Tubulanus rhabdotus Corrêa, 1955

Mendes, Cecili B., Matthews-Cascon, Helena & Norenburg, Jon L., 2016, New records of ribbon worms (Nemertea) from Ceará, Northeast Brazil, Zootaxa 4061 (2), pp. 146-156 : 148

Tubulanus rhabdotus Corrêa, 1955

( Figure 2 [1])

Tubulanus rhabdotus: Corrêa, 1955: 12 , pl. 1, figs 1–6, pl. 2, figs 7–9, pl. 3, figs 10, 11, pl. 4, figs 12–18; Corrêa, 1961: 5, figs 5, 6; Corrêa, 1963: 42; Fox & Ruppert, 1985: 37; Norenburg, 1985: 40, fig. 4; Jespersen & Lützen, 1987: 187; Jespersen, 1994: 124; Gibson, 1995: 531; Reunov & Klepal, 1997:132; Stricker et al. 2001: 225; Thollesson & Norenburg, 2003: 409; Ritger & Norenburg, 2006: 932; Santos & Norenburg, 2011.

Material examined. One specimen, MZUSP 0 0 0 0 1, Brazil, Ceará, São Gonçalo do Amarante, Pecém harbor, 3°32.08’ S 38°47.78’ W, on settlement plates, coll. PROCAD team, 29.I.2010.

Two specimens, MZUSP 0 0 0 0 2, Brazil, Ceará, São Gonçalo do Amarante, Pecém harbor, 3°32.08’ S 38°47.78’ W, on settlement plates, coll. PROCAD team, 13.X.2010.

Three specimens, MZUSP 0 0 0 0 3, Brazil, Ceará, São Gonçalo do Amarante, Pecém harbor, 3°32.08’ S 38°47.78’ W, on settlement plates, coll. PROCAD team, 12.VIII.2011.

One specimen, MZUSP 0 0 0 0 4, Brazil, Ceará, São Gonçalo do Amarante, Pecém harbor, 3°32.08’ S 38°47.78’ W, on settlement plates, coll. PROCAD team, 01.IX.2011.

One specimen, MZUSP 0 0 0 0 5, Brazil, Ceará, São Gonçalo do Amarante, Pecém harbor, 3°32.08’ S 38°47.78’ W, on settlement plates, coll. PROCAD team, 01.XI.2011.

One specimen, MZUSP 0 0 0 0 6, Brazil, Ceará, São Gonçalo do Amarante, Pecém harbor, 3°32.08’ S 38°47.78’ W, on settlement plates, coll. PROCAD team, 16.VIII.2012.

Two specimens, MZUSP 0 0 0 0 7, Brazil, Ceará, São Gonçalo do Amarante, Pecém harbor, 3°32.08’ S 38°47.78’ W, on settlement plates, coll. PROCAD team, 20.XI.2012.

One specimen (26 mm long after preservation), MZUSP 0 0 0 0 8, Brazil, Ceará, Caucaia, Praia do Pacheco, 3°41.11' S 38°37.91' W, between algae, coll. Cecili Mendes, 03.I.2013.

Field diagnosis. Body beige with transverse black rings variably spaced; color persists after fixation; first four rings widest; first ring with median constriction dorsally, interrupted ventrally by mouth. Body with scattered small black dots surrounded by greenish halos; halos can disappear after fixation. Lateral sensory organs visible at fourth black ring as non-pigmented small circular depressions. No eye spots evident. Rhynchopore sub-terminal near anterior margin of cephalic lobe.

Distribution. Western Atlantic: USA (Florida [ Corrêa 1961]; South Carolina [ Fox & Ruppert 1985]); Panama (Bocas del Toro region [Norenburg unpublished data]); Curaçao ( Gibson 1995); Brazil (Ceará [present study] and São Sebastião [ Corrêa 1955]).

Ecology. Worms of this species live in the littoral zone, between algae on rocks, on recruitment plates, on old mangrove roots, under logs in tide pools, in seagrass or algae beds ( Corrêa 1955; Corrêa 1961). Most of the specimens in this study were found on offshore recruitment plates installed at Pecém harbor but one was found among algae. These animals, as others of the genus, produce thin cellophane-like tubes in which they shelter ( Corrêa 1961). None of the specimens found in this study were encased in those tubes, some tubes were found on the recruitment plates.

Remarks. The only species that can be confused with T. rhabdotus is Tubulanus riceae Ritger and Norenburg, 2006 ; however adult specimens of the latter generally are smaller, body ground color is whitish, and the lateral sensory organs are in the third dark ring (in the fourth black ring in T. rhabdotus ). Specimens collected during the PROCAD project could not be measured because most of them fragmented during the fixation process. Two specimens remained intact and measured 92 mm and 75 mm long. Corrêa (1955; 1961; 1963) reports specimens up to 25 mm long.

Figures

FIGURE 2. (1) Tubulanus rhabdotus Corrêa, 1955, lateral view; (2) Carinomella cf. lactea Coe, 1905: (a) head, dorsal view; (b) posterior end, lateral view; (3) Baseodiscus delineatus (Delle-Chiaje, 1825): dorsal view; (4) Cerebratulus cf. lineolatus Coe, 1905, dorsal view; (5) Cerebratulus sp. 1: (a) dorsal view; (b) posterior end, dorsal view; (6) Cerebratulus sp. 2: (a) whole body, dorsal view; (b) head, ventral view; (7) Lineid sp. 1: (a) head, dorsal view; (b) posterior end, dorsal view. Scale bars: 1, 2 a, 2 b, 6 b and 7 a, 1 mm; 3, 5 a, 5 b and 6 a, 5 mm; 4 and 7 b, 10 mm.