[Ichthyology • 2026] Hemigrammus serrazul • A New Hemigrammus (Characiformes: Acestrorhamphidae) from the rio Cuiabazinho Drainages, upper rio Paraguai Basin, Mato Grosso, Brazil

   

Hemigrammus serrazul  

Ferreira, Ribeiro & Carvalho, 2026

DOI: doi.org/10.1590/1982-0224-2025-0157

 

Abstract

A new species of Hemigrammus is described from tributaries of the rio Cuiabazinho, upper rio Paraguai basin, Mato Grosso State, Brazil. It can be readily distinguished from all its congeners by a unique combination of characters, including a distinctive body coloration pattern without spots, the number of perforated lateral-line scales (12–15), the number of branched rays on anal fin (21–25), and the presence of small bony hooks at the tips of the lepidotrichia of the second to fourth branched rays of the pelvic fins, which are absent in the anal fin. We also provide a brief discussion on the recent taxonomic reconfiguration of Hemigrammus.

Keywords: Freshwater fish; Rio Cuiabá drainage; Serra Azul; Serrana Province of Mato Grosso; Taxonomy

 Color pattern variations in live specimens of Hemigrammus serrazul: A. Male; B. Female.

Photo by Alexandre C. Ribeiro.  

Hemigrammus serrazul, new species

Diagnosis. Hemigrammus serrazul can be distinguished from most congeners (except of H. apiaka (Esguícero& Castro, 2017), H. erythrozonus Durbin, 1909, H. gracilis (Lütken, 1875), H. mimus Böhlke, 1955, and H. tupebas (Esguícero& Castro, 2017) by flank uniformly colored, without spots, i.e., no humeral and caudal spots, just a tiny and narrow longitudinal stripe (vs. species with spots in humeral and/or caudal peduncle). From H. apiaka, H. erythrozonus, H. gracilis, H. mimus, and H. tupebas, H. serrazul differs by premaxillary teeth in two rows: outer with three to five tricuspid teeth, inner with five ...

Etymology. The specific epithet serrazul refers to the type locality where the new species was collected, the Serra Azul, the local portion of the so-called Serrana Province of Mato Grosso, a range of escarped relief that serves as a watershed divide between the rio Cuiabá, Paraguai, and Arinos basins. A noun in apposition.

Hemigrammus serrazul, live specimen in aquarium, photographed just after capture in córrego Cocal (CPUFMT 8218), upper rio Paraguai basin, municipality of Rosário Oeste, Mato Grosso State, Brazil. Inserir:

Photo by Alexandre C. Ribeiro.

Katiane Mara Ferreira, Alexandre Cunha Ribeiro and Fernando Rogério Carvalho. 2026. A New Hemigrammus (Characiformes: Acestrorhamphidae) from the rio Cuiabazinho Drainages, upper rio Paraguai Basin.  Neotrop. ichthyol. 24 (01); DOI: doi.org/10.1590/1982-0224-2025-0157

[Mollusca • 2026] Landouria tumpeesuwanorum & L. flagellolonga • Molecular Phylogeny of recognised Thai Landouria Species (Gastropoda: Camaenidae), with Descriptions of Two New Species

 

Landouria tumpeesuwanorum & L. flagellolonga  

 Nahok & K. Tanmuangpak, 

in Nahok, Chanlabut et Tanmuangpak, 2026. 

DOI: doi.org/10.3897/zookeys.1278.172545

Abstract

The molecular phylogeny and morphological–anatomical characteristics of the terrestrial snail genus Landouria Godwin-Austen, 1918 from Thailand are investigated, and we describe two new species. Phylogenetic analysis of 11 recognised Thai Landouria species reveal that these species are phylogenetically well separated from each other by mtDNA phylogeny and COI sequence divergences of 0.048–0.192. Landouria tumpeesuwanorum sp. nov. is described from a limestone hill in Nong Bua Lamphu Province, northeastern Thailand; it is characterised by its angulated whorls, a strongly keeled shell, and small flagellum with curved ends. The second new species, Landouria flagellolonga sp. nov. is described from a limestone hill in Sa Kaeo Province, eastern Thailand. It has a conical-lenticular, sharply keeled shell, and a very long, slender flagellum.

