Spurilla braziliana ( MacFarland, 1909 )

Cetra, Nicolás & Roche, Andrea, 2023, Nudibranchia (Mollusca: Gastropoda) from San Matías Gulf, Northern Argentine Patagonia, Zootaxa 5244 (5), pp. 455-473 : 466

Spurilla braziliana ( MacFarland, 1909)

( Figures 4E, 4F , 5H )

Material examined. Argentina, Río Negro: Caleta Los Hornitos, 15 specimens, intertidal, 18/12/2016 (two specimens deposited, MLP-Ma 14659); four specimens, intertidal, 03/02/2017; San Antonio Este, one specimen, intertidal, 24/08/2016 (ESCM-Ma-79); Fuerte Argentino, two specimens, intertidal, 03/03/2011 (ESCM-Ma-81); El Buque, two specimens, intertidal, 15/06/2016 (ESCM-Ma-31); Bahía San Antonio , two specimens, intertidal, 28/05/2016 (ESCM-Ma-32); Plataforma; one specimen, 12 m, 03/2017 (ESCM-Ma-80); Chubut, Puerto Lobos, one specimen (MLP-Ma 13108) .

Description. Length up to 50 mm, body elongated, orange. Rhinophores lamellate, with a white apex. Cerata arranged in 6 to 9 arches, with the tips clearer and curved towards the dorsal area of the body. Digestive glands are visible in the cerata ( Figure 4E ). Radular formula 23 x 0.1.0. (MLP-Ma 14659). Teeth progressively smaller in the posterior region of the radula. Rachidian teeth bicurved, with between 55 to 70 denticles on each side of the central, small, and triangular cusp. ( Figure 5H ).

Geographic distribution and depth range. Pacific and Atlantic Ocean. Hawaiian Islands, Costa Rica, Peru, Japan, China, and Australia. From Florida to Argentinean Patagonian ( Carmona et al. 2014). San Matías gulf, Argentina (Ģller & Zelaya 2017). Found in soft and intertidal bottoms under rocks up to 10 m depth.

Biology. The egg mass is a spiral white ribbon, about 30 mm in length. The egg masses are deposited on the rocks ( Figure 4F ).

Remarks. This species has often been recorded under the name Spurilla neapolitana (Delle Chiaje 1841) . Externally, the color and morphology are not sufficient to differentiate the two species. Based on genetic data, Carmona et al. (2014) identified the southwestern Atlantic species as S. braziliana .

Figures

FIGURE 4. (A) Trapania rocheae, (B) Cadlina sparsa, (C) Polycera marplatensis, (D) egg mass of Polycera marplatensis, (E) Spurilla braziliana, (F) egg mass of Spurilla braziliana, (G-F) Aeolidia cf. campbellii photo by Nicolás Battini.

FIGURE 5. Scanning electron micrographs. (A–B) Trapania rocheae (MLP-Ma 14834), (A) radular teeth, (B) jaw, detail of the masticatory border. (C-D) Cadlina sparsa (MLP-Ma 14658), (C) radular teeth, (D) detail of the lateral teeth. (E–F) Polycera marplatensis (MLP-Ma 14661), (E) radular teeth, (F) detail of the lateral teeth. (G) Aeolidia cf. campbellii (MLP-Ma 14575): radular teeth. (H) Spurilla braziliana (MLP-Ma 14659): radular teeth.