Syllis bella ( Chamberlin, 1919 )

Salcedo, Diana L. & Solís-Weiss, Guillermo San Martín And Vivianne, 2012, The genus Syllis (Polychaeta: Syllidae: Syllinae) in the southern Mexican Pacific, with the description of two new species and three new records, Zootaxa 3263, pp. 47-62 : 48-49

Syllis bella ( Chamberlin, 1919)

Typosyllis bella: Chamberlin, 1919: 7 ; Hartman, 1968: 438; Kudenov & Harris, 1995: 85 –87, Fig. 1.33; Licher, 1999: 94 –96, Fig. 45. Syllis bella: Capa et al., 2001: 107 ; López et al., 1997: 63; Aguado & San Martín, 2007: 211, Figs 1–3 .

Material examined. 7 specimens (CPICML PO-37-085). 1 specimen, Palmitas E2B2, 16°42.420’N, 99°54.733’W, 25 May 2006, 10.5 m, coarse sand. 5 specimens, El Jardín E3B1, 16°49.436’N, 99°54.981’W, 26 May 2006, 12 m, coarse sand. 1 specimen, El Jardín E3B2, 16°49.436’N, 99°54.981’W, 26 May 2006, 12 m, coarse sand.

Comparative material examined. Syllis bella . PANAMA: 2 specimens ( MNCN 16.01/11470). Pacific, Jicarita Island, Chiriqui Gulf, 12 m. Syllis bella . PANAMA: 25 specimens ( MNCN 16.01/11535). Pacific, Ensenada Maria, Coiba Island, Chiriqui Gulf, 3 m.

Remarks. The specimens examined agree well with the original and additional descriptions from the Pacific coasts of Panama ( Capa et al., 2001). However, the present specimens have smaller dorsal cirri than specimens from the Mediterranean (33–36 articles instead of 36–40) ( Aguado & San Martín, 2007), have a longer pharynx (throughout 13 segments instead of 11), and are slightly shorter (10 mm instead of 12 mm). Although the species was described as having a distinctive color pattern on its anterior end, none of the specimens from Acapulco exhibited it, perhaps because of their state of preservation. The number of aciculae in the anterior and midbody parapodia is greater than in specimens from other localities and they protrude slightly from the parapodial lobes. However, these variations are non-consistent, as they occur even in some specimens from Panama and from the Mediterranean and might be related to the developmental status of each specimen. The distribution of S. bella is likely to be extended throughout the Tropical Eastern Pacific. Nonetheless, its presence in the Mediterranean Sea ( Aguado & San Martín, 2007) may confirm that it has a disjunct distribution, not confined to warm waters, or may suggest the possible existence of two different species, which would need to be confirmed by a molecular approach.

Habitat. Medium to coarse sand.

Distribution. California, Pacific coasts of Panama, eastern Mediterranean Sea and southern Mexican Pacific.

Figures

FIGURE 1. Syllis antoniae n. sp. (A) Anterior end, dorsal view. (B) Anterior chaetae. (C) Anterior aciculae. Scale 40 µm.

FIGURE 2. SEM of Syllis antoniae n. sp. (A) Anterior end, dorsal view. (B) Detail of dorsum (pores). (C) Superior chaetae, anterior chaetiger. (D) Median and most inferior chaetae, anterior chaetiger. (E) Dorsal simple chaeta. (F) Ventral simple chaeta. Scale: (A) 50 µm. (B, D) 10 µm. (C, E – F) 5 µm.

FIGURE 3. Syllis antoniae n. sp. (A) Midbody chaetae. (B) Midbody aciculae. (C) Posterior chaetae. (D) Posterior aciculae. (E) Dorsal simple chaeta. (F) Ventral simple chaeta.