[Ichthyology • 2022] Moema juanderibaensis • A New Species of the Seasonal Killifish Genus Moema (Cyprinodontiformes: Rivulidae) from the Piraí watershed in the Southwest Amazon Basin

 

Moema juanderibaensis

 Drawert, 2022 

DOI: 10.1590/1982-0224-2022-0067  

   Researchgate.net/publication/366335860

 

Abstract

Moema, a genus of the Rivulidae family, currently comprises 20 valid species. Most of these species inhabit temporary pools in the Amazon basin and only one species is found in the upper Paraguay basin. A new member of this genus from the upper Río Madeira drainage is here described. Males of the new species differ from all congeners by the combination of a color pattern consisting of oblique, sometimes chevron-like, irregular rows of red and light blue double-dots on body; dark yellowish to golden pectoral fins with no visible markings; and a stripe pattern on the ventral section of caudal fin with a very narrow black marginal line, intermittent or even absent. The existence of infrageneric species groups within Moema, the geographic distribution and taxonomic aspects of the species present in the Ríos Mamoré and Iténez/Guaporé rivers drainages, and the observation of intraspecific aggression between males and amphibious lifestyle in the new species are discussed.

Keywords: Bolivian Amazon basin; New species; Rivulids; Taxonomy; Temporary water bodies

 

Moema juanderibaensis, MNKP 16539, holotype, male, 41.9 mm SL
(24 days after collection, left side),
Bolivia, Santa Cruz, Santa Rosa del Sara.

Moema juanderibaensis, MNKP 16539, holotype, male, 41.9 mm SL
(2 days after collection, right side),
Bolivia, Santa Cruz, Santa Rosa del Sara.

Moema juanderibaensis, new species

Diagnosis. Moema juanderibaensis differs from congeners by a unique combination of the following characters on males: pattern of oblique, sometimes chevron-like, irregular rows of red and light blue double-dots on flanks; dark yellowish to golden pectoral fin with no visible markings (dots or spots); and ventral part of caudal-fin stripe pattern with very narrow black marginal line, intermittent or even absent (vs. never in this combination). The new species is distinguished from Moema apurinan, M. beucheyi, M. funkneri, M. hellneri, M. heterostigma, M. nudifrontata, M. pepotei, M. piriana, M. portugali, M. quiii, M. schleseri, and M. staecki by the oblique arrangement of red and light blue double-dots on flanks (vs. flank color pattern arranged in horizontal lines or rows of dots). It differs from M. manuensis, M. obliqua, M. peruensis, M. rubrocaudata, M. schleseri, and M. wischmanni by the presence of red dots on flanks mostly arranged in oblique, sometimes chevron-like, rows (vs. absence of dots, or arranged in vertical rows or randomly distributed). It is distinguishable from M. boticarioi, M. kenwoodi, and M. obliqua by the absence of dots, spots or any other markings on pectoral fins of males (vs. presence of dark reddish-brown dots, few dark green dots or longitudinally elongated dark brown spots); from M. claudiae by the absence of black humeral blotch in males (vs. presence); and from M. schleseri by the ground color of pectoral fins (brown-yellowish to golden vs. hyaline) and color pattern of ventral section of caudal fin (thin black marginal line, sometimes intermittent and inconspicuous or even absent, and broad deep orange to red stripe vs. ventralmost black stripe broad, and orange stripe with dark red dots). Additionally, it is also distinguished from M. boticarioi by the absence of brown dots or other marks on dorsum (vs. dorsum with brown dots).

Etymology. Named juanderibaensis in reference to the name of the ranch “Juan Deriba” where the type locality is situated. An adjective.

Heinz Arno Drawert. 2022. A New Species of the Seasonal Killifish Genus Moema (Cyprinodontiformes: Rivulidae) from the Piraí watershed in the Southwest Amazon basin.   Neotrop. ichthyol. 20(4). DOI: 10.1590/1982-0224-2022-0067   

  Researchgate.net/publication/366335860_A_new_species_of_Moema_from_the_Pirai_watershed_in_the_SW_Amazon_basin

Resumen: Moema, un género de la familia Rivulidae, actualmente comprende 20 especies válidas. La mayoría de estas especies habitan en charcos temporales de la cuenca amazónica y solo una especie se encuentra en la cuenca alta del Río Paraguay. Un nuevo miembro de este género de la cuenca alta del Río Madeira es descrito aquí. Los machos de la especie nueva se diferencian de todos los congéneres por la combinación de un patrón de color de filas irregulares oblicuas, a veces en forma de chevrón, de puntos dobles rojos y azul claro en el cuerpo; aletas pectorales de color amarillento oscuro a dorado sin marcas visibles; y un patrón de rayas en la sección ventral de la aleta caudal con una línea marginal negra muy estrecha, intermitente o incluso ausente. Se discute la existencia de grupos infragenéricos de especies dentro de Moema, la distribución geográfica y aspectos taxonómicos de las especies presentes en el drenaje de los Ríos Mamoré e Iténez/Guaporé, y la observación de agresión intraespecífica entre machos y estilo de vida anfibio en la nueva especie.

