Glossobalanus berkeleyi Willey, 1931

Cameron, Christopher B. & Ostiguy, Angélica, 2013, Three new species of Glossobalanus (Hemichordata: Enteropneusta: Ptychoderidae) from western North America, Zootaxa 3630 (1), pp. 143-154 : 145-146

Glossobalanus berkeleyi Willey, 1931

Material examined. None; the following description is based on that of Willey (1931).

Description. Total length of only known fragment 40 mm and the dorsoventral diameter 6 mm. Proboscis, as seen in Willey’s figure, rather short and only slightly longer than collar. Collar a little broader than long. Branchial region c. 18 mm long, c. 60 pairs of gill pores. Gonads (ovaries) commence anteriorly between fifth and sixth gill pores. Genital ridges rather small (almost non-existent) in branchial region, becoming distinct beyond the pharyngeal region (“acquire the form which they possess in G. sarniensis ” according to Willey’s original description). Color in life not known.

Stomochord with a distinct lumen in the anterior part, but further posteriorly the lumen is broken up; there are two ventrolateral blind pouches for the stomochord, not directly connected with each other but independently in connection with main lumen of stomochord. Anterior part of proboscis skeleton a rounded disk-shaped structure continuous with basement membrane surrounding proboscis complex (as shown in Fig. 3 of Willey 1931). Skeletal cornua are long for a ptychoderid, extending almost to posterior end of collar. Proboscis ventral septum not extending to posterior end of ventral coelomic cavity of proboscis.

Dorsal septum of collar not complete anteriorly but begins only about middle of collar, at first dorsal root; two dorsal nerve roots in collar. Collar nerve cord with no canal, only lacunae. Anteriorly, collar nerve cord with flat dorsal surface but posteriorly almost U-shaped in cross section (as shown in Fig. 8 of Willey 1931).

Distribution. The anterior portion of only a single individual was collected near the Biological Station at Nanaimo, British Columbia, by Mrs C. Berkeley in January 1929, and was sent to Prof. Willey who described it as G. berkeleyi in 1931. CBC has returned to the site, which has been much modified in the past 70 years, and found no further specimens.

Figures

FIGURE 3. Light micrographs of transverse sections of Glossobalanus hartmanae. A, Proboscis with conspicuous circularmuscle layer, radial muscle bundles, heart-kidney complex and ventral septum. B, Proboscis peduncle showing the ventrolateral pouches of the stomochord and short skeletal keel. C, Collar showing a midventral vascular plexus. D, Dorsal nerve cord of collar with dorsal roots. E, Posterior collar showing canals. F, Anterior pharynx with plicate gill-bar epithelium. G, Intestinal region with lateral septum and median gonads. Abbreviations: a, atrium; bv, blood vessel; cc, collar canal; cg, ciliated groove; cl, collar lumen; cv, cardiac vesicle; ds, dorsal septum; ep, epidermis; g, glomerulus; gb, gill bar; gbe, gill-bar epithelia; gd, gonad; gp, gill pore; mg, median gonad; lg, lateral gonad, ls, lateral septum; nc, nerve cord; nr, nerve roots; pbd, peribuccal diverticula; pc, proboscis coelom; pcm, proboscis circular muscles; phd, perihaemal diverticula; pl, pharynx lumen; plm, proboscis longitudinal muscles; pr, parabranchial ridges; s, stomochord; sc, skeletal cornua; sk, skeletal keel; tlm, trunk longitudinal muscles; vp, vascular plexus. Scale bars: A, C, F, G = 500 μm; B = 200 μm; D, E = 250 μm.