Cradoscrupocellaria severoi, Reverter-Gil & Souto, 2021

Reverter-Gil, Oscar & Souto, Javier, 2021, Two new species of cheilostomate Bryozoa from Iberian waters, European Journal of Taxonomy 760, pp. 16-31 : 17-22

Cradoscrupocellaria severoi sp. nov.

urn:lsid:zoobank.org:act:AF6D2F75-42FE-4AD5-A1A2-A8D587ECA7F7

Figs 1–2 ; Table 1

Scrupocellaria reptans – Templado et al. 2002: 203.

? Scrupocellaria macrorhyncha – Zabala 1986: 318, fig. 88, pl. 3 figs a–d.

? Scrupocellaria reptans – Zabala & Maluquer 1988: 97, figs 159–160, pl. 5 figs a–b.

Differential diagnosis

Cradoscrupocellaria with erect, branched colonies, with internodes comprising 5–10 alternating autozooids. Chitinous joints passing across proximal gymnocyst of outer and inner zooids. Large scutum, stout and flat, highly branched, completely covering the opesia. Two inner spines and 3 outer spines. Small distolateral avicularium frequent. Large monomorphic frontal avicularium in outer zooids oriented upwards on the branch. Ovicells globular, wider than long, perforated by 10–18 rounded pores; ovicelled zooids with 2 inner and 2 outer spines.

Etymology

This species is dedicated to Severo Ochoa de Albornoz (1905–1993), Spanish physician and biochemist, winner of the 1959 Nobel Prize in Physiology or Medicine for the discovery of the mechanisms in the biological synthesis of nucleic acids.

Material examined

Holotype MEDITERRANEAN SPAIN • colony; Columbretes Islands; 39º87.967´N, 0º66.817´E; stn 277B15; depth 3–40 m; 1996; Fauna Ibérica IV exped.; MNCN 25.03/3059 ( Figs 1A, D , 2A, D ).

Paratypes MEDITERRANEAN SPAIN • 1 colony; Columbretes Islands; 39º85.450´N, 0º67.617´E; stn 285B1; depth 42 m; 1996; Fauna Ibérica IV exped.; MNCN 25.03/2999 • several fragments; Columbretes Islands; 39º87967´N, 0º66817´E; stn 277B14; depth 7.5 m; 1996; Fauna Ibérica IV exped.; MNCN 25.03/3057 , 25.03/4234 ( Figs 1C , 2C ) • several fragments; Columbretes Islands; 39º89.800´N, 0º68.883´E; stn 275B5; depth 35 m; 1996; Fauna Ibérica IV exped.; MNCN 25.03/3200 ( Figs 1B , 2B ).

Other material

Paralectotypes of Scrupocellaria macrorhyncha Gautier, 1962 (here designated, see explanation below):

MEDITERRANEAN FRANCE • several fragments; Marseille, SW Cap Caveaux; stn 258; 1 Dec. 1952; Gautier leg.; MNHN-IB-2008-11319 • several fragments; same collection data as for preceding; MNHN- IB-2008-11321 ( Fig. 3 ).

Description

Colony erect, up to 1 cm in height, branched, with internodes comprising 5–10 alternating autozooids. Internodes slender, almost straight, angled at axis, with acute bifurcating pattern; chitinous joints

passing across proximal gymnocyst of outer (C and D) and inner zooids (F and G) at bifurcation. Autozooids cylindrical with straight sides. Oval opesia occupying two thirds of zooidal length; cryptocyst reduced to narrow rim around opesia. Large scutum inserted at midline of the inner edge of opesia, stout but relatively flat, its tips highly branched, fully developed and completely covering entire opesia. Distal spines short, unbranched; 2 inner and 3 outer spines, with outer distal spines closer to scutum; axial zooid with 5 spines. Small distolateral avicularium frequent and easily visible in frontal view. Monomorphic frontal avicularium often present in outer zooids of each internode; large but variable in size, with elongate rostrum 0.22–0.28 mm long, with fringed edges, proximally upright, with strongly hooked tip; mandible long, hooked distally. Vibracular chamber laterally placed on the basal surface of each zooid, visible in frontal view; chamber of vibraculum almost trapezoidal, with a proximal rhizoidal foramen; setal groove transverse to internode axis, straight, with smooth seta longer than one autozooid. Single axial vibraculum without rhizoidal foramen. Rhizoids tubular and smooth. Ovicells globular, wider than long, with an even, almost straight proximal rim; ectooecium perforated by 10–18 rounded pores; ovicelled zooids with 2 inner and 2 outer spines. Ancestrula unknown.