Palabras clave: Cuenca amazónica de Bolivia; Cuerpos de agua temporales; Nueva especie; Rivúlidos; Taxonomía

[Ichthyology • 2024] Austrolebias ayoreode • Redescription of Austrolebias accorsii (Cyprinodontiformes: Rivulidae) and Description of A New Species of the Genus from the upper Paraguay River Basin

Austrolebias ayoreode

 Drawert & Ergueta, 2024

DOI: 10.1590/1982-0224-2024-0001  

Abstract

Austrolebias accorsii is redescribed based on specimens from type-locality, nearby temporary pools, and other locations within the same hydrologic unit. Additionally, a novel Austrolebias species is described, exclusively found in two temporary waterbodies in “Abayoy”, a unique vegetation type situated in the transitional zone between the Dry Chaco, Chiquitano Dry Forest, and Pantanal Flooded Savannas ecoregions in southeastern Bolivia, bordering Paraguay, where the last voluntarily isolated indigenous people outside the Amazon in America reside. Diagnostic characters for both species are presented. Within Austrolebias two species groups are recognized with different morphological characters, geographical distribution, and ecological traits of their habitats. Furthermore, we suggest the usage of median and interquartile range rather than mean and standard deviation to analyze morphometric and meristic data of rivulids, given the typically non-Gaussian distribution of this data.

Keywords: Chaco; Killifish; Seasonal fish; Taxonomy; Temporary water bodies

Austrolebias ayoreode. Males (immediately after collection).
Two uppermost: MNKP 16590, paratypes, 34.7–34.8 mm SL, Bolivia, Santa Cruz, Cordillera, Charagua Iyambae Guarani Autonomous Territory, Ñembi Guasu Conservation and Ecological Importance Area.
Lower six: MNKP 16587, paratypes, 21.2–34.7 mm SL, collected with uppermost.

Austrolebias ayoreode. Male and female (1 day after collection).
Above: MNKP 16612, holotype, male, 50.7 mm SL, Bolivia, Santa Cruz, Cordillera, Charagua Iyambae Guarani Autonomous Territory, Ñembi Guasu Conservation and Ecological Importance Area.
Below: MNKP 16587, paratype, female, 38.1 mm SL, collected with holotype.

Austrolebias ayoreode. Females (immediately after collection).
Above: MNKP 16590, paratype, 26.1 mm SL; Bolivia, Santa Cruz, Cordillera, Charagua Iyambae Guarani Autonomous Territory, Ñembi Guasu Conservation and Ecological Importance Area.
Below: MNKP 16587 (vertically flipped), paratype, female, 38.1 mm SL, collected with MNKP 16590.

Austrolebias ayoreode, new species 

Diagnosis. Austrolebias ayoreode males differs from all congeners, except A. accorsii, A. ephemerus,and A. vandenbergi, by presence of 1–3 transverse rows of scales on basal anterior and median portion of anal fin. Males of A. ayoreode can be distinguished from A. accorsii, A. ephemerus, A. melanoorus, A. queguay, and A. vandenbergi by presence of whitish to pale yellowish dots on flanks usually vertically aligned in unarranged rows (vs. absent in A. accorsii; mostly coalesced in vertical bars in A. ephemerus, A. melanoorus, and A. queguay; absent or, when rarely present, sparse and scattered in A. vandenbergi); from A. accorsii and A. vandenbergi by urogenital papilla mostly ...

Etymology. The name ayoreode is an eponym conferred in reference to the indigenous Ayoréode people, who historically occupied vast expanses of the northern Dry Chaco, and of whom a few groups still persist in the area of the type-locality of this species, standing as the last indigenous people in voluntary isolation outside of the Amazon in the Americas. Through this nomenclature, we intent to perpetuate the memory of the existence of the Ayoréode and emphasize the imperative of preserving their ancestral territory, which also is the habitat of the species described herein.

Heinz Arno Drawert and Carlos Ergueta. 2024. Redescription of Austrolebias accorsii (Cyprinodontiformes: Rivulidae) and Description of A New Species of the Genus from the upper Paraguay River basin.   Neotrop. ichthyol. 22 (2); DOI: 10.1590/1982-0224-2024-0001  

[Ichthyology • 2024] Phylogenetic and Phylogeographic insights into Sri Lankan Killifishes (Teleostei: Cyprinodontiformes: Aplocheilidae)

 

Aplocheilus dayi phenotype (a) male and (b) female,
Aplocheilus werneri phenotype (c) male and (d) female,
Aplocheilus parvus (e) male and (f) female.

 in Sudasinghe, Ranasinghe, Wijesooriya,  Rüber et Meegaskumbura, 2024. 

 DOI: 10.1111/jfb.15792

 facebook.com/HiranyaSud 

  Researchgate.net/publication/380732853

Abstract

Three nominal species of the killifish genus Aplocheilus are reported from the lowlands of Sri Lanka. Two of these, Aplocheilus dayi and Aplocheilus werneri, are considered endemic to the island, whereas Aplocheilus parvus is reported from both Sri Lanka and Peninsular India. Here, based on a collection from 28 locations in Sri Lanka, also including a dataset of Asian Aplocheilus downloaded from GenBank, we present a phylogeny constructed from the mitochondrial cytochrome b (cytb), mitochondrial cytochrome c oxidase subunit 1 (cox1), and nuclear recombination activating protein 1 (rag1), and investigate the interrelationships of the species of Aplocheilus in Sri Lanka. The endemic Sri Lankan aplocheilid clade comprising A. dayi and A. werneri is recovered as the sister group to the clade comprising A. parvus from Sri Lanka and Aplocheilus blockii from Peninsular India. The reciprocal monophyly of A. dayi and A. werneri is not supported in our molecular phylogeny. A. dayi and A. werneri display strong sexual dimorphism, but species-level differences are subtle, explained mostly by pigmentation patterns. Their phenotypes exhibit a parapatric distribution and may represent locally adapted forms of a single species. Alternatively, the present study does not rule out the possibility that A. dayi and A. werneri may represent an incipient species pair or that they have undergone introgression or hybridization in their contact zones. We provide evidence that the Nilwala-Gin region of southwestern Sri Lanka may have acted as a drought refugium for these fishes.

