[Ichthyology • 2026] The prolonged Reemergence of Megapredatory Pelagic Fishes

  

the diversification of living large-bodied (> 2 m) marine predatory fishes such as tunas and mackerels (Scombridae)

in Brownstein, Alencar, Kindsvater, Thacker, Wainwright, Near et Harrington, 2026. 

DOI: doi.org/10.1098/rspb.2026.1257 

 x.com/ChaseBrownstein

 

Abstract

The assembly of modern ocean ecosystems was fundamentally affected by the Cretaceous–Palaeogene (K-Pg) mass extinction. Among the casualties of this event were many extinct clades of large pelagic predatory fishes. The extinction of these lineages is thought to have created ecological opportunity that spurred the diversification of living large-bodied (> 2 m) marine predatory fishes such as tunas and mackerels (Scombridae). However, it remains unclear whether a large, endothermic body plan evolved in tunas and mackerels directly after the K-Pg boundary or in a stepwise manner throughout the Cenozoic. Here, we demonstrate that Scombridae, which includes half of living endothermic ray-finned fish species, evolved endothermy and large body sizes long after the initial radiation of the clade at the K-Pg boundary. Our time-calibrated phylogeny also reveals that the origins of endothermy, large body size and increased longevity in true tunas are staggered over evolutionary time. These findings indicate that the evolution of large endothermic scombrids was not triggered by the K-Pg extinction and substantiate the protracted development of the endothermic predatory body plans of tunas and relatives over more than 50 million years of evolutionary history.

Keywords: Scombridae, tunas, phylogenomics, K-Pg mass extinction, endothermy

Origin of large body sizes in Scombridae. The phylogeny is coloured according to the ancestral state reconstruction for log-transformed standard length. Warmer colours indicate body sizes approaching 4 m. Body size increases over 2 m are denoted by Roman numerals. The innermost dashed circle indicates the K-Pg boundary. Illustrations of scombrids are by Julie Johnson (lifesciencestudios.com).

Tempo of trait shifts in Scombridae. Inferred histories of significant trait optima shifts across Scombridae plotted on the time-calibrated phylogeny of this clade. Shifts inferred with over 30% posterior probability are included. The full bayou outputs are in the electronic supplementary material associated with this article. Illustrations of scombrids are by Julie Johnson (lifesciencestudios.com).

Chase D. Brownstein; Laura R. V. Alencar; Holly K. Kindsvater; Christine E. Thacker; Dylan K. Wainwright; Thomas J. Near and Richard C. Harrington. 2026. The prolonged Reemergence of Megapredatory Pelagic Fishes.  Proc Biol Sci. 293 (2074): 20261257. DOI: doi.org/10.1098/rspb.2026.1257 [08 Jul 2026] 

 x.com/ChaseBrownstein/status/2074791152318865890

[Ichthyology • 2025] Allohistium anas • Genomic and Phenotypic Delimitation of Species in a Temperate Aquatic Biodiversity Hotspot

 

Allohistium anas Near & MacGuigan,

in MacGuigan, Taylor, Ghezelayagh, Wood, Simmons, Mollish et Near, 2025. 

Cinder Darter  ||  DOI: doi.org/10.1093/sysbio/syaf083 

Abstract

Biologists have relied on morphological characteristics to identify, define, and formally describe species for the past 250 years. The advent of phylogenetic species concepts and the introduction of molecular data have spawned new species delimitation methods applicable to a wide range of eukaryotic lineages. However, these approaches heavily emphasize genomic data, often overlooking phenotypic traits. We present and implement a species delimitation approach that utilizes genome-wide markers from ddRAD-seq and meristic morphological traits, which have long been used to identify and delineate fish species. Our methodology employs unsupervised machine learning to analyze morphological data without a priori species assignments, allowing phenotypic patterns to emerge independently from genomic-based species delimitation. We apply our combined genomic and phenotypic methodology to the freshwater systems of Southeastern North America, a biodiversity hotspot where conservation efforts are hampered by an incomplete knowledge of species diversity. Our investigation focuses on the darter clade Allohistium, a threatened lineage comprising two described species. Through phylogenomic, population genetic, and phenotypic model comparisons, we provide evidence supporting the delimitation of a third species of Allohistium, which we formally describe. Our approach shows how unsupervised machine learning can reveal cryptic morphological diversity that might otherwise be obscured by taxonomic preconceptions. This study demonstrates that model testing using diverse lines of evidence yields a more comprehensive, data-driven hypothesis of species diversity.

Darters, ddRAD-seq, methodology, North America, phenotype, species delimitation

Live photographs of Allohistium specimens.

Photo credit to Jon M. Mollish. YPM = Yale Peabody Museum, YFTC = Yale Fish Tissue Collection.

