Retroculus acherontos is described from the Rio Tocantins basin, Brazil. It is distinguished from all congeners by the presence of a nuchal hump in large specimens, an irregular black blotch located on the middle of the anterior soft dorsal-fin rays, fewer pectoral-fin rays (15-16), a deeper body, a convex ventral profile, a more transversely convex ventral surface of the body, and by chest sca...

The swordlike exaggerated caudal fin extensions of male swordtails are conspicuous traits that are selected for through female choice. Swords are one of only few examples where the hypothesis of a pre-existing bias is believed to apply for the evolution of a male trait. Previous laboratory experiments demonstrated that females prefer males with longer swords and even females from some swordless...

A new goby species Tridentiger radiatus sp. nov. is described from Zhuhai, Guangdong Province of China. The new species, found in sympatry with a widely distributed barbeled congener Tridentiger barbatus (Günther, 1861), is one of the only two Tridentiger species known to possess mandibular and cheek barbels. Tridentiger radiatus is diagnosed by having higher longitudinal and transverse scale c...

Background: The coloured righteye flounder, Poecilopsetta colorata Günther, 1880 was previously known from the eastern Indian Ocean to the South China Sea and Indonesia. Here, a new record from the western Indian Ocean is reported. Results: The new record is based on a specimen collected on the Sakalaves seamounts at 375 m in depth in the Mozambique Channel during a recent oceanographic survey....

The maintenance of sexual reproduction in the face of its supposed costs is a major paradox in evolutionary biology. The Red Queen hypothesis, which states that sex is an adaptation to fast-evolving parasites, is currently one of the most recognized explanations for the ubiquity of sex and predicts that asexual lineages should suffer from a higher parasite load if they coexist with closely rela...

Didogobius helenae is described from the Canary Islands. It has a sensory papillae pattern that is consistent with the current diagnosis for Didogobius, but lacks all head canals and pores that are present in other members of the genus. Pores, in general, are replaced by large papillae.  The species is defined by first dorsal fin VI; second dorsal fin I,10; anal fin I,9; pectoral fin 16-17; pel...

Pseudochromis oligochrysus new species is described from nine specimens collected from Nusa Penida (off Bali) and Pura Island (between Pantar and Alor), Indonesia. It resembles P. flavopunctatus Gill & Randall from Komodo, Indonesia, but differs in live coloration and scale counts. Pseudochromis rutilus new species is described from the holotype collected from Nusa Penida. It differs from simil...

Horabagrus melanosoma was described from West Venpala in the lower reaches of the Manimala River, in the state of Kerala, India. It was distinguished from its nearest congener, H. brachysoma based on a combination of characters including darker body colour, shorter pelvic fin and greater number of anal fin rays. Examination of the type material revealed significant morphometric and meristic dis...

In our earlier paper (Ho et al., 2013), we described three new species of the eel genus Neenchelys Bamber, 1915. Unfortunately, the critical step of registering the work in ZooBank was omitted, thus rendering the names unavailable. In this paper, we present abbreviated descriptions of the new species in order to make these names available in accordance with the amended Article 8.5 of the Intern...

Jaydia erythrophthalma n. sp. is described from specimens collected during two recent biodiversity surveys along the east and west coasts of Luzon, Philippines. It is characterized by a first dorsal fin with eight spines, serrated posterior and crenulated ventral preopercular edges, reddish orange iris and two series of brown spots tinged in orange on the upper part of the body.