Keywords: Aplocheilus, Cyprinodontiformes, phylogeography, sexual dichromatism

Diversity of Sri Lankan aplocheilids.
Aplocheilus dayi phenotype (a) male, Kandumulla, Attanagalu basin; and (b) female, Gilimale, Kalu basin.
Aplocheilus werneri phenotype (c) male, Ampanagala, Nilwala basin; and (d) female, Bambarawana, Bentara basin.
Aplocheilus parvus (e) male, Kandumulla, Attanagalu basin; and (f) female, Mannar, Malwathu basin.

(a) Molecular phylogenetic relationships of Aplocheilus killifishes based on maximum likelihood inference of the (3168 bp) concatenated mitochondrial + nuclear dataset for 347 individuals. Node support above and below represents ultrafast bootstrapping for 1000 iterations and Bayesian posterior probabilities. Node support below 70 is not labeled. Newly generated sequences of Sri Lankan species of Aplocheilus are denoted by color, their identity inferred from external morphology. Scale bar represents number of changes per site. Numbers in parentheses represent the sampling localities listed in Table 1. LK, Sri Lanka; IN, India. The alternating light and dark‐gray bars indicate the results of the mPTP molecular species delimitation analysis. (b) Live color pattern of male aplocheilid killifishes.

(a) Geographical origin of Sri Lankan samples of the Dayi‐Werneri group used in the molecular analysis. Numbers on the map represent the sampling localities listed in Table 1. Median‐joining haplotype networks for the Dayi‐Werneri group group, based on the analysis of (b) a 621 bp fragment of the cox1 gene, (c) a 1081 bp fragment of the cytb gene, and (d) a 1466 bp fragment of the rag1 gene. The number of mutational steps >1 is shown. Legend colors correspond to river basins. The 50 m isobath (dark blue) is that derived by GEBCO Compilation Group (2020). Major river basins in Sri Lanka are labeled in black. The geographic distribution of the Aplocheilus dayi and Aplocheilus werneri phenotypes are represented by orange and blue overlays on the map, respectively.

Hiranya Sudasinghe, Tharindu Ranasinghe, Kumudu Wijesooriya, Lukas Rüber and Madhava Meegaskumbura. 2024. Phylogenetic and Phylogeographic insights into Sri Lankan Killifishes (Teleostei: Aplocheilidae). Journal of Fish Biology. DOI: 10.1111/jfb.15792

 facebook.com/Tharindu2010ac/posts/8468383033188002

 facebook.com/KumuduWijesooriya90/posts/3806986412912229

 facebook.com/HiranyaSud/posts/470590205478609

 Researchgate.net/publication/380732853_Phylogenetic_phylogeographic_SriLankan_Aplocheilidae

    

[Ichthyology • 2024] Malagodon honahona • A New Extinct Species of Malagodon (Cyprinodontiformes: Pantanodontidae) from Southeastern Coastal Madagascar, with a Discussion of its Phylogenetic Relationships and a Redescription of the Genus

Malagodon honahona

 Carr, Martin & Sparks, 2024

DOI: 10.1206/4012.1

Abstract  

A new species belonging to the recently described genus Malagodon Meinema and Huber, 2023, is herein described from specimens collected in a single, small, isolated Pandanas swamp in southeastern coastal Madagascar, located within the Réserve Spéciale de Manombo, south of the town of Farafangana, its only known locality. The new species was last collected in the late 1990s, and despite repeated attempts over the past three decades, no additional specimens have been collected at the type locality or from any other suitable habitats within the region, and the species is presumed to be extinct. The new species is distinguished from its only congener, Malagodon madagascariensis, formerly known from forested swamps in northeastern coastal Madagascar, and also now considered to be extinct, by the following apomorphic features: a lower anal-fin ray count (15–17 vs. 18–19), a longer caudal peduncle (26.8%–39.8% vs. 21.9%–26.7% SL), and the presence of a platelike (vs. thin and spinelike) neural spine on the fifth vertebral centrum in both sexes. Additionally, the new species exhibits neural spines on both the sixth and seventh vertebral centra that are also somewhat expanded and platelike dorsally compared with those in M. madagascariensis, which are narrow and spinelike. We also provide a rediagnosis of Malagodon based on the examination of additional material unavailable in the original description, which was based on only three specimens (two males of M. madagascariensis and one female of the new species).

Live adult male Malagodon honahona, UMMZ 240245, holotype, 23.9 mm SL, photographed shortly after capture. (Photo by P. Reinthal and J.S. Sparks.)

Malagodon honahona, new species, holotype, UMMZ 240245, adult male, 23.9 mm SL. Réserve Spéciale de Manombo, southeastern coastal Madagascar. Preserved in ethanol.

