New observations on the axial skeleton of the extant lungfish Neoceratodus forsteri (Dipnoi; Sarcopterygii) indicate that neural and haemal arch elements develop more independently than previously believed. For example, while the cartilaginous neural arches/spines begin development anteriorly, just behind the skull, the distal supraneurals first form separately in the posterior region of the ax...

Swimming fishes exhibit remarkable diversities of the caudal fin geometries. In this work, a computational study is conducted to investigate the effects of the caudal fin shape on the hydrodynamic performance and wake patterns in flapping propulsion. We construct the propulsor models in different shapes by digitizing the real caudal fins of fish across a wide range of species spanning homocerca...

This article took the trevally crescent-shaped caudal fin mode fishes as bionic object, based on the biological observation and bionic research, established the fish swimming model of trevally crescentshaped caudal fin mode, and designed the three degrees of freedom, tailtail fins pectoral fin, robotic fish. It detailed focuses on the fish propulsion theory and robotic fish overall design, incl...

Weakly electric knifefish are exceptionally maneuverable swimmers. In prior work, we have shown that they are able to move their entire body omnidirectionally so that they can rapidly reach prey up to several centimeters away. Consequently, in addition to being a focus of efforts to understand the neural basis of sensory signal processing in vertebrates, knifefish are increasingly the subject o...

Adult zebrafish completely regenerate their caudal fins following partial amputation. Fin regrowth can easily be monitored in vivo and regenerating tissues can be used to study this dynamic developmental process. In this study we determined that fin regeneration is significantly affected by exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Zebrafish caudal fins were partially amputated, a...

Traccatichthys tuberculum, new species, is herein described from the Jian-Jiang, a coastal river in Guangdong Province, South China. Photo by Bosco P.L. Chan. This new species differs from all other Chinese congeners (i.e., T. pulcher and T. zispi) in interorbital width, caudal-peduncle length, and pectoral-fin length. It, together with T. zispi, lacks the color patterns of the dorsal and anal ...

Psilorhynchus kaladanensis, a new psilorhynchid, is described from the Kaladan basin of Mizoram, India. The new species is diagnosed by having the following combination of characters: caudal fin with small but distinct dark brown triangular spot at mid-base, slightly elongated dark mark near base of lower lobe, indistinct V-shaped vertical bar across center, dark brown oblique bar across fin an...

Male swordtail fish of the genus Xiphophorus develop a sword, a colourful extension of the caudal fin, that evolved by sexual selection through female choice. Swords and gonopodia, an intromittent organ developing from the male anal fin, can be prematurely induced by exogenous testosterone, offering the opportunity to examine the identity and expression profiles of genes required during various...

Pseudophoxinus mehmeti, new cyprinid species from the Alanköy basin in south-western Turkey, is distinguished from all species of Pseudophoxinus in adjacent regions by the combination of the following characters: body slender, its length 1.3-1.5 times its depth; caudal peduncle length 1.6-2.0 times its depth; mouth almost superior, with the tip of the mouth-cleft approximately level with the mi...

Taxonomic investigation of spined loaches from Dalmatia and Herzegovina was conducted on specimens from 14 localities. The results of the detailed morphological investigations were combined with genetic data (based on one mitochondrial and two nuclear genes) in order to resolve the taxonomic status of each Cobitis population. Among the investigated features of external morphology, the appearanc...