The high speed radular prey strike of a fish-hunting cone snail.

Cone snails are venomous marine gastropods that hydraulically propel a hollow, chitinous radular harpoon into prey [1,2]. This radular harpoon serves both as projectile and conduit for venom delivery. In the fish-hunting cone snail Conus catus, the radular harpoon is also utilized to tether the snail to its prey, rapidly paralyzed by neuroexcitatory peptides [2,3].

Primary cell culture of adult zebrafish spinal neurons for electrophysiological studies.

Background: Zebrafish (Danio rerio) are growing in popularity as a vertebrate model organism for the study of spinal neurocircuitry and locomotion. While many studies have used the zebrafish model system for electrophysiological analyses in embryonic and larval stages, there is a growing interest in studying spinal circuits and neurons from adult fish.

New Method: To expand upon the existing toolset available to the zebrafish research community, we have developed the first primary cell culture system of adult zebrafish spinal neurons.

Venom variation during prey capture by the cone snail, Conus textile.

Observations of the mollusc-hunting cone snail Conus textile during feeding reveal that prey are often stung multiple times in succession. While studies on the venom peptides injected by fish-hunting cone snails have become common, these approaches have not been widely applied to the analysis of the injected venoms from mollusc-hunters. We have successfully obtained multiple injected venom samples from C.

Venom kinematics during prey capture in Conus: the biomechanics of a rapid injection system.

Cone snails use an extensile, tubular proboscis as a conduit to deliver a potent cocktail of bioactive venom peptides into their prey. Previous studies have focused mainly on understanding the venom's role in prey capture but successful prey capture requires both rapid physiological and biomechanical mechanisms. Conus catus, a fish-hunting species, uses a high-speed hydraulic mechanism to inject its hollow, spear-like radular tooth into prey.

Two toxins from Conus striatus that individually induce tetanic paralysis.

We describe structural properties and biological activities of two related O-glycosylated peptide toxins isolated from injected (milked) venom of Conus striatus, a piscivorous snail that captures prey by injecting a venom that induces a violent, spastic paralysis. One 30 amino acid toxin is identified as kappaA-SIVA (termed s4a here), and another 37 amino acid toxin, s4b, corresponds to a putative peptide encoded by a previously reported cDNA. We confirm the amino acid sequences and carry out structural analyses of both mature toxins using multiple mass spectrometric techniques.

Intraspecific variation of venom injected by fish-hunting Conus snails.

Venom peptides from two species of fish-hunting cone snails (Conus striatus and Conus catus) were characterized using microbore liquid chromatography coupled with matrix-assisted laser desorption/ionization-time of flight-mass spectrometry and electrospray ionization-ion trap-mass spectrometry. Both crude venom isolated from the venom duct and injected venom obtained by milking were studied. Based on analysis of injected venom samples from individual snails, significant intraspecific variation (i.

Ion channel activity of membrane vesicles released from sea urchin sperm during the acrosome reaction.

The sperm acrosome reaction (AR) involves ion channel activation. In sea urchin sperm, the AR requires Ca2+ and Na+ influx and K+ and H+ efflux. During the AR, the plasma membrane fuses with the acrosomal vesicle membrane forming hybrid membrane vesicles that are released from sperm into the medium.