Allohistium anas Near and MacGuigan new species

Cinder Darter

Diagnosis. Allohistium anas differs from Allohistium cinereum and Allohistium maydeni by a higher number of lateral line scales (Supplementary Table S4), modally 43 versus 42 vertebrae (Shepard and Burr 1984), a larger proportion of individuals with greater than 80% of the cheek covered with scales, and more than 50% of the individuals with 10–40% of the nape covered with scales. In addition, Allohistium anas is never resolved as the sister lineage of Allohistium cinereum sensu stricto in mtDNA gene trees (Powers et al. 2004, 2012) or phylogenomic analyses of ddRAD-seq loci (see below). Allohistium maydeni differs from Allohistium anas and Allohistium cinereum in having modally 11 versus 12 dorsal fin spines (Supplementary Table S5; Powers et al. 2012), 12 versus 13 dorsal fin rays (Supplementary Table S6; Powers et al. 2012), and the presence of conspicuous red coloration on the skin covering the upper and lower oral jaws (Fig. 2).

Etymology. The species name anas is from the Latin word for duck, in reference to the distribution of the species in the Duck River system. The common name Cinder Darter is in reference to the common name of A. cinerum, the Ashy Darter.

Daniel J MacGuigan , Adam Taylor , Ava Ghezelayagh , Julia E Wood , Jeffrey W Simmons , Jon M Mollish and Thomas J Near. 2025. Genomic and Phenotypic Delimitation of Species in a Temperate Aquatic Biodiversity Hotspot. Systematic Biology. syaf083. DOI: doi.org/10.1093/sysbio/syaf083 [27 November 2025]

[Ichthyology • 2025] Rypticus africanus • Integrative Taxonomy reveals A New Species of the Soapfish Genus Rypticus (Perciformes: Grammistidae) from the eastern Atlantic Ocean

 

Rypticus africanus   

 Araujo, Sampaio, Rocha & Ferreira, 2025

African soapfish | Peixe sabão africano  ||  DOI: doi.org/10.1111/jfb.70132 

Abstract

A new species of the soapfish genus Rypticus is described based on 14 specimens from the eastern Atlantic Ocean. The new species was previously misidentified as the greater soapfish, R. saponaceus, due to their similar appearance. However, it differs from R. saponaceus in several key characteristics, including a comparatively shorter head, snout and upper jaw, and a deeper body. Molecular data, obtained from the mitochondrial cytochrome oxidase I gene, strongly suggest the monophyly of the new species and support its description as new.

Keywords: Biogeography, cryptic species, DNA barcode, Gulf of Guinea, Isthmus of Panama, reef fish

(a–c) Rypticus africanus from São Tomé and Príncipe, illustrating the variation in colour pattern between individuals: (a) São Tomé Island, (b, c) Príncipe Island
and (d) R. saponaceus from Salvador, Bahia, Brazil, shown for comparison.

Rypticus africanus Araujo, Sampaio, Rocha & Ferreira, new species

English proposed common name: African soapfish.

Portuguese (São Tome and Príncipe) proposed common name: Peixe sabão africano.

Diagnosis: A species of Rypticus distinguished from its congeners by the following unique combination of characters: dorsal-fin spines always three vs. two/typically two in Rypticus bistrispinus (Mitchill 1818), Rypticus bornoi Beebe & Tee-Van 1928, Rypticus courtenayi McCarthy 1979, Rypticus maculatus Holbrook 1855, and R. nigripinnis, and almost always four in Rypticus carpenteri Baldwin & Weigt, 2012; head length 30.0%–35.3% of SL (average 33.5%) vs. 35.0%–39% (average 36.88%) in R. bicolor; body depth 34.2%–40.5% of SL (average 36.2%) vs. 26%–34% (average 30.0%) in Rypticus randalli Courtenay, 1967; body brown to dark grey, with the head and sides displaying numerous or sparse pale, spots of variable size vs. lighter background coloration with several widely scattered small dark spots; head shorter than body depth vs. head larger than body depth in R. saponaceus.

Etymology: The specific name africanus is given for the known distribution of the new species and its probable widespread distribution off the coast of west Africa.

Gabriel Soares Araujo, Cláudio L. S. Sampaio, Luiz A. Rocha and Carlos Eduardo Ferreira Leite. 2025. Integrative Taxonomy reveals A New Species of the Soapfish Genus Rypticus (Teleostei: Grammistidae) from the eastern Atlantic Ocean. Journal of Fish Biology. DOI: doi.org/10.1111/jfb.70132 [21 July 2025]

[Ichthyology • 2025] Hypoplectrus espinosai (Teleostei: Serranidae) • A New hamlet on Coral Reefs in the southwestern Gulf of Mexico

Phenotypic variation of Hypoplectrus espinosai 

Puebla, Aguilar-Perera, Robertson & Domínguez-Domínguez, 

 

  in Puebla, Aguilar-Perera, Helmkampf, Robertson, C.J. Estapé, A.M. Estapé et Domínguez-Domínguez, 2025

DOI: doi.org/10.11646/zootaxa.5618.4.3

Photographs from Alacranes reef by Carlos and Allison Estapé (a, b, c, d), Isai Dominguez Guerrero (e), and Alfonso Aguilar-Perera (f).

