Notoplites marsupiatus ( Jullien, 1882 )

Souto, Javier, Reverter-Gil, Oscar & Fernández-Pulpeiro, Eugenio, 2011, Redescription of some bryozoan species originally described by J. Jullien from Iberian waters, Zootaxa 2827, pp. 31-53 : 36-39

Notoplites marsupiatus ( Jullien, 1882)

( Figs 12–15 ; Table 3)

Scrupocellaria marsupiata Jullien, 1882: 506 , pl. 13, figs 17–20; Prenant & Bobin 1966: 411 (part), fig. 133 I–IV. Not Notoplites marsupiatus: Harmer, 1923: 351 .

Not Scrupocellaria marsupiata: d’Hondt 1974: 29 (part or whole).

Material examined. Lectotype (designated here): MNHN 2817, Travailleur, 1881, D. 1, 43°00'40'' N, 11°57'40'' W, 2018 m, 10/6/1881. Paralectotype (designated here): MNHN 1042, Travailleur, 1881, D. 1, 43°00'40'' N, 11°57'40'' W, 2018 m, 10/6/1881. Other material examined: Menipea clausa Busk, 1884 : Lectotype (designated here; Figs 16–20 ): NHMUK 1887.12.9.83, 38º25’ N, 35º50’ W, 3063 m, figured by Busk 1884, pl. IV, figs 5, 5a.

Description. Colony erect, jointed, dichotomously branched. Branches formed by two series of alternating autozooids.

Autozooids elongate, smooth, nearly cylindrical proximally, wider distally, turned outwards alternatively to right or to left. Distal half of the autozooid occupied by extensive oval membranous area, completely covered by very large, convex flabelliform scutum, attached proximally to inner proximal angle of orifice; outline almost completely coincident with edge of area, with about 15 narrow radial fissures, variable in length, reaching at most half of scutum length. Inner distal angle of autozooids with one inarticulate spine, short and pointed; outer angle with one articulated spine, broken in material examined but long and cylindrical in original description. Rarely a spine base lateral to orifice, just distal of attachment of scutum.

Mean SD Minimum Maximum N Autozooid length 0.527 0.0559 0.467 0.607 6 Autozooid width 0.263 0.0109 0.220 0.249 6 Opesia length 0.114 0.0024 0.111 0.117 6 Opesia width 0.111 0.0039 0.107 0.117 6 Scutum lenght 0.222 0.0113 0.213 0.243 6 Scutum width 0.205 0.0069 0.198 0.217 6 Ovicell length 0.357 0.0226 0.333 0.378 3 Ovicell width 0.195 0.0359 0.154 0.219 3

SD, Standard deviation; N, number of measurements.

Avicularia of two kinds: one large, distolateral to scutum, the triangular mandible directed outwards; one small, prominent, on frontal gymnocyst near scutum; its triangular mandible directed proximally. Rhizoids produced from a prominent small pore near proximal end of some autozooids.

Ovicell large, helmet-shaped, much longer than wide, with central suture and small radial grooves, the latter visible by SEM.

Remarks. Scrupocellaria marsupiata was originally described from several fragments collected from Galicia Bank at 2018 m depth ( Jullien 1882; Calvet 1907). Both original samples are very badly preserved, but have been designated here as lectotype (MNHN 2817) and paralectotype (MNHN 1042).

Shortly after the original description of the species, both Jullien (1888) and Waters (1888) suggested that Menipea clausa Busk, 1884 , described from west of the Azores at 3063 m depth, is a junior synonym of S. marsupiata . This synonymy was accepted by later authors (e.g. Calvet 1907; Harmer 1923; Prenant & Bobin 1966).

An original sample of M. clausa (NHMUK 1887.12.9.83) (see figs 16–20 and Table 4) has been checked; it is not known how much material of this species was originally collected, though Waters (1888) made reference to several samples. The only preserved sample, illustrated by Busk (1884), is designated here as the lectotype of the species; however, in case there is further evidence that this colony was the only one originally collected, it should be considered as the holotype.

Mean SD Minimum Maximum N Autozooid length 1.003 0.1209 0.859 1.168 6 Autozooid width 0.222 0.0069 0.213 0.231 6 Opesia length 0.096 0.0066 0.089 0.104 6 Opesia width 0.121 0.0048 0.115 0.127 6 Scutum lenght 0.240 0.0112 0.222 0.253 6 Scutum width 0.195 0.0091 0.180 0.205 6 Ovicell length 0.216 0.0233 0.185 0.237 4 Ovicell width 0.223 0.0207 0.198 0.246 4

SD, Standard deviation; N, number of measurements.

