Tricellaria inopinata d’Hondt and Occhipinti Ambrogi, 1985 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 : 24

Tricellaria inopinata d’Hondt and Occhipinti Ambrogi, 1985 Introduced

( Fig. 10 ; Table 10)

Tricellaria inopinata d’Hondt & Occhipinti Ambrogi, 1985: 35–46 , figs 2, 3; Fernández-Pulpeiro et al. 2001: 209–210, figs 2,3; Souto et al. 2023: 13, fig. 10A, B.

Figured material. Marina Lanzarote (29/06/23) (1C on buoy).

Other material examined. Marina Tenerife (19/06/23) (1C on rope), Las Galletas (19/06/23) (2C on buoy), Garachico (20/06/23) (1C on buoy), Taliarte (26/06/23) (1C on buoy), Morro Jable (27/06/23) (3C on buoy) ( MNCN 25.03/4458), Gran Tarajal (28/06/23) (1C on buoy), Corralejo (28/06/23) (1C on buoy), Playa Blanca (29/06/23) (1C on buoy).

Description. Colony whitish, erect, articulated with dichotomous branching ( Fig. 10A ). Zooids disposed on a biserial pattern, separated by articular joints ( Fig. 10B ). Five to eleven zooids within internodes ( Fig. 10B, C ). Autozooids elongate, wider in their distal end, with membrane occupying slightly more than half of frontal surface ( Fig. 10D ). Outer distal margin with three spines, and inner distal margin with two ( Fig. 10E ). Morphology of the scutum very variable (bifid, cerviform, kidney-shaped or palmate), located medio-proximally in the inner margin ( Fig. 10C ). Distolateral avicularia constant, with a triangular mandible ( Fig. 10E ). Ovicell hyperstomial, porous and globular.

Remarks. Tricellaria inopinata is clearly distinguished from similar species (like Tricellaria occidentalis ( Trask, 1857) and Tricellaria porteri ( MacGillivray, 1889)) primarily by the variability in the scutum morphology and in the number of zooids within internodes ( Dyrynda et al. 2000; Fernández-Pulpeiro et al. 2001). While T. inopinata has a very variable scutum morphology within a colony, T. occidentalis shows the scutum slender or slightly spatulate, and T. porteri large and reniform. The number of zooids per internode is variable in T. inopinata (3–19 zooids) and in T. porteri (3–13 zooids), but more consistent in T. occidentalis (usually three zooids, but sometimes five) ( Dyrynda et al. 2000).

Distribution and status. Although T. inopinata was originally described from the lagoon of Venice ( d’Hondt & Ambrogi 1985), this species probably originated in the North-Eastern Pacific ( De Blauwe & Faasse 2001). From there, it has been widely introduced, being recorded in Australia, New Zealand, Japan, Mediterranean Sea ( Dyrynda et al. 2000; Ramalho & Caballero 2022), and the North-Eastern Atlantic ( Bishop et al. 2015; Porter et al. 2015; Reverter-Gil et al. 2019), including Madeira ( Ramalhosa et al. 2019; Souto et al. 2023) and the Azores ( Micael et al. 2016). To our knowledge, the present study constitutes the first record of the introduction of T. inopinata in the Canary Islands, occurring in all the sampled islands in this study.

Figures

FIGURE 10. Tricellaria inopinata d’Hondt and Occhipinti Ambrogi, 1985.A. Live colony on a buoy in Morro Jable. B. View of the colony through SEM. C. Autozooids. D. Ramification of colony. E. Lateral avicularium, outer and inner spines. Scale bars: A = 1 cm; B, C = 200 µm; D = 100 µm; E = 40 µm.