Microporella browni Harmelin, Ostrovsky, Cáceres-Chamizo & Sanner, 2011 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 : 35-36

Microporella browni Harmelin, Ostrovsky, Cáceres-Chamizo & Sanner, 2011 Introduced

( Fig. 17 ; Table 17)

Microporella browni Harmelin, Ostrovsky, Cáceres-Chamizo & Sanner 2011: 5 , figs 1, 2; Baradari et al. 2019: 477, figs 64–67; Rosso et al. 2025: 79, fig. 6.

Figured material. Marina Lanzarote (29/06/23) (2C on buoy) ( MNCN 25.03/4465).

Description. Colony encrusting and unilaminar. Autozooids oval, nearly hexagonal, longer than wide ( Fig. 17A ). Frontal shield slightly convex, filled with small nodes and pseudopores ( Fig. 17B ). Primary orifice wider than long, denticulated distally (12–15 denticles) and corrugated proximally, with one shoulder-shaped low condyle on each side of the edge. Oral spines (3–5 but usually four) surrounding the distal edge of the primary orifice ( Fig. 17C ). Ascopore separated from the orifice at a distance shorter than orifice length, C-shaped with spinous processes, surrounded by a rim ( Fig. 17D ). Avicularium generally single (rarely paired), located near the corner of the marginal border of the orifice, either in the left or right, rostrum distolaterally oriented, mandible thin, moderately long and setiform ( Fig. 17E ). Ovicell personate (with prominent arched and granular collar surrounding the primary orifice, not including the ascopore), without visible oral spines ( Fig. 17F ).

Remarks. Our M. browni material clearly resembles eastern Mediterranean material ( Harmelin et al. 2011; Rosso et al. 2025), with similar dimensions ( Table 17), corrugation in the proximal edge of the orifice not very defined, low and wide condyles and, above all, a similar range of distal denticles within the primary orifice (12– 16 denticles in Harmelin et al. (2011), and 12–15 in our case). Although Harmelin et al. (2011) described the avicularian mandible as pointed, our material shows a slightly bent tip appearing vaguely similar to the hooked tip in Microporella orientalis Harmer, 1957 . Nevertheless, it should be noted the presence of shoulder-shaped condyles and length of the avicularian mandible that matches the original material from Harmelin et al. (2011). Specifically, the avicularian mandible length ranged from 150 to 277 µm in material from Lebanon, Tadjoura, Oman and the Maldives in Harmelin et al. (2011), while our measurements ranged from 160 to 180 µm (see Table 17 for dimensions in mm). Arístegui (1984b) recorded some Microporella species with personate ovicells in the Canary Islands that were later assigned to other species and are probably introduced. For example, Microporella harmeri Hayward, 1988 , which was identified as M. orientalis . Microporella harmeri has been recorded throughout the Indo-Pacific ( Baradari et al. 2019), Red Sea, Eastern Mediterranean and Eastern Atlantic Ocean ( Harmelin et al. 2011), suggesting that it is another introduced Microporella species in the Canary Islands. This is also the case for Microporella genisii ( Audouin, 1826) , described in Arístegui (1984b) as a new species ( Microporella intermedia ). Microporella genisii has been recorded in the northern Red Sea, eastern Mediterranean and eastern Atlantic Ocean ( Harmelin et al. 2011). Nevertheless, all the Microporella species recorded in Arístegui (1984b) differ from our material in (1) the lack of denticulation on the distal border and condyles on the proximal one, (2) the absence of oral spines in ovicellate zooids (particularly M. genisii ( Di Martino & Rosso 2021)) and (3) the mandible morphology in the avicularia ( Harmelin et al. 2011) .

Distribution and status. Microporella browni was described from the Indian Ocean and eastern Mediterranean Sea, particularly Lebanon ( Harmelin et al. 2011). This species has extended its geographical distribution towards the western Mediterranean ( Rosso et al. 2025), and it has been also recorded in the Persian Gulf ( Baradari et al. 2019; Shabani et al. 2019). This observation constitutes the most western record of M. browni , being recorded for the first time in the Atlantic Ocean, where we consider this species introduced.

Figures

FIGURE 17. Microporella browni Harmelin, Ostrovsky, Cáceres-Chamizo & Sanner, 2011 (MNCN25.03/4465). A. View of colony through SEM. B. Autozooid. C. Primary orifice and ascopore. D. Ascopore. E. Avicularium mandible. F. Ovicell. Scale bars: A = 200 µm; B, C = 40 µm; D = 20 µm; E = 30 µm; F = 100 µm.