Porella belli ( Dawson, 1859 )

Grischenko, Andrei V., Dick, Matthew H. & Mawatari, Shunsuke F., 2007, Diversity and taxonomy of intertidal Bryozoa (Cheilostomata) at Akkeshi Bay, Hokkaido, Japan, Journal of Natural History 41 (17 - 20), pp. 1047-1161 : 1101-1103

publication ID

https://doi.org/ 10.1080/00222930701391773

persistent identifier

https://treatment.plazi.org/id/877A7251-CC71-DE0C-FE36-2247D1451A91

treatment provided by

Felipe

scientific name

Porella belli ( Dawson, 1859 )
status

 

Porella belli ( Dawson, 1859)

( Figure 21 View Figure 21 )

Lepralia belli Dawson 1859, p 256 .

Porella concinna var. a (Belli, Dawson): Hincks 1880, p 324, Plate 46, Figure 2 View Figure 2 .

Porella concinna var. belli: Kluge 1952, p 158 ; Gontar and Denisenko 1989, p 353. Smittina concinna var. belli: Androsova 1958, p 155 , Figure 84; Kluge 1962, p 432, Figure 283. Porella concinna belli: Gontar 1980, p 10 ; 1992, p 146; Grischenko 1997, p 179.

Porella belli: Hayward 1994, p 188 , Figure 4c, d View Figure 4 ; Kubanin 1997, p 123.

Material examined

ANC, eight colony fragments ( NHM 2006.2.27.9) and two colonies on rocks ( NHM 2006.2 About NHM .27.10, NHM 2006.2.27.66). Additional material: 85 specimens .

Description

Colony encrusting, unilaminar, coherent, tightly attached to substratum, irregularly circular, up to 2.5 cm across; yellowish, greyish, or off-white when alive. Zooids ( Figure 21B–E View Figure 21 ) hexagonal or rectangular, sometimes tapering proximally, 0.35–0.60 mm long (0.48¡ 0.07 mm), 0.23–0.38 mm wide (0.31¡ 0.04 mm), delineated by a deep groove with a suture line when young, and by deep, undulating lateral groove with age; transverse boundaries indistinct. Frontal wall imperforate centrally, coarsely granulated, with four to seven circular areolar pores along each lateral margin; inflated and convex in young zooids; increasingly thick with age, quite convex, roughly granulose, sometimes with a prominent umbo in suboral or proximolateral region. Primary orifice semicircular, deeply submerged, difficult to measure, but about 0.10–0.13 mm long by 0.12–0.15 mm wide; lyrula low and broad, occasionally lacking in some zooids, which have a slightly convex proximal border; condyles low, tapering distally, located near proximal corners of orifice. Peristome deep, secondary orifice pyriform in outline, 0.11–0.16 mm long (0.14¡ 0.02 mm), 0.12–0.16 mm wide (0.15¡ 0.01 mm), cormidial, its distal half formed by indented proximal margin of succeeding zooid; this is confluent with thick, rounded lateral flanges that meet proximally with sides of suboral avicularian chamber; in ovicellate zooids lateral flanges connect with proximolateral corners of ovicell; suture lines separate contributions of secondary calcification from a zooid and its neighbour that make up the secondary orifice. A large, oval median suboral avicularium lies within peristome, below secondary orifice, orientated vertically or tilted slightly proximally; mandible semicircular, cross-bar complete; avicularian chamber broader than long, lunate, occupying frontal surface from margin to margin, with two to five small pores around chamber margin or in chamber itself; in young zooids chamber is convex, inflated, finely granulated, but with age it becomes immersed and rugose. Ovicell ( Figure 21C–E View Figure 21 ) hyperstomial, spherical, 0.16–0.21 mm long (0.19¡ 0.01 mm), 0.20–0.25 mm wide (0.23¡ 0.02 mm), initially finely granulated, rapidly immersed with thick, roughly granulose calcification from surrounding zooids, becoming flush with colony surface. Oral spines lacking. Two multiporous septula in transverse wall and four circular multiporous septula in each lateral wall. Ancestrular complex ( Figure 21F View Figure 21 ) comprises five zooids radiating from common centre; in the specimen illustrated, the ancestrula proper is completely obscured by periancestrular zooids.

Remarks

The structure of the frontal wall varies considerably in P. belli according to substratum. In general, the frontal wall is inflated in young zooids and becomes gradually mucronate with age. Colonies on flat surfaces tend to retain the inflated appearance of the frontal wall, without an umbo, whereas those on irregular substrata may comprise entirely heavily calcified zooids with a strongly mucronate frontal wall.

Distribution

This is a circumpolar, Arctic-Boreal, species. Kluge (1962, 1975) and Gontar and Denisenko (1989) gave many distributional records for the Arctic. In the northern Pacific, P. belli has been reported from the Commander Islands ( Grischenko 1997; Kubanin 1997), eastern Kamchatka ( Kluge 1961), the Kuril Islands ( Gontar 1980), Sakhalin Island, and Primorye ( Androsova 1958). Akkeshi Bay is the southernmost known locality of P. belli in the Asian Pacific.

ANC

Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche

NHM

University of Nottingham

A

Harvard University - Arnold Arboretum

Kingdom

Plantae

Phylum

Marchantiophyta

Class

Jungermanniopsida

Order

Porellales

Family

Porellaceae

Genus

Porella

Loc

Porella belli ( Dawson, 1859 )

Grischenko, Andrei V., Dick, Matthew H. & Mawatari, Shunsuke F. 2007
2007
Loc

Porella belli: Hayward 1994 , p 188

Kubanin AA 1997: 123
Hayward PJ 1994: 188
1994
Loc

Porella concinna var. belli:

Grischenko AV 1997: 179
Gontar VI & Denisenko NV 1989: 353
Gontar VI 1980: 10
Kluge GA 1962: 432
Androsova EI 1958: 155
Kluge GA 1952: 158
1952
Loc

Porella concinna

Hincks T 1880: 324
1880
Loc

Lepralia belli

Dawson JW 1859: 256
1859
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