Megalomma heterops Perkins, 1984

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 : 35-37

publication ID

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

persistent identifier

https://treatment.plazi.org/id/03CF87C4-295C-1246-FF5C-5DDBFB7C44EE

treatment provided by

Felipe

scientific name

Megalomma heterops Perkins, 1984
status

 

Megalomma heterops Perkins, 1984

Figures 13F–N View FIGURE 13 , 14A–L View FIGURE 14 , 28C View FIGURE 28 , 29C View FIGURE 29

Megalomma heterops Perkins, 1984: 359–363 , Figs 42–43.— Tovar-Hernández and Salazar-Vallejo, 1996: 40–42, Fig. 9 View FIGURE 9 .

Type material examined. [ USNM] 54721, Acc. No. 324461, holotype, St. Lucie County, Hutchinson Island , E of FP and L Electric generation plant, 27° 20’ 24’’ N, 80° 13’ 04’’ W, Colls Gallagher, Hollinger & Cobb, September 15, 1971 GoogleMaps , Sta. 4, 12.1 m. [ USNM] 50480, Acc. No. 255041, one paratype, Florida, Whistle buoy, near alligator harbor, on sponge, Coll. Forbes M, July 02, 1958 . [ USNM] 54722, one paratype. [ USNM] 67953, Acc. 324461, five paratypes, 32.18 km W of Sanibel Island, 26° 24’ N, 82° 28’ W, Coll. Presley B., May 11, 1966 GoogleMaps , Sta. J. Hernan Cortez R / V, Project Hourglass, 18 m, on Solenastrea coral. [ FSBC] I 27696 View Materials , one paratype, St. Lucie Co., Hutchinson Island , 27° 20’ 24’’ N, 83° 13’ 04’’ W, Sta. 4, 12.1 m, Colls R. Gallagher & M. Hollinger, September 15, 1971 GoogleMaps . [ FSBC] I 27698 View Materials , one paratype, St. Lucie Co., Hutchinson Island , 27° 23’’ N, 80° 13’ 24’’ W, 11.2 m, Colls R. Gallagher & M. Hollinger, September 15, 1971 .

Additional material examined. [ ECOSUR] Mexican Caribbean , HOL–10, Holbox island, private pier, June 03, 2005, Colls. BYR & AR (1 spec.) . Xahuayxol , Colls SISV & LFCP, October 13, 1998 (1 spec.) . El Hueso, Campeche , Colls SISV & LFCP, May 25, 2005, 2 m (2 specs). [ OSCAR DIAZ, personal collection] Venezuela, Laguna Charupata, Coll. Liñero, April, 29, 1995 (1 spec.) . [ USNM] Florida , 090414, 29° 54’ 59’’N, 86° 04’ 59’’ W, November 1977, Sta. V –2528, MAFLA, 37 m, Acc. No. 332151 (1 spec.) GoogleMaps . 185970 Everglades National Parks , Shark river delta, March 25, 1965 (1 spec.) . Georgia , 186511, Sapelo Island , 4.5 mi and 160 degrees from Sapelo Whistle , Sta. 157, Coll. Gray M, November 15, 1961, 16.7 m, in bryozoans tubes (8 specs). Louisiana , 06785, South Tombalier lease area, 28° 34’ 09’’ N, 90° 24’ 32’’ W, Coll. SWR1 for MML Biofouling study, June 14, 1978, Sta. 04P, 45 m, Acc. 333929 (1 spec.) GoogleMaps . Panama, 182834, Margarita Island , 09° 23’ 02’’ N, 79° 53’ 54’’ W, STRI for MMS, September 4, 1986, oil spill project (2 specs). 073664, Galeta reef flat, Coll. Brattstrom, HO, 1973, Sta. 515–6, as M. vesiculosum (1 spec.) GoogleMaps .

Diagnosis. Eyes in most radioles (spherical); dorsal margins of collar fused to faecal groove; thoracic chaetae Type C; companion chaetae with tear-drop and sickle-shaped membranes; abdominal chaetae broadly hooded.

