Havelockia mansoae, Martins & Tavares, 2018

Martins, Luciana & Tavares, Marcos, 2018, New species of the genera Havelockia and Thyone (Echinodermata: Holothuroidea) and first record of T. crassidisca from the southwestern Atlantic Ocean, Zootaxa 4407 (4), pp. 533-542 : 539

Havelockia mansoae sp. nov.

( Figs. 5–6 )

Type material. Holotype: Brazil: Santos , São Paulo, 3.x.1967, depth unknown, 1 spm 30 mm ( MZUSP 1525 ).

Type locality. Santos , São Paulo, Brazil.

Etymology. This species is named after echinoderm taxonomist Cynthia Manso, who introduced LM to the taxonomy of echinoderms.

Diagnosis. Body wall tables two-pillared, discs four-holed. Introvert with plates, tentacles with rods. Tube feet with endplate, supporting tables and arched plates.

Description. Body barrel-shaped ( Fig. 5A ). Color white in ethanol. Tube feet scattered over body. Ten tentacles, ventral pair reduced. Internal organs degraded, not observed. Calcareous ring tubular, radial plates tapering anteriorly; short and subdivided posterior processes (about 3–4 pieces); interradial plate pointed anteriorly. Radial and interradial plates undivided and united along entire length ( Fig. 5B–C ). Body wall and anal ossicles: tables disc oval, four-holed, margins undulating; spire short, two pillared, united at apex by horizontal bar bearing one tooth at each end (100–130 µm long, Fig. 6A–B ). Introvert with irregular perforated plates (80–90 µm long, Fig. 6C ), tentacles with rods. Tube feet ossicles: supporting tables two-pillared; disc curved, four-holed centrally, perforated at ends (about 3 holes); spire short, ending in four teeth (160–240 µm long, Fig. 6D ), arched perforated plates with irregular margins (80–140 µm long, Fig. 6E ), endplates with large holes around margin, smaller ones medially (100–200 µm long, Fig. 6F ).

Remarks. The genus Havelockia comprises about 25 species world-wide (Worms, 2018), with Havelockia pegi Martinez, Thandar & Penchaszadeh, 2013 [Villarino, Golfo San José, Chubut Province, Argentina], and Havelockia scabra ( Verril 1873) [from Florida to Gulf of Mexico] being the only species in the genus known from the western Atlantic Ocean.

Havelockia mansoae sp. nov. is herein assigned to the genus Havelockia , whose diagnostic characters (cf. Thandar, 1989) are readily recognized in the new species, namely: calcareous ring with short posterior processes, posterior processes from radial plates sudivided into several pieces; body wall ossicles tables with to oval disc usually perforated by four large central and four smaller peripheral holes, the later sometimes reduced or absent; spire of two pillars joined at apex, terminating in few blunt teeth.

Havelockia mansoae sp. nov. can be readily separated from H. pegi by the presence of plates in the introvert, whereas the introvert is provided with rosettes in H. pegi , and differs from H. scabra in having four-holed tables instead of multilocular tables in the latter.

Havelockia mansoae sp. nov. is superficially similar to Havelockia vankampeni Sluiter, 1901 and Havelockia versicolor Semper, 1868 , in having four-holed body wall tables. However, in H. mansoae sp. nov. the body wall tables are provided with low spires, versus body wall tables with tail spires in H. vankampeni and H. versicolor .

Figures

FIGURE 5. (A–C) Havelockia mansoae sp. nov., holotype (MZUSP 1525). (A) Specimen preserved in ethanol. (B) Calcareousring, dorsal view.(C) Calcareous ring, ventral view. Scale bars:A, 10 mm. B–C, 1.5 mm.

FIGURE6. (A–F)Havelockiamansoae sp.nov.,holotype (MZUSP1525).SEM imagesof theossicles.(A)Body walltables,top view. (B) Body wall tables, lateral view. (C) Plates from introvert. (D) Supporting tables from tube feet, lateral view. (E) Plates from tube feet.(F) Endplate from tube feet.Scale bars:A–B, 50 µm.C,40 µm. D, 100 µm.E, 50 µm.F, 50 µm.