Abstract

The hamlets (Hypoplectrus spp., Teleostei: Serranidae) are a group of small predatory reef-associated fishes endemic to the tropical northwestern Atlantic that are characterized by an exceptionally high diversification rate. Currently 18 species are recognized, with seven described or redescribed in the last 14 years. Here, we describe the Campeche Bank hamlet, Hypoplectrus espinosai sp. nov. As indicated by its common name, this species is distributed throughout the Campeche Bank in the southwest Gulf of Mexico. Hypoplectrus espinosai sp. nov. differs from two similar hamlets, the butter hamlet H. unicolor (Walbaum) and the Veracruz hamlet H. castroaguirrei Del Moral Flores, Tello-Musi & Martínez-Pérez in terms of geographic distribution and color pattern. Furthermore, phylogenetic and population genetic analyses based on whole-genome data from 68 individuals indicate that H. espinosai sp. nov. is genetically distinct from H. unicolor and H. castroaguirrei.

Pisces, Gulf of Mexico, Campeche Bank, Serranidae, reef fishes, hamlets, Hypoplectrus

Phenotypic variation of Hypoplectrus espinosai sp.  nov. A black saddle blotch covers the caudal  peduncle  and extends over the posterior part of the body, sometimes over the posterior border of the dorsal fin. Note the consistency of the thin vertical lines.

Photographs from Alacranes reef by Carlos and Allison Estapé (a, b, c, d), Isai Dominguez Guerrero (e), and Alfonso Aguilar-Perera (f).

Hypoplectrus espinosai sp. nov. Puebla, Aguilar-Perera, Robertson & Domínguez-Domínguez 2025 

English common name: Campeche Bank hamlet 

Spanish common names: mero del Banco de Campeche (AFS), vaca del Banco de Campeche (FAO), hamlet del Banco de Campeche (vernacular) 

Diagnosis. Hypoplectrus  espinosai sp.  nov. is distinguished  from  all named congeners  by  coloration. Body white with thin vertical lines but no bars (or very faint). Black spot on snout surrounded by electric blue lines. Caudal peduncle entirely covered by black saddle blotch, which extends over posterior part of body, and sometimes over posterior part of dorsal fin. Black saddle blotch is more extensive than in H. unicolor. Black eye-mask characteristic of H. castroaguirrei absent.

Etymology. We assign the species name espinosai sp. nov. in honor of Héctor Salvador Espinosa Pérez (1954–2022), a dedicated Mexican ichthyologist, founder of the Mexican Ichthyological Society and curator of the Mexican National Fish Collection. The common name refers  to  the  geographic distribution of the species, the  Campeche Bank off the north coast of the Yucatan Peninsula in the southwestern Gulf of Mexico, Mexico.

Oscar PUEBLA, Alfonso AGUILAR-PERERA, Martin HELMKAMPF, D. Ross ROBERTSON, Carlos J. ESTAPÉ, Allison Morgan ESTAPÉ and Omar DOMÍNGUEZ-DOMÍNGUEZ. 2025. Hypoplectrus espinosai sp. nov. (Teleostei: Serranidae), A New hamlet on Coral Reefs in the southwestern Gulf of Mexico. Zootaxa. 5618(4); 509-524. DOI: doi.org/10.11646/zootaxa.5618.4.3 [2025-04-04]

[Ichthyology • 2023] Opistognathus ctenion • A New Jawfish (Perciformes: Opistognathidae) from southern Japan

Opistognathus ctenion

Fujiwara, Motomura & Shinohara, 2023

DOI: 10.3897/zookeys.1179.109813

Abstract

Opistognathus ctenion sp. nov. (Perciformes: Opistognathidae) is described on the basis of three specimens (17.3–30.6 mm in standard length) collected from the Osumi and Ryukyu islands, southern Japan in depths of 35–57 m. Although most similar to Opistognathus triops, recently described from Tonga and Vanuatu, the new species differs in mandibular pore arrangement, dorsal- and caudal-fin coloration, fewer gill rakers, and lacks blotches or stripes on the snout, suborbital region and both jaws.

Key words: Actinopterygii, dredge, new species, Osumi Islands, Ryukyu Islands, taxonomy

Opistognathus ctenion Fresh coloration of two paratypes
A, C KAUM–I. 174226, 30.6 mm SL; B, D KAUM–I. 174227, 26.2 mm SL
A, B lateral views; C, D dorsal views.

photographed by KAUM 

 Opistognathus ctenion sp. nov. 

