Notobranchaea hjorti (Bonnevie, 1913)
Overview
This is a medium sized naked pelagic snail, up to 0.9 cm long, with an opaque body the visceral organs are vaguely seen through the body wall. The anterior tentacles are small. It is a good swimmer that hunts zooplankton. It lives in the N-Atlantic Ocean (Notobranchaea hjorti).
Taxonomic Description
Skin transparent, unpigmented. Lateral gills absent. Posterior gill greatly reduced and only represented by a circular ring around the posterior body tip with four small distinct crests. The foot parts are composed of two lateral lobes and a short posterior lobe. The truncated wings have a narrow base. The Notobranchaea hjorti radula formula is 6-1-6, the lateral plates are provided with a relative small cusp on a large basal plate. The median teeth are typical for this genus being provided with a concave anterior border ornamented with numerous small denticles. The jaw is composed of a median row of 14 to 17 spines and 7 to 8 smaller, isolated spines. The hook sacs each have 13 to 14 strong hooks of a broad based triangular shape. A median foot tubercle is absent, but an accessory penial sucker is present. Van der Spoel found, however, a triangular fold, between the lateral footlobes, which resembles the structures found in other representatives of the family.
Body length up to 9 mm.
Juveniles
A special description is not available.
Reproduction
This species is a protandric hermaphrodite.
Ecology
This species is a carnivore.
Distribution
This species is found in the N-Atlantic Ocean, see the Notobranchaea hjorti map.
Types
Fowlerina hjortii Bonnevie, 1913 (1933): 64 figs. 37-58, pl. 8, figs. 63-68.
Lectotype: ZMVB 30415 dissected specimen (alcohol collection). Paralectotypes: ZMVB 30414 1 spec., ZMVB 30413 1 specimen, ZMVB 17656 1 specimen (alcohol collection) and 3 slides with buccal organs.
Type locality: 45°26'N 9°20'W, 48°29'N 13°55'W Coll.,: CMSE stat 92, stat. 10.