Harmothoe magellanica ( McIntosh, 1885 )

Barnich, R., Fiege, D., Micaletto, G. & Gambi, M. C., 2006, Redescription of Harmothoe spinosa Kinberg, 1856 (Polychaeta: Polynoidae) and related species from Subantarctic and Antarctic waters, with the erection of a new genus, Journal of Natural History 40 (1 - 2), pp. 33-75 : 52-55

publication ID	https://doi.org/ 10.1080/00222930500445044
persistent identifier	https://treatment.plazi.org/id/AD336007-FFF7-FFE4-FE10-FF5C90604192
treatment provided by	Felipe
scientific name	Harmothoe magellanica ( McIntosh, 1885 )
status

Treatment

Harmothoe magellanica ( McIntosh, 1885) View in CoL

( Figures 6A–L View Figure 6 , 7A, B View Figure 7 ; Table III)

Lagisca magellanica McIntosh 1885, p 82 View in CoL , Plate 13 Figure 5 View Figure 5 , Plate 18 Figures 3 View Figure 3 , 4 View Figure 4 , Plate 7A Figures 1 View Figure 1 , 2 View Figure 2 .

Harmothoe magellanica: Bergström 1916, p 280 View in CoL , Plate 4 Figures 1–3 View Figure 1 View Figure 2 View Figure 3 ; Uschakov 1962, p 150, Plate 2 Figures A, B, Plate 3 Figure H; Averincev 1972, p 117, Plate 9 Figures 1–5 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 .

Harmothoe cf. magellanica: Stiller 1996, p 36 View in CoL , Plate 17.

Lagisca magellanica murrayi McIntosh 1885, p 83 View in CoL , Plate 19 Figure 1 View Figure 1 , Plate 9A Figures 13 View Figure 13 , 14.

Lagisca magellanica grubei McIntosh 1885, p 84 View in CoL , Plate 3 Figure 5 View Figure 5 , Plate 18 Figure 2 View Figure 2 , Plate 7A Figures 14–16.

Hermadion molluscum Ehlers 1897, p 16 View in CoL , Plate 1 Figures 1–8 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 .

Harmothoe molluscum: Averincev 1972, p 118 View in CoL , Plate 9 Figures 6–9 View Figure 6 View Figure 7 View Figure 8 View Figure 9 .

Hermadion ambiguum Ehlers 1901a, p 209 View in CoL .

Harmothoe brevipalpa Bergström 1916, p 277 View in CoL , Plate 2 Figure 1 View Figure 1 , Plate 4 Figures 4–7 View Figure 4 View Figure 5 View Figure 6 View Figure 7 ; Augener 1932a, p 100; Monro 1936, p 86, Figure 5 View Figure 5 . [new synonymy]

Harmothoe impar notialis Monro 1930, p 58 View in CoL , Figure 13a–d View Figure 13 ; Hartman 1964, p 31, Plate 7 Figures 9–10 View Figure 9 View Figure 10 .

Harmothoe (Harmothoe) spinosa Gruppe B View in CoL : Hartmann-Schröder and Rosenfeldt 1988, p 31, Plate 2 Figures 3–8 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 . [not H. spinosa Kinberg, 1856 View in CoL ]

Type material

Lagisca magellanica: BMNH 85.12.1.69, lectotype (cs in two fragments; designated, described, and figured herein), ‘‘Challenger’’ Expedition, St. 149H, 48 ° 459S, 69 ° 149E, Kerguelen, off Christmas Harbour, 29 January 1874, 127 fathoms, volcanic mud. BMNH 85.12.1.74, five paralectotypes (4 af, 2 mf, 1 pf), ‘‘Challenger’’ Expedition, St. 308, 50 ° 89300S, 74 ° 419W, Magellan Strait, 5 January 1876, 175 fathoms, blue mud.

Lagisca magellanica murrayi: BMNH 85.12.1.62, one syntype (af, 2 mf), ‘‘Challenger’’ Expedition, St. 310, 51 ° 279300S, 74 ° 39W, Magellan Strait, 10 January 1876, 400 fathoms, blue mud.

Lagisca magellanica grubei: BMNH 85.12.1.64, six syntypes (6 af, 3 pf), ‘‘Challenger’’ Expedition, St. 145A, 46 ° 419S, 38 ° 109E, off Prince Edward Island, 27 December 1873, 310 fathoms, volcanic sand.

Hermadion molluscum: ZMH V 1192 , holotype (cs), South Georgia, on stones.

Hermadion ambiguum : SMNH-type-2471, three syntypes (3 cs), SMNH-type-2472, two syntypes (1 cs, 1 af), SMNH-type-2473, two syntypes (2 cs), Argentina, Patagonia , Puerto Madryn, 8 and 9 November 1895, 1–5 fathoms, sandy bottom, at low tide, leg. Nordenskjöld.

Harmothoe brevipalpa : SMNH-type-591, holotype (af, juvenile), Swedish South Polar Expedition 1901–03, St. 13, 54 ° 509S, 68 ° 169W, South America, Patagonia archipelago, off Ushuaia, 15 March 1902, 8 m, shells, debris, and algae.

Additional published material

Harmothoe (Harmothoe) spinosa Gruppe B (published in Hartmann-Schröder and Rosenfeldt 1988; only specimens with elytra considered): two spms ZMH P-19291, Antarktis ANT III/2 Expedition, RV Polarstern/Polarfuchs, St. PF-001, Arctowsky, off Shag Point/Ragusa, 1984, 20 m; 15 spms ZMH P-19309, Antarktis ANT III/2 Expedition, RV Polarstern, St. PS-06/207, 62 ° 599S, 57 ° 059W, Bransfield Strait, 3 December 1984, 68 m.

