Haplognathia gubbarnorum ( Sterrer, 1969 )

Sterrer, Wolfgang, 2006, Gnathostomulida from the Otago Peninsula, southern New Zealand, Zootaxa 1172, pp. 1-19 : 5-7

Haplognathia gubbarnorum ( Sterrer, 1969)

(Fig.3.1–3.3)

Material Three juveniles/anterior fragments from samples SI 10 and SI 16.

Distribution North Sea, Irish Sea, Adriatic ( Sterrer 1969); (sub)tropical NW Atlantic ( Sterrer 1998), NE Australia ( Sterrer 2001).

Description

Colorless­transparent. The only complete specimen, a juvenile, measured 470 µm in length and 35 µm in width. The eyeglass­shaped basal plate is 5.67 µm long and 9.67 µm wide (index 0.59); its dorsal surface is set with thorns. Jaws are 16.00 µm long, with one pair of teeth, horn­shaped rostral apophyses, and a transversely oval symphysis.

Discussion

The forma typica of this species is remarkably constant over its great geographic range, as evidenced in jaw length (North Sea: 20.6 µm, NW Atlantic 16.8 µm, NE Australia 18.0 µm).

Haplognathia rosea ( Sterrer, 1969)

(Fig.3.4–3.6)

Material Four juveniles from sample SI 16. Distribution

North Sea, Irish Sea ( Sterrer 1969), Fiji ( Sterrer 1991a), Tahiti ( Sterrer 1991c), Canary Islands ( Sterrer 1997), (sub)tropical NW Atlantic ( Sterrer 1998), NE Australia ( Sterrer 2001).

Description

Body uniformly pink to blotchy crimson. A juvenile was 570 µm long and 35 µm wide at U 43.9 (index 16.29), with a rostrum 152 µm long and 28 µm wide at U 19.3 (rostrum index 5.43). The pharyngeal bulb, which measures 7–13 µm in length behind the symphysis, contains a pair of conspicuous granular glands. The delicate basal plate, lensshaped to hexagonal, is 6.00 µm long and 6.50 µm wide (index 0.93). It carries two pairs of longitudinal dorsal ridges but no thorns. The jaws are 17.50 µm long, and have short rostral apophyses (index 0.41) but a wide, crescent­shaped symphysis.

Discussion The four specimens conform with the original description of this widely distributed, variable species (see discussion of ‘red’ Haplognathia species in Sterrer 1998:26).