Protankyra benedeni ( Ludwig 1881 )

Christoffersen, Martin Lindsey, 2017, Taxonomic status of Protankyra ramiurna and Protankyra benedeni (Holothuroidea: Apodida: Synaptidae), Zootaxa 4324 (3), pp. 518-528 : 522-524

Protankyra benedeni ( Ludwig 1881)

Figures 3–4 , Table 2

Synapta benedeni LUDWIG 1881: 55 –56, FIGS. 19–20; CLARK 1907: 106, PL. 14.

Protankyra benedeni : DEIcHMANN 1930: 209 –210; TOMMASI 1969: 17; AMARAL et al. 2011: 458; TOMMASI IN AMARAL & ROSSI- WONtScHOWSKI 2004: 161; NEttO et al. 2005: 212; MOURA et al. IN HARRIS et al. 2010: 251; BRItES et al. IN AMARAL & NALLIN 2011: 278; PIRES-VANIN et al. 2014: 806; ALIttO et al. 2016: 10, FIG. 8G.

Material examined. Port, Salvador, Bahia , Brazil, 2 spec. ( UFBA.ECH-01138); Baía do Araçá, São Sebastião , São Paulo, Brazil, 1 spec. ( ZUEC HOL 63 ) ; 5 spec. (ZUEC HOL 64); 2 spec. (ZUEC HOL65); 1 spec. (ZUEC HOL 66); 1 spec. (ZUEC HOL 68) and, 1 spec. (ZUEC HOL70).

Diagnosis. Species usually small, body elongated, with robust extremities, not slender, measuring up to about 15 cm. Purple to white color. Mouth surrounded by twelve digitate tentacles, each with two pair of digits, with very short terminal digit. Ossicles of the body wall comprise anchors, anchor plates with numerous holes and dumbbellshaped miliary granules. About seven or more teeth in the arms of the anchor. These teeth do not reach the tip of the arm (from Tommasi 1969, amended herein).

Type locality. Coast of Brazil , Bahia ( Deichmann 1930).

Type material. The Holotype was not localized. According to Deichmann (1930), the holotype would be in Brussels , Belgium, but this information is not correct (Yves Samyn, personal communication). Maybe this material can be in Bremen , Germany. Van Beneden sent the specimens to H. Ludwig who was at that time director in Bremen, Germanny. However, we could not check the information about the Ludwig types.

Description. Specimen ZUEC HOL70 measuring 15 mm long and 9 mm in diameter. Body cylindrical, thin, rough, because of the anchors that project out from the body ( Fig. 3A–B ). Muscle bands externally visible, undivided, narrowing near the anus. Twelve digitate subequal tentacles, each with two pairs of digits and a short central digit ( Figs. 3C, 3E ). Color white, translucent, with purple spots, more abundant near the tentacles. Calcareous ring simple, with radial and interradial plates low, sub-triangular. Radial plates slightly wider than interradial, with a perforation ( Fig. 3D ). Six polian vesicles, balloon-shaped, 2–4 mm long, with two short stone canals, one apparently free and the other attached to mesentery, two rounded madreporites. Numerous long, nonbranched, tubular gonads, ciliated funnels attached to mesentery, bag-shaped, not bifurcated ( Fig. 3F ). Body wall with large multi-perforated anchor plates with rectangular base, slightly concave centrally ( Fig. 4H ); central holes greater than marginal perforations, holes in base smaller; each hole can present up to ten teeth or they can be absent ( Figs. 4A, 4F ); bridge of anchor plates well developed ( Fig. 4C ); anchors elongated ( Fig. 4B ), large arms with five to ten serrations, not reaching to tip of arm ( Fig. 4D ); stock non-branched, with many aggregated teeth and ends curved towards the central axis ( Fig. 4E ). Keel between stock and central axis poorly developed ( Fig. 4I ); plates of different sizes occur anteriorly, some about half the size of larger plates ( Fig. 4G ). In general, the anchor plates vary between 340–365 µm long and 235–265 µm wide. Anchors 440–480 µm long and 275–285 µm wide. In anterior region the anchor plates seem to be larger than in posterior region; the arms of anchors are large, reaching about half of the length of anchor ( Tab. 2). Miliary granules numerous, dumbbell-shaped ( Fig. 4J ). Tentacles with short rods, usually elongated, un-branched, some straight.

Distribution. Coast of Brazil, Bahia ( Deichmann 1930) to São Paulo ( Tommasi 1969; Brites et al. 2011), found up to 20 m ( Tommasi 1969).

Ecological notes. Common in dendritic bottoms in the littoral of São Paulo ( Tommasi 1969). Along the northeast coast of Brazil the specimens were found buried in the sediment.

Remarks. According to Ludwig (1881) the morphology and anatomy of the tentacles, and the habit of Protankyra benedeni are similar to Oestergrenia digitata (Montagu 1815) , but the ossicles are different. The name of the species refers to Édouard Van Beneden, who provided the material from Brazil to Ludwig.

Figures

FIGURE 3. Protankyra benedeni (LUDWIG). A, EXtERNAL VIEW; B, ANtERIOR VIEW; C, TENtAcLES; D, CALcAREOUS RING; E, TENtAcLE; F, CILIAtED FUNNELS. ScALE bARS: A – B, 0.5 cM; C, E, 1 MM; D, F, 0.5 MM;

FIGURE 4. Protankyra benedeni (LUDWIG). A, ANcHOR PLAtE; B, ANcHORS; C, DEtAIL OF bRIDGE IN tHE ANcHOR PLAtE; D, ARM OF tHE ANcHOR; E, DEtAIL OF tHE StOcK; F, LARGE ANcHOR PLAtE; G, SMALL ANcHOR PLAtE AND ANcHOR; H, DEtAIL OF bASE OF ANcHOR PLAtE; I, DEtAIL OF KEEL IN ANcHOR; J, MILIARY GRANULES. ScALE bARS: A, 80 µM; B, F – G, 100 µM; C, E, H, 50 µM; D, 40 µM; I – J, 10 µM.