Dasychone bairdi McIntosh, 1885: 495–497 Branchiomma sp. A Monro 1933a: 267 Species of Branchiomma (Polychaeta: Sabellidae) from the Caribbean Sea and Pacific coast of Panama Tovar-Hernández, María Ana Knight-Jones, Phyllis Zootaxa 2006 2006-05-01 1189 1 1 37 N6NH (McIntosh, 1885) McIntosh 1885 [264,737,1364,1390] Polychaeta Sabellidae Branchiomma Animalia Sabellida 12 13 Annelida species bairdi   Figures 3A–D, H–K, 9C–D, 10C, 11B, with figures 3E–G representing  Branchiommasp. A.      Dasychone bairdi McIntosh, 1885: 495–497, pl. 30A, figs 13–15; pl. 39A, figs 2, 9, Bermuda(only two syntypespresent, one is  Branchiommasp. A, and the other is here designated lectotype.—  Monro 1933a: 267, Dry Tortugas, Florida.   Material examined Type material:   Dasychone bairdi McIntosh, 1885,  lectotype[ NHML1885.12.1.391] Bermudashore,  June 1873, “Challenger” ( MAT­H& PK­J). Non­type material:   Florida( Monro 1933a) [ NHML1932.12.22.91–102, PK­J] Dry Tortugas, stns 328 & 347). Newmaterial ( MAT­H):  Mexican Caribbean[ ECOSUR] Rio Huach, 18° 25’ 22” N, 87° 46’ 13” W, SAT6­0398, Coll. J. Schmitter(1). Isla Contoy, Camping, 21° 30’ 8.4’’ N, 86° 47’ 45.3’’ W, Coll. M. A. Tovar,  March 01, 2001, 1 m (1);  Coll. V. Delgado,  March 01, 2001, 1 m (3);  Coll. J. R. Bastida,  Feb. 21, 1999,  1 m(1);   Feb. 22, 1999,  1 m(1).  Hualalpich, Bahía Ascención, 19° 59’ 37.9’’ N, 87° 27’ 52’’ W, Coll. M. A. Tovar,  June 19, 1986,  1 m(1).  Holbox, 21° 31’ 24’’ N, 87° 22’ 42’’ W, Coll. S. I. Salazar,  May 04, 2000, 1 m (12).  San Felipe, 21° 27’ N, 88° 06’’ W, Coll. J. R. Bastida& S. I. Salazar,  Feb. 19, 1999,  1 m(6).  Celestún, 20° 53’ N, 90° 21’ W, Coll. J. R. Bastida& S. I. Salazar,  Feb. 17, 1999,  1 m(1).  Isla Mujeres, Bajo Pepito, 21° 13’ 39.7’’ N, 86° 43’ 53.5’’ W, Coll. M. Díaz, July  1997, 1 m (42);   Feb. 5, 1997,  1 m(1).  Cancún, Laguna Nichupté, 21° 06’ 11.6’’ N, 86° 47’ 21.1’’ W, E2M1+1, July05,  1 m(2).   Panama[ ECOSUR] Fuerte Sherman, Colon, Tercer Arroyo, 09° 33.2’ N, 79° 39.6’ W, Coll. S. I. Salazar,  June 2, 2002,  1 m(32); LH02­756E, Coll. L. Harris, June 2, 2002(1); Club Nautico,  Colon, 09° 21.8’ N, 79° 53.7’ W, Coll. S. I. Salazar,  June 3, 2002,  1 m(13).   Lesser Antilles[ ZMA] V. Pol.181, Curaçao, Yacht Chazalie Marguerita, C. J.van der Horst,  Jan. 24, 1896, in lagoon (4). V. Pol.0068.01, Curaçao, Spaansche Water,  Coll. C. J. van der Horst,  Apr. 8, 1920, in mangrove roots (1);  Apr. 19, 1920(3);  Apr. 25, 1920(50). V. Pol.1677, Jamaica, Kingston Harbour, Fortrocky lagoon, W of airport, Coll. P. Wagenaar Hummelinck, May 7, 1973,  Rhizophoratimber, muddy sand and coral debris, decaying wood, 0–1 m(55).  V. Pol.1008, Aruba, Spaans Lagoen, NWside,  Coll. P. Wagenaar Hummelinck,  Jan. 1, 1949, limestone shore of muddy lagoon with many algae near  Rhizophora(23). V. Pol.1674, Saint­Thomas, Benner BayLagoon,  0–1 m, Coll. P. Wagenaar Hummelinck, Apr. 30, 1973,  Rhizophorain sandy mud (27).  Description   Dasychone bairdias originally described by McIntosh was based on specimens of two species. The following redescription is based on the lectotypedesignated here (see remarks for comments on selection). Small thin worm with body (excluding crown) 15 mmlong, 1.7 mm wide; crown 10 mmlong ( Fig. 3B). Radiolar crown united at base by short web, bearing 20 radioles with apinnulate tips and stylodes. Basal stylode small, unpaired and digitiform. Stylodes: 26 pairs [s, s, s, s, s, s, s, s, m, m, m, m, m, L, m, m, XL, m, m, m, m, L, s, s, s, s]. Macrostylodes strap­like ( Fig. 9D) up to four times as long as neighbouring pairs, mostly in distal half of radiole ( Fig. 3A), with remaining stylodes digitiform ( Fig. 9C); all stylodes about one third width of rachis ( Fig. 9C–D). Eyes small and compound (with sub­conical lenses), not present between last four pairs of stylodes. Dorsal lips long and tapered, supported by longitudinal ridge (mid­rib) about one half length of radioles. Dorsal collar with free well separated margins each side of midline faecal groove ( Fig. 3C), lateral margins above junction with crown and thorax ( Fig. 3D), ventral lappets triangular and well spaced at