Malagodon honahona, new species

Diagnosis: The new species is readily distinguished from Malagodon madagascariensis, its only congener, by the following apomorphic features: lower anal-fin ray count (15–17 vs. 18–19), longer caudal peduncle (26.8–39.8 vs. 21.9–26.7% SL), and notably expanded and platelike neural spine on arch of fifth vertebral centrum in both sexes (vs. thin and spinelike in M. madagascariensis). In addition, neural spines on both sixth and seventh vertebral centra in new species also somewhat expanded and platelike dorsally versus narrow and spinelike in P. madagascariensis.

Etymology: Named for the swampy Pandanas dominated habitat in which this species occurred within the Réserve Spéciale de Manombo, in southeastern coastal Madagascar. Hohahona translates as swamp or swampy in Malagasy. The epithet, honahona, is used as a noun in apposition.

Emily M. Carr, Rene P. Martin and John S. Sparks. 2024. A New Extinct Species of Malagodon (Cyprinodontiformes: Pantanodontidae) from Southeastern Coastal Madagascar, with a Discussion of its Phylogenetic Relationships and a Redescription of the Genus. American Museum Novitates. (4012), 1-16. DOI: 10.1206/4012.1  

[Ichthyology • 2021] Profundulus adani • A New Species of Killifish of the Genus Profundulus (Atherinomorpha: Profundulidae) from the Upper Reaches of the Papaloapan River in the Mexican State of Oaxaca

Profundulus adani

 Dominguez-Cisneros, Velázquez-Velázquez, McMahan & Matamoros, 2021

DOI: 10.1643/i2020156 

twitter.com/IchsAndHerps 

Abstract

Profundulus adani, new species, is described from the upper reaches of the Papaloapan River in the Mexican state of Oaxaca. The uniqueness of this new species is supported by morphological and molecular evidence. A combination of color patterns and counts separate P. adani, new species, from its congeners. Profundulus adani, new species, is distinguished from all congeners by the absence of a humeral spot in individuals larger than 45 mm SL. It can further be distinguished from P. balsanus, P. chimalapensis, P. kreiseri, P. oaxacae, P. parentiae, and P. punctatus based on the absence of series of dark dots on the sides of the body. Profundulus adani, new species, shows a faded dark band that extends from the tip of the operculum to the end of the caudal peduncle; this band is absent in P. balsanus and P. parentiae. The new species is described using specimens collected in the upper reaches of the Papaloapan River in the Mexican state of Oaxaca; geographically this represents a significant range expansion and extends the Atlantic slope northernmost limit of the Profundulidae.

Known geographic distributions of species in the genus Profundulus. Localities of Profundulus adani depicted by yellow stars. Distributional data from UNICACH-MZ-P and complemented with data from global aggregators such as FishNet2 (accessed through the Fishnet2 Portal, www. fishnet2.net, 2020-12-10) and the Global Biodiversity Information Facility (GBIF, 2020).

 Profundulus adani, new species

 Papaloapan Killifish

Distribution and habitat.—The known distribution of P. adani is limited to the three localities reported here in the upper reaches of the Papaloapan River in the Mexican state of Oaxaca (Fig. 1). These three localities are small creeks of high order at altitudes above 1500 masl, characterized by shallow streams with boulders, rocks, and gravel dominating the substrate (Fig. 5). 

Etymology.—In recognition of his contributions to the study and conservation of freshwater fishes in southern Mexico, this species is named after our friend, colleague, and Mexican ichthyologist Adán E. Gómez González who tragically passed away in January 2018.

 

Sara E. Dominguez-Cisneros, Ernesto Velázquez-Velázquez, Caleb D. McMahan, and Wilfredo A. Matamoros. 2021. A New Species of Killifish of the Genus Profundulus (Atherinomorpha: Profundulidae) from the Upper Reaches of the Papaloapan River in the Mexican State of Oaxaca.  Ichthyology & Herpetology. 109(4), 949-957. DOI: 10.1643/i2020156

 twitter.com/IchsAndHerps/status/1451649791679729669

Profundulus adani especie nueva se describe de la cuenca alta del r´ıo Papaloapan en el estado mexicano de Oaxaca. La distintividad de esta nueva especie esta´ respaldada por evidencia morfologica y molecular. Una combinaci ´ on de ´ patrones de coloracion y conteos separan a ´ P. adani especie nueva de sus congeneres. ´ Profundulus adani especie nueva se distingue de todos sus congeneres por la ausencia de una mancha humeral en individuos mayores de 45 mm SL. Adema ´ ´s, se puede distinguir de P. balsanus, P. chimalapensis, P. kreiseri, P. oaxacae, P. parentiae y P. punctatus por la ausencia de l´ıneas de puntos oscuros en los lados del cuerpo. Profundulus adani especie nueva muestra una banda oscura descolorida que se extiende desde la punta del operculo hasta el final del ped ´ unculo caudal; esta franja esta ´ ´ ausente en P. balsanus y P. parentiae. La nueva especie se describe con espec´ımenes recolectados la cuenca alta del r´ıo Papaloapan en el estado mexicano de Oaxaca; geogra´ficamente esto representa una expansion de rango significativa en la vertiente del ´ Atla´ntico para Profundulus.

