Notobranchaea grandis Pruvot-Fol, 1942
Overview
This is a large naked pelagic snail, up to 1.5 cm long, with an opaque body the visceral organs are seen vaguely through the body wall. The anterior tentacles are dark brown or black. There are two pairs of buccal cones. It is a good swimmer that hunts shelled pteropods as food. It lives in the E-Pacific Ocean at greater depths (Notobranchaea grandis).
Taxonomic Description
Notobranchaea grandis has a relatively large head, bearing on the cap two very large anterior tentacles (palps), as seen in Notobranchaea grandis lateral view. Posterior gill is triradiate. This was also found by Tesch (1950) for specimens from the Gulf of Panama, though the original description is not clear on this point. In our opinion, the type specimen only shows three crests. The body colour is grayish-yellow in preserved specimens. The rhinophores, anterior borders of the fins and anterior tentacles are black-brownish due to dark chromatophores. The median foot tubercle is present forming a triangularly shaped protrusion. The foot flagellum, a very strange structure for Gymnosomata, is situated at the cranial border of the lateral footlobes, in the median line where the lateral lobes joint. This 'tentacle' is conical, pointed and only slightly asymmetrical; any homology with the structures of the copulatory organ could not be found. The lateral footlobes are attached to the body nearly over their entire length. The buccal parts resemble those of Notobranchaea macdonaldi, the median plate is also unicuspoid.
Body length up to 15 mm.
Juveniles
A special description is not available.
Reproduction
This species is a protandric hermaphrodite.
Ecology
This species is a carnivore.
Distribution
Notobranchaea grandis is only known from the Panama area caught from 2500 meter depth with an open net, see the Notobranchaea grandis map. This is probably a bathypelagic species.
Types
Notobranchaea grandis Pruvot-Fol, 1942: 31, figs. 33-37. (Notobranchaea grandis type)
Holotype ZMUC slightly damaged (alcohol; col.) u.s.
Type locality: 6°40'N 80°47'W Collection: CDAE stat. 1206v.