New English name: Japanese White spotted Jawfish 

New standard Japanese name: Shiratama-agoamadai

 

Diagnosis: A species of Opistognathus distinguished from congeners by the following combination of characters: posterior end of upper jaw rigid, without flexible lamina; dorsal-fin rays XI, 16–18; anterior dorsal-fin spines very stout and straight, and their distal ends not transversely forked; anal-fin rays II, 17; gill rakers 6 or 7 + 13 or 14 = 20 or 21; vertebrae 10 + 22 = 32; longitudinal scale rows c. 40–50; lateral line terminating below 4th–6th soft ray of dorsal fin; 4th and 5th mandibular pore positions usually included 2 and 6–7 pores, respectively; body scales absent anterior to vertical below 4th or 5th dorsal-fin spine; vomerine teeth 2; body reddish-brown with 3 or 4 longitudinal rows of c. 8–10 whitish blotches; cheek and opercle with five or six whitish blotches; snout, suborbital region, and both jaws without blotches or stripes; spinous dorsal fin with ocellus between 2nd to 5th spines; dorsal-fin soft-rayed portion with two reddish-orange stripes; pectoral-fin base with one or two whitish blotches; caudal fin uniformly faint orange or reddish-yellow.

Etymology: The specific name is a noun in apposition derived from the Greek diminutive κτενίον, meaning “a small comb”. It refers to the low gill raker numbers in the new species, one of the lowest recorded for Indo-Pacific species of Opistognathus (see below).

Distributional records of Opistognathus ctenion.

Kyoji Fujiwara, Hiroyuki Motomura and Gento Shinohara. 2023. Opistognathus ctenion (Perciformes, Opistognathidae): A New Jawfish from southern Japan. ZooKeys. 1179: 353-364. DOI: 10.3897/zookeys.1179.109813

 

[Ichthyology • 2023] Incipient Speciation in Allopatric Etheostoma rupestre (Percidae: Etheostomatinae) Lineages, with the Description of Three New Subspecies

 

Male pigmentation of

A) Etheostoma rupestre rupestre Gilbert & Swain, in Gilbert 1887
B) E. r. piersoni  C) E. r. uphapeense 

Hilburn, Janosik & Johnston 2023 

 DOI: 10.11646/zootaxa.5343.2.3

(Photos by K. Boone & B. Hilburn).

 

Abstract

In recent years, new species descriptions for the North American darters have proliferated. Most species concepts accepted by contemporary ichthyologists require that a valid species be both monophyletic and diagnoseable, yet many lineages exhibit modal or range differences in morphological characteristics without individuals being diagnosable. Such scenarios present difficulties with regards to proper taxonomic recognition of divergent lineages and often prohibit appropriate conservation action. Following the example of recent authors, we provide meristic, geometric morphometric, and pigmentation data to support the recognition of three subspecies of Etheostoma rupestre, a species endemic to the Mobile Basin. These morphological data cohere with previous genetic work for E. rupestre. The nominate subspecies Etheostoma rupetsre rupestre (Tsai’s Rock Darter) is endemic to the Tombigbee River and Black Warrior River watersheds in Alabama and Mississippi and is characterized by having lower numbers of lateral blotches, lower range and mean of lateral line scales, lower modal number of scales above the lateral line, and lower degrees of nape squamation than other subspecies. Etheostoma rupestre piersoni (Shamrock Darter), ssp. nov., is endemic to the Cahaba and Alabama River Watersheds in Alabama and is characterized by intermediate counts of lateral blotches and higher scale counts and nape squamation than E. r. rupestre. Etheostoma rupestre uphapeense (Jade Darter), ssp. nov., is restricted to several small, disjunct populations in the Coosa and Tallapoosa watersheds in Alabama, Georgia, and Tennessee. Etheostoma r. uphapeense is characterized by having a higher mean number of lateral blotches than both other subspecies and higher scale counts than E. r. rupestre. While E. r. rupestre and E. r. piersoni are widespread and abundant within their respective ranges, E. r. uphapeense has a disjunct range and is often uncommon where it occurs. Etheostoma r. uphapeense should be monitored where it occurs to discern population trends.

Key words: species concepts, Mobile Basin, endemism, Rock Darter, intraspecific diversity

Male pigmentation of A) Etheostoma rupestre rupestre—47 mm SL, Cottondale Creek, County Road 32, Tuscaloosa, Alabama (photo by K. Boone),
B) E. r. piersoni—61 mm SL, Chilatchee Creek, Highway 5, 1 mile north of Alberta, Alabama (photo by K. Boone),
and C) E. r. uphapeense—45 mm SL, Opintlocco Creek, County Highway 20, ~3 miles East of Tuskegee, Alabama (Photo by B. Hilburn).

