Radular structure and function.

Abstract

The radula is a special feature of molluscs. It is a cuticular structure of the ectodermal foregut epithelium and is part of the buccal mass, the mollusc feeding apparatus. This paper discusses the anatomy of the buccal mass, radula formation, radula transport, radula function and role of the jaw in gastropods.

Not just scratching the surface: Distinct radular motion patterns in Mollusca

“…Within Heterobranchia, we observed motion pattern V in most species (also described in e.g. in Eigenbrodt, 1941 ; Wägele, 1983 ; Mackenstedt and Märkel, 2001 ; Neustadter et al, 2002a , b ; Montroni et al, 2019 ; Kehl et al, 2019 ; Krings et al, 2019a ), only S. marmorata was distinct (motion pattern VI; see also Eigenbrodt, 1941 ). We would, hence, propose that the licking movement is plesiomorphic in Heterobranchia and was modified within the Physidae.…”

“… Graham, 1973 ; Fretter and Graham, 1976 ; Crampton, 1977 ; Morse, 1984 ; Simone, 2005 , 2011 ; Evans et al, 2009 ; Golding et al, 2009 ; Balog et al, 2012 ) and the radular supporting structures, which are of different shape, quantity, volume (see e.g. Mackenstedt and Märkel, 2001 ; Katsuno and Sasaki, 2008 ; Golding et al, 2009 ) and probably bending capacity. The precise interaction of these structures enables the functioning and feeding performance.…”

“…Usually, the feeding motion described in textbooks is the feeding pattern documented for Heterobranchia, which can be described as a licking movement involving the protruding of the radula enabling the teeth to loosen the ingesta (for details see, e.g. Mackenstedt and Märkel, 2001 ; Neustadter et al, 2002a , b ; Montroni et al, 2019 ; Kehl et al, 2019 ; Krings et al, 2019a ). However, studies on the musculature of the buccal mass (e.g.…”

“… Graham, 1973 ; Fretter and Graham, 1976 ; Crampton, 1977 ; Morse, 1984 ; Simone, 2005 , 2011 ; Evans et al, 2009 ; Golding et al, 2009 ; Balog et al, 2012 ) and the analysis of feeding tracks (e.g. Ankel, 1936 , 1938 ; Eigenbrodt, 1941 ; Hickman and Morris, 1985 ; Janssen and Triebskorn, 1987 ; Mackenstedt and Märkel, 2001 ) demonstrate that the motion apparatus is highly diverse and complex. Traditionally the radula was compared to a flat ribbon or a ‘belt-and-pulley’ model ( Ankel, 1938 ; Märkel, 1964 ; Solem, 1974 ; Hickman, 1980 ), but this view has subsequently changed.…”

Groping through the black box of variability: An integrative taxonomic and nomenclatural re-evaluation of Zospeum isselianum Pollonera, 1887 and allied species using new imaging technology (Nano-CT, SEM), conchological, histological and molecular data (Ellobioidea, Carychiidae)

“…The colostyle (col) (Fig. 15A) is considered to play a role in supplying nutrients to the epithelia of the radular sac and may be integral in the disposal of degenerated cells (Mackenstedt and Märkel 2001).…”