Steginoporella perplexa Livingstone 1929
- Dataset
- Living and fossil Steginoporellidae (Bryozoa: Cheilostomata) from New Zealand
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Bryozoa
- class
- Gymnolaemata
- order
- Cheilostomata
- family
- Steginoporellidae
- genus
- Steginoporella
- species
- Steginoporella perplexa
description
Measurements. In micrometres: ZL 1054 ± 26, 1017 – 1100 (1, 10); ZW 582 ± 19, 556 – 623 (1, 10); OpL 346 ± 28, 300 – 383 (1, 10); OpW 474 ± 37, 399 – 522 (1, 10).
diagnosis
Diagnosis. Colony erect, large, planar, bilamellar and flabellate with undissected margin, up to 125 mm high and wide, attached to sediment grains and very small shells by basal tangle of rootlets. Colour in life pale brown. Zooids monomorphic, roundly subhexagonal but longer than wide (mean L / W = 1.81), widest at level of opercular pivots or median process. Cryptocyst occupying about half length of frontal surface, shelf depressed, flat, densely pseudoporous. Opercular opening delimited proximally by triangular opercular pivots and median process, with distolateral ‘ wings’ that do not meet pivots or lateral margin; proximomedial foramen of moderate size, generally roundly quadrate, sometimes roundly triangular. Opercular sclerites reticulate, defining mostly 21 – 22 (sometimes fewer) areas of variable size. Thickness of sclerites may increase with age of zooid. Polypide, ancestrula and early astogeny not seen.
discussion
Remarks. This is the largest species of Steginoporella in New Zealand and its fan-shaped colonies are highly distinctive. It is restricted to a small geographical area at the far north of North Island. Although locally common, its limited distribution to sandy bottoms where the scallop Pecten novaezelandiae Reeve is found makes it vulnerable to scallop dredging (Cryer et al. 2000). Older parts of large colonies are an important substratum for a number of species of epizoic cheilostome and cyclostome bryozoans.
distribution
Distribution. Endemic to northern New Zealand: Three Kings Shelf in vicinity of Three Kings Islands, Cape Reinga and Spirits Bay; 30 – 119 m.
materials_examined
Material examined. NIWA 76404, Stn Z 15617; NIWA 101450, Stn Z 15929; NIWA 122670, Stn Z 8662. Plus unregistered (non-separated) specimens in multispecies samples from NIWA Stations D 896, Z 8662, Z 9671, Z 9672, Z 9673, Z 9677, Z 9678, Z 9679, Z 9680, Z 9681, Z 9686, Z 9687, Z 9688, Z 9689, Z 9896, Z 9698, Z 9700, Z 9701, Z 9702, Z 9703, Z 9707, Z 9708, Z 9710, Z 9715, Z 15617, Z 15929, Z 15935.