Bryson G. Hilburn, Alexis M. Janosik and Carol E. Johnston. 2023. Incipient Speciation in Allopatric Etheostoma rupestre (Percidae: Etheostomatinae) Lineages, with the Description of Three New Subspecies.  Zootaxa. 5343(2); 151-172. DOI: 10.11646/zootaxa.5343.2.3

 

[Ichthyology • 2023] Species-Level Recognition and Redescription of the Kentucky Arrow Darter, Etheostoma spilotum Gilbert (Percidae: Litocara)

 

in Thomas, Blanton, Ghezelayagh & Near, 2023 

DOI: 10.3374/014.064.0103

  twitter.com/TJNear

 Abstract  

The Kentucky Arrow Darter, Etheostoma spilotum, endemic to the upper Kentucky River basin of eastern Kentucky, is redescribed and recognized as a distinct species closely related to E. sagitta in the upper Cumberland River basin and E. nianguae in the Osage River drainage (Missouri River basin). Originally described as a subspecies of E. nianguae, it was later considered a full species and then a subspecies of E. sagitta, based on close geographic proximity to Cumberland basin populations and overlapping meristic variation interpreted as character intergradation. We present meristic, morphometric, and genetic data that support species-level recognition of E. spilotum. It differs from E. sagitta by lower counts of total and pored lateral scales, lower counts of caudal peduncle scales, fewer second dorsal-fin rays, and fewer pectoral-fin rays. Interspecific divergence of E. spilotum and E. sagitta is further demonstrated through analyses of variation in the mitochondrial nd2 gene and species delimitation using genome-wide double digest restriction-site associated DNA sequencing. Although allopatrically distributed, both species inhabit upland headwater streams on the Cumberland Plateau and have similar life history characteristics. Endemism, fragmented distributions, and low densities and genetic diversity within populations make these species extremely vulnerable to anthropogenic activities. Etheostoma spilotum was federally listed as threatened in 2016 due to degradation of stream habitat and water quality in the upper Kentucky basin that has eliminated the species from a significant portion of its range.

 

KEYWORDS: Arrow Darter, Cumberland Plateau, taxonomy, species delimitation, subspecies

Etheostoma sagitta and E. spilotum

Matthew R. Thomas, Rebecca E. Blanton, Ava Ghezelayagh and Thomas J. Near. 2023. Species-Level Recognition and Redescription of the Kentucky Arrow Darter, Etheostoma spilotum Gilbert (Percidae: Litocara). Bulletin of the Peabody Museum of Natural History. 64(1); 39-80. DOI: 10.3374/014.064.0103

  twitter.com/TJNear/status/1643216820495630336

[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

 

[Ichthyology • 2022] Synchiropus flavistrigatus • A New Species of Dragonet (Teleostei: Callionymidae) from the tropical eastern Atlantic

 Synchiropus flavistrigatus

Fricke, Ordines & Ramírez-Amaro, 2022

,

DOI:  10.18476/2022.874590 

 Abstract

A new species of dragonet, Synchiropus flavistrigatus sp. n. from the eastern tropical Atlantic, is described on the basis of 15 specimens. The new species is characterised within the subgenus Yerutius Whitley, 1931 by having 8 rays in the second dorsal fin (the last divided at its base), 8 anal-fin rays (the last divided at its base), 20–21 pectoral-fin rays, a single upper unbranched pectoral-fin ray, 1–2 curved dorsal points on the upper margin of the preopercular spine (additional to the main tip), length of first spine of first dorsal fin in male 12.8–15.9% of standard length, in female 14.5–15.4%; caudal-fin length in male 27.7–32.2% of standard length, in female 25.5–27.9%; length of last ray of second dorsal fin in male 18.2–21.6% of standard length; length of last ray of anal fin in male 14.6–17.1% of standard length, in female 13.5–15.1%; second dorsal fin and caudal fin with oblique yellow bars in both sexes; anal fin with a distal dark streak in both sexes. We also provide molecular information, based on two mitochondrial fragments (COI and 12s rRNA), that clearly supports the morphological results confirming that S. flavistrigatus sp. n. corresponds to a new species, distinct from S. phaeton (Günther, 1861). The new species is compared with other species of the subgenus.

KEYWORDS: distribution, dragonets, fishes, Guinea-Bissau, new species

Synchiropus flavistrigatus sp. n.

Guinea dragonet

Diagnosis: A species of the subgenus Synchiropus (Yerutius) with 8 rays in the second dorsal fin, the last divided at its base, 8 anal-fin rays (the last divided at its base), 20–21 pectoral-fin rays, a single upper unbranched pectoral-fin ray, 1–2 curved dorsal points on the upper margin of the preopercular spine (additional to the main tip), length of first spine of first dorsal fin in male 12.8–15.9% of standard length, in female 14.5–15.4%; caudal-fin length in male 27.7–32.2% of standard length, in female 25.5–27.9%; length of last ray of second dorsal fin in male 18.2–21.6% of standard length; length of last ray of anal fin in male 14.6–17.1% of standard length, in female 13.5–15.1%; second dorsal fin and caudal fin with oblique yellow bars in both sexes; anal fin with a distal dark streak in both sexes.

