Schistura andrewi, a new species of loach, is described from a tributary of Kaladan River in Mizoram, northeastern India. It is distinguished from its congeners in having the following combination of characters: long axillary pelvic lobe; complete lateral line with 82-95 pores; 2 unbranched dorsal and anal fin rays; 6-7 broad, wider than interspace, black bars on the body; 2 rows of black spots...

Schistura paucireticulata, new species, is described from the Tuirial River in Mizoram, India. It is distinguished from its congeners by a combination of characters: 8-9 brown bars on the body, bars in front of the dorsal fin divided into 2-3 small bars forming a reticulations; basicaudal bar black, dissociated; dorsal fin spotted, with 4 simple and 8 1/2 branched rays; anal fin with 3 simple a...

A new species of hoplichthyid, Hoplichthys imamurai, is described on basis of three specimens (128.9-143.6 mm SL) collected from northern Western Australia. It is clearly distinguished from its congeners by the following combination of characters: short preoptic snout (31.2-32.7% HL); vomer without teeth; long, thin, gill rakers; low first dorsal fin, its ad-pressed tips not reaching origin of ...

Psilorhynchus khopai, a new species of Psilorhynchidae, is described from Tuisi River, a tributary of Kaladan River, in Mizoram, India. The species is proposed to be a member of the Psilorhynchus homaloptera species group and can be distinguished from its congeners in having a forked caudal-fin with 9 + 9 principal caudal rays, 14-17 predorsal scale rows, 39-41 lateral-line scale rows, mid-late...

Acanthoplesiops cappuccino is described from the 16.4 mm SL holotype collected from Jeddah, Saudi Arabia, Red Sea. The following combination of characters distinguishes it from congeners: dorsal-fin rays XVIII,4; anal-fin rays VII,4; pectoral-fin rays 18; caudal fin not connected to last rays of dorsal and anal fins by membrane; and caudal peduncle with a pale yellowish brown bar, which extends...

Two new species of the gobiid genus Cabillus, C. nigromarginatus sp. nov. and Cabillus nigrostigmus sp. nov. are described. Cabillus nigromarginatus (from Rodrigues, Western Indian Ocean) is distinguished from congeners by having 18-20 pectoral-fin rays; predorsal area naked; two scales with enlarged ctenii ventrally and dorsally at the caudal-fin base; head with anterior and posterior oculosca...

Male swordtail fish of the genus Xiphophorus (Poeciliidae) possess a "sword" that is composed of several colored elongated ventral fin rays of the caudal fin. The sword is a secondary sexual trait that evolved through sexual selection by female preference. To uncover the developmental mechanisms underlying the metamorphosis from a juvenile caudal fin to the sword, we have devised a transplantat...

To determine the effect of development and environment on fin growth, we measured fin lengths of juvenile Atlantic salmon (Salmo salar) from two hatcheries (August, October and April–May), stream-reared fish (July and October) stocked as fry into two tributaries, and smolts from the main stem of the Connecticut River (May). For stream-reared parr, there was a linear relationship between the dor...

Aphanius marassantensis, new species, is described from the Kızılırmak River drainage in northern Anatolia based on colouration, meristic and morphometric characters, and the mtDNA COI barcode region. It is distinguished from other Anatolian Aphanius by one or several of the following characters: a stout body shape (BD/SL 28.2-39.6%), complete scale cover, and 25-28 scales along the lateral lin...

We use mitochondrial and nuclear sequence data to show that three weakly electric mormyrid fish specimens collected at three widely separated localities in Gabon, Africa over a 13-year period represent an unrecognized lineage within the subfamily Mormyrinae and determine its phylogenetic position with respect to other taxa. We describe these three specimens as a new genus containing two new spe...