the midline ( Figs 3B). Thorax with nine segments with interramal dark spots. Ventral shields subquadrangular, anterior margin of first shield fairly straight ( Fig. 3G). Collar chaetae slender, weakly geniculate, arranged in compact fascicles. Thoracic notochaetae arranged within each fascicle in irregular oblique rows of superior and inferior chaetae ( Fig. 10C); each superior chaeta slender, weakly geniculate, knee region slightly wider than shaft; inferior chaetae with knee up to twice as wide as shaft ( Fig. 3K). Thoracic tori abutting ventral shields; avicular uncini with the crest surmounted by two rows of teeth (side view), occupying about one third of crest ( Fig. 3H), with three distinct teeth in anterior row and a few very small teeth above ( Fig. 11B). Abdomen with about 70 segments, tori smaller than most in thorax. Fascicles of abdominal chaetae forming compact tufts, with outer geniculate chaetae arranged in C­shaped arcs around clusters of more slender capillary chaetae; number of chaetae per fascicle decreases gradually towards posterior. Abdominal uncini similar to those in thorax ( Fig. 3J). Faecal groove passes around right side of body from the last thoracic segment to second segment of ventral abdomen ( Fig. 3D) and on to bilobed pygidium. In Mexican material body dark olive­green with small brown spots over the whole body. Interramal dark spots present, larger on first thoracic segments and progressively smaller toward the posterior region. Crown with olive­green bands around the radioles, each band occupying space of three pinnules, crown base bearing longitudinal bands of diffuse brown spots in line with each radiole axil. Midline ridge of dorsal lips orange and an orange spot between each pair of eyes.  Remarks Two original syntypesof  Branchiomma bairdi(McIntosh NHML1885.12.1.391) with a label “Redet. by Prof J. H. Day as identical with  D. nigromaculata Baird 1865” were examined. Both specimens have radioles with strap­like macrostylodes, that agree with McIntosh’s original radiole illustration ( Fig. 2, pl. 39A), which are much longer than those of  B. nigromaculatum(see above). The smaller more slender syntypeis here designated as lectotype[ NHML1885.12.1.391], because of McIntosh’s comments: “The long radioles are more flexible than usual so that they form a lax brush anteriorly.” and later “The flexibility of the radioles is apparently due to the diminution or alteration of the barred cartilaginous axis.” The crown of the designated lectotypeis certainly unusual in that the radioles have a springy quality, differing from those of the other syntype. The lectotypealso differs in having a fairly long narrow thorax, with length of the ventral shields no more than half the breadth (c.f. Figs 3B &G). The paralectotype, now labelled  Branchiommasp. A[ NHML1885.12.1.391], is incomplete, the abdomen having been removed behind the 6 thabdominal segment ( Fig. 3G). It differs from the lectotypein having a thorax with size and proportion similar to that of  Branchiomma nigromaculatum(c.f. Fig. 1G and Fig. 3G). It would have been this specimen that influenced, Day (1955)to wrongly suggest synonomy with  B. nigromaculatum( Baird, 1865), but  B. nigromaculatumdiffers from  Branchiommasp. A, in having narrower thoracic shields, compared with body width, fleshy ventral collar lappets touching at the midline and much shorter macrostylodes. McIntosh’s histology, gut content observations and figures must have come from  Branchiommasp. A. because of the evidence of sectioning, but the rest of his text description could apply to either species. McIntosh noted the average measurements of  B. bairdiindicating that he originally had examined more specimens than two.  Monro (1933b)mentioned that his material differed from McIntosh’s description only in that they tend to be smaller and Monro’s collections (e. g. from stations 328 & 347, NHML 1932 12. 