[Ichthyology • 2021] Nothobranchius elucens • A New Species of Seasonal Killifish (Cyprinodontiformes: Nothobranchiidae) from the upper Nile drainage in Uganda

Nothobranchius elucens 

DOI:  10.11646/zootaxa.4915.1.10

Abstract

Nothobranchius elucens, new species, from a seasonal habitat in the Aringa system of the Achwa River in the upper Nile drainage in northern Uganda, is described. It belongs to the N. rubroreticulatus species group, whose members are characterised by male coloration of anal and caudal fins with slender light blue subdistal band and slender dark distal band. Nothobranchius elucens is distinguished from all other members of the genus by the following characters in males: body colouration golden-grey with brown scale margins creating irregular vertical stripes on trunk; anal fin yellow with brown spots proximally, with slender brown median band, followed by a slender light blue subdistal band and a slender black distal band; caudal fin brown proximally and medially, followed by a slender light blue subdistal band and a slender black distal band; dorsal fin golden with irregular brown stripes and narrow light blue subdistal band and with narrow black distal band. Furthermore, it differs from the closest known relative, N. taiti, also by the morphometric characters of having a smaller head length of 29.5–33.1 % SL; smaller prepectoral length of 31.2–33.9 % SL; greater head depth of 81–87 % HL; greater interorbital width of 43–49 % HL; and greater caudal peduncle length of 145–152 in % of its depth.

Keywords: Pisces, Achwa River drainage, Madi Opei area, upper Nile ecoregion

Nothobranchius elucens, new species

Béla Nagy. 2021. Nothobranchius elucens, A New Species of Seasonal Killifish from the upper Nile drainage in Uganda (Cyprinodontiformes: Nothobranchiidae). Zootaxa. 4915(1); 133–147. DOI:  10.11646/zootaxa.4915.1.10

[Ichthyology • 2020] Melanorivulus larissae • A New Species of the Melanorivulus pictus Species-group (Cyprinodontiformes: Rivulidae) from the Rio Paraná Basin in Brazil

Melanorivulus larissae 

Ywamoto, Nielsen & Oliveira, 2020

 DOI: 10.11646/zootaxa.4852.1.6

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Abstract

A new species of the genus Melanorivulus belonging to the Melanorivulus pictus species group is herein described, from a tributary of the Rio Grande, Rio Paraná basin, São Paulo State, Brazil. The new species can be distinguished from all other species of the Melanorivulus pictus species group by the unique presence of sides of body of males light bluish gray with 10–12 oblique red bars, 8 of which chevron-like, bifurcated and complete, i.e., running from dorsum to ventral area, and 2–4 incomplete, with vertices of the chevron-like bars along midbody, pointing forward. Comments on the putative relationships of the new species, as well as concerning its conservation status, are presented.

Keywords: Cyprinodontiformes, Rio Grande basin, Rivulus, Melanorivulus apiamici, Melanorivulus leali, Cerrado, Killifishes

 

Melanorivulus larissae, new species, living holotype, male, ZUEC 17154, male, 23.4 mm SL. 

Photo by Eric V. Ywamoto.

Melanorivulus larissae, new species 

Etymology. Named in honor of Larissa da Silva Sobral, daughter of the discoverer of the species.  

 Eric Venturini Ywamoto, Dalton Tavares Bressane Nielsen and Claudio Oliveira. 2020. Description of A New Species of the Melanorivulus pictus Species-group (Cyprinodontiformes: Rivulidae) from the Rio Paraná Basin in Brazil.  Zootaxa. 4852(1); 125–132. DOI: 10.11646/zootaxa.4852.1.6

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[Ichthyology • 2020] Limia mandibularis • A New Livebearing Fish (Cyprinodontiformes: Poeciliidae) from Lake Miragoane, Haiti

Limia mandibularis 

 Rodriguez-Silva, Torres-Pineda & Josaphat, 2020

DOI: 10.11646/zootaxa.4768.3.6

Abstract

Limia mandibularis, a new livebearing fish of the family Poeciliidae is described from Lake Miragoane in southwestern Haiti on Hispaniola. The new species differs from all other species in the genus Limia by the presence of a well-developed lower jaw, the absence of preorbital and preopercular pores, and preorbital and preopercular canals forming an open groove each. The description of this new Limia species from Lake Miragoane confirms this lake as an important center of endemism for the genus with a total of nine described species so far.

Keywords: Pisces, Caribbean, jaw, morphology, endemism, preopercular canal

FIGURE 6. Female of Limia mandibularis sp. nov. (48.5 mm SL) showing coloration in a live specimen.

Limia mandibularis, sp. nov.  

Diagnosis. Limia mandibularis sp. nov. is uniquely diagnosed by the presence of a well-developed lower jaw due to the presence of an elongate anguloarticular bone (Fig. 3). The new species can also be identified by the lack of preorbital and preopercular pores and by the presence of single preorbital and preopercular canals forming open grooves (Fig. 4). Limia mandibularis sp. nov. can be further distinguished by the combination of the following characters: dorsal fin with 8 rays and its origin is slightly behind of the origin of the anal fin in females; 13 predorsal scales; caudal fin symmetrical and truncate or slightly convex; no crossbars, spots or blotches on body in both sexes. ...

FIGURE 7. Habitat where Limia mandibularis sp. nov. was collected. 

Distribution and ecological notes. Limia mandibularis sp. nov. is only known from the north bight of Lake Miragoane in Haiti. The lake seems very isolated in terms of connectivity with other water bodies as we did not see any tributary river or stream, but only mountain springs that lead to the lake. Our observations agree with the classification of Curtis & Hodell (1993) of the lake as an endorheic drainage. The species herein described was collected in a clear water path with slow current exiting the lake. Water temperature was 29.9 °C and water conductivity was 321 microS/cm on the collecting date (June 5th, 2019). The area is characterized by the presence of muddy bottoms and some semi-submerged and submerged vegetation growing near the banks (Fig. 7). Limia mandibularis was sympatric with Gambusia beebei, five other Limia species (L. miragoanensis, L. immaculata, L. nigrofasciata, L. garnieri and L. islai), Nandopsis haitiensis and two species of African cichlids introduced in the lake (Oreochromis aureus and Tilapia sp.). 

