Chelonodontops bengalensis Habib et al. 2018, a junior synonym of Tetrodon patoca Hamilton 1822, with a type species designation for Chelonodon Müller 1841.

A comparison of the recent description of Chelonodontops bengalensis Habib, Neogi, Og, Lee & Kim 2018 with that of Tetrodon patoca Hamilton 1822 reveals that the former is a junior synonym of the latter. Chelonodon patoca appears to be restricted in its distribution to coastal brackish waters at the mouth of the Ganges/Brahmaputra/Meghna system in India and Bangladesh and further south to at least the mouth of the Mahanadi. The valid name for the widespread Indo-Pacific species previously confused with C.

The genome sequence of the Dracula fish, (Britz, Conway & Rüber, 2009).

We present a genome assembly from an individual (the Dracula fish; Chordata; Actinopterygii; Cypriniformes; Danionidae; Danioninae). The genome sequence is 665.21 megabases in span.

Ultrafast sound production mechanism in one of the smallest vertebrates.

Motion is the basis of nearly all animal behavior. Evolution has led to some extraordinary specializations of propulsion mechanisms among invertebrates, including the mandibles of the dracula ant and the claw of the pistol shrimp. In contrast, vertebrate skeletal movement is considered to be limited by the speed of muscle, saturating around 250 Hz.

The larval attachment organ of the bowfin Amia ocellicauda Richardson, 1836 (Amiiformes: Amiidae) and its phylogenetic significance.

Larval attachment organs (LAOs) are unicellular or multicellular organs that enable the larvae of many actinopterygian fishes to adhere to a substrate before yolk-sac absorption and the free-swimming stage. Bowfins (Amiiformes) exhibit a sizable LAO on the snout, which was first described in the late 19th and early 20th centuries. In this study, we document the LAO of Amia ocellicauda (Richardson, 1836) using a combination of scanning electron microscopy (SEM) and light microscopy, and histochemistry.

Dario tigris and Dario melanogrammus, two new species of miniature chameleon fishes from northern Myanmar (Teleostei: Badidae).

Dario tigris, new species, is described from mountain streams south of Mogaung, in the Ayeyarwaddy River basin, Myanmar. It differs from congeneric species by its unique colour pattern, which consists of a series of eight straight vertical bars, the first two of which in males are ash-grey and the subsequent six are orange-red in life, combined with a series of small black spots arranged in three to four rows dorsolaterally on the head and nape. It differs further from its close relative Dario hysginon, with which it may occur syntopically, by fewer dorsal-fin spines (modally 14 vs modally 15), and fewer vertebrae (modally 12+12=24 vs modally 12+13= 25).

Evolutionary divergence of locomotion in two related vertebrate species.

Locomotion exists in diverse forms in nature; however, little is known about how closely related species with similar neuronal circuitry can evolve different navigational strategies to explore their environments. Here, we investigate this question by comparing divergent swimming pattern in larval Danionella cerebrum (DC) and zebrafish (ZF). We show that DC displays long continuous swimming events when compared with the short burst-and-glide swimming in ZF.

Three scleral ossicles in the West African Denticle herring Denticeps clupeoides (Clupeiformes: Denticipitidae).

The eyes of teleostean fishes typically exhibit two ossifications, the anterior and posterior sclerotics, both associated with the scleral cartilage. The West African Denticle herring Denticeps clupeoides has three scleral ossifications, including the typical two associated with the scleral cartilage (anterior and posterior sclerotic) and a third ossification (Di Dario's ossicle), spatially separated from the scleral cartilage and located within the anteromedial wall of the sclera. The medial rectus muscle inserts on the medial surface of Di Dario's ossicle, suggesting that this third sclerotic may play a role in forward rotation of the eye in this surface feeding fish.

The emerging vertebrate model species for neurophysiological studies is Danionella cerebrum, new species (Teleostei: Cyprinidae).

The four described species of Danionella are tiny, transparent fishes that mature at sizes between 10-15 mm, and represent some of the most extreme cases of vertebrate progenesis known to date. The miniature adult size and larval appearance of Danionella, combined with a diverse behavioral repertoire linked to sound production by males, have established Danionella as an important model for neurophysiological studies. The external similarity between the different species of Danionella has offered an important challenge to taxonomic identification using traditional external characters, leading to confusion over the identity of the model species.

Poor groundwater governance threatens ancient subterranean fishes.

Groundwater depletion is a significant global issue, but its impact on the often-enigmatic subterranean biodiversity and its conservation remains poorly understood. In the Western Ghats biodiversity hotspot of India, poor governance of groundwater resources is threatening its evolutionarily distinct subterranean freshwater fauna, some taxa of which represent Gondwanan relics.

