Selenkiella siamense Heding & Panning, 1954

Martins, Luciana & Tavares, Marcos, 2022, Additions to the morphology of the Phyllophoridae and the Sclerodactylidae. I. Type species of Phyllophorella, Selenkiella, Cladolella and Clarkiella, with the description a new species of Thorsonia (Holothuroidea: Dendrochirotida), Zootaxa 5120 (4), pp. 559-572 : 563-565

publication ID	https://doi.org/ 10.11646/zootaxa.5120.4.6
publication LSID	lsid:zoobank.org:pub:58CAB25D-CA92-44EE-BF1D-67DB91EB9596
DOI	https://doi.org/10.5281/zenodo.6392893
persistent identifier	https://treatment.plazi.org/id/03B887C1-4B0F-8136-BEE1-6AB0FBE9903C
treatment provided by	Plazi
scientific name	Selenkiella siamense Heding & Panning, 1954
status

Treatment

Selenkiella siamense Heding & Panning, 1954 View in CoL

( Figures 5 – 7 View FIGURE 5 View FIGURE 6 View FIGURE 7 )

Material examined. Holotype: Ko Kradat , Thailand, 8–10 m, 27.i. 1900, 45 mm length ( ZMUC –HOL– 250) . Paratype: Koh Kram , Thailand 25.ii. 1900, 50 mm length ( ZMUC –HOL–251) .

Redescription. Body barrel-shaped; tube feet scattered throughout body ( Fig. 5a View FIGURE 5 ). Color, in ethanol, gray. 25 dendritic tentacles arranged in 2 circles (15 + 10): 15 in outer circle, 10 in inner circle. Anal papillae present. Longitudinal and circular muscles well developed ( Fig. 5b View FIGURE 5 ). Longitudinal muscle split at anterior end ( Fig. 5b View FIGURE 5 ). Retractor muscle short, attached to middle of radial plate.

Calcareous ring robust. Radial plates slightly taller, much larger than interradial ones. Interradial plate articulated with base of radial plate and first piece of posterior process, such that half of interradial plate is connected to the posterior process ( Figs. 5c View FIGURE 5 ; 6a View FIGURE 6 ). MidIR (IR5) and midR (RI) not modified ( Fig. 6b, c View FIGURE 6 , respectively). Radial plates undivided, rectangular, base convex, without projection, two AP, one wider than the other ( Fig. 6 a; c View FIGURE 6 ). Posterior processes longer than radial plates, subdivided into about 3 – 4 large pieces ( Figure 5c View FIGURE 5 ). Interradial plates elongated, with straight ( Fig.6 View FIGURE 6 ) or slightly concave base ( Fig. 6b View FIGURE 6 ) and pointed anterior end. Marginal grooves for AB deep ( Fig. 6e View FIGURE 6 ). TCT rectangular ( Fig. 6f View FIGURE 6 ).

Body wall with four–pillared tables with circular disc (70–100 μm long; Fig.7 a,b View FIGURE 7 ); disc with one large central hole, eight marginal perforations, margin undulated; spire ending in 8–12 spines. Introvert with rosettes (30–80 μm long; Fig.7c, d View FIGURE 7 ). Tentacles with rods branched or perforated at both ends (former 50–100 μm long;latter 40–100 μm long). Tube feet with flat perforated plates, with irregular margins (140–200 μm long; Fig.7e View FIGURE 7 ) and endplate with minute holes, larger around margin and smaller medially (endplates up to 300 μm diameter; Fig.7f View FIGURE 7 ).

Remarks. The following illustrations are additions to the data provided by Heding & Panning (1954): the aquapharyngeal bulb attachment; longitudinal muscle attachment and retractor muscle attachment (fig 6d), the grooves in the radial plate for water vascular canals (fig 6e) and transverse cross-sections at the top region (fig 6f). We also provide a photograph of the general aspect of the body ( Fig. 5a View FIGURE 5 ) and described for the first time by means optical microscopy the morphology of the longitudinal retractor and circular muscles Fig. 5b View FIGURE 5 .