Neopentamera anexigua Deichmann 1941
Creators: name: Martins, Luciana
name: Tavares, Marcos
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Holothuroidea
Dendrochirotida
Sclerodactylidae
Neopentamera
Neopentamera anexigua

description: Neopentamera anexigua Deichmann, 1941
(Figs. 1–2)
Material examined. Conception Bay, Gulf of California, Baja California, Mexico 15.iii.1938, holotype 20 mm (LACM E.1937-85.2). Sonora, Gulf of California, Mexico 28.xi.1980, 1 spm 20 mm (USNM E 21478).
Diagnosis. The present diagnosis is based on Deichmann's (1941) and is amended herein to include previously unused characters from the calcareous ring. The amended diagnosis is as follows: Body fusiform. Tube feet arranged in double rows restricted to ambulacral region. Ten tentacles, ventral-most pair smaller. Calcareous ring with undivided radial and interradial plates united at the base and posterior processes divided, broken into few large pieces (about 3-4 pieces). Posterior process of radial plate twice as long as radial plate. Ossicles. Body wall knobbed buttons and plates; tentacles with rods; introvert with plates; tube feet with supporting rods. End plate star-shaped.
Description. The following is in addition to other descriptions thus far. Body U-shaped slightly upturned at both ends (Fig. 1A). Color brown in ethanol. Tube feet arranged in double rows restricted to the ambulacra. One Polian vesicle, madreporite circular and long stone canal (Fig. 1D). Radial plates of the calcareous ring short, undivided and notched anteriorly; posterior processes broken up into few large pieces (Fig. 1C). Interradial plates pointed anteriorly. Radial and interradial plates united at base (Fig. 1B).
Body wall ossicles comprising four holed knobbed buttons (40–60 µm long, Fig. 2A), perforated plates (100– 120 µm long, Fig. 2B–D). Introvert with perforated plates. In the tentacles perforated tentacle rods and rosettes (20–60 µm long, Fig. 2E). In the tube feet perforated rods (100–120 µm long, Fig 2F) and a star shapedend plate.
Remarks. Thandar (1989) recognized three subfamilies in the Sclerodactylidae: Cladolabinae Heding & Panning, 1954 (sclerodactylids with 15–20 tentacles), Sclerodactylinae (sclerodactylids with 10 tentacles and radial and interradial plates of the calcareous ring united along their entire length) and Sclerothyoninae Thandar, 1989 (sclerodactylids with 10 tentacles and radial and interradial plates of the calcareous ring united at the base). Smirnov (2012) that elevated Sclerothyoninae to familial status, whereas Miller et al. (2017) have seemingly treated Sclerodactylidae to encompass the Sclerothyoninae.
Originally, Neopentamera anexigua was described in Cucumariidae Ludwig, 1894. Panning (1949: 456) erected the subfamily Sclerodactylinae (within Cucumariidae), whose diagnosis included the presence of 10 tentacles, calcareous ring with undivided radial and interradial plates and posterior processes divided, broken into few large pieces (about 3-4 pieces). Panning (1949) included nine genera in Sclerodactylinae, among which Neopentamera. Pawson & Fell (1965) assigned familial status to Sclerodactylinae, Sclerodactylidae. Thandar (1989) created the subfamily Sclerothyoninae, which differed from Sclerodactylinae in having radial and interradial plates of the calcareous ring united at base only (whilst the radial and interradial plates are united along the entire length in Sclerodactylinae). The examination of the holotype of N. anexigua revealed that the radial and interradial plates of its calcareous ring are actually united at the base only (Fig. 1B), as typically found in the Sclerothyoninae. Therefore, Neopentamera anexigua can no longer be assigned to the Sclerodactylinae and is herein transferred to the Sclerothyoninae. This conclusion was reached independently in an unpublished dissertation by Arumugam (2011) brought to our attention by Prof. A. S. Thandar. Neopentamera differs from the others Sclerothyoninae genera by the presence of knobbed buttons and plates in the body wall, and absence of tables and cups.
description: Published as part of Martins, Luciana & Tavares, Marcos, 2018, A new genus and species of Sclerodactylidae (Echinodermata: Holothuroidea: Sclerothyoninae) from the Pacific coast of Panama, and assignment of Neopentamera anexigua to Sclerothyoninae, pp. 157-164 in Zootaxa 4429 (1) on pages 158-160, DOI: 10.11646/zootaxa.4429.1.8, http://zenodo.org/record/1280866