Additional material. One spm., SMF 15163 (cs), ANT XIII/3, 39/005, EBS; one spm. (cs), ANT XIII/3, 39/005 EBS; one spm. (af), ANT XIII/3, 39/005, EBS; two spms (cs) ANT XIII/3, 39/005, EBS; one spm. (af, mf), ANT XIII/3, 39/007, EBS; four spms (3 cs, 1 af), ANT XIII/3, 39/007, EBS; one spm. (af, pf, several mf missing), ANT XIII/3, 39/009, AGT; nine spms (2 cs, 7 af), ANT XIII/3, 39/011, GSN; five spms (cs), ANT XIII/3, 39/024, AGT.

Diagnosis

Outer lateral elytral margin and posterior half of surface with few digitiform papillae; anterior half of elytra covered with conical microtubercles, number of microtubercles and surface covered variable (papillae and microtubercles missing in posterior elytra).

Description (based on lectotype of Lagisca magellanica )

Body with 42 segments. At anterior end ( Figure 6A View Figure 6 ), prostomium bilobed, with cephalic peaks; ceratophore of median antenna in anterior notch, lateral antennae inserted ventrally, styles of antennae missing in lectotype; anterior pair of eyes situated dorsolaterally on widest part of prostomium, posterior pair dorsally near hind margin of prostomium; palps missing. [Prostomial and tentacular appendages present in some of the paralectotypes: styles of antennae and tentacular cirri papillate, abruptly tapering subdistally; palps papillate, tapering.]

Tentaculophores inserted laterally to prostomium, each with a single notochaeta and a dorsal and ventral tentacular cirrus with styles of cirri missing. Second segment with first pair of elytra (missing in lectotype), biramous parapodia, and long buccal cirri.

Fifteen pairs of elytra, covering dorsum, on segments 2, 4, 5, 7, then on every second segment to 23, 26, 29, 32; last 10 segments cirrigerous; few digitiform papillae present at outer lateral margin of elytra and on posterior half of elytral surface, in posterior elytra papillae missing at margin; anterior half of elytra covered with conical microtubercles; number of microtubercles and surface covered variable, diminishing from anterior to posterior elytra; posteriormost elytra without microtubercles ( Figure 6B–D View Figure 6 , 7A, B View Figure 7 ). Cirrigerous segments with distinct dorsal tubercles; dorsal cirri with cylindrical cirrophore, style papillate, abruptly tapering subdistally ( Figure 6E View Figure 6 ).

Parapodia biramous; notopodia with elongate acicular lobe; neuropodia with elongate prechaetal acicular lobe with digitiform supra-acicular process; neuropodial postchaetal lobe shorter than prechaetal lobe, rounded; tips of noto- and neuroacicula penetrating epidermis ( Figure 6F View Figure 6 ). Notochaetae of about same width as neurochaetae; notochaetae with distinct rows of spines and blunt tip ( Figure 6G, H View Figure 6 ); neurochaetae falcate, with rows of spines distally, uppermost row with one or two stout spines; tip of neurochaetae bidentate with stout secondary tooth, some lower neurochaetae with unidentate tip ( Figure 6I–L View Figure 6 ).

Nephridial papillae distinct from segment 12 (in other investigated specimens distinct generally from segment 6).

Measurements

Lectotype of Lagisca magellanica (BMNH 85.12.1.69), figured herein, cs in two fragments ( Figure 6 View Figure 6 ): L 23 mm, W 5.5 mm for 42 segments. Additional specimen from the Weddell Sea (SMF 15163) figured herein, cs ( Figure 7 View Figure 7 ): L 26 mm, W 7 mm for 39 segments. Further measurements: paralectotype of L. magellanica (BMNH 85.12.1.74), af: L 17 mm, W 6 mm for 25 segments; syntype of L. magellanica murrayi (BMNH 85.12.1.62), af: L 7 mm, W 8 mm for 11 segments; largest syntype of L. magellanica grubei (BMNH 85.12.1.64), cs in two fragments: L 48 mm, W 7 mm for 47 segments; holotype of Hermadion molluscum (ZMH V 1192) , cs: L 35 mm, W 7 mm for 52 segments; largest syntype of Hermadion ambiguum (SMNH-type-2471), cs: L 24 mm, W 9 mm for 41 segments.

Remarks

As described above for the lectotype of L. magellanica , the area covered by the microtubercles on the elytral surface and by the papillae at the elytral margin varies depending on the position of the elytron on the body. Furthermore, we observed also an individual variability regarding these characters in the investigated type and additional material, some specimens showing a larger area covered by the tubercles in anterior elytra, while in others the area covered is reduced to an anterior patch.

Having studied the type material listed above we confirm the opinion of Bergström (1916) that Lagisca magellanica murrayi McIntosh, 1885 , L. magellanica grubei McIntosh, 1885 , Hermadion molluscum Ehlers, 1897 , and H. ambiguum Ehlers, 1901 are junior synonyms of Harmothoe magellanica .

Ehlers (1897) considered L. magellanica and the two subspecies murrayi and grubei to be junior synonyms of H. spinosa Kinberg, 1856 . But, as we demonstrated above, H. spinosa mainly differs from H. magellanica in the presence of elongate, conical macrotubercles near the posterior elytral margin and microtubercles covering more or less the complete elytral surface, while in H. magellanica macrotubercles are missing, and microtubercles are present only in the anterior half of the elytron.

Distribution

Magellan region : Magellan Strait and South Patagonia ; Subantarctic region : Kerguelen Islands (type locality) and Prince Edward Island; Antarctic region: South Georgia, Antarctic Peninsula, and Weddell Sea (cf. also Stiller 1996) .