Schizotheca tuberigera

Reverter-Gil, Oscar & Fernández-Pulpeiro, Eugenio, 2007, Species of genus Schizotheca Hincks (Bryozoa, Cheilostomata) described in the Atlantic-Mediterranean region, with notes on some species of Parasmittina Osburn, Journal of Natural History 41 (29 - 32), pp. 1929-1953 : 1944-1947

Schizotheca tuberigera (Jullien, in Jullien and Calvet, 1903)

( Figure 5D–F )

Strophiella tuberigera Jullien , in Jullien and Calvet 1903, p 66, Plate 9, Figure 1 . Schizotheca fissa (Busk) : Calvet 1906, p 429 (part: D.10 Talisman, 1883 ).

Schizotheca fissa (Busk) : Canu and Bassler 1925, p 47 (part: st. no. 29).

Schizotheca serratimargo (Hincks) : Canu and Bassler 1925, p 48 (part).

Schizoporella fallax Canu and Bassler 1928, p 32 , Plate 3, Figures 12, 13.

Strophiella tubigera [sic] Jullien: d’Hondt 1978, p 455; Fernández Pulpeiro, Reverter Gil, and Ramil 1990, p 62.

Schizotheca fissa (Busk) : d’Hondt 1978, p 449 (part or whole).

Schizotheca levis Cook 1985, p 178 , Figure 46; Arístegui Ruiz 1984, p 359, Figure 78a, b, Plate 28, Figures 7 , 8.

Schizotheca tuberigera (Jullien) : Harmelin and d’Hondt 1992, p 49, Plate 7C, D.

not Strophiella tubigera [sic] Jullien 1903?: d’Hondt 1975, p 576.

Material examined

Holotype (by original designation): MNHN-3758: as Strophiella tuberigera . Hirondelle, st. 53. 135 m.

Other material. MNHN-300: as Schizotheca fissa . Talisman, Gulf of Cadiz. 717 m. MNHN- 1035: as Schizotheca fissa . Talisman, Gulf of Cadiz. 717 m. MNHN-1036: as Schizotheca fissa . Talisman, Gulf of Cadiz. 717 m. MNHN-2180: as Schizotheca fissa . Talisman, Gulf of Cadiz. 717 m. MNHN-2341: as Schizotheca fissa . Talisman, Gulf of Cadiz. 717 m. MNHN-2696: (with more species), as Schizotheca …? MNHN-4026: as Schizotheca fissa . Talisman, Gulf of Cadiz. 717 m. MNHN-4348: as Schizotheca fissa . Vanneau, st. XXIX. MNHN-4352: as Schizotheca serratimargo . Vanneau, st. XXIX. MNHN-4362: as Schizotheca serratimargo . Vanneau, st. XXIX. 160 m. MNHN-6292: (with more species), as Strophiella tubigera . Vanneau, st. XXXI. MNHN-9980: as Schizotheca fissa . Vanneau, st. CX. MNHN-13718: as Schizoporella fallax . Vanneau, st. XLIII. MNHN-13763: as Schizoporella cf. fallax . Vanneau st. XXI. MNHN-13770: as Schizoporella fallax . Vanneau, st. LV. MNHN-13790: as Schizoporella fallax . Vanneau, st. XXXVII. MNHN-13831: as Schizoporella fallax . Vanneau, st. XXXI. MNHN-13896: as Schizoporella fallax . Vanneau, st. XLIV. 145 m. MNHN-14018: as Schizoporella fallax . Vanneau, st. CXXVI. MNHN-14035: as Schizoporella fallax . Vanneau, st. XXI. 150 m. MNHN-14047: (with more species), as Schizoporella fallax . Vanneau, st. CXXVI. MNHN-14061: as Schizoporella fallax . Vanneau, st. XXXVII. MNHN-14097: as Schizoporella fallax . Vanneau, st. LX. 132 m. MNHN-14121: as Schizoporella fallax . Vanneau, st. XCI. MNHN-14165: as Schizoporella fallax . Vanneau, st. XLIV. MNHN-14199: as Schizoporella fallax . Vanneau, st. XLIII. 133 m. MNHN-14325: (with more species), Vanneau st. XLIII. MNHN-14419: (with more species), as Schizoporella fallax . Vanneau, st. CXXIX. MNHN- 14457: as Schizoporella fallax . Vanneau, st. XLVI. MNHN-14469: (with more species), as Schizoporella fallax . Vanneau, st. XXXVII. MNHN-14542: as Schizoporella fallax . Vanneau, st. XXXV. MNHN-16833: as Schizotheca fissa . PTT. MNHN-(Paléontologie): as Schizotheca serratimargo . Vanneau, st. LV. MNHN-(Paléontologie): as Schizotheca serratimargo . Vanneau, st. XXIX. MNHN-(Paléontologie): as Schizotheca serratimargo . Vanneau, st. LXIX. MNHN- (Paléontologie): as Schizotheca serratimargo . Vanneau, st. XXVIII. MNHN-(Paléontologie): (with more species). Oran. NHM-1973.3.22.7: as Schizotheca levis . st. 60. 78 m. Paratype. Figured. NHM-1973.3.22.8: as Schizotheca levis . Ghana. Holotype and paratypes.

