Molecular data from three chloroplast markers resolve individuals attributable to Radula buccinifera in six lineages belonging to two subgenera, indicating the species is polyphyletic as currently circumscribed. All lineages are morphologically diagnosable, but one pair exhibits such morphological overlap that they can be considered cryptic. Molecular and morphological data justify the re-insta...

Coordination between different motor centers is essential for the orderly production of all complex behaviors, in both vertebrates and invertebrates. The current study revealed that rhythmic activities of two feeding structures of the pteropod mollusk Clione limacina, radula and hooks, which are used to extract the prey from its shell, are highly coordinated in a phase-dependent manner. Hook pr...

Results obtained from a histological, autoradiographic, and operative investigation of the radulae of two pulmonates have led to the formulation of the following theory of radula replacement. The radula is secreted continually by the permanent odontoblasts and continually moves anteriorly. The superior epithelium of the radular gland is produced by division of cells near the odontoblasts and mo...

The limpet radula is a feeding organ, which contains more than 100 rows of teeth. During their growth the teeth mature and advance in position along the radula. The simpler doccoglossan radulae operate by grinding rocky substrates, extracting the algae by rasping and scraping with the teeth functioning as shovels. Less is known about the rhipidoglossan radulae, used as rakes or brooms that brus...

A comparative study of the chemical composition of essential oils of two very similar species of the Verbenaceae family (Lantana camara and L. radula) revealed that the main components of essential oil of L. camara were germacrene-D (19.8%) and E-caryophyllene (19.7%), while those of L. radula were E-caryophyllene (25.3%), phytol (29.2%) and E-nerolidol (19.0%). We have hypothesized that the ob...

In many systems used to study rhythmic motor programs, the structures that generate behavior are at least partially internal. In these systems, it is often difficult to directly monitor neurally evoked movements. As a consequence, although motor programs are relatively well characterized, it is generally less clear how neural activity is translated into functional movements. This is the case fo...

Two kinematic models of the radula/odontophore of the marine mollusc Aplysia californica were created to characterize the movement of structures inside the buccal mass during the feeding cycle in vivo. Both models produce a continuous range of three-dimensional shape changes in the radula/odontophore, but they are fundamentally different in construction. The radulacentric model treats the radul...

The serotonergic metacerebral cells (MCCs) and homologous neurons in related mollusks have been extensively investigated within the context of feeding. Although previous work has indicated that the MCCs exert widespread actions, MCC modulation of sensory neurons has not been identified. We characterized interactions between the MCCs and a cell that is part of a recently described group of bucca...

A cold-shock technique was used to determine radula production rates for the chitons Acanthopleura hirtosa and Plaxiphora albida, and for the limpet Patelloida alticostata, which replaced their radular teeth at rates of 0.40, 0.36 and 0.51 rows d, respectively. These rates are far slower than those determined previously for non-iron-mineralizing molluscs, suggesting that the improvedworking lif...