Etymology. The specific epithet mandibularis, from the Latin mandibula (jaw), is in reference to the well-developed lower jaw, a character that distinguishes the species.

 The vernacular name “Jawed Limia” is proposed for this species, due to the distinct protuberance that can be seen in the lower jaw.

Rodet Rodriguez-Silva, Patricia Torres-Pineda and James Josaphat. 2020. Limia mandibularis, A New Livebearing Fish (Cyprinodontiformes: Poeciliidae) from Lake Miragoane, Haiti. Zootaxa. 4768(3); 395–404. DOI: 10.11646/zootaxa.4768.3.6

     

[Ichthyology • 2019] Jenynsia sulfurica • Molecular and Morphological Convergence to Sulfide-tolerant Fishes in A New Species of Jenynsia (Cyprinodontiformes: Anablepidae), the First Extremophile Member of the Family

 Jenynsia sulfurica 

Aguilera, Terán, Mirande, Alonso, Rometsch, Meyer & Torres-Dowdall, 2019

  DOI: 10.1371/journal.pone.0218810

Abstract
Freshwater sulfide springs have extreme environmental conditions that only few vertebrate species can tolerate. These species often develop a series of morphological and molecular adaptations to cope with the challenges of life under the toxic and hypoxic conditions of sulfide springs. In this paper, we described a new fish species of the genus Jenynsia, Anablepidae, from a sulfide spring in Northwestern Argentina, the first in the family known from such extreme environment. Jenynsia sulfurica n. sp. is diagnosable by the lack of scales on the pre-pelvic area or the presence of a single row of scales, continuous or not, from the isthmus to the bases of the pelvic fins. Additionally, it presents a series of morphological and molecular characteristics that appear convergent with those seen in other fish species (e.g., Poeciliids) inhabiting sulfide springs. Most notably, J. sulfurica has an enlarged head and postorbital area compared to other fish of the genus and a prognathous lower jaw with a hypertrophied lip, thought to facilitate respiration at the air-water interface. Analyses of cox1 sequence showed that J. sulfurica has two unique mutations resulting in amino acid substitutions convergent to those seen in Poeciliids from sulfide springs and known to provide a physiological mechanism related to living in sulfide environments. A phylogenetic analysis, including molecular and morphological characters, placed J. sulfurica as sister taxa to J. alternimaculata, a species found in nearby, non-sulfide habitats directly connected to the sulfide springs. Thus, it can be inferred that the selection imposed by the presence of H2S has resulted in the divergence between these two species and has potentially served as a barrier to gene flow.

 Fig 2. Live specimens of the sulfide-tolerant species Jenynsia sulfurica sp. nov. 
Lateral view of a (A) male and (B) female individual, exhibiting large heads and a prognathous lower jaw with a hypertrophied lip (indicated by arrows) which facilitate respiration at the air-water interface. (C) dorsal and (D) ventral view of a female individual.

Fig 1. Preserved holotype and paratype specimens of Jenynsia sulfurica sp. nov. Above: holotype CI-FML 7286, male, 21.6 mm SL; below: paratype CI-FML: 7287, female, 32.8 mm SL, from the La Quinta lagoon, Santa Barbara department, Jujuy province, Argentina.

Jenynsia sulfurica, new species

Diagnosis

The genus Jenynsia is subdivided into two subgenera, one containing five species only known from inland habitats in Brazil (Plesiojenynsia) and a more widely distributed subgenus including nine previously described species (Jenynsia). The new species herein described (Fig 1) presents the three synapomorphies considered by Ghedotti [1998] as diagnostic for the subgenus Jenynsia: (1) a modified sixth anal-fin ray segmented on its proximal quarter; (2) unsegmented on its distal quarter in adult males and (3) the vertically inclined proximal radials associated with the first six anal-fin rays in the gonopodium. Also, in the analyses under both, equal and implied weightings, the additional synapomorphies proposed by Aguilera et al. [2013] for the subgenus Jenynsia were recovered (i.e. character state 17–1; 47–1; 51–1 and 64–2; S1 Table). In the new species herein described, character 64 is reversed to state 0 (S1 Table).

The new species is diagnosable from all other species of the genus by the absence of scales on the ventral surface of the body or the presence of a single row of scales, continuous or not, from the isthmus to the pelvic-fin bases (vs. completely scaled ventral surface of body in all species of Jenynsia; Fig 3). Additionally, J. sulfurica presents a unique coloration pattern, exhibiting eight to eleven irregular blotches along the mid-lateral surface of the body. These are formed by dark-brown chromatophores, ranging from rounded spots to vertical bars spreading up to three scales in depth (vs. different configuration pattern; Fig 1).

Etymology: The specific epithet “sulfurica” is a Spanish adjective, meaning “related to sulfur or from the sulfur”. In this case refers to the environment rich in sulfur that this species inhabits.

Distribution: Jenynsia sulfurica is currently only known from Laguna La Quinta, which is part of a thermal system in the western flank of the Santa Bárbara hills, Santa Bárbara Department, Jujuy Province, Northwestern Argentina (Fig 5). It connects to the San Francisco River, tributary of the Bermejo River in the Paraná River basin.

