Callopora dumerilii ( Audouin, 1826 )

López-Gappa, Juan, Liuzzi, María G., Castro, Karen L., Bobinac, Magalí & Schwindt, Evangelina, 2022, Fouling bryozoans in Argentine harbours (Southwest Atlantic): new records and the description of a new species, Zootaxa 5205 (4), pp. 374-400 : 381

Callopora dumerilii ( Audouin, 1826)

( Figs 12–14 )

Flustra dumerilii Audouin, 1826: 240 .

Callopora dumerilii : Ryland 1965: 33, fig. 15b; Hayward & Ryland 1998: 160, figs 40, 42a; De Blauwe 2009: 194, figs 180, 181.

Material examined. MACN-In 43874, Storni pier, Puerto Madryn, October 27, 2016, collected by Karen Castro.

Description. Colony encrusting, unilaminar. Autozooids oval, separated by deep grooves. Gymnocyst smooth, reduced, visible only on the proximo-lateral corners of the autozooid. Cryptocyst developed as a narrow and beaded raised border encircling the oval opesia. Four pointed and erect oral spines at the distal end of the autozooid. The proximal pair usually present, the distal pair absent or occluded in ovicelled zooids. Avicularia adventitious, sometimes absent, located proximo-laterally to the opesia, small, mounted on the gymnocyst, with a triangular pointed rostrum directed proximally or distally. Kenozooids scattered among the autozooids, with a peripheral, smooth gymnocyst and a well-developed beaded cryptocyst. Communication between autozooids by dietellae. Ovicell globular, spherical, ectooecium almost completely membranous, except for a narrow peripheral band; entooecium coarsely granular, with a reticulate appearance. Ancestrula tatiform, with ten delicate, erect spines.

Remarks. Callopora dumerilii was found on the ribbed mussel, Aulacomya atra ( Molina, 1782) . It was included by Ryland (1965) in his study of fouling bryozoans from European harbours. This is the first record of C. dumerilii for South America. Its disjoint geographic distribution and the appearance in the fouling assemblage of a Patagonian harbour suggests that it should be regarded as a NIS that probably arrived in Argentina by maritime traffic.

Distribution. From Norway to Morocco and Madeira, the Mediterranean Sea ( Hayward & Ryland 1998), Holland and Belgium ( De Blauwe 2009) and Chubut Province (this study). Its presence in the Atlantic coast of North America is based on the records of Whiteaves (1901) for the Gulf of St. Lawrence, Osburn (1933) for Maine, and Maturo (1968) for the Atlantic coast of the United States, although the species was not included in the comprehensive study by Winston & Hayward (2012) on the bryozoans from Maine to Virginia. Callopora dumerilii has also been cited for remote archipelagos in the Southern Hemisphere, such as Tristan da Cunha ( Waters 1888) and Amsterdam Island ( Balavoine 1958), in both cases without descriptions or illustrations.

Figures

FIGURES 12–17. FIGURES 12–14. Callopora dumerilii (MACN-In 43874); 12, general aspect; 13, ovicelled zooids; 14, detail of zooid and avicularium. FIGURE 15. Bugula neritina, general aspect (MACN-In 43875). FIGURE 16. Bugulina flabellata, general aspect (MACN-In 43876). FIGURE 17. Bicellariella edentata, general aspect (MACN-In 32310). Scale bars. 12, 15, 17: 200 µm; 13, 14: 100 µm; 16: 300 µm.