fish species.

First Northwest Pacific Record of the Apogonid Fish, <i>Pristiapogon taeniopterus</i> (Actinopteri: Kurtiformes) from Minamidaito Island, Okinawa Prefecture, Japan

A single specimen of apogonid fish, Pristiapogon taeniopterus (Bennett, 1836) (Actinopteri: Kurtiformes) previously reported from Micronesia, Polynesia, Melanesia, the Hawaiian Islands, Madagascar and Indian Ocean, was recently caught at Minamidaito Island, Okinawa Prefecture, Japan. This specimen is the first record of the species from the Northwest Pacific including Japan and is now the most northerly record. Pristiapogon taeniopterus differs from its congeners in having developed gill rakers 15–17; circumpeduncular scales 15–18; upper-jaw length 17.9–21.5% SL; distinct dark stripes on both dorsal, anal and both lobes of caudal fin; dark vertical bar posterior to the base of caudal fin incompletely developed or interrupted at the central portion of the fin; dark band or blotch on posterior part of caudal peduncle just anterior to caudal-fin base; and pectoral-fin rays usually 13. The new standard Japanese name “Sumihiki-ishimochi” is proposed for the species.

Description of a New Deep-Water Eulophiid Fish (Perciformes: Zoarcoidei) from Japan

The genus Eulophias, which is an enigmatic group of the suborder Zoarcoidei, previously comprised two rare species: Eulophias tanneri Smith, 1902 (type species and a senior synonym of Eulophias owashii Okada and Suzuki, 1954) and Eulophias koreanus Kwun and Kim, 2012. Here we describe a new species, Eulophias spinosior, based on 71 specimens (94.9–182.3 mm in standard length, SL) collected from the upper slope of the northwestern Pacific off southern Japan at depths of 257–555 m. It readily differs from its two congeners in having 133–143 dorsal-fin spines, 109–116 anal-fin soft rays, 5–6 pectoral-fin rays, and 146–156 total vertebrae, and in lacking a dark band posterior to the eye and a series of dark blotches midlaterally on the trunk and tail. Regarding bathymetric distribution, the new species occurs much deeper than E. koreanus and E. tanneri. Eulophias spinosior, new species, is sexually dimorphic, with males having large, stout, modified canines at the tips of the premaxillary and dentary (vs. only slightly enlarged in females). Dentition of males also differs from that of females in that most teeth are uniserially arranged in each jaw (vs. distinct two rows anteriorly).

Two New species of Impatiens (Balsaminaceae) from Myanmar

Impatiens yinyinkyii M.M.Latt, B.B.Park & Nob.Tanaka and I. horizontalis M.M.Latt, B.B.Park & Nob.Tanaka (Balsaminaceae) are described and illustrated. Those new species were discovered in Htamanthi Wildlife Sanctuary, northwestern Myanmar. Description, photographic data as well as the comparative characters with their similar species are provided. Impatiens yinyinkyii is similar to I. masonii Hook.f., but differs in having three dark purple blotches in center of flower, specifically at base of dorsal and upper petals of united petals. Impatiens horizontalis resembles I. stenantha Hook.f., I. prostrata Hook. f., I. repens Moon, I. procumbens Franch and I. reptans Hook. f. in having larger, glabrous and elliptic to lanceolate leaves, serrate margin with antrorse bristles, deeply bucciniform lower sepal, twisted spur with abruptly capitate tip, linear ovary, spheroid seed and finally uncommon conspicuous stout stem which is horizontally creeping.

A new species of Leporinus (Characiformes: Anostomidae) from the Serra do Cachimbo, Pará State, Brazil

Abstract A new small-sized species of Leporinus is described from rio Braço Norte, a tributary of rio Teles Pires, in the Tapajós drainage in the Brazilian Amazon, and its phylogenetic position is proposed based on molecular data. The new species is diagnosed among Anostomidae by having three unicuspid teeth on the premaxilla and four on the dentary, 12 scale rows around the caudal peduncle, dark blotches on the trunk, and large non-midlateral dark blotches over the body, with one or two large blotches in region ventral to the lateral line between the pectoral and pelvic fins. DNA Barcode sequences suggest that the new species is closely related to Leporinus octomaculatus. In addition, samples of intermediate forms in altered areas are herein identified as putative hybrids between the new species and L. octomaculatus. The new species is popular in the international aquarium market, and its area of occurrence has been affected by anthropogenic changes in the last years.

A new species of Loricaria (Loricariidae: Loricariinae) from the upper Amazon River basin, Colombia

Abstract A new species of Loricaria is described from the upper Amazon River basin, Colombia. The new species is distinguished from its congeners primarily by having the dorsal portion of head with uniform black or dark brown coloration extending to three or four plates posterior to dorsal fin base, or with two longitudinal bands from tip of the snout to origin of dorsal fin; abdominal plates tightly joined and completely covering the median abdominal space and pectoral girdle; and pectoral and dorsal fins totally black or dark brown, without bands, spots, or blotches. The new species is further distinguished by plate counts, and body measurements. An analysis of genetic distances using the cytochrome oxidase c subunit 1 marker of the mitochondrial genome showed a clear differentiation between the new species and Loricaria cataphracta (5.8–7.6%), L. nickeriensis (5.7–6.1%), and L. simillima (2.7–7.0%). Species delimitation analyses were carried out, which further supported the new species as a divergent lineage within the genus. Fish species diversity of the upper Amazon River basin and taxonomic issues related to L. simillima are included as part of the discussion.

A new species of Corydoras (Siluriformes: Callichthyidae) from the rio Madre de Dios basin, Peruvian Amazon, with comments on Corydoras aeneus identity

Abstract A new species of Corydoras is described from tributaries to the rio Araza, an affluent of the rio Inambari, itself a tributary to the rio Madre de Dios, rio Madeira basin in the Peruvian Amazon. The new species can be distinguished from its congeners by the following features: (I) absence of contact between the posterior process of the parieto-supraoccipital and the nuchal plate, (II) a single, large conspicuous dark brown or black blotch on anterodorsal portion of flank; blotch somewhat rounded to roughly diamond shaped, and (III) absence of dark blotches on fins. General comments on the identity of Corydoras aeneus are also provided.

New record of anthiadine fish, Plectranthias yamakawai (Actinopterygii: Perciformes: Serranidae), from the Philippines

A single specimen of Plectranthias yamakawai Yoshino, 1972, 168.86 mm SL, obtained in a fish market in Zambales, Philippines, represents the first report in the country. Currently, the fish is only known to occur in Japan, Taiwan, and Samoa Islands. This anthiadine fish varies from other species of genus Plectranthias by having 30–33 lateral-line scales, a single red blotch below the lateral line, and numerous dark green blotches on the upper half of the body. The mitochondrial cytochrome oxidase subunit I (COI) is also described for the first time for this species in this article. The pairwise genetic distance computation reveals that P. yamakawai has a very low distance from the sequences of the other eight species of Plectranthias that have been submitted to GenBank. This is the sixth species of the genus Plectranthias to be reported from the western coast of Luzon, Philippines.