Cellaria harmelini d’Hondt, 1973

Berning, Björn, 2013, New and little-known Cheilostomata (Bryozoa, Gymnolaemata) from the NE Atlantic, European Journal of Taxonomy 44, pp. 1-25 : 5-8

Cellaria harmelini d’Hondt, 1973

Fig. 2 , Table 2

Cellaria harmelini d’Hondt, 1973: 374 , pl. 1, figs 2-4.

Material examined

Lectotype (here designated)

MNHN 6888 , Thalassa Stn 436, 4 Aug. 1967, northern Bay of Biscay , 47°56’ N – 07°52.7’ W, 360 m.

Paralectotype (here designated)

MNHN 6902, Thalassa Stn 451, 4 Aug. 1967, northern Bay of Biscay, 47°57.5’ N – 07°50.7’ W, 358 m, on hydroids.

When introducing this species, d’Hondt (1973) did not indicate type material. The subsequent listing of the “ holotype ” and “ paratype ” of Cellaria harmelini without further information in a catalogue of the potential type specimens kept at the MNHN ( Tricart & d’Hondt 2009) violates Article 73.1.3. of the ICZN Code ( ICZN 1999). Therefore, the lectotype and paralectotype are formally designated here for the “ holotype ” and “ paratype ”, respectively, of Tricart & d’Hondt (2009).

Description

Colony erect, flexible, dichotomously branching, about 3 cm in height and composed of 6-7 internodes; internodes slender ( Fig. 2A ), cylindrical, composed of 6 alternating longitudinal series of zooecia (4 in one horizontal row), basal internodes some 2-4 mm long, distal ones up to 8-9 mm in length, with 1 or 2 fertile zones per internode producing distinctly thicker (ca. 0.7-0.9 mm) segments, zooecia separated by a thin ridge flanked by a shallow groove on each side. Autozooecia in sterile segments elongated subhexagonal ( Fig. 2B ), successive zooecia in a series not in direct contact and being well spaced, contact with lateral neighbours in the next series after the alternating one along a straight boundary, proximal zooecial margin V-shaped. Fertile zooecia elongated hexagonal, about as long and wide as sterile zooecia, in direct contact with the successive zooecia in the same series and with those in the alternating neighbour-series, proximal zooidal margin usually straight ( Fig. 2D ). Central cryptocyst depressed, framed by a pair of longitudinal ridges reaching from the distolateral zooecium margin lateral to opesia toward proximal part of zooecium, where they level with the depressed cryptocyst ( Fig. 2B ); cryptocyst smooth in autozooecia, in fertile zooecia granular along zooecial margins, particularly so proximally and distally. Opesia semi-elliptical, broader than long, proximal edge convex with a pointed denticle near each corner that is bent at a 90° angle and directed terminally, distal opesial rim finely beaded, proximal rim occasionally very faintly beaded ( Fig. 2 B-D).

Opening of fully formed ooecia roughly trapezoidal ( Fig. 2D ), very short and broad, situated at the maternal zooid’s extreme distal end, with the proximal cryptocyst of the succeeding zooecium or avicularium forming the distal margin of the ooecium, slightly less than proximal half occluded by a square plate with small lateral denticles extending from its lateral edges; “ooecial” opening in zooecia situated in proximal parts of the thickened fertile internodal zones, subrounded, placed between opesia and distal zooecium margin and therefore less distal than in fully formed ooecia.

Avicularium of fistulosa - type ( Fig. 2C ), situated directly distal to a zooecium, proximal border straight and the distolateral outline forming two-thirds of a full circle in sterile internodal zones and with a rather square outline in fertile zones, both forms slightly broader than long. Proximal cryptocyst in autozoocial zones short and smooth, extremely reduced distolaterally, thin margin granular all around, proximal cryptocyst in fertile zones slightly more extensive and granular; rostrum semicircular, arched and very slightly raised with straight proximolateral edges extending into the subcircular opesia, directed distally or distolaterally.

Perforations for rhizoidal kenozooids were not observed.

Remarks

Almost all of the species’ characters were already given by d’Hondt (1973) in the original description in French, which are largely transcribed here. However, whereas some SEM photos of general zoarial features were given in that publication, images of cleaned zooecia were not provided.

The new measurements given above occasionally differ from those in the original account. Whereas some of these differences may be due either to the few internodes available in the present study and/or to the use of different measuring techniques (optical with a microscope vs. digital from SEM images), other values in the original paper seem unrealistic. For instance, significant morphometric differences in zooecium and opesia dimensions between fertile and sterile zooecia, as stated by d’Hondt (1973), could not be affirmed in the paralectotype studied.

Cellaria harmelini was subsequently reported by Hayward (1978) and Hayward & Ryland (1978) from several other stations along the northern shelf margin of the Bay of Biscay, whereas d’Hondt (1973) recorded the species also from a location in the southern Bay of Biscay (44°01.6’ N – 07°01.9’ W, 510- 630 m). Most samples were taken from gravelly sediment surfaces, and the species’ depth of occurrence ranges from 180 to 700 m.

The status of Cellaria harmelini subsp. tenuis d’Hondt, 1974 , recorded from the northern and northwestern Spanish shelf edge, cannot be commented on at present.

Figures

Fig. 2. Cellaria harmelini d’Hondt, 1973 (MNHN 6902, paralectotype). A. Overview of an infertile internode with a distal avicularium. B. Close-up of an autozooecium. C. An avicularium situated distal to an autozooecium. D. Ovicellate zooecia, one with a distal avicularium at left. Scale bars: A = 200 µm; B, C = 50 µm; D = 100 µm.