Distribution: The species is only from the tropical eastern Atlantic, distributed off the coast of West Africa between Guinea-Bissau and Angola (Fig. 3). It was collected at depths of 104–386 m.

Etymology: Flavus (Latin) means yellow; strigatus (Latin) means striped. The name of this species refers to the yellow bars on the second dorsal fin. The name is an adjective in the male form when in the male genus Synchiropus.

Ronald Fricke, Francesc Ordines and Sergio Ramírez-Amaro. 2022. Synchiropus flavistrigatus, A New Species of Dragonet from the tropical eastern Atlantic (Teleostei: Callionymidae). Integrative Systematics: Stuttgart Contributions to Natural History. 5(2); 87-101. DOI:  10.18476/2022.874590 

Eine neue Leierfischart, Synchiropus flavistrigatus sp. n. aus dem tropischen Ostatlantik, wird anhand von 15 Exemplaren beschrieben. Die neue wird innerhalb der Untergattung Yerutius Whitley, 1931 durch folgende Merkmale charakterisiert: 8 Strahlen in der zweiten Rückenflosse (der letzte an der Basis geteilt), 8 Strahlen in der Afterflosse (der letzte an der Basis geteilt), 20–21 Brustflossenstrahlen, ein einziger Brustflossenstrahl oben unverzweigt, 1–2 gebogene Spitzen auf der dorsalen Seite des Präoperkulardorns (zusätzlich zur Hauptspitze), Länge des ersten Strahls der ersten Rückenflosse beim Männchen 12.8–15.9% der Standardlänge, beim Weibchen 14.5–15.4%; Schwanzflossenlänge beim Männchen 27.7–32.2% der Standardlänge, beim Weibchen 25.5–27.9%; Länge des letzten Strahls der zweiten Rückenflosse beim Männchen 18.2–21.6% der Standardlänge; Länge des letzten Strahls der Afterflosse beim Männchen 14.6–17.1% der Standardlänge, beim Weibchen 13.5–15.1%; zweite Rückenflosse und Schwanzflosse bei beiden Geschlechtern mit gelben Schrägstreifen; Afterflosse bei beiden Geschlechtern distal mit einem dunklen Streifen. Eine molekulare Untersuchung basierend auf zwei mitochondrialen Fragmenten (COI und 12s rRNA) unterstützt die morphologischen Befunde und bestätigt, daß es sich bei S. flavistrigatus sp. n. um eine neue Art handelt, die sich von S. phaeton (Günther, 1861) deutlich unterscheidet. Die neue Art wird mit anderen Arten der Untergattung verglichen.

[Ichthyology • 2022] Rhonciscus pauco • A New Species of Deep-sea Grunt (Lutjaniformes: Haemulidae) from Puerto Rico

Rhonciscus pauco 

 Tavera​, Schärer-Umpierre & Acero P., 2022

DOI: 10.7717/peerj.13502

 

Abstract

A fourth species of the genus Rhonciscus (Lutjaniformes: Haemulidae) is described from various specimens collected by small-scale fishers from the insular upper slope of western Puerto Rico. The new species was molecularly recovered as sister to the Eastern Pacific R. branickii, to which it bears many morphological similarities. It is distinguished from other Rhonciscus species by the number of scale rows between the dorsal fin and the lateral line (7), larger and thus fewer scales along the lateral line (48–50), large eyes (9.4–10.4 times in SL), longer caudal peduncle (15.2–20% of SL), larger sized penultimate (14.7–19.1% in SL) and last (7.4–9.5% in SL) dorsal fin spines which translates to a less deeply notched dorsal fin, and its opalescent silver with golden specks live coloration. This grunt, only now recognized by ichthyologists, but well known by local fishers that target snappers and groupers between 200 and 500 m in depth, occurs in far deeper waters than any western Atlantic grunt.

Rhonciscus pauco, sp. nov. OMNH 86864, holotype, 266 mm SL,
from Tres Cerros, Rincón, Puerto Rico.

Rhonciscus pauco, sp. nov. Underwater photograph taken at 218 m depth in western Puerto Rico.

 Image: NOAA NCCOS 2022.

Rhonciscus pauco sp. nov. 