Both species are indeed very similar. In each of them the scutum is large and convex, concealing almost the entire area, and presents lateral fissures (marginal fimbriation); the frontal avicularium is also very prominent and located just proximal to the scutum. However, there are some obvious differences. In S. marsupiata there are about 12–14 marginal fimbriae of variable length, with generally long, narrow fissures between them. In M. clausa the fimbriae are fewer (8–10) and shorter with wider fissures between them. In Busk’s original figure (1884, pl. 4, fig. 5) these fissures are not well represented, appearing numerous, radial, and occupying most of the scutum edge. On the other hand, autozooids are more elongate in M. clausa while their orifice is shorter than in S. marsupiata . In addition, in S. marsupiata the lateral avicularium is clearly visible in frontal view, while in M. clausa it is smaller and located basally and not visible in frontal view. In M. clausa there may be a lateral spine on the outer rim of the orifice whereas in S. marsupiata an avicularium is in this position. Finally, the ovicell is very different in both species: in S. marsupiata it is much longer than originally illustrated by Jullien (1882) while in M. clausa it is shorter circular and frontally flat with a small proximal pore (visible by SEM). The maternal orifice and operculum are longer than wide in S. marsupiata but wider than long in M. clausa .

Jullien (1882) mentioned a single basal vibraculum behind the lateral avicularium in all examined material. No vibraculum was found in his original material, perhaps because samples are not well preserved. Busk (1884) mentioned a minute avicularium behind the autozooid near the summit in M. clausa , but made no reference to a vibraculum. Waters (1888), who initially did not study the basal surface of Busk’s material, asked R. Kirkpatrick, his contemporary at the British Museum (Natural History), to do so. Kirkpatrick noted the presence of vibracula in a couple of zooids, not found by us in the original material, and it is likely that he interpreted the small basal avicularium as the vibraculum noted by Jullien. In conclusion, we consider that both species are indeed different, although apparently very closely allied.

In his original description of S. marsupiata, Jullien (1882) noted that it did not resemble any other species of Scrupocellaria , and that it would probably be the type of a different genus. Harmer (1923) included it in his new genus Notoplites along with M. clausa as a synonym of S. marsupiata , but he actually had in mind the features of M. clausa , which is a different species, as discussed above. Both species share the diagnostic features of Notoplites (see Hayward & Ryland 1998), and both should be placed in this genus. Basal photographs of the dichotomy, an important character of the genus, are not included because the material of S. marsupiata is very badly preserved, and the material of M. clausa is glued on a glass slide, making impossible to take SEM images.

Notoplites marsupiatus was cited by d’Hondt (1974, as S. marsupiata ) from some stations north and northwest of the Iberian Peninsula. However, some of his samples (MNHN 7055, Thalassa W374; MNHN 7073, Thalassa W405; MNHN 7317, Thalassa U851) actually correspond to Notoplites jeffreysii ( Norman, 1868) so this record should be considered as uncertain. D’Hondt (1975) also reported N. marsupiatus (as S. marsupiata ) from several stations northeast of the Azores at 525–3360 m depth. The paper includes only three photographs without description or further comments. From the shape of the orifice and scutum this record could match Notoplites clausus , although the lateral avicularium is visible in frontal view. Therefore, the original material should be re-examined. Notoplites marsupiatus was also reported by Hayward (1978a) at 1980 m depth north of the Iberian Peninsula and at 1550 m in northwestern Bay of Biscay. We were not able to locate this material in the collections at the MNHN or the NMHUK so it has not been re-examined; it is not known if it corresponds to N. marsupiatus or to N. clausus .

Figures

FIGURES 12 – 15. Notoplites marsupiatus (Jullien, 1882) (MNHN 2817, lectotype). 12, Detail of a branch; 13, dorsal side of a branch showing a prominent small pore where a rhizoid is produced; 14, an autozooid with the two types of avicularia; 15, ovicelled zooid.

FIGURES 16 – 20. Notoplites clausus (Busk, 1884) (NHMUK 1887.12. 9.83, lectotype). 16, Detail of the colony; 17, dichotomy; 18, an autozooid; 19, basal avicularium; 20, ovicell.