Celleporaria cf. inaudita Tilbrook, Hayward & Gordon, 2001 Introduced

Ruiz-Velasco, Sofía, Ros, Macarena, Guerra-García, José M. & López-Fé, Carlos M., 2025, Fouling bryozoans in recreational marinas of the Canary Islands (North-Eastern Atlantic) with new records of non-indigenous and cryptogenic species, Zootaxa 5656 (1), pp. 1-63 : 28-29

Celleporaria cf. inaudita Tilbrook, Hayward & Gordon, 2001 Introduced

( Fig. 13 ; Table 13)

Celleporaria inaudita Tilbrook, Hayward & Gordon, 2001: 72 , fig. 13D–F; Souto et al. 2016: 979, fig. 2; McCann et al. 2019: 102, figs 6D, 7, 8A–D.

Figured material. Corralejo (28/06/23) (2C on buoy) ( MNCN 25.03/4461).

Description. Colony encrusting, multilaminar. Autozooids with irregular morphology and disposition ( Fig. 13A, B ). Frontal wall nodular with pores surrounding the margin of the autozooid. Primary orifice slightly broader than long, distal border semicircular, proximal border slightly concave and very variable, usually with one shallow and wide sinus, and more rarely, two ( Fig. 13C, D ). No condyles, peristome nor oral spines. Suboral avicularia raised on an umbo, denticulated distally ( Fig. 13C ). Vicarious avicularia large, including occasionally a pointed protuberance at the tip, spatulate, rostrum raised and rounded, sometimes appearing serrated, crossbar complete ( Fig. 13E ). Ooecium cap-shaped and widely open ( Fig. 13F ).

Remarks. Our material closely resembles C. inaudita , except for the proximal margin of the orifice. Although the presence of two cusps in the proximal area of the orifice is typical in C. inaudita colonies ( Souto et al. 2016), in our case they were infrequent in most autozooids, with the appearance of just one shallow sinus, and rarely, two sinuses. Generally, species from genus Celleporaria often show high intra- and intercolonial morphological variability in some characters, such as the proximal border of the primary orifice of C. brunnea and C. inaudita , especially in young or frontally budded zooids ( Tilbrook et al. 2001; Souto et al. 2023). For this reason, orifice morphology can be confusing as a diagnostic character in some Celleporaria species ( Souto et al. 2023). Tilbrook et al. (2001) mention that the distal part of the primary orifice can vary between the early ontogeny of the colony (gently convex) and later stages (thickening and forming cusps). The figured material represents a frontally budded colony, which may influence the observation of well-defined sinuses. Regarding the single shallow sinus in our specimens, this character is reminiscent of Celleporaria sherryae Winston, 2005 , that has one off-center shallow sinus, sometimes with an adjacent shallow indentation ( Winston 2005; Winston & Jackson 2021). However, the sinus in C. sherryae is shorter in width in comparison to those in our specimens. Celleporaria sherryae also shows a thicker vicarious avicularium. The width of the vicarious avicularia ranges between 0.216 and 0.468 mm in Winston & Jackson’s (2021) material but has a maximum of 0.18 mm in ours ( Table 13). The width of the vicarious avicularia in our material is close to that recorded by Souto et al. (2016) in C. inaudita collected from Madeira, having a maximum width of 0.204 mm. Our specimens also resemble Celleporaria aperta ( Hincks, 1882) material recorded by Arístegui (1984b) in Tenerife, which included two proximal denticles that limited a wide sinus. Nevertheless, while the material from Arístegui (1984b) showed mostly four oral spines, our specimens showed none. Additionally, our specimens also lack the lanceolate rostrum in vicarious avicularia, similarly as C. inaudita (compared in Tilbrook et al. 2001 and Souto et al. 2016).

Distribution and status. Celleporaria inaudita was described from Vanuatu (Southern Pacific) ( Tilbrook et al. 2001) and has been later recorded in the Red Sea ( Ostrovsky et al. 2011a, b), the Galapagos ( McCann et al. 2019), and Macaronesia, where it has been observed in Madeira ( Canning-Clode et al. 2013a; Souto et al. 2016; Ferrario et al. 2020; Castro et al. 2023), Cape Verde and the Canary Islands ( Castro et al. 2023). Although we consider this species as introduced, the taxonomical uncertainties of our samples hinder its confirmed establishment in Fuerteventura. Therefore, the occurrence of this species can only be confirmed in Tenerife ( Castro et al. 2023) as casual.

Figures

FIGURE 13. Celleporaria cf. inaudita Tilbrook, Hayward & Gordon, 2001 (MNCN25.03/4461).A, B. View of bleached colony through SEM, arrows indicate dentation in avicularia rostrum. C, D. Primary orifices and suboral avicularium. E. Vicarious avicularium. F. Ovicell. Scale bars: A, B = 200 µm; C, E, F = 100 µm; D = 40 µm.