Fig 6. Photographs of the habitat of Jenynsia sulfurica sp. nov. 
(A) the lagoon and (B) the sulfide spring which drains into the lagoon. (C) Pond of more than 10 cm water depth where adults of J. sulfurica were found and (D) small pond of 2 cm water depth inhabited by juveniles of J. sulfurica.

Fig 5. Hydrological map of South America. Red rectangle highlights the Province of Jujuy, where the type locality of Jenynsia sulfurica sp. nov. is indicated by a red dot. (Digital map from catalog.data.gov, U.S. Government Works subject to no copyright).

    

Conclusions: 

So far, fishes of only four taxonomic families were known to have representatives in freshwater sulfide springs: Poeciliidae, Cyprinodontidae, Rivulidae (all Cyprinodontiformes), and Synbranchidae (Synbranchiformes). Moreover, only six of these species are endemic to sulfide springs (i.e., Cyprinodon bobmilleri, Aphanius ginaonis, Gambusia eurystoma, Limia sulphurophila, Poecilia sulphuraria, and P. thermalis). Jenynsia sulfurica is the first species of the genus Jenynsia, and the only species within Anablepidae currently known to inhabit sulfide springs, a very extreme freshwater environment. Moreover, Jenynsia sulfurica is the first microendemism within the genus, being present only in a small sulfide thermal spring in Northwestern Argentina.

Members of the order Cyprinodontiformes are in general highly tolerant to high temperatures, different concentrations of salinity, and a wide range of physicochemical environmental conditions, including environments with high concentrations of sulfide. In the genus Jenynsia, only a few studies were conducted to evaluate the tolerance of these fish to different environmental conditions, and almost all focused on J. lineata (= J. multidentata). This species is considered to be highly tolerant (e.g., euryhaline, eurythermic and euryoic), as it is commonly found to inhabit a wide range of abiotic conditions. Although there are no studies in the remaining species of the genus, it is possible that closely related species also show high tolerance to variation in different abiotic factors. This is in line with the pattern of diversity within the genus, where different species are found across drainages (i.e., in the absence of gene flow) rather than within drainages (i.e., in the presence of gene flow). Thus, Jenynsia sulfurica is, from an ecological and an evolutionary perspective, an interesting species that attests to the extreme conditions of H2S enriched environments.


 Gastón Aguilera, Guillermo Enrique Terán, Juan Marcos Mirande, Felipe Alonso, Sina Rometsch, Axel Meyer and Julian Torres-Dowdall. 2019. Molecular and Morphological Convergence to Sulfide-tolerant Fishes in A New Species of Jenynsia (Cyprinodontiformes: Anablepidae), the First Extremophile Member of the Family. PLoS ONE. 14(7): e0218810. DOI: 10.1371/journal.pone.0218810

[Ichthyology • 2014] Papiliolebias ashleyae • A New Annual Fish (Cyprinodontiformes: Rivulidae) from the upper Rio Mamoré basin, Bolivia

Papiliolebias ashleyae 

 Nielsen & Brousseau, 2014 

Abstract 

Papiliolebias ashleyae n. sp. is described from Bolivia, departamento de Santa Cruz, Rio San Pablo, upper Mamoré basin. Papiliolebias ashleyae n. sp. is distinguished from other Papiliolebias species by a combination of characters: male overall color pattern of body, caudal- and pelvic-fins brownish red (vs. dark blue); transverse brownish red bars in dorsal and anal fins located between black and white bar at base of dorsal and anal fins and blue area in distal part of dorsal and anal fins (vs. absence of redbrown stripe on the remaining species of the genus, where the color of dorsal and anal fins is blue with a black stripe and white spots at the base of the fins); dorsal-fin origin at vertical through base of anal fin rays 9th-10th (vs. dorsal fin origin at vertical through base of anal fin rays 7th-8th in P. bitteri and 6th-9th in P. hatinne) and pelvic fins separated by small interspace of 4 mm (vs. not separated).

Fig. 1. Papiliolebias ashleyae, male, holotype, 34.7 mm SL: Bolivia, San José dos Chiquitos (in life).

Photo by D. Nielsen.

Papiliolebias ashleyae, n. sp.

Diagnosis: Papiliolebias ashleyae differs from the remaining species of Papiliolebias by a lower prepelvic length in males (43.6-44.7% SL vs. 44.9- 51.5% SL), a lower pre-pelvic length in females (43.3-46.8% SL vs. 48.2-51.7% SL), and by the color pattern of males which shows an overall redbrownish coloration, including the dorsal, caudal and pelvic fins basis (vs. overall color pattern dark blue, but never red-brown). It also presents a reddish-brown stripe on the basis of the dorsal and anal fins, with whitish blotches, and distal portion of anal- and caudal-fins bluish (vs. absence of reddish-brown stripe in the remaining species of the genus, where the caudal and anal-fin basis possess white and black spots); dorsal-fin origin at vertical through base of anal-fin rays 9th-10th (vs. 7th-8th in P. bitteri and 6th-9th in P. hatinne); body with brownish-red background and iridescent greenishblue scales, forming slender, oblique, ladder-like stripes (vs. oblique thick lines arranged parallel to each other); pelvic-fin red, with three spots (from basal to distal portion of fin): white, dark red and white (vs. dark blue without spots); third pelvic fin-rays transformed into a filament (vs. third pelvic-fin ray not transformed into a filament), and pelvic-fin separated by a small 4 mm interspace (vs. not separated).