Remarks

The genus Cradoscrupocellaria has been recently described by Vieira et al. (2013). Nine already existing species were transferred to this genus, and the same authors described 18 new species.Among all these species, only C. gautieri Vieira, Spencer Jones & Winston, 2013 and C. macrorhyncha ( Gautier, 1962) show similarities with C. severoi sp. nov., mainly regarding the very stout scutum with truncate tips and the large frontal avicularia. The description of C. gautieri is based on a single sample collected by Gautier (1962) in Algeria. Cradoscrupocellaria macrorhyncha was redescribed by Vieira et al. (2013) based on the only original sample of Gautier deposited at NHMUK, designated as lectotype, and other Mediterranean samples by other authors. However, the MNHN collection includes two other original samples of Gautier from the same station as the lectotype that seem to have been overlooked in the redescription of the species, perhaps because in the museum’s catalogue and in the external labels of the samples both are simply marked as “ Scrupocellaria reptans ”: sample MNHN-IB-2008-11319 contains a handwritten label by Gautier stating “ Scrupocellaria reptans group? Dry specimen”; being written in English, it is highly probable that this sample together with the lectotype were sent by Gautier to A. Hastings at the NHMUK, and later returned. Sample MNHN-IB-2008-11321 ( Fig. 3 ) includes a label handwritten by Gautier indicating “ Scrupocellaria reptans ? grand avic.”. Since both samples actually correspond to C. macrorhyncha and were collected by Gautier at the type locality of the species and studied by him, they should be considered as part of the type series and consequently considered as paralectotypes of the species according to Arts 73.2.2 and 74.1.3 of the ICZN Code ( ICZN 1999).

Cradoscrupocellaria severoi sp. nov. differs from C. macrorhyncha and C. gautieri by several characters: the frontal avicularium is monomorphic in C. severoi sp. nov. because the small columnar avicularium present in the other species is absent; this frontal avicularium is oriented upwards on the branch, not proximally ( Figs 2A–B , 3C ). The lateral avicularium is more frequent and more visible ( Fig. 2A–B ). In the bifurcations of C. severoi sp. nov., the chitinous joints pass through the gymnocyst of the external zooids (C and D) instead of through their opesiae ( Figs 1C , 3A ). The ovicell is wider than long in C. severoi sp. nov., usually uniformly perforated by small pseudopores ( Figs 1D , 2A–B ), whilst in C. macrorhyncha the ovicell is more spherical and usually exhibits an imperforate flat frontal area ( Fig. 3B ) (in C. gautieri the ovicell is unknown). The autozooids of C. severoi sp. nov. are clearly smaller than those of C. macrorhyncha , but similar in size to those of C. gautieri . Finally, the internodes are short in C. severoi sp. nov., formed by 5–10 autozooids ( Fig. 1A–B ), as in C. gautieri , but the scutum is flatter and not swollen as in that latter species.

Cradoscrupocellaria severoi sp. nov. is known with certainty only from its type localities at the Columbretes Islands (Mediterranean Spain) between 3 and 42 m depth. Zabala (1986) reported Scrupocellaria macrorhyncha Gautier, 1962 from several Catalonian localities, but these records were later reassigned to S. reptans ( Linnaeus, 1758) by Zabala & Maluquer (1988). Vieira et al. (2013), however, stated that these specimens are distinct from C. macrorhyncha and C. reptans , as well as from C. ellisi ( Vieira & Spencer Jones, 2012) , and that they may belong to a new undescribed species. Figures by Zabala (1986) and Zabala & Maluquer (1988) are quite similar to C. severoi sp. nov., but the description given (actually an almost literal translation of the original description of S. macrorhyncha by Gautier) show several differences from the present description of the new species. A revision of the original material and collection of new material will be necessary to clarify which species was reported from Catalonia, as well as to determine the possible presence of C. severoi sp. nov. at other Iberian localities.

Figures

Fig. 1. Cradoscrupocellaria severoi sp. nov. A. View of the colony (MNCN 25.03/3059: holotype). B. View of the colony (MNCN 25.03/3200: paratype). C. Branching pattern (MNCN 25.03/4234: paratype). D. Detail of a branch with large frontal avicularia, ovicells and scuta (MNCN 25.03/3059: holotype).

Fig. 2. Cradoscrupocellaria severoi sp. nov. A. Detail of branches with large frontal avicularia, ovicells, scuta and a lateral avicularium (centre left) (MNCN 25.03/3059: holotype). B. Detail of a branch with large frontal avicularia, ovicells and a lateral avicularium (bottom left) (MNCN 25.03/3200: paratype). C. Basal view of the branching pattern (MNCN 25.03/4234: paratype). D. Single axial vibraculum (MNCN 25.03/3059: holotype).

Fig. 3. Cradoscrupocellaria macrorhyncha (Gautier, 1962) (MNHN-IB-2008-11321: paralectotype), SW Cap Caveaux (Marseille, France), Gautier Coll. A. Frontal view of the branching pattern. B. Detail showing the scuta, ovicells, large frontal avicularia and a small frontal avicularium (bottom right). C. Lateral view showing the large frontal avicularia and basal vibracula. D. Basal view of the branching pattern.