Iduliana papillata   O'Donoghue,  1932 (Sea Slug)
Organism information awaits expert curation
Class: Gastropoda

Size: 4 mm long, 2 mm high to the top of the elevation, 2.5 mm to the top of the cerata, and 12.5 mm wide, excluding the cerata.

Color: It is of a uniform dirty grey with no signs of color or color pattern.

The body is limaciform, the dorsum is rounded and passes over into the vertical sides without any line of demarcation, but along the line of transition lie 7 cerata on each side. In the middle of the dorsum occupying almost its entire width, about one-third of the way back is an almost hemispherical vesicular swelling. From this elevation a tube-like ridge passes backwards to the hinder end, getting gradually smaller as it does so. From the antero-lateral regions of the swelling pair of tubular ridges pass outwards and on to the posterior faces of the first pair of cerata. Similar but progressively smaller tubular ridges pass to the posterior sides of each of the remaining cerata from the median tube. In each instance the lateral tubes run up the cerata for a short way before entering them. In the mid-dorsal line in front of the elevation are two small pointed papillae, and a line of papillae 10-12 in number come off from the median ridge; they resemble the anterior ones, but terminate in 3-4 points. The cerata are club-shaped and bear 8-9 knobs on them. The knobs, however, are not evenly distributed, but are all on the lateral aspect, leaving the median side smooth.
The head is retracted and covered by the cephalic veil which, unlike that oildulia, bears at each side a group of 6 small digitiform papillae. The foot is well developed, muscular but narrow, and marked off from the sides of the body by a well-marked flange. It is bluntly rounded at the anterior end with a small notch in the middle line, and at the posterior end it passes on into a pointed tail. The rhinophore is much retracted and appears as a short, bluntly conical papilla with no lamella in the top of the rhinophore sheath. The sheath is cylindrical, slightly flaring at the top where it bears a circle of evenly spaced, short, digitiform papillae 11 in number.
The lips are covered with a chitinous layer, which is continued back inside the buccal tube, leaving an oval aperture with a smooth edge; no true jaws were found. The radula is triseriate and contains 51 rows of teeth, of which the last three are not fully formed. The median tooth has a stout, short, horseshoe-shaped base, its front corners instead of being rounded are carried out into short points. It bears a median, sharp, conical spine, flanked by 5 smaller spines on each side. The lateral teeth are very distinctive. Each consists of a trapezoidal plate five times as long as wide, passing out obliquely backwards from the median tooth at an angle of almost 45°. Three of its corners are rounded, but one mesial one is produced into a sharp point facing the same way as the spines on the median tooth. The plate on the whole is very thin, and laterally becomes so thin that it almost merges into the basal membrane of the radula. Its median end is slightly stouter and the point thickened.

Synonym (s)

Common Name (s)
Economic Importance and Threats



• Tamil Nadu, Krusadai Island INDIA

Literature Source(s)
  • O'Donoghue, CH (1932) Notes on Nudibranchiata from southern India Journal of Molluscan Studies The Malacological Society of London 20(3) 141-166 Available at -
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -

Page last updated on:2010-11-26

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