Etymology: In honor of the daughter of Dr. Roger Brousseau, Ashley Kimberly Brousseau, who collected the first specimen of the species.

Dalton Tavares Bressane Nielsen and Roger Brousseau. 2014. Description of A New Annual Fish, Papiliolebias ashleyae (Cyprinodontiformes: Rivulidae) from the upper Rio Mamoré basin, Bolivia. aqua, International Journal of Ichthyology. 20(1); 53-59. 

http://www.aqua-aquapress.com/pdf/20(1)-Papiliolebias-ashleyae.pdf

theguardian.com/environment/gallery/2017/sep/06/upto-381-new-species-discovered-in-the-amazon-in-pictures

[Ichthyology • 2019] Leptopanchax sanguineus • A New Species of Cynopoeciline Killifish (Cyprinodontiformes, Aplocheilidae), possibly Extinct, from the Atlantic Forest of south-eastern Brazil

Leptopanchax sanguineus  

Costa, 2019

 DOI: 10.3897/zookeys.867.34034 

Abstract

Specimens found between 1985 and 1988 in the Magé River Basin, south-eastern Brazil were misidentified as L. splendens. The recent rediscovery of other specimens in the Estrela River Basin near the type locality of L. splendens has clarified the species’ concept, making it possible to recognise the Magé River Basin specimens as a new species. The new species is herein described as Leptopanchax sanguineus sp. nov. and is distinguished from all other cynopoecilines by a unique colour pattern in males, including red bars with sinuous margins. It was collected in a well-preserved, temporary shallow swampy area within dense moist forest, but since 1990 the species has not been found again. Leptopanchax sanguineus sp. nov. is one of three species of cynopoeciline killifishes living in lowland moist forests of the coastal plains of Rio de Janeiro State, where the greatest diversity of endemic cynopoecilines is concentrated. Each of these species has been recorded a single time in the last 30 years, a surprisingly low record attributable to intense deforestation during the last several decades resulting in small fragmented lowland moist forests of today. This study indicates that seasonal killifishes adapted to uniquely live in this kind of habitat should be regarded with special concern in studies evaluating conservation priorities.

Keywords: Biodiversity, conservation, moist tropical forest, systematics, taxonomy

Figure 2. Male fin morphology and life colour patterns in Leptopanchax.
A coloured pencil drawing illustrating Leptopanchax sanguineus sp. nov. in life, about 20 mm SL B L. splendens, UFRJ 6902, 22.7 mm SL
C L. aureoguttatus, UFRJ 6331, 22.3 mm SL D L. itanhaensis, UFRJ 6453, 20.7 mm SL
E L. citrinipinnis, UFRJ 8899, 20.6 mm SL F L. opalescens, UFRJ 8986, 20.2 mm SL.

Leptopanchax sanguineus sp. nov.

Diagnosis: Leptopanchax sanguineus differs from other cynopoecilines, except L. splendens, by the presence of red bars on the whole flank in males (vs. absence); uniquely in L. sanguineus, the bars are broad, wider than the interspace width (vs. narrow, half interspace width or less) and have sinuous margins (vs. straight). Leptopanchax sanguineus is further distinguished from L. splendens by having 15 dorsal-fin rays (vs. 12–14), 6 pelvic-fin rays (vs. 5), 27 scales on the longitudinal series and 9 on the transverse series (vs. 24–25 and 7, respectively), 29 vertebrae (vs. 26–27), pelvic fin tip posteriorly reaching the anal fin in males (vs. reaching urogenital papilla), pelvic-fin bases medially separated, in close proximity (vs. medially united), absence of filamentous rays on the caudal fin (vs. short filamentous rays on the posterior margin of the caudal fin in males), presence of a golden stripe on the distal margin of the dorsal fin in males (vs. white stripe), absence of contact organs on the male pectoral fin (vs. presence) and absence of the dermosphenotic bone (vs. presence). Leptopanchax sanguineus also differs from L. splendens and all other cynopoecilines by the presence of a small red spot on the posterior portion of the iris (vs. spot absent).

Etymology: The name sanguineus, from the Latin, meaning blood-coloured, is an allusion to the predominantly red colouration in males, unique among Neotropical killifishes.

Figure 4. Habitat of Leptopanchax sanguineus sp. nov. in 1988.

 Wilson J. E. M. Costa. 2019. Description of A New Species of Cynopoeciline Killifish (Cyprinodontiformes, Aplocheilidae), possibly Extinct, from the Atlantic Forest of south-eastern Brazil.  ZooKeys. 867: 73-85. DOI: 10.3897/zookeys.867.34034

Abstract: A recent collection of the seasonal killifish found Leptopanchax splendens c. 5 km from the type locality, 74 years after its last record. The species was historically common in its type locality, the Estrela River basin in south‐eastern Brazil, until 1950, after which it was not encountered and thought to have become extinct due to widespread deforestation and urbanization in the region. Despite the rediscovery, this study finds that other recently published reports of L. splendens are misidentifications.

Wilson J. E. M. Costa, José L. O. Mattos and Pedro F. Amorim. 2019. Rediscovery of Leptopanchax splendens (Cyprinodontiformes: Aplocheilidae): A Seasonal killifish from the Atlantic Forest of south‐eastern Brazil that was recently considered extinct. Journal of Fish Biology.  DOI: 10.1111/jfb.13898