A note on emMuraena/em emalba/em Zuiew, 1793 (Teleostei: Synbranchidae).

Originally described as Muraena alba by the Russian ichthyologist Basilius Zuiew (1793) [Vasilij Fyodorovich Zuev'], the name Monopterus albus has long been used for a species of swamp eel (Synbranchidae) with a reportedly widespread occurrence in Asia (Rosen Greenwood 1976, Kottelat 2013). In recent years molecular studies have shown that Monopterus albus of authors is a species complex and several authors have recommended that up to three (Collins et al. 2002, Matsumoto et al.

The larval attachment organ of the tropical gar Atractosteus tropicus Gill, 1863 (Lepisosteiformes: Lepisosteidae).

Larval attachment organs (LAOs) are unicellular or multicellular organs that allow larvae to adhere to a substrate before yolk-sac absorption and the free-swimming stage. This study documents the LAO of tropical gar, Atractosteus tropicus, using a combination of scanning electron microscopy and light microscopy. It is shown that the LAO of A.

Extreme evolutionary shifts in developmental timing establish the miniature Danionella as a novel model in the neurosciences.

Background: Species of Danionella rank among the smallest of all vertebrates and their miniature size is correlated with an extreme case of progenesis, resulting in tiny, transparent sexually mature individuals. Progenesis has affected the entire skeleton of Danionella, in which 60 skeletal elements are absent, including some of the skull roofing bones. This lack of a skull roof combined with the presence of a fully formed hearing and sound producing apparatus has led to Danionella being used as an important model for neurophysiological studies.

Aenigmachannidae, a new family of snakehead fishes (Teleostei: Channoidei) from subterranean waters of South India.

Pronounced organism-wide morphological stasis in evolution has resulted in taxa with unusually high numbers of primitive characters. These 'living fossils' hold a prominent role for our understanding of the diversification of the group in question. Here we provide the first detailed osteological analysis of Aenigmachanna gollum based on high-resolution nano-CT scans and one cleared and stained specimen of this recently described snakehead fish from subterranean waters of Kerala in South India.

Unexpected species diversity within Sri Lanka's snakehead fishes of the Channa marulius group (Teleostei: Channidae).

The taxonomic status of the large snakeheads of the Channa marulius group that occur in Sri Lanka is reviewed and clarified. Two species are recognized from the island, based on both morphological and molecular (cytochrome c oxidase subunit 1: cox1) differentiation: C. marulius Hamilton from the northern dry zone and C.

The subterranean Aenigmachanna gollum, a new genus and species of snakehead (Teleostei: Channidae) from Kerala, South India.

Aenigmachanna gollum, new genus and species, is described from Kerala, South India. It is the first subterranean species of the family Channidae. It has numerous derived and unique characters, separating it from both the Asian Channa Scopoli and the African Parachanna Teugels Daget.

Pangio bhujia, a new, peculiar species of miniature subterranean eel loach lacking dorsal and pelvic fins from India (Teleostei: Cobitidae).

A unique, new species of eel loach, Pangio bhujia, is described from Kerala, India. It is the first species of Pangio to be described from subterranean waters. It possesses several unusual characters including absence of both dorsal and pelvic fins, the presence of only 3 pectoral-fin rays, 6 anal-fin rays and a unique count of 38 precaudal + 24 caudal vertebrae.

Channa rara, a new species of snakehead fish from the Western Ghats region of Maharashtra, India (Teleostei: Labyrinthici: Channidae).

Channa rara, new species, is described from the Jagbudi River in Maharashtra, India. It belongs to the Gachua group and differs from all its members by the possession of one or more ocelli in the posterior part of the dorsal fin in adults (vs. ocelli absent or 1, rarely 2-3 ocelli in juveniles only).

Channa auroflammea, a new species of snakehead fish of the Marulius group from the Mekong River in Laos and Cambodia (Teleostei: Channidae).

Channa auroflammea is a new freshwater fish species of the Marulius group from the Mekong River system. Previously reported as C. marulius, C.

Ontogeny of the catfish pectoral-fin spine (Teleostei: Siluriformes).

The characteristic and morphologically variable pectoral-fin spine of catfishes (order Siluriformes) has been well-investigated based on later developmental stages (juveniles and adults) but information on the earliest life stages are lacking. Here, we document the ontogeny of pectoral-fin spines in four siluroid (Ictalurus punctatus, Noturus gyrinus, Silurus glanis and Akysis vespa) and two loricarioid catfishes (Corydoras panda and Ancistrus sp.).

The snakehead fish Channa aurolineata is a valid species (Teleostei: Channidae) distinct from Channa marulius.

Channa aurolineata is a valid species of the Marulius group. Previously treated as a synonym of C. marulius, C.