Megalomma lanigera ( Grube, 1846 )

Tovar-Hernández, María Ana & Carrera-Parra, Luis F., 2011, Megalomma Johansson, 1925 (Polychaeta: Sabellidae) from America and other world-wide localities, and phylogenetic relationships within the genus 2861, Zootaxa 2861 (1), pp. 1-71 : 37-39

publication ID 10.11646/zootaxa.2861.1.1

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Megalomma lanigera ( Grube, 1846 )


Megalomma lanigera ( Grube, 1846)

Figures 13O–R View FIGURE 13 , 15A–J View FIGURE 15

Sabella lanigera Grube, 1846: 51 .

Branchiomma vesiculosum neapolitana Claparède, 1868: 164–166 , Pl. 22, Fig. 5 View FIGURE 5 fide Giangrande and Licciano, 2008: 209. Branchiomma köllikeri Claparède, 1869: 163–164 , Pl. 22, Fig. 4 View FIGURE 4 fide Giangrande and Licciano, 2008: 209.

Megalomma neapolitana .— Knight-Jones, 1997: 314.

Megalomma lanigera .— Giangrande and Licciano, 2008: 209–213, Figs 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 , 5C–D View FIGURE 5 .

Material examined. [ MCZ] 1517, topotypes, Gulf of Naples, Coll. Naples Zoological Station, label note R. V Chamberlin “Catalogue of worms” List # 1517 as Branchiomma köllikeri Claparède (3 specs). [ USNM] 97444, Aegean Sea, Gulf of Kassandra, Greece, Kassandra Peninsula, near the village of Kalithea, Coll. Lessios H, August 6, 1971, 4–5 m, as M. vesiculosum (2 specs).

Diagnosis. Eyes in most radioles (spherical, spiraled and oval); dorsal margins of collar fused to faecal groove; dorsal lappets and dorsal pockets present; thoracic chaetae Type B; abdominal chaetae narrowly hooded.

Description. Branchial crown longer than thorax with 23, 23, 17 pairs of radioles with brown bands. Outer surfaces of radioles quadrangular basally, rounded distally. Subdistal compound eyes present in most radioles. Dorsalmost pair of radioles with eyes distinctly larger, spherical, radiolar tips short ( Fig. 15G View FIGURE 15 ). Other dorsal eyes spiraled, decreasing towards lateral radioles and radiolar tips longer gradually towards lateral radioles ( Fig. 15 View FIGURE 15 ). Lateral radiolar eyes oval, smaller than dorsal radioles with radiolar tips longer than lateral radioles ( Fig. 15I View FIGURE 15 ). Ventral radioles with small spherical eyes and very long radiolar tips relative to eyes size ( Fig. 15J View FIGURE 15 ). Dorsal collar margins fused to faecal groove, forming a broad gap ( Figs 15A–B, D View FIGURE 15 ). Dorsal lappets highly developed, rounded, covering junction of crown ( Fig. 13O View FIGURE 13 , 15D View FIGURE 15 ). Dorsal pockets well developed, folded and deep ( Figs 13O–P View FIGURE 13 , 15A–B, D View FIGURE 15 ). Dorsal margins of collar higher than lateral margins ( Figs 13O, R View FIGURE 13 , 15D View FIGURE 15 ). Epithelium of dorsal pockets translucent and narrow, as a membrane, it is easily broken longitudinally ( Fig. 15A View FIGURE 15 ). Anterior peristomial ring exposed dorsally between dorsal pockets. Ventral lappets triangular, overlapFigs 13Q, 15C, E). Lateral collar margins not covering basal union of radioles ( Fig. 13R View FIGURE 13 , 15E View FIGURE 15 ). Caruncle absent. Keel absent. Dorsal lips erect, triangular about one-quarter length of branchial crown, with mid-rib and dorsal pinnular appendages ( Fig. 15F View FIGURE 15 ). Ventral lips, about one quarter length of dorsal lips, broadly rounded ( Fig. 15F View FIGURE 15 ). Ventral sacs present. Body long, depressed dorso-ventrally. Total thorax-abdomen length 63, 57, 48 mm, maximum width 5, 3.5, 3 mm throughout most of thorax. Six to eight thoracic chaetigers. Thoracic tori same length throughout. Tori in chaetigers 2–3 short, occupying a half of the distance between notopodia and ventral shield margins, not contacting shields ( Fig. 15E View FIGURE 15 ). Inferior thoracic chaetae Type B. Thoracic uncini with crest surmounted by 11 rows of numerous minute teeth, handles 2x length of main fang. Companion chaetae with teardrop-shaped membranes. Abdomen with 98, 84, 62 chaetigers. Abdominal chaetae narrowly hooded; chaetae in posterior row longer than those in anterior row. Abdominal uncini with main fang surmounted by nine rows of numerous minute teeth. Pygidium rounded. Tubes composed of sand grains.

Remarks. Sabella lanigera Grube, 1846 , and Branchiomma köllikeri Claparède, 1869 , were previously considered by Hartman (1959) as junior synonyms of Megalomma vesiculosum (Montagu, 1815) . Knight-Jones (1997) considered both specimens as the same species, but different from M. vesiculosum in having collar margins, especially those of the dorsal lappets, well above the junction between crown and thorax, and as a consequence she suggested that M. lanigera should be considered a subspecies of M. vesiculosum , and M. köllikeri a junior synonym of lanigera . Giangrande and Licciano (2008) based on examination of type material, confirmed the synonymy of S. lanigera , B. köllikeri and B. vesiculosum neapolitana but recognized the validity of M. vesiculosum as an independent taxon. Megalomma lanigera is a Mediterranean species; M. vesiculosum is distributed in north Atlantic waters.

In the genus Megalomma , ten species share the presence of dorsal lappets (see remarks on M. acrophthalmos ). Among these, M. lanigera , M. acrophthalmos , M. phyllisae and M. vesiculosum have the anterior peristomial ring exposed dorsally between dorsal pockets. Megalomma lanigera and M. vesiculosum the lateral collar margins not covering the basal union of radioles (these cover the basal union of radioles in M. acrophthalmos and M. phyllisae ). Megalomma lanigera differs from M. vesiculosum in having the ventral lappets triangular, overlapping (rounded, not overlapping in M. vesiculosum ) and the handle of thoracic uncini 2x the length of main fang (1.5x in M. vesiculosum ).


Museum of Comparative Zoology


Departamento de Geologia, Universidad de Chile


Royal British Columbia Museum - Herbarium


Smithsonian Institution, National Museum of Natural History














Megalomma lanigera ( Grube, 1846 )

Tovar-Hernández, María Ana & Carrera-Parra, Luis F. 2011

Megalomma lanigera

Giangrande, A. & Licciano, M. 2008: 209

Branchiomma vesiculosum neapolitana Claparède, 1868: 164–166

Giangrande, A. & Licciano, M. 2008: 209
Giangrande, A. & Licciano, M. 2008: 209
Claparede, E. 1869: 164
Claparede, E. 1868: 166

Sabella lanigera

Grube, A. E. 1846: 51