Dr Harmelin’s personal collection: Balgim DW43, 35 ° 54.19N, 06 ° 14.59W, 150 m, May– June 1984. One colony.

The authors’ personal collection: 42 ° 489300N, 09 ° 239420W, 115 m. Several colonies on a cetacean bone.

Description

Colony encrusting, extensive, unilaminar. Autozooids oval to rhomboid, arranged in alternating series and separated by fine sutures; frontal surface slightly convex, finely granular, bearing small denticulations; imperforate, except for up to five (often two) marginal circular pores.

Primary orifice orbicular; anter denticulate, poster with a small median notch, marked by two thick teeth and two long condyles; denticles characteristically blunt, formed as a continuation of the condyles. Peristome fine, more developed laterally and distally, describing a secondary elliptical orifice, longer than wide. Four to six cylindrical hollow oral spines, reduced to two in ovicellate or calcified zooids.

Autozooids bear a lateral adventitious avicularium, sometimes two, situated towards the middle of the frontal surface; mandible triangular, laterally directed, with slightly curved distal end that often touches the peristome of the neighbouring zooid. Foramen usually divided into two small lacunae, formed by separation of a more or less triangular foramen; the distalmost lacuna may sometimes be lacking. Cross bar fine, with a thick denticle. The avicularium has one or two conspicuous lateral pores. Avicularium sometimes associated with the ovicell of the proximal autozooid, then directed proximally.

Large vicarious avicularium with a narrow triangular mandible distally hooked; orientation variable, generally towards the peripheral of the colony; foramen similar to the adventitious avicularium, although less commonly the small most distal lacuna is absent. Large columella. Proximal opesia generally closed over by calcification.

Kenozooids irregularly shaped and variable in size, sometimes very abundant; may sometimes bear one or more adventitious avicularia similar to those existing in the autozooids.

Prominent, smooth, imperforate hyperstomial ovicell with a wide, more or less triangular fissure that narrows at the apex.

Ancestrula not observed.

Measurements

MNHN-3758 (holotype). AZL: 0.58¡0.05 (17); AZW: 0.36¡0.05 (17); OVL: 0.23¡0.01 (13); OVW: 0.25¡0.02 (13); VAL: 0.34 (1); VAW: 0.19 (1); AAL: 0.16¡0.01 (17); AAW: 0.066¡0.009 (17); VAL/AAL52.1. We were unable to measure the orifice of this specimen because of the poor state of conservation of the sample.

MNHN-14061. AZL: 0.60¡0.08 (20); AZW: 0.40¡0.05 (20); OL: 0.12¡0.009 (20); OW: 0.12¡0.008 (20); OVL: 0.24¡0.016 (13); OVW: 0.27¡0.03 (13); VAL: 0.41¡0.04 (13); VAW: 0.20¡0.02 (13); AAL: 0.165¡0.02 (20); AAW: 0.067¡0.008 (20); VAL/ AAL52.5.

Remarks

Schizotheca tuberigera is characterized by a primary orbicular orifice with two small teeth on the proximal edge and blunt teeth along the inner edge; a secondary elliptical orifice; and by the form of the foramen of the avicularia, frequently divided into two small lacunae, and cross bar with a large denticle; the vicarious avicularia are more than twice the size of the adventitious avicularia.

This species was described by Jullien (in Jullien and Calvet 1903) from material collected in the NW of the Iberian Peninsula, and placed in the genus Strophiella Jullien in Jullien and Calvet, 1903. In the description of the species ( Jullien and Calvet 1903, p 66) it was indicated that the orifice is of variable form, and three different types were therefore established. We were able to examine numerous colonies of S. tuberigera (amongst these the type material of the species, MNHN-3758), demonstrating that the difference in the form of the orifice is simply due to the intrinsic variability in the autozooids, presence or absence of ovicells, degree of calcification and state of conservation of the material. Harmelin and d’Hondt (1992) studied material of this species originating from the Balgim expedition and proposed its inclusion in the genus Schizotheca Hincks, 1877 .

Schizotheca tuberigera has been described as Schizotheca levis by Cook (1985), whose type material we have examined. As indicated by Harmelin and d’Hondt (1992), this species should be considered a junior synonym of S. tuberigera .

