Megalomma splendidum ( Moore, 1905 )

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: 52-56

publication ID

http://doi.org/ 10.11646/zootaxa.2861.1.1

persistent identifier

http://treatment.plazi.org/id/03CF87C4-294D-1255-FF5C-5AD0FDEA43D5

treatment provided by

Felipe

scientific name

Megalomma splendidum ( Moore, 1905 )
status

 

Megalomma splendidum ( Moore, 1905)  

Figures 24A–J View FIGURE 24 , 25A–K View FIGURE 25 , 28F, H View FIGURE 28 , 29F View FIGURE 29

Pseudopotamilla splendida Moore, 1905: 564–566   , Pl. 37, Figs 23–27 View FIGURE 23 View FIGURE 24 View FIGURE 25 View FIGURE 26 View FIGURE 27 .

Pseudopotamilla anoculata Moore, 1905: 566–569   fide Hartman, 1959: 556.

Branchiomma disparoculatum Treadwell, 1914: 223–224   , Pl. 12, Figs 44–46 fide Hartman, 1956: 298.

Branchiomma burrardum Berkeley, 1930: 7–8   , Fig. 1 View FIGURE 1 fide Knight-Jones, 1997: 314.

Megalomma splendida   .— Rioja, 1962: 212–213, Figs 143–144.

Type material examined. [ ANSP] I 2205, syntype, Pseudopotamilla splendida Moore, 1905   , right side of branchial crown removed, left side in regeneration, posterior abdomen lost, Kassan Bay, Prince of Wales Island, Alaska, Albatross Sta. 4245, 173– 179 m, in a bottom of dark green mud and sand mixed with shell and rock fragments, July 11, 1903. [ USNM] 5534, holotype, Pseudopotamilla anoculata Moore, 1905   , with histolysis, tube complete, dissected transversally along the entire length, Vicinity of Naha Bay, Behm Cannal, Sta. 4230, 197– 438 m, SE Alaska. [ LACM – AHF] n 4257, 003463, lectotype, Branchiomma disparoculatum Treadwell, 1914   , designated in this study from San Diego, California. [ USNM] 32828, Acc. No. 256920, holotype, Branchiomma burrardum Berkeley, 1930   , Burrard inlet, British Columbia, September 15, 1928, Colls E. & C. Berkeley. [ USNM] 32829, Acc. No. 256920, two paratypes (one entire, second broken into two pieces), Branchiomma burrardum Berkeley, 1930   , Burrard inlet, off five fingers, British Columbia, June 5, 1929, lime, Colls E. & C. Berkeley.

