Rostanga calumus
- Radula


From Figure 13. radular morphology of specimen from Tasmania, AM C141312. A, Central region; B, central region and inner right laterals; C, transition zone on right; D, outer right lateral teeth; E, central region and whole right side of radula. Scale bar = 100 ┬Ám in all cases. Photo G.J. Avern. [Rudman, W.B. & Avern, G.J. (1989). The genus Rostanga Bergh, 1879 (Nudibranchia: Dorididae) in the Indo-West Pacific. Zoological Journal of the Linnean Society 96: 281-338.]

Return to Rostanga calumus.

The innermost lateral tooth on each side has a broad basal plate and a recurved triangular blade with a fringe of approximately 25 long rounded denticles down the whole of the inside edge. There are no outer denticles (Figs A, B). From Tooth 2, the inner laterals are slightly larger than Tooth 1 and the broad triangular blade is replaced by a non-denticulate pointed cusp (Fig E). The cusp gradually lengthens towards the outside of each row until about two-thirds of the way out. At this point one or two teeth develop a long cusp-like denticle on the outside (Fig C). The remaining outer lateral teeth have a long inner cusp, a shorter elongate denticle on the outside, and in the fork between is a branch with three of four long rodlike denticles. Each outer lateral has a brush-like end and the rod-like elements making the 'brush' are precisely arranged with the longest (the cusp) on the inside, and the shortest on the outside (Figs C,D). The jaw plates are prominent with up to fourteen rows of tightly packed rodlets. Half the rodlets are covered by a thin membrane.

The radular formulae of the following specimens are:
52.0.52 x 54(+2) - 5mm preserved Sydney (AM C126477)
56.0.56 x 52(+1) - 9mm alive Sydney (AM C126485)
48.0.48 x 55(+1) - 12mm alive Northern NSW (AM C136149)
50.0.50 x 52(+1) - 12mm alive Northern NSW (AM C146144)
48.0.48 x 47(+ l) - 17mm alive Tasmania (AM C141312)
67.0.67 x 62(+ 2) - 21mm alive Tasmania (AM C141243)
48.0.48 x 43 (+ l) - 10mm alive W. Australia (MV F53312)
48.0.48 x 44 (+ 1) - 9mm alive W. Australia (WAM 734-83)
69.0.69 x 74 (+2) - 20mm preserved W. Australia (WAM 787-83)

Authorship details
Rudman, W.B., 2002 (February 5) Rostanga calumus - Radula. [In] Sea Slug Forum. Australian Museum, Sydney. Available from