Cribralaria curvirostris Silén, 1941

Martino, Emanuela Di, 2023, Scanning electron microscopy study of Lars Silén’s cheilostome bryozoan type specimens in the historical collections of natural history museums in Sweden, Zootaxa 5379 (1), pp. 1-106 : 37-38

publication ID

https://doi.org/ 10.11646/zootaxa.5379.1.1

publication LSID

lsid:zoobank.org:pub:430102D2-4EAA-41B3-B57F-CC532F929DA3

DOI

https://doi.org/10.5281/zenodo.10248899

persistent identifier

https://treatment.plazi.org/id/4B6E902E-FF8E-FFB0-FF46-FAA91D78FC9A

treatment provided by

Plazi

scientific name

Cribralaria curvirostris Silén, 1941
status

 

Cribralaria curvirostris Silén, 1941 View in CoL

( Fig. 17 View FIGURE 17 ; Table 16)

Cribralaria curvirostris Silén, 1941: 122 View in CoL , figs 182, 183.

Material examined. Holotype by original designation UPSZTY 2484 , Bonin Islands (Ogasawara), Japan; depth 100–135 m. Leg. Prof. S. Bock 1914.

Description. Colony encrusting, multiserial, unilaminar ( Fig. 17A View FIGURE 17 ).

Autozooids cribrate, oval with straight distal margin ( Fig. 17A View FIGURE 17 ), almost twice as long as wide (mean L/ W 1.85), distinct, separated by thin furrows; frontal shield convex, smooth, formed by 13–17 partially fused costae, 20–60 µm wide, the distalmost pair the widest, rectangular in the distal half of the zooid, triangular in the proximal half, interdigitated along zooidal midline, separated by 3–4 intercostal pores, 15–40 µm in maximum diameter, circular if single or figure-eight-shaped if double ( Fig. 17A, C, D View FIGURE 17 ). Gymnocyst absent except for a narrow region lateral to the orifice.

Orifice rounded rectangular, longer than wide (mean L/ W 0.60), slightly constricted laterally at about mid-length; distalmost pair of costae forming two short, stout, pointed spines laterally projecting towards the orifice at the same level as the constrictions, and a blunt proximal process centrally at the fusion line ( Fig. 17C–E View FIGURE 17 ).

Avicularia interzooidal, placed distally to most autozooids, lodged on a rectangular cystid, needle-shaped ( Fig. 17B, D View FIGURE 17 ); rostrum acicular, long (110–200 µm), curved, serrated, channelled, accommodated along the margins of two neighbouring autozooids, directed obliquely distally ( Fig. 17B, D View FIGURE 17 ); opening figure-eight-shaped due to a broad immersed opesial shelf with two small, straight condyles ( Fig. 17B–D View FIGURE 17 ).

A single kenozooid observed ( Fig. 17A View FIGURE 17 ), irregularly shaped, 280 × 190 µm, the frontal surface occupied by a circular costate shield with nine costae separated by 1–2 intercostal pores, surrounded by smooth gymnocyst.

Ovicells endozooidal, immersed in the proximal half of the avicularium cystid ( Fig. 17B View FIGURE 17 ); ooecium smooth, cap-like.

Remarks. An SEM micrograph of part of the holotype was previously published in Gordon (1989, pl. 2, fig. B) using the former catalogue number #387. This SEM image was fundamental to clarify that the lacunae were intercostal and not intracostal as might appear from the original drawings of Silén (1941).

Soule et al. (1998, p. 8, table 1) compared measurements and characters of all Cribralaria species described at that time. Measurements reported for C. curvirostris were taken from illustrations and are very different from those obtained from the new SEM images of the holotype and reported in Table 16. In particular, zooid width and avicularium length are much larger in Soule et al. (1998): zooidal size is 658 × 448–492 µm vs 448–629 × 237–361, while avicularium length is 463 µm (palate and opesia, therefore excluding the rostrum) vs 220–300 µm (rostrum included).

Based on the similarities between this genus and Hincksina , including the absence of basal pore chambers and pelmatidia in the spines, and the presence of endozooidal ovicells with cap-shaped ooecia formed by the distal avicularium, Berning et al. (2021) interpreted Cribralaria as a derived flustrid and transferred it from Cribrilinidae to Flustridae .

Kingdom

Animalia

Phylum

Bryozoa

Class

Gymnolaemata

Order

Cheilostomatida

Family

Flustridae

Genus

Cribralaria

Loc

Cribralaria curvirostris Silén, 1941

Martino, Emanuela Di 2023
2023
Loc

Cribralaria curvirostris Silén, 1941: 122

Silen, L. 1941: 122
1941
GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF