Distansescharella alcicornis ( Jullien, 1882 )

Souto, Javier, Berning, Björn & Ostrovsky, Andrew N., 2016, Systematics and diversity of deep-water Cheilostomata (Bryozoa) from Galicia Bank (NE Atlantic), Zootaxa 4067 (4), pp. 401-459: 419-421

publication ID

http://doi.org/10.11646/zootaxa.4067.4.1

publication LSID

lsid:zoobank.org:pub:1CC5D0E7-0B60-4E62-BACD-9775931ED7F9

persistent identifier

http://treatment.plazi.org/id/862A8F25-FF9D-0C6D-FF65-FE675E2F3CD9

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Plazi

scientific name

Distansescharella alcicornis ( Jullien, 1882 )
status

 

Distansescharella alcicornis ( Jullien, 1882) 

( Figs 39–45View FIGURES 39 – 45, Table 9)

Cribrilina alcicornis Jullien, 1882: 12  , pl. 14, figs 23–25; d'Hondt 1973: 378, pl. 3 A, B; Harmelin 1978: 178, text-figs 3, 4, pl. 1, fig. 3; Harmelin & d'Hondt 1992: 28 (listed).

Cribrilaria alcicornis: Hayward & Ryland 1978: 146  (listed); Hayward 1979: 60 (listed).

" Cribrilina  " alcicornis: Harmelin et al. 1989  : pl. 1, figs 5, 6.

Not Distansescharella alcicornis  : López-Fé 2006: 1807, figs 7, 8.

Material examined. Lectotype (designated here): MNHNAbout MNHN 3736, Cribrilina alcicornis Jullien 1882  , NW de l’Espagne, Travailleur, 14 June 1881, 1068 m; Coll. Calvet, nº 383 ‘type’. Paralectotype (designated here): MNHNAbout MNHN 3787, Cribrilina alcicornis, Travailleur  , 13 June 1881, station Dr. 1 (1 ª ser.), 2018 m, Coll. Calvet, nº 56 ‘type’ (colony in poor condition). Other material from Galicia Bank: MNCNAbout MNCN 25.03 /3938, 3939, 3940, locality DR09; OLL 2015 / 898, 899, locality V01. Other material examined: MNHNAbout MNHN 19796, Cribrilaria alcicornis  , BALGIM DR 153, 568 m, 27 June 1984; MNHNAbout MNHN 18351, Cribrilaria alcicornis, Th.  71, X348, 44º 7.5 ’ N 4 º 43.6 ’ W, 600–900 m, 16 October 1971; MNHNAbout MNHN 18362, Cribrilaria alcicornis, Th.  71, X 348; MNHNAbout MNHN 7024, Cribrilaria alcicornis  (Reverter, IV- 98), X359, 17 October 1971, 605– 650 m, 44 º07.2’ N 04º 49.4 ’ W; MNHNAbout MNHN 7102, Cribrilina alcicornis, Th W  423, 11 October 1970, 710– 1070 m, 44 º 3.7 ’ N, 07º07.5’ W; MNHNAbout MNHN 7185, Cribrilina alcicornis Thalassa, Y  395; MNHNAbout MNHN 7197, Cribrilaria alcicornis  , Y 410, 360 m, 40 º 34.4 ’ N 09º 22.1 ’ W; MNHNAbout MNHN 6983, Cribrilina alcicornis  var. bifurcata  , type var., st. X 313.

SD, standard deviation; N, number of measurements.

Description. Colonies encrusting, unilaminar, multiserial, forming spots or small patches. Zooids oval, separated by deep grooves; costate frontal shield flattened, surface smooth with growth striations; shield comprising 16–19 broad flattened costae with up to 5 intercostal spaces, round in central part and elongated at periphery; distalmost pair of costae usually broader than others, both distal costae with distal projection centrally that forms short but broad central denticle with straight distal margin; gymnocystal walls relatively well developed, especially in proximal region. Zooidal orifice D-shaped, distinctly wider than long, distal margin with 4 thick jointed oral spines in ovicellate and non-ovicellate autozooids, forming a kind of collar around orifice with slightly wider gap between bases of distal pair; spines reminiscent of elk horns, slightly tilted, closely spaced and sometimes almost touching each other; either relatively small with 3–4 tines, or large with 4–5 flattened triangular tines, forming a broad ‘elk horn’, to which species name alludes.

Ovicells hyperstomial, cleithral. Bilobate ooecium produced by distal autozooid and positioned on its proximal gymnocyst; globular, usually longer than wide, with prominent suture along entire midline; ectooecium smooth with growth striations, proximal margin incorporating bases of distal pair of oral spines.

Avicularia interzooidal, small, with irregular cystid outline, only slightly longer than wide, usually 2 per zooid, situated lateral to zooidal orifice, mandibles directed laterally to distally; gymnocystal lateral walls well developed, particularly extensive proximolaterally; avicularium pyriform frontally, framed by elevated rim, rostrum at acute angle to colony surface; palatal foramen and postmandibular opesia united in one opening, oval and subelliptical to pyriform, surrounded by smooth cryptocyst that is broadest proximally and narrowing distally; palatal opesia separated from postmandibular area by very small indentations (condyles) on which mandible is hinged.

Kenozooids common, irregular in shape, relatively large, sometimes almost attaining length and width of autozooid; frontal area flattened or slightly convex, almost entirely composed of smooth gymnocyst apart from round to oval membranous window with slightly elevated rim usually situated in centre of kenozooid; oval opesia of variable size, surrounded by narrow smooth cryptocyst that in some cases closes opesia almost completely. Basal pore-chambers present in all types of zooids.

Ancestrula not seen.

Remarks. This species was originally described by Jullien (1882) as Cribrilina alcicornis  , collected from two stations on the northern Iberian continental slope close to Galicia Bank at 1068 and 2018 m depth. The systematic position of C. alcicornis  was clarified by López-Fé (2006), who formally assigned it to the genus Distansescharella  following a suggestion of Harmelin et al. (1989) and a review of the genus Cribrilina  by Bishop (1986, 1994). The specimens from the Canary Islands reported by López-Fé (2006) as D. alcicornis  , however, obviously do not belong to this species (see Remarks on Distansescharella cervicornis  n. sp. below). In contrast, the specimens collected from Galicia Bank are indistinguishable from the type specimens of D. alcicornis  described by Jullien ( Figs 39–41View FIGURES 39 – 45).

The species has also been reported from the Bay of Biscay (d’Hondt 1974), the Strait of Gibraltar ( Harmelin 1978), NW Iberia ( Harmelin 1978; Reverter-Gil & Fernández-Pulpeiro 2001) and the continental slope of Portugal ( Reverter-Gil et al. 2014) between 450 and 2018 m depth. Most of these data need to be revised, however, before a decision on their conspecificity can be made.

On Galicia Bank, D. alcicornis was recorded at almost all localities on coral, rocks, and shells from 765 to 1697 m depth.

TABLE 9. Measurements (in mm) of Distansescharella alcicornis.

Minimum Maximum
24
24
24
24
26
26
Avicularium frontal area length 26
26
MNHN

Museum National d'Histoire Naturelle

MNCN

Museo Nacional de Ciencias Naturales

Kingdom

Animalia

Phylum

Bryozoa

Class

Gymnolaemata

Order

Cheilostomatida

Family

Cribrilinidae

Genus

Distansescharella

Loc

Distansescharella alcicornis ( Jullien, 1882 )

Souto, Javier, Berning, Björn & Ostrovsky, Andrew N. 2016
2016
Loc

Distansescharella alcicornis

Lopez-Fe 2006: 1807
2006
Loc

Cribrilina alcicornis

Harmelin 1978: 178
Jullien 1882: 12
1978
Loc

Cribrilaria alcicornis:

Hayward 1978: 146