Additional material examined. [ LACM – AHF] California, USA, Velero III   , 003438, Sta. 1417–41, 7.2 km NE of Sandy Point, Santa Rosa Island , 34º 04’ 30’’ N, 120º 13’ 14’’ W, September 16, 1941, 64 m, flat rocks (1 spec.). Velero III GoogleMaps   , 003440, Sta. 1151–40, SE end of Santa Catalina Island , 33º 15’ 55’’ N, 118º 13’ 50’’ W, July 5, 1940, 234 m (1 spec.). Velero III GoogleMaps   , 003441, Sta. 1123–40, off San Nicolas Island   , California, 33º 16’ 10’’ N, 119º 24’ 30’’ W, April 10, 1940, 56.6 m, sponge, rock (1 spec.). Velero III GoogleMaps   , 003443, Sta. 1384–41, 0.8 km. NE of Long Point, Santa Catalina Island , 33º 00’ 10’’ N, 118º 21’ 40’’ W, August 10, 1941, 199.3 m, green, sandy mud (1 spec.). Velero III GoogleMaps   , 003444, Sta. 1435–41, 2.4 km. SW off Santa Cruz Island , 33º 56’ 00’’ N, 119º 50’ 55’’ W, November 8, 1941, 87.7 m, mud, sponge (3 specs). Velero III GoogleMaps   , 003466, 2249, False Navaos , Departure Bay, BC, July 18, 1940 (1 spec.). Velero III   , 003467, n 4266 Monterrey Bay   , California, Colls Chin Yip & Ricketts, June 25, 1932, 64–128 m, rocky bottom (4 specs). Velero III   , Sta. 1010–39, F3352, off San Benito Islands , August 20, 1939, 28º 12’ 45’’ N, 115º 34’ 05’’ W, 173 m, fine green sand (4 specs) as E. tenella   . Velero III GoogleMaps   , Sta. 1252–41, T3280, 13.6   km. S of San Benito Islands , México, 28º 10’ 00’’ N, 115º 34’ 20’’ W, February 26, 1941, 131 m, coral sand, fine pebbles (2 specs) as E. tenella   . Velero III GoogleMaps   , Sta. 1304–41, 4.8 km. N of Arch Rock, Santa Cruz Island   , California, 34º 06’ 20’’ N, 119º 48’ 25’’ W, April 1941, 100 m, mud, broken shell (1 spec.). Velero IV, 003437, Cruise 324, Sta. 5502–57, 3.2 km, 246.5º, T GoogleMaps   . from Pt. Fermin Light, 33º 41’ 30’’ N, 118º 19’ 50’’, December 16, 1957, fine gray and silty sand (6 specs). Velero IV, 003445, Cruise 89, Sta. 2126–52, 14.8 km. 156.5º from Los Angeles lighthouse, 33º 34.5’ N, 118º 10’ 41’’ W, June 25, 1952, coralline clumps (1 spec.). Velero IV, 003446, Cruise 89, Sta. 2127- 52, 18 km 152º T GoogleMaps   . from Los Angeles Lighthouse , 33º 32’ 38’’ N, 118º 8’ 39’’ W, June 25, 1952, mud and sand (1 spec.). Velero IV, 003447, Cruise 132, Sta. 2436–53, 8.7 km 143º T GoogleMaps   . from Long Pt. Light, Santa Catalina Island, November 10, 1953 (1 spec.). Velero IV, 003448, Cruise 222, Sta. 3539–55 Santa Monica Bay   , California, 33º 54’ 18’’ N, 118º 33’ 18’’ W, 67.6 m, December 10, 1955, hung up on bottom, rocky bottom (1 spec.). Velero IV, 003491, Cruise 131, Sta. 2417–53, 3.4 km 261º T GoogleMaps   . from Pt. Fermin Light, California, 33º 41’ 57’’ N, 118º 20’ 8’’, September 29, 1953 (2 specs). Velero IV, Cruise 121, Sta. 2357–53, February 07, 1953, 1.7 km 252º T   . from Pt. Vicente Light, CA   , 33º 44’ 8’’ N, 118º 25’ 48’’ W (1 spec.). [ LACSD – MBL] GoogleMaps   California, USA, 0101–1B (1 spec.), 0704–10B (1 spec.), 0705– 10B (1 spec.), 0796–2B (1 spec.). [ CSD – MBL]   California, USA, PLOO   , P–207, Sta. A4– 3, 79 m, April 07, 1988 (2 specs), PSDBE   , P–207 Dup , Sta. PSDBE   8230, 112 m, August 16, 1994 (1 spec.), Bight 98, 981077, Sta. 2411, 89 m, August 06, 1998 (1 spec.), Bight 03, 3972, Sta. 4561, 119 m, August 19, 2003 (1 spec.), PLOO   , Sta. B10– 1, 120 m, July 23, 2007 (1 spec.), Sta. A4, 4, October 23, 1990, 80 m, DN (1 spec.), A4, 4, October 7, 1991, 79.5 m (1 spec.). [ CMN] Canada   , British Columbia, Straits of Georgia , 49º 23’ N, 123º 44.2’’ W, Coll. R   . M. O’Clair, 1976– 6, Sta. 74–21, Cat. 5542 (1 spec.). Swanson Bay , 53º 0’ 50’’ N, 128º 30’ 30’’ W, Coll. C. D. Levings, November 18, 1975, Sta. 51B, 005, Acc. 1979–191 (1 spec.). [ USNM] Canada, 5739, Gulf of Georgia , Halibut Bank GoogleMaps   , British Columbia, Sta. 4197, Coll. Str. Albatross, 1903, 164–85.9–56.6 m (1 spec.). 41506, Departure Bay   , British Columbia, April 16, 1937, as M. burrardum   (1 spec.). 41511, off Shake Island   , British Columbia, 109 m, July 7, 1926 (2 specs). 41510, Pendrell harbor, Vancouver Island, June 6, 1960, Coll. Quayle (2 specs). 41509 Head of Princess Louise inlet   , British Columbia, 36.5 m, August 15, 1934 (2 specs). Washington, 38237, Puget Sound Washington, Sta. 4, 47° 44’ 31’’ N, 122° 32’41’’ W, Haul 6, 12 m, January 9, 1963, Coll. K. Banse (2 specs). California , 123272, 41° 30’ 51’’ N, 124° 21’ 38’’ W, Coll. Saic & Mec for MMS GoogleMaps   , November 22, 1987, Sta. SB 05, 95 m (1 spec.). 41508, Monterey Bay, 91–109 m, August 15, 1932, Coll. McGinites (1 spec.). 41507, Pacific Grove, California , November 25, 1960, Coll. McLean (2 specs)   .

Diagnosis. Eyes in dorsalmost, second or third dorsal radioles (spiraled); dorsal margins of collar fused to faecal groove; thoracic chaetae Type B; companion chaetae with teardrop and sickle-shaped membranes; abdominal chaetae narrowly hooded.

