Buskia socialis Hincks, 1887

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 : 377-378

Buskia socialis Hincks, 1887

( Figs 3–5 )

Buskia socialis Hincks 1887: 310 , pl. 9, fig. 7; Marcus 1937: 143, pl. 28, fig. 77B, pl. 29, fig. 77A; Prenant & Bobin 1956: 310, fig. 141; Gordon & Mawatari 1992: 14, fig. 2G; Vieira et al. 2008: 9; Schwindt et al. 2020: 15.

Material examined. MACN-In 35765. April, 1968, Mar del Plata harbour, collected by Ricardo Bastida, identified by Analía Amor. MACN-In 43871, San Antonio Este harbour, December 6, 2016, collected by Karen Castro.

Description. Colony erect, flexible, yellowish, up to 3 cm long. Branching opposite or alternate. Stolon diameter about 104 µm near the apex of the branches, to about 237 µm in older parts of the colony. Retracted zooids flaskshaped, disposed in two longitudinal series along the stolon, about 521–778 µm long and 176–212 µm wide, with proximal end widened and recumbent on the stolon, and anterior end narrower and raised. Insertion point of the zooid on the stolon near the base. The lateral edges near the proximal end of the zooid may be produced into one or two projections adjacent to the stolon.

Remarks. Although Mar del Plata harbour has been intensively sampled, B. socialis was not found again there after 1968. The species was not mentioned in a comprehensive study of the bryozoans of three harbours of Buenos Aires Province ( Lichtschein de Bastida & Bastida 1980). Buskia socialis is a widespread species and was previously found in Rio de Janeiro ( Marcus 1937) and São Sebastião ( Brazil), where it has been regarded as non-indigenous ( Xavier et al. 2021). It should also be regarded as a NIS in Argentina, due to its global disjunct distribution and its restricted geographic range in the Southwest Atlantic. This record, together with the mention in Schwindt et al. (2020), confirms the establishment of B. socialis in Argentina.

Distribution. Mediterranean Sea ( Hincks 1887), Portugal ( Reverter-Gil et al. 2014), Red Sea ( Hastings 1927), Atlantic coast of the United States ( Maturo 1968), Brazil ( Marcus 1937; Xavier et al. 2021), Buenos Aires and Río Negro provinces (this study). Gordon & Mawatari (1992) suggest that its presence in New Zealand could be due to transport by recreational vessels.

Figures

FIGURES 2–5. FIGURE 2. Arachnidium fibrosum (MACN-In 43869), zooids and stolons. FIGURES 3–5. Buskia socialis (MACN-In 35765); 3, general aspect; 4–5, close-up of branches and zooids. Scale bars. 2, 4, 5: 200 µm; 3: 1000 µm.