Description. Branchial crown longer than thorax with 13–16 pairs of radioles. Branchial crown with row of elongate pigment spots on fused portion below beginning of radioles ( Fig. 14B View FIGURE 14 ); 4–5 narrow, transverse, purple bands on radioles; bands formed of short pigmented areas on outer and lateral surfaces of radioles ( Fig. 14C–E View FIGURE 14 ), pigment not extending onto pinnules. Outer surfaces of radioles rounded. Subdistal compound eyes present in most radioles. Dorsalmost radioles with eyes greatly enlarged, spherical and short radiolar tips ( Fig. 14H View FIGURE 14 ). Others radioles with eyes much smaller, spherical, gradually decreasing ventrally. Radiolar tips increasing gradually towards ventral radioles ( Figs 13I–K View FIGURE 13 , 14I–L View FIGURE 14 ). Dorsal collar margins square, fused to faecal groove ( Figs 13F View FIGURE 13 , 14B, E–F View FIGURE 14 ). Dorsal lappets absent. Dorsal pockets well developed, U-shaped ( Figs 13F View FIGURE 13 , 14B, E–F View FIGURE 14 ). Ventral lappets triangular, overlapped slightly, as long as the ventral shield of collar ( Figs 13H View FIGURE 13 , 14C View FIGURE 14 ). Anterior peristomial ring exposed dorsally between dorsal pockets. Lateral collar margins covering the basal union of radioles ( Fig. 13G View FIGURE 13 ). Dorsal lips pigmented on upper surface, erect, triangular, with mid rib. Dorsal pinnular appendages present ( Fig. 14G View FIGURE 14 ). Ventral lips broadly rounded. Ventral sacs absent. Caruncle and keel absent. Body depressed with paired purple spots dorsally on anterior margin of collar segment below collar, paired spots on chaetigers 1–3 medial to notopodia ( Fig. 14E–F View FIGURE 14 ); some specimens with similar paired spots ventrally on anterior segments and small pigment spots below thoracic and above abdominal tori on posterior thoracic and abdominal segments. Total thorax-abdomen length 23 mm, 1.8 mm wide. Seven thoracic chaetigers. Thoracic tori of equal length in all segments. Tori in chaetigers 2–3 occupying three quarters of the distance between notopodia and ventral shield margins, not contacting shields ( Fig. 14C–D View FIGURE 14 ). Inferior thoracic chaetae Type C ( Fig. 28C View FIGURE 28 ). Thoracic uncini with crest surmounted by 9–10 rows of numerous minute teeth, handles 2x length of main fang ( Fig. 13L View FIGURE 13 ). Companion chaetae with tear-drop and sickleshaped membranes ( Figs 13N View FIGURE 13 , 29C View FIGURE 29 ). Abdominal chaetae broadly hooded. Abdominal uncini with main fang surmounted by nine rows of numerous minute teeth ( Figs 13M View FIGURE 13 , 29C View FIGURE 29 ). Pygidium broadly rounded with two groups of eyespots. Tube formed of small silicate sand grains in a rigid translucid matrix, with large shell fragments ( Fig. 14A View FIGURE 14 ).

Remarks. Megalomma heterops is unique among the species in the genus in having paired purple spots dorsally on anterior margin of collar segment below collar and paired spots on chaetigers 1–3 medial to notopodia. As above mentioned, 14 species of Megalomma have radiolar eyes in most radioles (Appendix 1, Character 3, State 2). Among these species, M. claparedei , M. heterops , M. lanigera , M. pacifici , M. sp., M. georgiense n. sp., M. nechamae , M. mushaense and M. vesiculosum the eyes of the dorsalmost radioles are spherical. Megalomma lanigera , M. sp., M. nechamae , M. mushaense and M. vesiculosum have dorsal lappets while these structures are lacking in M. heterops , M. claparedei , M. pacifici and M. georgiense n. sp. In M. georgiense n. sp., the dorsal collar margins of collar are not fused to faecal groove (fused in M. heterops , M. claparedei , M. pacifici ). Megalomma heterops and M. pacifici have anterior peristomial ring exposed dorsally between dorsal pockets (not exposed in M. claparedei ). Tori in chaetigers 2–3 in M. heterops occupies three quarters of the distance between notopodia and ventral shields, and shields are separated from tori (tori in chaetigers 2–3 occupy the entire distance between notopodia and ventral shield margins and all shields are in contact with tori in M. pacifici ).

USNM

Smithsonian Institution, National Museum of Natural History

R

Departamento de Geologia, Universidad de Chile

V

Royal British Columbia Museum - Herbarium

ECOSUR

El Colegio de la Frontera Sur (Mexico)

MML

Medical Microbiological Laboratory

MMS

Montshire Museum of Science

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Carabidae

Genus

Megalomma

Loc

Megalomma heterops Perkins, 1984

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

Megalomma heterops

Perkins, T. H. 1984: 363
1984