Opalescent Grunt

(Spanish name: Ronco opalescente)

Diagnosis. A species of the genus Rhonciscus with XIII, 12 (total 25) dorsal-fin rays; anal-fin rays III, 7; pectoral-fin rays 15–16, 17(1); rather elongate body, maximum depth 32–37.4% SL; convex predorsal profile; eye large, its diameter 9.4% to 10.4% SL; snout subequal to eye, its length 7.6% to 11.5% SL; very coarse serrations on angle of preopercular margin; pectoral fin long (28–32.5% SL) extending beyond the tip of pelvic fin, barely reaching anus; head length 30–37.3% SL; longest dorsal-fin spine (fifth) (12.1–19.1% SL); relatively long and much thicker second anal-fin spine (16.4–21.8% SL), long caudal peduncle (15.2–20% of SL), and a large size of the penultimate (14.7–19.1% in SL) and last dorsal-fin (7.4–9.5% in SL) spines which translate to a less deeply notched dorsal fin, eye diameter 0.5 to 0.6 times length of anal fin spine; maxilla reaching anterior border of pupil; seven scale rows between dorsal fin and lateral line; 48 to 50 lateral–line scales.

Distribution. Rhonciscus pauco is found on the deep shelf and upper slope of the western coast of the northeastern Caribbean island of Puerto Rico. We are uncertain of the species’ exact range, but fishers report capturing them exclusively in fine sediment habitats distributed between the municipalities of Rincón and Mayagüez, off western Puerto Rico (Fig. 1). No additional information is currently available.

Habitat. Collection depths range from 200–360 m in fine unconsolidated sediment or mud habitats (Fig. 5).

Etymology. The name pauco comes from the fisher’s nickname Paúco, Edwin Font, who already knew of this fish locally called burro or ronco (grunt). Mr. Font was the first to report and provided specimens to MS, although it is recognized by various fishers as a component of the deep-water catch in western Puerto Rico.

Jose Tavera​, Michelle T. Schärer-Umpierre and Arturo Acero P. 2022. A New Species of Deep-sea Grunt, Rhonciscus pauco (Lutjaniformes: Haemulidae), from Puerto Rico. PeerJ. 10:e13502 . DOI: 10.7717/peerj.13502

[Ichthyology • 2021] Percina freemanorum • A New Species of Bridled Darter (Percidae: Etheostomatinae: Percina) Endemic to the Etowah River System in Georgia

 Percina freemanorum Near & Dinkins,  

in Near, MacGuigan, Boring, Simmons, ... et Dinkins, 2021

Etowah Bridled Darter || DOI: 10.3374/014.062.0102

 

Abstract

Percina freemanorum, the Etowah Bridled Darter, is described as a new species endemic to the Etowah River system in Georgia, specifically in Long Swamp Creek, Amicalola Creek, and the upper portion of the Etowah River. The earliest collection records for Percina freemanorum date to 1948 and in 2007 the species was delimited as populations of Percina kusha. Our investigation into the systematics of Percina kusha is motivated by the uncertain status of populations in the Coosawattee River system and observed morphological disparity in several meristic traits between populations in the Conasauga and Etowah River systems. Our analyses of morphological divergence, nuclear genotypes, and mitochondrial DNA (mtDNA) haplotype networks confirm the distinctiveness of Percina freemanorum. Morphologically, Percina freemanorum is distinguished from Percina kusha through lower average numbers of lateral line scales (65.4 vs. 72.3); rows of transverse scales (18.0 vs. 21.4); scales around the caudal peduncle (22.1 vs. 24.9); and modally more pectoral fin rays (14 vs. 13). The two species are not reciprocally monophyletic in phylogenetic analysis of mtDNA sequences, but the two species do not share mtDNA haplotypes. Analysis of up to 158,000 double digest restriction-site associated DNA (ddRAD) sequencing loci resolve each of the two species as reciprocally monophyletic and genomic clustering analysis of single nucleotide polymorphisms identifies two genetic clusters that correspond to the morphologically delimited Percina freemanorum and Percina kusha.

KEYWORDS: Teleostei, species delimitation, ddRAD, phylogeography

Live holotype and allotype specimens of Percina freemanorum. Both specimens collected from Amicalola Creek, Dawson County, Georgia, USA, April 2020.
A. holotype, YPM ICH 034382, 68.0 mm standard length (SL) male.
B. allotype, YPM ICH 034383, 65.5 mm SL female.

Photographs by Georgia Department of Natural Resources.

Percina freemanorum Near & Dinkins 

Etowah Bridled Darter

 Percina freemanorum type locality: Dawson County, Georgia, USA.
 A. Amicalola Creek; B. Underwater, Amicalola Creek.

Photographs by Georgia Department of Natural Resources.

Etymology. Percina freemanorum is named in honor of Mary C. Freeman and Byron (Bud) J. Freeman, who have made substantial contributions to the study of freshwater fishes in the southeastern United States. In particular, their work has shed light on and significantly aided in the conservation ofthe biodiverse rich Etowah Riversystem.

