Although the pulsed jet is often considered the foundation of a squid's locomotive system, the lateral fins also probably play an important role in swimming, potentially providing thrust, lift and dynamic stability as needed. Fin morphology and movement vary greatly among squid species, but the locomotive role of the fins is not well understood. To begin to elucidate the locomotive role of the ...

We show that the exaggerated changes in fin lengths of zebrafish (Danio rerio) caused by a single gene mutation also resulted in changes in the lateral display rate. However, the increase in this threat display rate only occurred when both fish had very long fins. Fish with shorter fins did not show such an increase when they met fish with longer, same size, or shorter fins. Cutting the long fi...

The earliest known vertebrate copulatory organs are claspers, paired penis-like structures that are associated with evolution of internal fertilization and viviparity in Devonian placoderms. Today, only male chondrichthyans possess claspers, which extend from posterior pelvic fins and function as intromittent organs. Here we report that clasper development from pelvic fins of male skates is con...

We have compared the ability of RA to induce apoptosis in regenerating fins and limbs in order to establish whether there may be a possible causal relationship between RA-induced cell death and the different patterning abnormalities observed in these two systems following RA treatment. In regenerating fins RA affects the anteroposterior axis and induces narrowing of the fin and fusion of rays. ...

The objective of this study is to develop a controller to perform trajectory tracking for a Biomimetic Autonomous Underwater Vehicle (BAUV). A mathematical model of a BAUV including both a caudal fin and pectoral fins is proposed for the motion simulation. Control patterns to manipulate the caudal fin and a pair of pectoral fins are developed. For body-caudal fin control, parameters that are es...

This paper presents a numerical study of the thermal performance of fins mounted on the bottom wall of a horizontal channel and cooled with either pure water or an Al2O3-water nanofluid. The bottom wall of the channel is heated at a constant temperature and cooled by mixed convection of laminar flow at a relatively low temperature. The results of the numerical simulation indicate that the heat ...

In zebrafish, mutations in the gap junction gene connexin43 lead to short bony fin ray segments that give rise to the short fin phenotype. The sof(b123) mutant exhibits fins that are half the length of wild-type fins and have reduced levels of cx43 mRNA. We find that sof(b123) regenerating fins exhibit reduced levels of cell proliferation. Interestingly, the number of dividing cells per unit le...

Larval zebrafish innately perform a suite of behaviors that are tightly linked to their evolutionary past, notably escape from threatening stimuli and pursuit and capture of prey. These behaviors have been carefully examined in the past, but mostly with regard to the movements of the trunk and tail of the larvae. Here, we employ kinematics analyses to describe the movements of the pectoral fins...

Study of the osteological development in fishes is important from fisheries, biology and aquaculture points of views. It can be used as an early bio-indicator of non-optimal rearing conditions. The Caspian roach, Rutilus caspicus is a native cyprinid fish of the Caspian Sea that its artificial propagation has fulfilled in hatcheries to recruit its natural stocks. Hence, this study was conducted...