Integripelta, 2002

Gordon, Dennis P., Mawatari, Shunsuke F. & Kajihara, Hiroshi, 2002, New taxa of Japanese and New Zealand Eurystomellidae (Phylum Bryozoa) and their phylogenetic relationships, Zoological Journal of the Linnean Society 136 (2), pp. 199-216 : 209

INTEGRIPELTA UMBONATA SP. NOV.

( FIG. 3D, E )

Material examined

Holotype: NZOI H-751, from NZOI Stn Z 9697, 34°21.06¢S, 172°42.53¢E, 57 m, Spirits Bay , New Zealand.

Paratype: NZOI P-1219, same locality as holotype .

Other material: NZOI Stns Z 9667, Z9678, Z9684, Z9687 .

Description

Colony encrusting, unilaminar. Autozooids 0.33–0.60 mm long (0.45 ± 0.006 mm), 0.22–0.49 mm wide (0.35 ± 0.008 mm). Frontal shield smooth with a conspicuous umbo in its centre. No gymnocystal foramina; no peristome, spines, or avicularia. Autozooidal orifice broad, not very high-arched, the proximal rim gently and evenly concave, not sinuous; lateral corners slightly indented and excavated. Incompletely developed autozooids are kenozooidal, with a central foramen and cuticular structure that appears to be a nonfunctional operculum. Maternal zooids obviously dimorphic, broader than autozooids with broader, somewhat D-shaped orifice (0.25–0.30 mm wide at the proximal margin; cf. 0.16–0.24 mm in autozooids). Ooecium-associated kenozooid moderately well developed frontally, with a single large foramen facing distad. Interzooidal communications via rows of tiny uniporous septula. Ancestrula unknown.

Etymology

From umbo (L.) boss, protuberance, alluding to the umbonate frontal shield.

Remarks

Integripelta umbonata is the second-known frontally imperforate New Zealand species, the other being Z. crystallina , from the Kermadec Ridge, which is biserial and its zooids lack umbones. Both species lack basolateral pore-chambers but the proximolateral rim of the orifice in Z. crystallina is somewhat elevated and has a median suture.

Distribution

Endemic to New Zealand – known only from Spirits Bay, northernmost North Island, 29–57 m depth.

Figures

Figure 3. A–C, Integripeltra shirayamai sp. nov. Saiki-wan, Honshu. A, autozooids, x, 70. B, maternal zooids with foraminate kenozooids distally, ¥116. C, autozooidal orifice with proximal rim partly removed to show how the long crescentic slits are merely the frontal expressions of the proximolateral embayments of the orifice, ¥201. D, E, Integripelta umbonata sp. nov. NZOI Stn Z9697. F, autozooids and a maternal zooid with foraminate distal kenozooid, ¥106. G, prox- imolateral corner of an autozooidal orifice, ¥930.