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