 

  

Thomas J. Near, Daniel J. MacGuigan, Emily L. Boring, Jeffrey W. Simmons, Brett Albanese, Benjamin P. Keck, Richard C. Harrington and Gerald R. Dinkins. 2021. A New Species of Bridled Darter Endemic to the Etowah River System in Georgia (Percidae: Etheostomatinae: Percina). Bulletin of the Peabody Museum of Natural History. 62(1); 15-42. DOI: 10.3374/014.062.0102

https://news.uga.edu/new-fish-species-named-for-uga-ecologists/

https://mcclungmuseum.utk.edu/wp-content/uploads/sites/78/2021/04/Near_et_al2021.pdf

Researchgate.net/publication/350558911_A_New_Species_of_Percina_Endemic_to_the_Etowah_River_System_in_Georgia

[Ichthyology • 2021] New Records and Redescription of Labracinus atrofasciatus (Herre, 1933) (Teleostei: Pseudochromidae)

Labracinus atrofasciatus (Herre, 1933)

in Gill, Sorgon, Brun & Tea, 2021.

RAFFLES BULLETIN OF ZOOLOGY. 69 

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Photographs by V. Brun.

Abstract

 The pseudochromid Labracinus atrofasciatus (Herre, 1933) is redescribed based on examination of the holotype from Culion, Calamian Islands, and three newly acquired non-type specimens from a fish landing site in Barangay Sandoval, Municipality of Taytay, northern Palawan, Philippines. Prior to this, the species was known only from the holotype; from a photograph of a putative female taken in Lajo Island, Busuanga, Calamian Islands; and from observations at Lajo Island and Tangat Island, Calamian Islands. The new specimens from Macuao Island appear to be males, and their live colouration is reported here for the first time. We also briefly comment on the restricted distribution of other pseudochromids and coral-reef fishes in the Palawan region of the Philippines.

 Key words. dottyback, Philippines, endemic, Palawan, Calamian Islands, Culion, Taytay

Freshly dead Labracinus atrofasciatus specimens from Macuao Island, northern Palawan, Philippines.
A, PNM 15645, 146.5 mm SL; B, PNM 15646, 142.0 mm SL; C, AMS I.49470-001, 134.4 mm SL.

Photographs by V. Brun (A) and K. E. S. Sorgon (B, C).

Two specimens of Labracinus atrofasciatus (approximately 150 and 190 mm TL) amongst catch of other reef fishes at a fish landing site in Barangay Sandoval, Municipality of Taytay, northern Palawan, Philippines. Specimens not retained.

Photograph by V. Brun.

Labracinus atrofasciatus (Herre, 1933) 

Black-barred dottyback

Diagnosis. Labracinus atrofasciatus differs from congeners in having a series of narrow, dark blue to black oblique bars on the body. It also differs in having relatively high numbers of horizontal scale rows above the anal-fin origin (24–27 + 1 + 4–5 = 30–33), pseudobranch filaments (22–24), and circumpeduncular scales (30–32).

Etymology. The specific epithet is derived from the Latin ‘atrum’, black, and ‘fascia’, band, in reference to the striking markings on the body of this species. Labracinus atrofasciatus is known locally as ‘akot’ in Cuyonon, a language spoken mostly in Cuyo Islands and coastal areas of Palawan in the Philippines, where it shares the local name with the congeneric L. cyclophthalmus. 

Habitat and distribution. We extend the known distribution of L. atrofasciatus from Culion in the Calamian Islands southward to Taytay, Palawan (Fig. 4A). ...

Map of the Philippines, showing distribution records for selected species of pseudochromids endemic to the Calamian Islands and Palawan regions.
A, Labracinus atrofasciatus, photograph of PNM 15645; B, Pseudochromis colei, photograph of aquarium specimen (not retained);
C, P. eichleri, photograph of AMS I.45651-001 (paratype); D, Manonichthys scintilla, photograph of USNM 382744 (paratype).

Photographs by V. Brun (A), Y. K. Tea (B), G. R. Allen (C), and J. T. Williams (D).

A, putative female of Labracinus atrofasciatus, in situ photograph taken in Lajo Island, Palawan, Philippines;
B, holotype of L. atrofasciatus, CAS-SU 25518, 105.5 mm SL holotype (image adapted from Gill, 2004). Note the posterior dorsal-fin spot and faint vertical bars in both specimens.

Photographs by G. R. Allen & M. V. Erdmann (A) and P. Crabb (B).

Anthony C. Gill, Kent Elson S. Sorgon, Victor Brun and Yi-Kai Tea. 2021. New Records and Redescription of Labracinus atrofasciatus (Herre, 1933) (Teleostei: Pseudochromidae). RAFFLES BULLETIN OF ZOOLOGY. 69; 438–447.  

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