Steginoporella modesta Gordon, Voje, and Taylor 2017
- Dataset
- Living and fossil Steginoporellidae (Bryozoa: Cheilostomata) from New Zealand
- Rank
- SPECIES
- Published in
- Gordon, Dennis P., Voje, Kjetil L., Taylor, Paul D. (2017): Living and fossil Steginoporellidae (Bryozoa: Cheilostomata) from New Zealand. Zootaxa 4350 (2): 345-362, DOI: 10.11646/zootaxa.4350.2.9
Classification
- kingdom
- Animalia
- phylum
- Bryozoa
- class
- Gymnolaemata
- order
- Cheilostomata
- family
- Steginoporellidae
- genus
- Steginoporella
- species
- Steginoporella modesta
description
Description. Colony encrusting, comprising small lobate to sublinear pluriserial growths not more than six zooids across, up to 19 mm long and 5 mm wide. Colour of dried colonies pale brownish-beige. Zooids monomorphic, roundly hexagonal, with one of the pair of daughter zooids at the bifurcation of a zooid row more or less parallel-sided, with mostly arcuate distal and proximal margins (mean L / W = 1.45); widest mostly about mid-length. Cryptocystal area more than half zooid length, extensive shelf sunken, weakly concave, mostly granular-tubercular, with sloping pseudoporous semicircular area proximal to median process. Opercular area delimited proximally by stout triangular pivots; median process with distolateral ‘ wings’ that do not reach pivots or lateral margins; proximomedial foramen of small to moderate size. Inner face of operculum smooth, lacking sclerites. Polypide not seen. Ancestrula smaller than other zooids but resembling them, deep-bodied, the sides interiorwalled and granular; smooth thin margins of frontal cryptocyst on both sides converging without meeting proximally, descending to substratum, with narrow granular strip between. First daughter zooid budded laterally, followed near-simultaneously by distolateral pair from ancestrula. Measurements. In micrometres: ZL 1092 ± 173, 932 – 1389 (4, 10); ZW 751 ± 86, 643 – 912 (4, 10); OpL 310 ± 43, 256 – 367 (1, 10); OpW 513 ± 33, 456 – 557 (1, 10). AnL 978, AnW 400.
discussion
Remarks. Colonies of S. modesta n. sp., like those of Steginoporella lineata n. sp., another deep-sea species (see below), are very small and somewhat narrow. Unlike S. lineata n. sp., zooids of S. modesta n. sp. are monomorphic. The species is evidently pigmented in life — while a specimen was being prepared for SEM the bleaching solution turned pale purple. All specimens, including a small ancestrulate colony, were loose in the sample but their undersides are carpeted by a thin layer of sponge spicules, indicating the apparent substratum in life.
distribution
Distribution. Endemic to New Zealand, being known only from the type locality in the Bay of Plenty; 142 m.
etymology
Etymology. Latin modestus, modest, unassuming, alluding to the small size of the colony.
materials_examined
Material examined. Holotype: NIWA 23304, TAN 0413 / 109, 37.549 ° S, 176.988 ° E, west of White Island, Bay of Plenty, 13 November 2004, 142 m. Paratype: NIWA 122576, same data as for holotype.