Key words: 16S rRNA, Camaenidae, COI, genitalia, integrative systematics, phylogeny, taxonomy, terrestrial snail, Thailand

Systematics

Family Camaenidae Pilsbry, 1895

Subfamily Bradybaeninae Pilsbry, 1934

Tribe Aegistini Kuroda & Habe, 1949

Genus Landouria Godwin-Austen, 1918

 

Living adults of two Landouria new species.
A. Landouria tumpeesuwanorum sp. nov. (paratype: NHLRU027); B. L. flagellolonga sp. nov. (paratype: ZCPRU-0050).

Landouria flagellolonga Nahok & K. Tanmuangpak, sp. nov.

Etymology. Specific epithet derived from Latin word longus, meaning “long” and referring to the elongated flagellum of this species.

Diagnosis. Shell small, light brown-corneous, sharply keeled. Flagellum very long, epiphallus long and slender; penis long, cylindrical, dilated at its middle part; vagina and free oviduct short. Radula with lanceolate central and lateral teeth.

Landouria tumpeesuwanorum Nahok & K. Tanmuangpak, sp. nov.

Diagnosis. Shell large, brownish-corneous, angulated whorls, strongly keeled. Flagellum small with blunt ends; epiphallus cylindrical and abruptly tapering at its distal part; penis swollen at its basal; vagina large and bulged. Radula with triangular central and lateral teeth.

Etymology. In honour of Assoc. Prof. Chanidaporn Tumpeesuwan and Sakboworn Tumpeesuwan, Thai malacologists and our beloved advisor and co-advisor, respectively, who initiated the taxonomic study of Landouria in Thailand and whose inspiration has led to our study of molluscs.

 Benchawan Nahok, Utain Chanlabut and Kitti Tanmuangpak. 2026. Molecular Phylogeny of recognised Thai Landouria Species (Gastropoda, Camaenidae), with Descriptions of Two New Species. ZooKeys. 1278: 181-200. DOI: doi.org/10.3897/zookeys.1278.172545 [28 Apr 2026]

[Arachnida • 2026] Langelurillus sahyadri & L. udaipurensis • Further Notes on Indian Langelurillus Próchniewicz, 1994 (Araneae: Salticidae), with the Description of Two New Species

 

Langelurillus sahyadri Sanap, Tripathi, Thackeray & Caleb, 

in Sanap, Tripathi, Caleb, H. Koli, V.K. Koli, Intodia et Thackeray, 2026.

DOI: doi.org/10.11646/zootaxa.5792.1.11

Abstract

We describe two new species, Langelurillus sahyadri Sanap, Tripathi, Thackeray & Caleb sp. nov. (♂♀) from Maharashtra and Langelurillus udaipurensis Tripathi, Sanap & Caleb sp. nov. (♂) from Rajasthan. Additionally, the previously unknown females of L. lacteus Sanap, Joglekar & Caleb, 2017 and L. onyx Caleb, Sanap, Joglekar & Prajapati, 2017 are described for the first time. Detailed morphological descriptions, illustrations, diagnostic comparisons of the studied species, and a distributional map for all Indian species are provided.

Araneae, Aravalli hills, distribution, jumping spider, taxonomy, Western Ghats

 Langelurillus sahyadri Sanap, Tripathi, Thackeray & Caleb sp. nov. 

Langelurillus udaipurensis Tripathi, Sanap & Caleb sp. nov. 

Langelurillus lacteus Sanap, Joglekar & Caleb, 2017 

L. onyx Caleb, Sanap, Joglekar & Prajapati, 2017

RAJESH V. SANAP, RISHIKESH TRIPATHI, JOHN T.D. CALEB, HEMLATA KOLI, VIJAY KUMAR KOLI, ANJANA INTODIA and TEJAS THACKERAY. 2026. Further Notes on Indian Langelurillus Próchniewicz, 1994 (Araneae: Salticidae), with the Description of Two New Species. Zootaxa. 5792(1); 183-199. DOI: doi.org/10.11646/zootaxa.5792.1.11 [2026-04-10]