22, 91–102) agree well with the lectotype. He regarded McIntosh’s illustration of a single pair of more­distal stylodes (each wider with an embayed distal margin ( Fig. 9, pl. 39A), as erroneous. Such stylodes were not seen in Monro’s abundant material ( PK­J), but similar macrostylodes occur in  B. conspersum(see below). McIntosh (1885, at the start of his description of  B. bairdi) lists figures 5 and 6 from plate 38A as referring to  B. bairdi, but the legend for those figures uses the name  Dasychone occidentalis.There is no such species, either in the genus  Branchiommaor described in his monograph.  Augener (1918)at first wrongly recorded  B. bairdi(as  Dasychone) from the Ivory Coast. He described and figured (Fig. 230, pl. 7) a pair of broad stylodes each with an undulating distal border, similar to some of those found in  B. conspersum( Fig. 4H, J). After looking at West Indian material Augener (1922b)realised that his 1918 West African material was different and he then called it  Dasychone pseudoviolacea.It is in fact very different, because the dorsal collar margins are fused to the sides of the faecal groove ( ZMUH  V1788, PK­J) as in Group A. His 1922 records of  Dasychone bairdifrom Tortugas, Saint­Thomas, Jamaica, Haiti, Mexico, and Veracruzmay well be correctly identified, but the material has not been examined by us.  Johansson (1927)was the first to give the new combination of  Branchiomma bairdi. Rioja (1951)recorded  B. bairdifrom Isla Sacrificios ( Veracruz, Mexico). His specimens ( 5–20 mmlength, 1–2.5 mm width) were similar in size to the Bermudan lectotype. Day (1955)wrongly synonymised  B. bairdiwith  B. nigromaculatum. Hartman (1951: 115)recorded  B. bairdifrom the Gulf of Mexico, but later (1959: 537), probably following Day (1955), listed the species as a possible synonym of  B. nigromaculatum. Jones (1962)also wrongly synomyised  B. bairdi(and  B. conspersum), with  B. nigromaculatum. The most distinctive character separating  Branchiomma bairdifrom  B. nigromaculatumand other species studied here are the slender springy radioles bearing long strap­like macrostylodes on the distal half of the radiole. These are up to four (or more) times the length of the smallest stylode. They may vary in size amongst themselves, but they are always much longer than other stylodes on the radiole, including their immediate neighbours. Other differences from  B. nigromaculatum, apart from size, are that the ventral collar lappets are less fleshy and more pointed and the uncini bear two rows of crest teeth.  DistributionThe present studies show that this species is widely distributed in tropical North American waters from Bermudain the north, Florida, Lesser Antilles, Veracruz in the Gulf of Mexico, Mexican Caribbean and Pacific Panamain the south. 1873-06 NHML, MAT-H, PK-J Bermuda Bermuda 12 13 1 lectotype 2001-03-01 NHML, PK-J, MAT-H, ECOSUR Coll. J. Schmitter & Isla Contoy & Camping & Coll. M. A. Tovar Florida 13 14 21.502333 New 1 -86.79591 Dry Tortugas 12 13 1 [264,759,324,350] 2001-03-01 V Coll. Delgado 13 14 1 [772,1259,324,350] 1999-02-21 R Coll. J. 1 Bastida 13 14 1 1999-02-22 R Coll. J. 1 true Bastida 13 14 1 1986-06-19 Coll. M. A. Tovar 1 19.993862 Bahia Ascencion 14 -87.46444 Hualalpich 13 14 1 2000-05-04 Coll. S. I. Salazar 21.523333 Holbox 21 -87.378334 13 14 1 1999-02-19 R Coll. J. & Bastida & S. I. Salazar 1 21.45 San Felipe 13 14 1 1999-02-17 R Coll. J. & Bastida & S. I. Salazar 1 20.883333 Celestun 1266 -90.35 13 14 1 Coll. M. Diaz 1997 21.227695 Bajo Pepito 1 -86.73153 Isla Mujeres 13 14 1 [840,1110,564,590] 1997-02-05 Coll. M. Diaz 1 true 21.227695 Bajo Pepito 1 -86.73153 Isla Mujeres 13 14 1 July 1 21.103222 Laguna Nichupte 1 -86.78919 Cancun 13 14 1 2002-06-02 ECOSUR Coll. S. I. Salazar Panama 1 9.553333 Tercer Arroyo 129 -79.66 Fuerte Sherman 13 14 1 Colon [375,1318,724,750] 2002-06-03 Coll. S. I. Salazar Panama 1 9.363334 Colon 129 -79.895 13 14 1 Colon 1896-01-24 ZMA, V Lesser Antilles & Curacao & Yacht Chazalie Marguerita, C. J. & Horst Panama Pol. Curacao Pol. 13 14 1 Colon 1920-04-08 1920-04-25 1920-04-08 V Coll. C. J. van der Horst Panama Pol. Kingston Harbour Jamaica 13 14 1 Colon [629,1214,964,990] V Spaans Lagoen, NW Panama Aruba Pol. 13 14 1 Colon 1949-01-01 V Coll. P. Wagenaar Hummelinck Panama Pol. 5 Benner Bay Saint-Thomas 13 14 1 Colon