Description. Branchial crown longer than thorax with 33–34 pairs of radioles (20 pairs in syntype). Radioles with 4–6 purple bands distributed over outer and lateral radiole margins and adjacent pinnules. Outer surfaces of radioles quadrangular basally, rounded distally. Sub-distal spiraled compound eyes, present in dorsalmost radiolar pair ( Figs 24G View FIGURE 24 , 25F View FIGURE 25 ), sometimes also in the second ( Figs 24H View FIGURE 24 , 25G View FIGURE 25 ) or third dorsalmost radiolar pairs ( Figs 24I View FIGURE 24 , 25H View FIGURE 25 ). All radioles with short tips. Dorsal collar margins rounded posteriorly, fused to faecal groove, forming narrow gap ( Fig. 24B View FIGURE 24 ). Dorsal lappets absent. Dorsal pockets well developed, U-shaped ( Figs 24B View FIGURE 24 , 25C View FIGURE 25 ). Lateral collar margins not covering the bases of radioles ( Figs 24B–C View FIGURE 24 , 25A–B View FIGURE 25 ). Ventral rounded lappets, not overlapping ( Figs 24A, D View FIGURE 24 , 25A View FIGURE 25 ). Anterior peristomial ring exposed dorsally between dorsal pockets ( Fig. 24B View FIGURE 24 ). Dorsal lips erect, triangular, long, with mid-rib and dorsal pinnular appendages ( Fig. 25E View FIGURE 25 ). Ventral lips rounded with ventral parallel lamellae well developed, completely concealed by ventral collar margin ( Fig. 24D View FIGURE 24 ). Ventral sacs present ( Fig. 24D View FIGURE 24 ). Caruncle absent. Keel unknown. Total thorax-abdomen length 46–134 mm (57 mm in syntype), maximum width 2–6 mm throughout most of thorax (3.5 mm in syntype). Six-10 thoracic chaetigers (8 in syntype). Thoracic tori longest on chaetigers 2–3. Tori in chaetigers 2–3 occupy the entire distance between notopodia and ventral shield margins ( Fig. 24A, C, E View FIGURE 24 ), contacting shields. Thoracic fascicles ( Fig. 24F View FIGURE 24 ) with superior group of elongate, narrowly hooded chaetae; and inferior group of chaetae Type B ( Fig. 28F View FIGURE 28 ). Thoracic uncini with crest surmounted by 9–10 rows of numerous minute teeth, handles 2x length of main fang and extending beyond the base of shaft of companion chaetae ( Fig. 24I View FIGURE 24 ). Companion chaetae with teardrop and sickle-shaped membranes within the same torus ( Fig. 24I View FIGURE 24 , 29F View FIGURE 29 ). Abdomen with 80–144 chaetigers (59 in syntype but it is incomplete). Abdominal chaetae narrowly hooded ( Fig. 28H View FIGURE 28 ). Chaetae from posterior abdomen twice longer than those in anterior abdomen. Abdominal uncini with main fang surmounted by 7–8 rows of numerous minute teeth ( Fig. 25K View FIGURE 25 ). Pygidium rounded. Soft tubes with fine sand grains, some covered with sponges, small anemones and calcareous algae.

GAMETES: Sperm in posterior abdomen with a rounded nucleus, small acrosome, two rounded mitochondria and a long flagellum ( Fig. 25J View FIGURE 25 ).

Remarks. In this study, the synonymies of M. splendidum   with M. disparoculatum   by Hartman (1956), and of M. splendidum   with M. anoculata ( Moore, 1905)   by Hartman (1959) were corroborated based on examination of type material. Based on comparison of figures of M. splendidum   and M. burrardum ( Berkeley, 1930)   , Knight-Jones (1997) suggested a new synonymy for these two species. In this study, examination of holotype and paratypes of M. burrardum   confirms the synonymy suggested by Knight-Jones (1997).

Rioja (1947: 214–215) recorded M. mushaense Gravier   from La Paz (Baja California Sur); later in 1962 he corrected this identification to M. splendidum   and recorded some specimens from Macapule (Sinaloa) and Salina Cruz (Oaxaca). Re-examination of Rioja’s material was not possible since its collection is lost.

Megalomma splendidum   and M. inflata   have spiraled eyes in 1–3 dorsalmost radiolar pairs; but the ventral lappets are rounded and as long as the ventral shield of collar in M. splendidum   (triangular, longer than the ventral shield of collar in M. inflata   ); the length of thoracic torus in chaetigers 2–3 occupy the entire distance between notopodium and ventral shield margins (occupying ¾ in M. inflata   ) and all ventral shields are in contact with tori (separated from tori in M. inflata   ).

ANSP

Academy of Natural Sciences of Philadelphia

USNM

Smithsonian Institution, National Museum of Natural History

LACM

Natural History Museum of Los Angeles County

AHF

Allan Hancock Foundation, University of Southern California

T

Tavera, Department of Geology and Geophysics

CA

Chicago Academy of Sciences

MBL

Museu Nacional de Historia Natural

CMN

Canadian Museum of Nature

R

Departamento de Geologia, Universidad de Chile

MMS

Montshire Museum of Science

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Carabidae

Genus

Megalomma

Loc

Megalomma splendidum ( Moore, 1905 )

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

Megalomma splendida

Rioja, E. 1962: 212
1962
Loc

Branchiomma burrardum

Berkeley, E. 1930: 8
1930
Loc

Branchiomma disparoculatum

Hartman, O. 1956: 298
Treadwell, A. L. 1914: 224
1914
Loc

Pseudopotamilla splendida

Moore, J. P. 1905: 566
1905
Loc

Pseudopotamilla anoculata

Hartman, O. 1959: 556
Moore, J. P. 1905: 569
1905