This species has also been described as Schizoporella fallax Canu and Bassler, 1928 . We were not able to locate the type material of the species and we assume that it was not originally designated. However, the description and figures of these authors ( Canu and Bassler 1928, p 32, Plate 3, Figures 12, 13) are sufficiently representative. We also reexamined numerous colonies of S. fallax from the Balavoine Collection, deposited in the MNHN in Paris, from the Vanneau expedition, and which correspond perfectly to the original description of the species of Canu and Bassler (1928). We therefore consider that Schizoporella fallax is definitely a junior synonym of S. tuberigera .

Schizotheca tuberigera has often been confused with other species of the genus, particularly S. fissa and S. serratimargo .

We have studied several colonies from the Canu Collection (MNHN) originating from the Vanneau expedition, identified as S. serratimargo , part of which has been cited by Canu and Bassler (1925, p 48); six of the colonies were found to belong to S. tuberigera . We have also examined a sample identified as S. fissa , originating from station no. 29 of the Vanneau expedition (MNHN-4348), cited by Canu and Bassler (1925, p 47), which actually corresponds to S. tuberigera .

We examined six samples labelled as S. fissa , originating from dredge no. 10 of the Talisman expedition in 1883, cited by Calvet (1906, p 429), and which actually correspond to S. tuberigera ; however, we do not possess any information on the material cited from dredge no. 24 in the same survey.

d’Hondt (1978, p 449) cited S. fissa from st. 110 in the Vanneau expedition. We examined a sample from this locality (MNHN-9980), which corresponded to S. tuberigera ; however, we do not know how many colonies were collected at this site and therefore we do not know if the citation of S. fissa made by this author can be maintained.

The same author ( d’Hondt 1975, p 576) cited various colonies from the Azores Islands as Strophiella tubigera Jullien, 1903 ?. However, the reference material deposited in the MNHN belongs to S. carmenae sp. nov. (see above).

Schizotheca tuberigera is much more common than considered to date, as most of the previous citations have been made under other names. The area of distribution is also greater than previously thought, as it has been reported from Galicia (NW Spain) ( Jullien and Calvet 1903, as Strophiella tuberigera ; Fernández Pulpeiro, Reverter Gil, and Ramil 1990, as Strophiella tubigera [sic]; Reverter-Gil and Fernández-Pulpeiro 2001), Gulf of Cadiz ( Calvet 1906, as Schizotheca fissa , part), Morocco ( Canu and Bassler 1925, as Schizotheca serratimargo , part, and as Schizotheca fissa , part; Canu and Bassler 1928, as Schizoporella fallax ; d’Hondt 1978 as Strophiella tubigera [sic] and as Schizotheca fissa , part), Strait of Gibraltar ( Harmelin and d’Hondt 1992), Canaries ( Arístegui Ruiz 1984, as Schizotheca levis ), and Gulf of Guinea ( Cook 1985, as Schizotheca levis ).

Figures

Figure 1. Parasmittina talismani. (A) View of the colony (MNHN-299, holotype); (B) view in perspective, showing the development of the peristome and adventitious avicularia (MNHN-299, holotype); (C) an ovicellate zooid (MNHN- 1037); (D) primary orifice and adventitious avicularia (MNHN-1037); (E) primary orifice and adventitious avicularium (MNHN-299, holotype); (F) two broken zooids showing the lyrula, the adventitious avicularia and the remaining basis of spines under the ovicells (MNHN-1037); (G) growing edge of the colony (MNHN-299, holotype).

Figure 5. (A–C) Schizotheca buski sp. nov.: (A) group of ovicellate zooids with lanceolate adventitious avicularia (NHM-1899.7.1.5063, paratype); (B) a vicarious avicularium and a kenozooid with a porous plate (left) (NHM- 1899.7.1.5199, holotype); (C) primary orifice (NHM-1899.7.1.5199, holotype). (D–F) Schizotheca tuberigera: (D) group of autozooids, some ovicellate, with adventitious avicularia and a vicarious avicularium (MNHN-14121); (E) group of kenozooids with adventitious avicularia (MNHN-13831); (F) primary orifice (MNHN-14061).

Figure 7. Schizotheca aviculifera. (A–C) Casablanca, lectotype: (A) general view, showing orifices filled with sand; (B) orifice with well-developed proximal teeth; (C) orifice showing poorly developed proximal teeth. (D–F) Fedhala (as Schizotheca serratimargo): (D) general view, showing calcified zooids, and vicarious and adventitious avicularia; (E) orifice with well-developed proximal teeth; (F) orifice showing poorly developed proximal teeth.